Patchwork [09/13] ahci: add ahci emulation

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Submitter Alexander Graf
Date Dec. 8, 2010, 12:13 p.m.
Message ID <1291810400-11309-10-git-send-email-agraf@suse.de>
Download mbox | patch
Permalink /patch/74715/
State New
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Comments

Alexander Graf - Dec. 8, 2010, 12:13 p.m.
This patch adds an emulation layer for an ICH-7M AHCI controller. For now
this controller does not do IDE legacy emulation. It is a pure AHCI controller.

Signed-off-by: Alexander Graf <agraf@suse.de>

---

v1 -> v2:

  - rename IDEExtender to IDEBusOps and make a pointer (kraxel)
  - make dma hooks explicit by putting them into ops struct (stefanha)
  - use qdev buses (kraxel)
  - minor cleanups
  - dprintf overhaul
  - add reset function

v2 -> v3:

  - add msi support (kraxel)
  - use MIN macro (kraxel)
  - add msi support (kraxel)
  - fix ncq with multiple ports
  - zap qdev properties (kraxel)
  - redesign legacy IF_SATA hooks (kraxel)
  - don't build ahci as part of target
  - move to ide/ (kwolf)

v3 -> v4:

  - prepare for endianness safety
  - add lspci dump (herbszt)
  - use ich7 instead of ich7m (herbszt)
  - fix lst+fis mapping (kraxel)
  - coding style (blue swirl)
  - explicit mmio setters/getters (blue swirl)

v4 -> v5:

  - s/H2dNcqFis/NCQFrame/g (blue swirl)
  - redo -drive magic (blue swirl)
  - bump BAR to 4k
  - ahci.c: rename to ICH7_AHCI_RAID (herbszt)

v5 -> v6:
  - PCI config space fixes (isaku)
  - remove CONFIG_AHCI from default configs

v6 -> v7:

  - improve interrupt injection
  - combine tfdata code paths
  - update tfdata more often
  - reset port registers on port reset
  - improve debug output
  - add "feature" variable from fis for some extended commands
  - always set feature to DMA for atapi
  - osx 10.5.0 works as of this version
  - use non-raid ich7 ahci (herbszt)
  - reflect normal ich7 in pci dump
  - stick to new IDEBusOps (stefanha, kwolf)
  - ahci: stefan's ahci comments

v7 -> v8:
  - generate tfdata on the fly
  - reimplement immediate dma rw
  - add safety net for busy engine
  - adjust for new DMA interface
---
 Makefile.objs |    1 +
 hw/ide/ahci.c | 1374 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 1375 insertions(+), 0 deletions(-)
 create mode 100644 hw/ide/ahci.c
Stefan Hajnoczi - Dec. 8, 2010, 9:14 p.m.
On Wed, Dec 8, 2010 at 12:13 PM, Alexander Graf <agraf@suse.de> wrote:
> +struct AHCIDevice {
> +    IDEBus port;
> +    int port_no;
> +    uint32_t port_state;
> +    uint32_t finished;
> +    AHCIPortRegs port_regs;
> +    struct AHCIState *hba;
> +    uint8_t *lst;
> +    uint8_t *res_fis;
> +    uint8_t *cmd_fis;

Are these unmapped on reset?

> +    int cmd_fis_len;
> +    int dma_status;
> +    BlockDriverCompletionFunc *dma_cb;
> +    AHCICmdHdr *cur_cmd;
> +    NCQTransferState ncq_tfs[AHCI_MAX_CMDS];

Are the ncq_tfs[] elements cleaned up on reset (i.e. cancellation and
free sglist)?

> +static void map_page(uint8_t **ptr, uint64_t addr, uint32_t wanted)
> +{
> +    target_phys_addr_t len = wanted;
> +
> +    if (*ptr) {
> +        cpu_physical_memory_unmap(*ptr, 1, len, len);
> +    }
> +
> +    *ptr = cpu_physical_memory_map(addr, &len, 1);
> +    if (len < wanted) {
> +        cpu_physical_memory_unmap(*ptr, 1, len, len);

*ptr = NULL;

> +static void ncq_cb(void *opaque, int ret)
> +{
> +    NCQTransferState *ncq_tfs = (NCQTransferState *)opaque;
> +    IDEState *ide_state;
> +
> +    if (ret < 0) {
> +        /* XXX error */
> +    }

Missing error handling.

> +static void process_ncq_command(AHCIState *s, int port, uint8_t *cmd_fis,
> +                                int slot, QEMUSGList *sg)
> +{
> +    NCQFrame *ncq_fis = (NCQFrame*)cmd_fis;
> +    uint8_t tag = ncq_fis->tag >> 3;
> +    NCQTransferState *ncq_tfs = &s->dev[port].ncq_tfs[tag];
> +
> +    if (ncq_tfs->used) {
> +        /* error - already in use */
> +        fprintf(stderr, "%s: tag %d already used\n", __FUNCTION__, tag);
> +        return;
> +    }
> +
> +    ncq_tfs->used = 1;
> +    ncq_tfs->drive = &s->dev[port];
> +    ncq_tfs->drive->cmd_fis = cmd_fis;
> +    ncq_tfs->drive->cmd_fis_len = 0x20;
> +    ncq_tfs->slot = slot;
> +    ncq_tfs->lba = ((uint64_t)ncq_fis->lba5 << 40) |
> +                   ((uint64_t)ncq_fis->lba4 << 32) |
> +                   ((uint64_t)ncq_fis->lba3 << 24) |
> +                   ((uint64_t)ncq_fis->lba2 << 16) |
> +                   ((uint64_t)ncq_fis->lba1 << 8) |
> +                   (uint64_t)ncq_fis->lba0;
> +
> +    /* Note: We calculate the sector count, but don't currently rely on it.
> +     * The total size of the DMA buffer tells us the transfer size instead. */
> +    ncq_tfs->sector_count = ((uint16_t)ncq_fis->sector_count_high << 8) |
> +                                ncq_fis->sector_count_low;
> +
> +    DPRINTF(port, "NCQ transfer LBA from %ld to %ld, drive max %ld\n",
> +            ncq_tfs->lba, ncq_tfs->lba + ncq_tfs->sector_count - 2,
> +            s->dev[port].port.ifs[0].nb_sectors - 1);
> +
> +    ncq_tfs->sglist = *sg;
> +    ncq_tfs->tag = tag;
> +
> +    switch(ncq_fis->command) {
> +        case READ_FPDMA_QUEUED:
> +            DPRINTF(port, "NCQ reading %d sectors from LBA %ld, tag %d\n",
> +                    ncq_tfs->sector_count-1, ncq_tfs->lba, ncq_tfs->tag);
> +            ncq_tfs->is_read = 1;
> +
> +            /* XXX: The specification is unclear about whether the DMA Setup
> +             * FIS here should have the I bit set, but it suggest that it should
> +             * not. Linux works without this interrupt, so I disabled it.
> +             * If someone knows if it is needed, please tell me, or fix this. */
> +
> +            /* ahci_trigger_irq(s,s->dev[port],PORT_IRQ_STAT_DSS); */
> +            DPRINTF(port, "tag %d aio read %ld\n", ncq_tfs->tag, ncq_tfs->lba);
> +            dma_bdrv_read(ncq_tfs->drive->port.ifs[0].bs, &ncq_tfs->sglist,
> +                          ncq_tfs->lba, ncq_cb, ncq_tfs);
> +            break;
> +        case WRITE_FPDMA_QUEUED:
> +            DPRINTF(port, "NCQ writing %d sectors to LBA %ld, tag %d\n",
> +                    ncq_tfs->sector_count-1, ncq_tfs->lba, ncq_tfs->tag);
> +            ncq_tfs->is_read = 0;
> +            /* ahci_trigger_irq(s,s->dev[port],PORT_IRQ_STAT_DSS); */
> +            DPRINTF(port, "tag %d aio write %ld\n", ncq_tfs->tag, ncq_tfs->lba);
> +            dma_bdrv_write(ncq_tfs->drive->port.ifs[0].bs, &ncq_tfs->sglist,
> +                           ncq_tfs->lba, ncq_cb, ncq_tfs);
> +            break;
> +        default:
> +            hw_error("ahci: tried to process non-NCQ command as NCQ\n");

Guest triggerable abort.

> +            break;
> +    }
> +}
> +
> +static int handle_cmd(AHCIState *s, int port, int slot)
> +{
> +    IDEState *ide_state;
> +
> +    int sglist_alloc_hint;
> +    QEMUSGList sglist;
> +    int atapi_packet_len = 0;
> +    AHCIPortRegs *pr;
> +    uint32_t opts;
> +    uint64_t tbl_addr;
> +    AHCICmdHdr *cmd;
> +    uint8_t *cmd_fis;
> +
> +    target_phys_addr_t cmd_len;
> +    int i;
> +
> +    if (s->dev[port].port.ifs[0].status & (BUSY_STAT|DRQ_STAT)) {
> +        /* Engine currently busy, try again later */
> +        DPRINTF(port, "engine busy\n");
> +        return -1;
> +    }
> +
> +    pr = &s->dev[port].port_regs;
> +    cmd = &((AHCICmdHdr *)s->dev[port].lst)[slot];
> +
> +    if (!s->dev[port].lst) {
> +        hw_error("%s: lst not given but cmd handled", __FUNCTION__);

Guest triggerable abort.

> +    }
> +
> +    opts = le32_to_cpu(cmd->opts);
> +    tbl_addr = le64_to_cpu(cmd->tbl_addr);
> +
> +    sglist_alloc_hint = opts >> AHCI_CMD_HDR_PRDT_LEN;
> +    cmd_len = 0x80 + (sglist_alloc_hint * sizeof(AHCI_SG));
> +    cmd_fis = cpu_physical_memory_map(tbl_addr, &cmd_len, 1);

NULL dereference later if cpu_physical_memory_map() fails due to
invalid address (tbl_addr).

> +
> +    /* The device we are working for */
> +    ide_state = &s->dev[port].port.ifs[0];
> +
> +    if (!ide_state->bs) {
> +        hw_error("%s: guest accessed unused port", __FUNCTION__);

Guest triggerable abort.

> +    }
> +
> +    /* Get number of entries in the PRDT, init a qemu sglist accordingly */
> +    memset(&sglist, 0, sizeof(sglist));
> +
> +    if (sglist_alloc_hint > 0) {
> +        AHCI_SG *tbl = (AHCI_SG *)(&cmd_fis[0x80]);
> +
> +        qemu_sglist_init(&sglist, sglist_alloc_hint);
> +        /* Parse the PRDs and create qemu sglist entries accordingly */
> +        for (i = 0; i < sglist_alloc_hint; i++) {
> +            /* flags_size is zero-based */
> +            qemu_sglist_add(&sglist, le64_to_cpu(tbl[i].addr),
> +                            le32_to_cpu(tbl[i].flags_size) + 1);
> +        }
> +    }

Only the SATA_FIS_REG_H2D_UPDATE_COMMAND_REGISTER codepath seems to
clean up sglist.  The guest can leak host memory by setting
sglist_alloc_hint > 0 and not using
SATA_FIS_REG_H2D_UPDATE_COMMAND_REGISTER.

> +
> +    debug_print_fis(cmd_fis, (opts & AHCI_CMD_HDR_CMD_FIS_LEN) * 4);
> +
> +    switch (cmd_fis[0]) {
> +        case SATA_FIS_TYPE_REGISTER_H2D:
> +            break;
> +        default:
> +            hw_error("unknown command cmd_fis[0]=%02x cmd_fis[1]=%02x cmd_fis[2]=%02x\n",
> +                     cmd_fis[0], cmd_fis[1], cmd_fis[2]);

Guest triggerable abort.

> +            break;
> +    }
> +
> +    switch (cmd_fis[1]) {
> +        case SATA_FIS_REG_H2D_UPDATE_COMMAND_REGISTER:
> +            break;
> +        case 0:
> +            break;
> +        default:
> +            hw_error("unknown command cmd_fis[0]=%02x cmd_fis[1]=%02x cmd_fis[2]=%02x\n",
> +                     cmd_fis[0], cmd_fis[1], cmd_fis[2]);

Guest triggerable abort.

> +            break;
> +    }
> +
> +    switch (s->dev[port].port_state) {
> +        case STATE_RUN:
> +            if (cmd_fis[15] & ATA_SRST) {
> +                s->dev[port].port_state = STATE_RESET;
> +            }
> +            break;
> +        case STATE_RESET:
> +            if (!(cmd_fis[15] & ATA_SRST)) {
> +                ahci_reset_port(s, port);
> +            }
> +            break;
> +    }
> +
> +    if (cmd_fis[1] == SATA_FIS_REG_H2D_UPDATE_COMMAND_REGISTER) {
> +
> +        /* Check for NCQ command */
> +        if ((cmd_fis[2] == READ_FPDMA_QUEUED) ||
> +            (cmd_fis[2] == WRITE_FPDMA_QUEUED)) {
> +            process_ncq_command(s, port, cmd_fis, slot, &sglist);
> +            goto out;
> +        }
> +
> +        /* If the command is not NCQ, the sglist is needed in the core */
> +        ide_state->sg = sglist;
> +
> +        /* Decompose the FIS  */
> +        ide_state->nsector = (int64_t)((cmd_fis[13] << 8) | cmd_fis[12]);
> +        ide_state->feature = cmd_fis[3];
> +        if (!ide_state->nsector) {
> +            ide_state->nsector = 256;
> +        }
> +
> +        if (ide_state->drive_kind != IDE_CD) {
> +            ide_set_sector(ide_state, (cmd_fis[6] << 16) | (cmd_fis[5] << 8) |
> +                           cmd_fis[4]);
> +        }
> +
> +        /* Copy the ACMD field (ATAPI packet, if any) from the AHCI command
> +         * table to ide_state->io_buffer
> +         */
> +        if (opts & AHCI_CMD_ATAPI) {
> +            atapi_packet_len = ((ide_state->hcyl) << 8) + ide_state->lcyl;

Unused variable.

> +static int pci_ahci_init(PCIDevice *dev)
> +{
> +    struct AHCIPCIState *d;
> +    d = DO_UPCAST(struct AHCIPCIState, card, dev);
> +
> +    pci_config_set_vendor_id(d->card.config, PCI_VENDOR_ID_INTEL);
> +    pci_config_set_device_id(d->card.config,
> +                             PCI_DEVICE_ID_INTEL_ICH7_AHCI);
> +
> +    pci_config_set_class(d->card.config, PCI_CLASS_STORAGE_SATA);
> +    pci_config_set_prog_interface(d->card.config, AHCI_PROGMODE_MAJOR_REV_1);
> +
> +    d->card.config[PCI_CACHE_LINE_SIZE] = 0x08;  /* Cache line size */
> +    d->card.config[PCI_LATENCY_TIMER]   = 0x00;  /* Latency timer */
> +    pci_config_set_interrupt_pin(d->card.config, 1);
> +
> +    qemu_register_reset(ahci_reset, d);

Missing qemu_unregister_reset() in pci_ahci_uninit().

Stefan
Alexander Graf - Dec. 9, 2010, 3:48 p.m.
Stefan Hajnoczi wrote:
> On Wed, Dec 8, 2010 at 12:13 PM, Alexander Graf <agraf@suse.de> wrote:
>   
>> +struct AHCIDevice {
>> +    IDEBus port;
>> +    int port_no;
>> +    uint32_t port_state;
>> +    uint32_t finished;
>> +    AHCIPortRegs port_regs;
>> +    struct AHCIState *hba;
>> +    uint8_t *lst;
>> +    uint8_t *res_fis;
>> +    uint8_t *cmd_fis;
>>     
>
> Are these unmapped on reset?
>   

On which reset? Port reset sends a d2h fis to the guest, so we still
need at least the res mapping. I couldn't find the exact spot where the
state of registers after reset is defined.

>   
>> +    int cmd_fis_len;
>> +    int dma_status;
>> +    BlockDriverCompletionFunc *dma_cb;
>> +    AHCICmdHdr *cur_cmd;
>> +    NCQTransferState ncq_tfs[AHCI_MAX_CMDS];
>>     
>
> Are the ncq_tfs[] elements cleaned up on reset (i.e. cancellation and
> free sglist)?
>
>   
>> +static void map_page(uint8_t **ptr, uint64_t addr, uint32_t wanted)
>> +{
>> +    target_phys_addr_t len = wanted;
>> +
>> +    if (*ptr) {
>> +        cpu_physical_memory_unmap(*ptr, 1, len, len);
>> +    }
>> +
>> +    *ptr = cpu_physical_memory_map(addr, &len, 1);
>> +    if (len < wanted) {
>> +        cpu_physical_memory_unmap(*ptr, 1, len, len);
>>     
>
> *ptr = NULL;
>
>   
>> +static void ncq_cb(void *opaque, int ret)
>> +{
>> +    NCQTransferState *ncq_tfs = (NCQTransferState *)opaque;
>> +    IDEState *ide_state;
>> +
>> +    if (ret < 0) {
>> +        /* XXX error */
>> +    }
>>     
>
> Missing error handling.
>   

Yes, that's what the XXX stands for :).

>   
>> +static void process_ncq_command(AHCIState *s, int port, uint8_t *cmd_fis,
>> +                                int slot, QEMUSGList *sg)
>> +{
>> +    NCQFrame *ncq_fis = (NCQFrame*)cmd_fis;
>> +    uint8_t tag = ncq_fis->tag >> 3;
>> +    NCQTransferState *ncq_tfs = &s->dev[port].ncq_tfs[tag];
>> +
>> +    if (ncq_tfs->used) {
>> +        /* error - already in use */
>> +        fprintf(stderr, "%s: tag %d already used\n", __FUNCTION__, tag);
>> +        return;
>> +    }
>> +
>> +    ncq_tfs->used = 1;
>> +    ncq_tfs->drive = &s->dev[port];
>> +    ncq_tfs->drive->cmd_fis = cmd_fis;
>> +    ncq_tfs->drive->cmd_fis_len = 0x20;
>> +    ncq_tfs->slot = slot;
>> +    ncq_tfs->lba = ((uint64_t)ncq_fis->lba5 << 40) |
>> +                   ((uint64_t)ncq_fis->lba4 << 32) |
>> +                   ((uint64_t)ncq_fis->lba3 << 24) |
>> +                   ((uint64_t)ncq_fis->lba2 << 16) |
>> +                   ((uint64_t)ncq_fis->lba1 << 8) |
>> +                   (uint64_t)ncq_fis->lba0;
>> +
>> +    /* Note: We calculate the sector count, but don't currently rely on it.
>> +     * The total size of the DMA buffer tells us the transfer size instead. */
>> +    ncq_tfs->sector_count = ((uint16_t)ncq_fis->sector_count_high << 8) |
>> +                                ncq_fis->sector_count_low;
>> +
>> +    DPRINTF(port, "NCQ transfer LBA from %ld to %ld, drive max %ld\n",
>> +            ncq_tfs->lba, ncq_tfs->lba + ncq_tfs->sector_count - 2,
>> +            s->dev[port].port.ifs[0].nb_sectors - 1);
>> +
>> +    ncq_tfs->sglist = *sg;
>> +    ncq_tfs->tag = tag;
>> +
>> +    switch(ncq_fis->command) {
>> +        case READ_FPDMA_QUEUED:
>> +            DPRINTF(port, "NCQ reading %d sectors from LBA %ld, tag %d\n",
>> +                    ncq_tfs->sector_count-1, ncq_tfs->lba, ncq_tfs->tag);
>> +            ncq_tfs->is_read = 1;
>> +
>> +            /* XXX: The specification is unclear about whether the DMA Setup
>> +             * FIS here should have the I bit set, but it suggest that it should
>> +             * not. Linux works without this interrupt, so I disabled it.
>> +             * If someone knows if it is needed, please tell me, or fix this. */
>> +
>> +            /* ahci_trigger_irq(s,s->dev[port],PORT_IRQ_STAT_DSS); */
>> +            DPRINTF(port, "tag %d aio read %ld\n", ncq_tfs->tag, ncq_tfs->lba);
>> +            dma_bdrv_read(ncq_tfs->drive->port.ifs[0].bs, &ncq_tfs->sglist,
>> +                          ncq_tfs->lba, ncq_cb, ncq_tfs);
>> +            break;
>> +        case WRITE_FPDMA_QUEUED:
>> +            DPRINTF(port, "NCQ writing %d sectors to LBA %ld, tag %d\n",
>> +                    ncq_tfs->sector_count-1, ncq_tfs->lba, ncq_tfs->tag);
>> +            ncq_tfs->is_read = 0;
>> +            /* ahci_trigger_irq(s,s->dev[port],PORT_IRQ_STAT_DSS); */
>> +            DPRINTF(port, "tag %d aio write %ld\n", ncq_tfs->tag, ncq_tfs->lba);
>> +            dma_bdrv_write(ncq_tfs->drive->port.ifs[0].bs, &ncq_tfs->sglist,
>> +                           ncq_tfs->lba, ncq_cb, ncq_tfs);
>> +            break;
>> +        default:
>> +            hw_error("ahci: tried to process non-NCQ command as NCQ\n");
>>     
>
> Guest triggerable abort.
>   

Those happen. The guest can shoot itself in the foot. We have more of
these in other places. Just check virtio.c and search for abort() :).

>   
>> +            break;
>> +    }
>> +}
>> +
>> +static int handle_cmd(AHCIState *s, int port, int slot)
>> +{
>> +    IDEState *ide_state;
>> +
>> +    int sglist_alloc_hint;
>> +    QEMUSGList sglist;
>> +    int atapi_packet_len = 0;
>> +    AHCIPortRegs *pr;
>> +    uint32_t opts;
>> +    uint64_t tbl_addr;
>> +    AHCICmdHdr *cmd;
>> +    uint8_t *cmd_fis;
>> +
>> +    target_phys_addr_t cmd_len;
>> +    int i;
>> +
>> +    if (s->dev[port].port.ifs[0].status & (BUSY_STAT|DRQ_STAT)) {
>> +        /* Engine currently busy, try again later */
>> +        DPRINTF(port, "engine busy\n");
>> +        return -1;
>> +    }
>> +
>> +    pr = &s->dev[port].port_regs;
>> +    cmd = &((AHCICmdHdr *)s->dev[port].lst)[slot];
>> +
>> +    if (!s->dev[port].lst) {
>> +        hw_error("%s: lst not given but cmd handled", __FUNCTION__);
>>     
>
> Guest triggerable abort.
>
>   
>> +    }
>> +
>> +    opts = le32_to_cpu(cmd->opts);
>> +    tbl_addr = le64_to_cpu(cmd->tbl_addr);
>> +
>> +    sglist_alloc_hint = opts >> AHCI_CMD_HDR_PRDT_LEN;
>> +    cmd_len = 0x80 + (sglist_alloc_hint * sizeof(AHCI_SG));
>> +    cmd_fis = cpu_physical_memory_map(tbl_addr, &cmd_len, 1);
>>     
>
> NULL dereference later if cpu_physical_memory_map() fails due to
> invalid address (tbl_addr).
>
>   
>> +
>> +    /* The device we are working for */
>> +    ide_state = &s->dev[port].port.ifs[0];
>> +
>> +    if (!ide_state->bs) {
>> +        hw_error("%s: guest accessed unused port", __FUNCTION__);
>>     
>
> Guest triggerable abort.
>
>   
>> +    }
>> +
>> +    /* Get number of entries in the PRDT, init a qemu sglist accordingly */
>> +    memset(&sglist, 0, sizeof(sglist));
>> +
>> +    if (sglist_alloc_hint > 0) {
>> +        AHCI_SG *tbl = (AHCI_SG *)(&cmd_fis[0x80]);
>> +
>> +        qemu_sglist_init(&sglist, sglist_alloc_hint);
>> +        /* Parse the PRDs and create qemu sglist entries accordingly */
>> +        for (i = 0; i < sglist_alloc_hint; i++) {
>> +            /* flags_size is zero-based */
>> +            qemu_sglist_add(&sglist, le64_to_cpu(tbl[i].addr),
>> +                            le32_to_cpu(tbl[i].flags_size) + 1);
>> +        }
>> +    }
>>     
>
> Only the SATA_FIS_REG_H2D_UPDATE_COMMAND_REGISTER codepath seems to
> clean up sglist.  The guest can leak host memory by setting
> sglist_alloc_hint > 0 and not using
> SATA_FIS_REG_H2D_UPDATE_COMMAND_REGISTER.
>   

True, the sglist should only be created in dma_prepare (then the core is
responsible for cleanup) or ncq command issue.


Alex
Kevin Wolf - Dec. 9, 2010, 3:53 p.m.
Am 09.12.2010 16:48, schrieb Alexander Graf:
>>> +static void ncq_cb(void *opaque, int ret)
>>> +{
>>> +    NCQTransferState *ncq_tfs = (NCQTransferState *)opaque;
>>> +    IDEState *ide_state;
>>> +
>>> +    if (ret < 0) {
>>> +        /* XXX error */
>>> +    }
>>>     
>>
>> Missing error handling.
>>   
> 
> Yes, that's what the XXX stands for :).

I think Stefan wanted to tell us that he thinks this XXX should be
addressed. I don't disagree, by the way. ;-)

>>> +static void process_ncq_command(AHCIState *s, int port, uint8_t *cmd_fis,
>>> +                                int slot, QEMUSGList *sg)
>>> +{
>>> +    NCQFrame *ncq_fis = (NCQFrame*)cmd_fis;
>>> +    uint8_t tag = ncq_fis->tag >> 3;
>>> +    NCQTransferState *ncq_tfs = &s->dev[port].ncq_tfs[tag];
>>> +
>>> +    if (ncq_tfs->used) {
>>> +        /* error - already in use */
>>> +        fprintf(stderr, "%s: tag %d already used\n", __FUNCTION__, tag);
>>> +        return;
>>> +    }
>>> +
>>> +    ncq_tfs->used = 1;
>>> +    ncq_tfs->drive = &s->dev[port];
>>> +    ncq_tfs->drive->cmd_fis = cmd_fis;
>>> +    ncq_tfs->drive->cmd_fis_len = 0x20;
>>> +    ncq_tfs->slot = slot;
>>> +    ncq_tfs->lba = ((uint64_t)ncq_fis->lba5 << 40) |
>>> +                   ((uint64_t)ncq_fis->lba4 << 32) |
>>> +                   ((uint64_t)ncq_fis->lba3 << 24) |
>>> +                   ((uint64_t)ncq_fis->lba2 << 16) |
>>> +                   ((uint64_t)ncq_fis->lba1 << 8) |
>>> +                   (uint64_t)ncq_fis->lba0;
>>> +
>>> +    /* Note: We calculate the sector count, but don't currently rely on it.
>>> +     * The total size of the DMA buffer tells us the transfer size instead. */
>>> +    ncq_tfs->sector_count = ((uint16_t)ncq_fis->sector_count_high << 8) |
>>> +                                ncq_fis->sector_count_low;
>>> +
>>> +    DPRINTF(port, "NCQ transfer LBA from %ld to %ld, drive max %ld\n",
>>> +            ncq_tfs->lba, ncq_tfs->lba + ncq_tfs->sector_count - 2,
>>> +            s->dev[port].port.ifs[0].nb_sectors - 1);
>>> +
>>> +    ncq_tfs->sglist = *sg;
>>> +    ncq_tfs->tag = tag;
>>> +
>>> +    switch(ncq_fis->command) {
>>> +        case READ_FPDMA_QUEUED:
>>> +            DPRINTF(port, "NCQ reading %d sectors from LBA %ld, tag %d\n",
>>> +                    ncq_tfs->sector_count-1, ncq_tfs->lba, ncq_tfs->tag);
>>> +            ncq_tfs->is_read = 1;
>>> +
>>> +            /* XXX: The specification is unclear about whether the DMA Setup
>>> +             * FIS here should have the I bit set, but it suggest that it should
>>> +             * not. Linux works without this interrupt, so I disabled it.
>>> +             * If someone knows if it is needed, please tell me, or fix this. */
>>> +
>>> +            /* ahci_trigger_irq(s,s->dev[port],PORT_IRQ_STAT_DSS); */
>>> +            DPRINTF(port, "tag %d aio read %ld\n", ncq_tfs->tag, ncq_tfs->lba);
>>> +            dma_bdrv_read(ncq_tfs->drive->port.ifs[0].bs, &ncq_tfs->sglist,
>>> +                          ncq_tfs->lba, ncq_cb, ncq_tfs);
>>> +            break;
>>> +        case WRITE_FPDMA_QUEUED:
>>> +            DPRINTF(port, "NCQ writing %d sectors to LBA %ld, tag %d\n",
>>> +                    ncq_tfs->sector_count-1, ncq_tfs->lba, ncq_tfs->tag);
>>> +            ncq_tfs->is_read = 0;
>>> +            /* ahci_trigger_irq(s,s->dev[port],PORT_IRQ_STAT_DSS); */
>>> +            DPRINTF(port, "tag %d aio write %ld\n", ncq_tfs->tag, ncq_tfs->lba);
>>> +            dma_bdrv_write(ncq_tfs->drive->port.ifs[0].bs, &ncq_tfs->sglist,
>>> +                           ncq_tfs->lba, ncq_cb, ncq_tfs);
>>> +            break;
>>> +        default:
>>> +            hw_error("ahci: tried to process non-NCQ command as NCQ\n");
>>>     
>>
>> Guest triggerable abort.
>>   
> 
> Those happen. The guest can shoot itself in the foot. We have more of
> these in other places. Just check virtio.c and search for abort() :).

They are bugs which should be fixed in virtio rather than being spread
to new code.

Kevin
Alexander Graf - Dec. 9, 2010, 4:18 p.m.
Kevin Wolf wrote:
> Am 09.12.2010 16:48, schrieb Alexander Graf:
>   
>>>> +static void ncq_cb(void *opaque, int ret)
>>>> +{
>>>> +    NCQTransferState *ncq_tfs = (NCQTransferState *)opaque;
>>>> +    IDEState *ide_state;
>>>> +
>>>> +    if (ret < 0) {
>>>> +        /* XXX error */
>>>> +    }
>>>>     
>>>>         
>>> Missing error handling.
>>>   
>>>       
>> Yes, that's what the XXX stands for :).
>>     
>
> I think Stefan wanted to tell us that he thinks this XXX should be
> addressed. I don't disagree, by the way. ;-)
>
>   
>>>> +static void process_ncq_command(AHCIState *s, int port, uint8_t *cmd_fis,
>>>> +                                int slot, QEMUSGList *sg)
>>>> +{
>>>> +    NCQFrame *ncq_fis = (NCQFrame*)cmd_fis;
>>>> +    uint8_t tag = ncq_fis->tag >> 3;
>>>> +    NCQTransferState *ncq_tfs = &s->dev[port].ncq_tfs[tag];
>>>> +
>>>> +    if (ncq_tfs->used) {
>>>> +        /* error - already in use */
>>>> +        fprintf(stderr, "%s: tag %d already used\n", __FUNCTION__, tag);
>>>> +        return;
>>>> +    }
>>>> +
>>>> +    ncq_tfs->used = 1;
>>>> +    ncq_tfs->drive = &s->dev[port];
>>>> +    ncq_tfs->drive->cmd_fis = cmd_fis;
>>>> +    ncq_tfs->drive->cmd_fis_len = 0x20;
>>>> +    ncq_tfs->slot = slot;
>>>> +    ncq_tfs->lba = ((uint64_t)ncq_fis->lba5 << 40) |
>>>> +                   ((uint64_t)ncq_fis->lba4 << 32) |
>>>> +                   ((uint64_t)ncq_fis->lba3 << 24) |
>>>> +                   ((uint64_t)ncq_fis->lba2 << 16) |
>>>> +                   ((uint64_t)ncq_fis->lba1 << 8) |
>>>> +                   (uint64_t)ncq_fis->lba0;
>>>> +
>>>> +    /* Note: We calculate the sector count, but don't currently rely on it.
>>>> +     * The total size of the DMA buffer tells us the transfer size instead. */
>>>> +    ncq_tfs->sector_count = ((uint16_t)ncq_fis->sector_count_high << 8) |
>>>> +                                ncq_fis->sector_count_low;
>>>> +
>>>> +    DPRINTF(port, "NCQ transfer LBA from %ld to %ld, drive max %ld\n",
>>>> +            ncq_tfs->lba, ncq_tfs->lba + ncq_tfs->sector_count - 2,
>>>> +            s->dev[port].port.ifs[0].nb_sectors - 1);
>>>> +
>>>> +    ncq_tfs->sglist = *sg;
>>>> +    ncq_tfs->tag = tag;
>>>> +
>>>> +    switch(ncq_fis->command) {
>>>> +        case READ_FPDMA_QUEUED:
>>>> +            DPRINTF(port, "NCQ reading %d sectors from LBA %ld, tag %d\n",
>>>> +                    ncq_tfs->sector_count-1, ncq_tfs->lba, ncq_tfs->tag);
>>>> +            ncq_tfs->is_read = 1;
>>>> +
>>>> +            /* XXX: The specification is unclear about whether the DMA Setup
>>>> +             * FIS here should have the I bit set, but it suggest that it should
>>>> +             * not. Linux works without this interrupt, so I disabled it.
>>>> +             * If someone knows if it is needed, please tell me, or fix this. */
>>>> +
>>>> +            /* ahci_trigger_irq(s,s->dev[port],PORT_IRQ_STAT_DSS); */
>>>> +            DPRINTF(port, "tag %d aio read %ld\n", ncq_tfs->tag, ncq_tfs->lba);
>>>> +            dma_bdrv_read(ncq_tfs->drive->port.ifs[0].bs, &ncq_tfs->sglist,
>>>> +                          ncq_tfs->lba, ncq_cb, ncq_tfs);
>>>> +            break;
>>>> +        case WRITE_FPDMA_QUEUED:
>>>> +            DPRINTF(port, "NCQ writing %d sectors to LBA %ld, tag %d\n",
>>>> +                    ncq_tfs->sector_count-1, ncq_tfs->lba, ncq_tfs->tag);
>>>> +            ncq_tfs->is_read = 0;
>>>> +            /* ahci_trigger_irq(s,s->dev[port],PORT_IRQ_STAT_DSS); */
>>>> +            DPRINTF(port, "tag %d aio write %ld\n", ncq_tfs->tag, ncq_tfs->lba);
>>>> +            dma_bdrv_write(ncq_tfs->drive->port.ifs[0].bs, &ncq_tfs->sglist,
>>>> +                           ncq_tfs->lba, ncq_cb, ncq_tfs);
>>>> +            break;
>>>> +        default:
>>>> +            hw_error("ahci: tried to process non-NCQ command as NCQ\n");
>>>>     
>>>>         
>>> Guest triggerable abort.
>>>   
>>>       
>> Those happen. The guest can shoot itself in the foot. We have more of
>> these in other places. Just check virtio.c and search for abort() :).
>>     
>
> They are bugs which should be fixed in virtio rather than being spread
> to new code.
>   

Not sure about that. Would you prefer a broken guest to abort so you can
debug it or to have it spew your log files with error messages or to
silently ignore errors and never find bugs?


Alex
Kevin Wolf - Dec. 10, 2010, 9:35 a.m.
Am 09.12.2010 17:18, schrieb Alexander Graf:
> Kevin Wolf wrote:
>> Am 09.12.2010 16:48, schrieb Alexander Graf:
>>   
>>>>> +static void ncq_cb(void *opaque, int ret)
>>>>> +{
>>>>> +    NCQTransferState *ncq_tfs = (NCQTransferState *)opaque;
>>>>> +    IDEState *ide_state;
>>>>> +
>>>>> +    if (ret < 0) {
>>>>> +        /* XXX error */
>>>>> +    }
>>>>>     
>>>>>         
>>>> Missing error handling.
>>>>   
>>>>       
>>> Yes, that's what the XXX stands for :).
>>>     
>>
>> I think Stefan wanted to tell us that he thinks this XXX should be
>> addressed. I don't disagree, by the way. ;-)
>>
>>   
>>>>> +static void process_ncq_command(AHCIState *s, int port, uint8_t *cmd_fis,
>>>>> +                                int slot, QEMUSGList *sg)
>>>>> +{
>>>>> +    NCQFrame *ncq_fis = (NCQFrame*)cmd_fis;
>>>>> +    uint8_t tag = ncq_fis->tag >> 3;
>>>>> +    NCQTransferState *ncq_tfs = &s->dev[port].ncq_tfs[tag];
>>>>> +
>>>>> +    if (ncq_tfs->used) {
>>>>> +        /* error - already in use */
>>>>> +        fprintf(stderr, "%s: tag %d already used\n", __FUNCTION__, tag);
>>>>> +        return;
>>>>> +    }
>>>>> +
>>>>> +    ncq_tfs->used = 1;
>>>>> +    ncq_tfs->drive = &s->dev[port];
>>>>> +    ncq_tfs->drive->cmd_fis = cmd_fis;
>>>>> +    ncq_tfs->drive->cmd_fis_len = 0x20;
>>>>> +    ncq_tfs->slot = slot;
>>>>> +    ncq_tfs->lba = ((uint64_t)ncq_fis->lba5 << 40) |
>>>>> +                   ((uint64_t)ncq_fis->lba4 << 32) |
>>>>> +                   ((uint64_t)ncq_fis->lba3 << 24) |
>>>>> +                   ((uint64_t)ncq_fis->lba2 << 16) |
>>>>> +                   ((uint64_t)ncq_fis->lba1 << 8) |
>>>>> +                   (uint64_t)ncq_fis->lba0;
>>>>> +
>>>>> +    /* Note: We calculate the sector count, but don't currently rely on it.
>>>>> +     * The total size of the DMA buffer tells us the transfer size instead. */
>>>>> +    ncq_tfs->sector_count = ((uint16_t)ncq_fis->sector_count_high << 8) |
>>>>> +                                ncq_fis->sector_count_low;
>>>>> +
>>>>> +    DPRINTF(port, "NCQ transfer LBA from %ld to %ld, drive max %ld\n",
>>>>> +            ncq_tfs->lba, ncq_tfs->lba + ncq_tfs->sector_count - 2,
>>>>> +            s->dev[port].port.ifs[0].nb_sectors - 1);
>>>>> +
>>>>> +    ncq_tfs->sglist = *sg;
>>>>> +    ncq_tfs->tag = tag;
>>>>> +
>>>>> +    switch(ncq_fis->command) {
>>>>> +        case READ_FPDMA_QUEUED:
>>>>> +            DPRINTF(port, "NCQ reading %d sectors from LBA %ld, tag %d\n",
>>>>> +                    ncq_tfs->sector_count-1, ncq_tfs->lba, ncq_tfs->tag);
>>>>> +            ncq_tfs->is_read = 1;
>>>>> +
>>>>> +            /* XXX: The specification is unclear about whether the DMA Setup
>>>>> +             * FIS here should have the I bit set, but it suggest that it should
>>>>> +             * not. Linux works without this interrupt, so I disabled it.
>>>>> +             * If someone knows if it is needed, please tell me, or fix this. */
>>>>> +
>>>>> +            /* ahci_trigger_irq(s,s->dev[port],PORT_IRQ_STAT_DSS); */
>>>>> +            DPRINTF(port, "tag %d aio read %ld\n", ncq_tfs->tag, ncq_tfs->lba);
>>>>> +            dma_bdrv_read(ncq_tfs->drive->port.ifs[0].bs, &ncq_tfs->sglist,
>>>>> +                          ncq_tfs->lba, ncq_cb, ncq_tfs);
>>>>> +            break;
>>>>> +        case WRITE_FPDMA_QUEUED:
>>>>> +            DPRINTF(port, "NCQ writing %d sectors to LBA %ld, tag %d\n",
>>>>> +                    ncq_tfs->sector_count-1, ncq_tfs->lba, ncq_tfs->tag);
>>>>> +            ncq_tfs->is_read = 0;
>>>>> +            /* ahci_trigger_irq(s,s->dev[port],PORT_IRQ_STAT_DSS); */
>>>>> +            DPRINTF(port, "tag %d aio write %ld\n", ncq_tfs->tag, ncq_tfs->lba);
>>>>> +            dma_bdrv_write(ncq_tfs->drive->port.ifs[0].bs, &ncq_tfs->sglist,
>>>>> +                           ncq_tfs->lba, ncq_cb, ncq_tfs);
>>>>> +            break;
>>>>> +        default:
>>>>> +            hw_error("ahci: tried to process non-NCQ command as NCQ\n");
>>>>>     
>>>>>         
>>>> Guest triggerable abort.
>>>>   
>>>>       
>>> Those happen. The guest can shoot itself in the foot. We have more of
>>> these in other places. Just check virtio.c and search for abort() :).
>>>     
>>
>> They are bugs which should be fixed in virtio rather than being spread
>> to new code.
>>   
> 
> Not sure about that. Would you prefer a broken guest to abort so you can
> debug it or to have it spew your log files with error messages or to
> silently ignore errors and never find bugs?

If you need it for debugging, maybe have a DPRINTF_ERROR macro that
aborts with an error message if DEBUG is defined, and doesn't do
anything in normal builds? I'm still not sure if aborting is a good idea
there, but I think it would be acceptable.

For normal builds, the preferred behaviour is doing the same as real
hardware in such cases. And real hardware doesn't kill the machine when
the driver is doing stupid things, but rather sets an error bit in some
register or something.

Kevin

Patch

diff --git a/Makefile.objs b/Makefile.objs
index 04625eb..4f692e4 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -238,6 +238,7 @@  hw-obj-$(CONFIG_IDE_PIIX) += ide/piix.o
 hw-obj-$(CONFIG_IDE_CMD646) += ide/cmd646.o
 hw-obj-$(CONFIG_IDE_MACIO) += ide/macio.o
 hw-obj-$(CONFIG_IDE_VIA) += ide/via.o
+hw-obj-$(CONFIG_AHCI) += ide/ahci.o
 
 # SCSI layer
 hw-obj-$(CONFIG_LSI_SCSI_PCI) += lsi53c895a.o
diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
new file mode 100644
index 0000000..7e7aa89
--- /dev/null
+++ b/hw/ide/ahci.c
@@ -0,0 +1,1374 @@ 
+/*
+ * QEMU AHCI Emulation
+ *
+ * Copyright (c) 2010 qiaochong@loongson.cn
+ * Copyright (c) 2010 Roland Elek <elek.roland@gmail.com>
+ * Copyright (c) 2010 Sebastian Herbszt <herbszt@gmx.de>
+ * Copyright (c) 2010 Alexander Graf <agraf@suse.de>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ *
+ * lspci dump of a real device:
+ *
+ *  00:1f.2 SATA controller: Intel Corporation 82801GR/GH (ICH7 Family) SATA AHCI Controller (rev 01) (prog-if 01 [AHCI 1.0])
+ *        Subsystem: Intel Corporation 82801GR/GH (ICH7 Family) SATA AHCI Controller
+ *        Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+
+ *        Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
+ *        Latency: 0
+ *        Interrupt: pin B routed to IRQ 221
+ *        Region 0: I/O ports at e880 [size=8]
+ *        Region 1: I/O ports at e800 [size=4]
+ *        Region 2: I/O ports at e480 [size=8]
+ *        Region 3: I/O ports at e400 [size=4]
+ *        Region 4: I/O ports at e080 [size=16]
+ *        Region 5: Memory at ffa3fc00 (32-bit, non-prefetchable) [size=1K]
+ *        Capabilities: [80] Message Signalled Interrupts: Mask- 64bit- Queue=0/0 Enable+
+ *                Address: fee0100c  Data: 41d9
+ *        Capabilities: [70] Power Management version 2
+ *                Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot+,D3cold-)
+ *                Status: D0 PME-Enable- DSel=0 DScale=0 PME-
+ *        Kernel driver in use: ahci
+ *        Kernel modules: ahci
+ *
+ *  00:1f.2 0106: 8086:27c1 (rev 01)
+ *
+ */
+
+#include <hw/hw.h>
+#include <hw/msi.h>
+#include <hw/pc.h>
+#include <hw/pci.h>
+
+#include "monitor.h"
+#include "dma.h"
+#include "cpu-common.h"
+#include "blockdev.h"
+#include "internal.h"
+#include <hw/ide/pci.h>
+
+/* #define DEBUG_AHCI */
+
+#ifdef DEBUG_AHCI
+#define DPRINTF(port, fmt, ...) \
+do { fprintf(stderr, "ahci: %s: [%d] ", __FUNCTION__, port); \
+     fprintf(stderr, fmt, ## __VA_ARGS__); } while (0)
+#else
+#define DPRINTF(port, fmt, ...) do {} while(0)
+#endif
+
+#define AHCI_PCI_BAR              5
+#define AHCI_MAX_PORTS            32
+#define AHCI_MAX_SG               168 /* hardware max is 64K */
+#define AHCI_DMA_BOUNDARY         0xffffffff
+#define AHCI_USE_CLUSTERING       0
+#define AHCI_MAX_CMDS             32
+#define AHCI_CMD_SZ               32
+#define AHCI_CMD_SLOT_SZ          (AHCI_MAX_CMDS * AHCI_CMD_SZ)
+#define AHCI_RX_FIS_SZ            256
+#define AHCI_CMD_TBL_CDB          0x40
+#define AHCI_CMD_TBL_HDR_SZ       0x80
+#define AHCI_CMD_TBL_SZ           (AHCI_CMD_TBL_HDR_SZ + (AHCI_MAX_SG * 16))
+#define AHCI_CMD_TBL_AR_SZ        (AHCI_CMD_TBL_SZ * AHCI_MAX_CMDS)
+#define AHCI_PORT_PRIV_DMA_SZ     (AHCI_CMD_SLOT_SZ + AHCI_CMD_TBL_AR_SZ + \
+                                   AHCI_RX_FIS_SZ)
+
+#define AHCI_IRQ_ON_SG            (1 << 31)
+#define AHCI_CMD_ATAPI            (1 << 5)
+#define AHCI_CMD_WRITE            (1 << 6)
+#define AHCI_CMD_PREFETCH         (1 << 7)
+#define AHCI_CMD_RESET            (1 << 8)
+#define AHCI_CMD_CLR_BUSY         (1 << 10)
+
+#define RX_FIS_D2H_REG            0x40 /* offset of D2H Register FIS data */
+#define RX_FIS_SDB                0x58 /* offset of SDB FIS data */
+#define RX_FIS_UNK                0x60 /* offset of Unknown FIS data */
+
+/* global controller registers */
+#define HOST_CAP                  0x00 /* host capabilities */
+#define HOST_CTL                  0x04 /* global host control */
+#define HOST_IRQ_STAT             0x08 /* interrupt status */
+#define HOST_PORTS_IMPL           0x0c /* bitmap of implemented ports */
+#define HOST_VERSION              0x10 /* AHCI spec. version compliancy */
+
+/* HOST_CTL bits */
+#define HOST_CTL_RESET            (1 << 0)  /* reset controller; self-clear */
+#define HOST_CTL_IRQ_EN           (1 << 1)  /* global IRQ enable */
+#define HOST_CTL_AHCI_EN          (1 << 31) /* AHCI enabled */
+
+/* HOST_CAP bits */
+#define HOST_CAP_SSC              (1 << 14) /* Slumber capable */
+#define HOST_CAP_AHCI             (1 << 18) /* AHCI only */
+#define HOST_CAP_CLO              (1 << 24) /* Command List Override support */
+#define HOST_CAP_SSS              (1 << 27) /* Staggered Spin-up */
+#define HOST_CAP_NCQ              (1 << 30) /* Native Command Queueing */
+#define HOST_CAP_64               (1 << 31) /* PCI DAC (64-bit DMA) support */
+
+/* registers for each SATA port */
+#define PORT_LST_ADDR             0x00 /* command list DMA addr */
+#define PORT_LST_ADDR_HI          0x04 /* command list DMA addr hi */
+#define PORT_FIS_ADDR             0x08 /* FIS rx buf addr */
+#define PORT_FIS_ADDR_HI          0x0c /* FIS rx buf addr hi */
+#define PORT_IRQ_STAT             0x10 /* interrupt status */
+#define PORT_IRQ_MASK             0x14 /* interrupt enable/disable mask */
+#define PORT_CMD                  0x18 /* port command */
+#define PORT_TFDATA               0x20 /* taskfile data */
+#define PORT_SIG                  0x24 /* device TF signature */
+#define PORT_SCR_STAT             0x28 /* SATA phy register: SStatus */
+#define PORT_SCR_CTL              0x2c /* SATA phy register: SControl */
+#define PORT_SCR_ERR              0x30 /* SATA phy register: SError */
+#define PORT_SCR_ACT              0x34 /* SATA phy register: SActive */
+#define PORT_CMD_ISSUE            0x38 /* command issue */
+#define PORT_RESERVED             0x3c /* reserved */
+
+/* PORT_IRQ_{STAT,MASK} bits */
+#define PORT_IRQ_COLD_PRES        (1 << 31) /* cold presence detect */
+#define PORT_IRQ_TF_ERR           (1 << 30) /* task file error */
+#define PORT_IRQ_HBUS_ERR         (1 << 29) /* host bus fatal error */
+#define PORT_IRQ_HBUS_DATA_ERR    (1 << 28) /* host bus data error */
+#define PORT_IRQ_IF_ERR           (1 << 27) /* interface fatal error */
+#define PORT_IRQ_IF_NONFATAL      (1 << 26) /* interface non-fatal error */
+#define PORT_IRQ_OVERFLOW         (1 << 24) /* xfer exhausted available S/G */
+#define PORT_IRQ_BAD_PMP          (1 << 23) /* incorrect port multiplier */
+
+#define PORT_IRQ_PHYRDY           (1 << 22) /* PhyRdy changed */
+#define PORT_IRQ_DEV_ILCK         (1 << 7) /* device interlock */
+#define PORT_IRQ_CONNECT          (1 << 6) /* port connect change status */
+#define PORT_IRQ_SG_DONE          (1 << 5) /* descriptor processed */
+#define PORT_IRQ_UNK_FIS          (1 << 4) /* unknown FIS rx'd */
+#define PORT_IRQ_SDB_FIS          (1 << 3) /* Set Device Bits FIS rx'd */
+#define PORT_IRQ_DMAS_FIS         (1 << 2) /* DMA Setup FIS rx'd */
+#define PORT_IRQ_PIOS_FIS         (1 << 1) /* PIO Setup FIS rx'd */
+#define PORT_IRQ_D2H_REG_FIS      (1 << 0) /* D2H Register FIS rx'd */
+
+#define PORT_IRQ_FREEZE           (PORT_IRQ_HBUS_ERR | PORT_IRQ_IF_ERR |   \
+                                   PORT_IRQ_CONNECT | PORT_IRQ_PHYRDY |    \
+                                   PORT_IRQ_UNK_FIS)
+#define PORT_IRQ_ERROR            (PORT_IRQ_FREEZE | PORT_IRQ_TF_ERR |     \
+                                   PORT_IRQ_HBUS_DATA_ERR)
+#define DEF_PORT_IRQ              (PORT_IRQ_ERROR | PORT_IRQ_SG_DONE |     \
+                                   PORT_IRQ_SDB_FIS | PORT_IRQ_DMAS_FIS |  \
+                                   PORT_IRQ_PIOS_FIS | PORT_IRQ_D2H_REG_FIS)
+
+/* PORT_CMD bits */
+#define PORT_CMD_ATAPI            (1 << 24) /* Device is ATAPI */
+#define PORT_CMD_LIST_ON          (1 << 15) /* cmd list DMA engine running */
+#define PORT_CMD_FIS_ON           (1 << 14) /* FIS DMA engine running */
+#define PORT_CMD_FIS_RX           (1 << 4) /* Enable FIS receive DMA engine */
+#define PORT_CMD_CLO              (1 << 3) /* Command list override */
+#define PORT_CMD_POWER_ON         (1 << 2) /* Power up device */
+#define PORT_CMD_SPIN_UP          (1 << 1) /* Spin up device */
+#define PORT_CMD_START            (1 << 0) /* Enable port DMA engine */
+
+#define PORT_CMD_ICC_MASK         (0xf << 28) /* i/f ICC state mask */
+#define PORT_CMD_ICC_ACTIVE       (0x1 << 28) /* Put i/f in active state */
+#define PORT_CMD_ICC_PARTIAL      (0x2 << 28) /* Put i/f in partial state */
+#define PORT_CMD_ICC_SLUMBER      (0x6 << 28) /* Put i/f in slumber state */
+
+#define PORT_IRQ_STAT_DHRS        (1 << 0) /* Device to Host Register FIS */
+#define PORT_IRQ_STAT_PSS         (1 << 1) /* PIO Setup FIS */
+#define PORT_IRQ_STAT_DSS         (1 << 2) /* DMA Setup FIS */
+#define PORT_IRQ_STAT_SDBS        (1 << 3) /* Set Device Bits */
+#define PORT_IRQ_STAT_UFS         (1 << 4) /* Unknown FIS */
+#define PORT_IRQ_STAT_DPS         (1 << 5) /* Descriptor Processed */
+#define PORT_IRQ_STAT_PCS         (1 << 6) /* Port Connect Change Status */
+#define PORT_IRQ_STAT_DMPS        (1 << 7) /* Device Mechanical Presence
+                                              Status */
+#define PORT_IRQ_STAT_PRCS        (1 << 22) /* File Ready Status */
+#define PORT_IRQ_STAT_IPMS        (1 << 23) /* Incorrect Port Multiplier
+                                               Status */
+#define PORT_IRQ_STAT_OFS         (1 << 24) /* Overflow Status */
+#define PORT_IRQ_STAT_INFS        (1 << 26) /* Interface Non-Fatal Error
+                                               Status */
+#define PORT_IRQ_STAT_IFS         (1 << 27) /* Interface Fatal Error */
+#define PORT_IRQ_STAT_HBDS        (1 << 28) /* Host Bus Data Error Status */
+#define PORT_IRQ_STAT_HBFS        (1 << 29) /* Host Bus Fatal Error Status */
+#define PORT_IRQ_STAT_TFES        (1 << 30) /* Task File Error Status */
+#define PORT_IRQ_STAT_CPDS        (1 << 31) /* Code Port Detect Status */
+
+/* ap->flags bits */
+#define AHCI_FLAG_NO_NCQ                  (1 << 24)
+#define AHCI_FLAG_IGN_IRQ_IF_ERR          (1 << 25) /* ignore IRQ_IF_ERR */
+#define AHCI_FLAG_HONOR_PI                (1 << 26) /* honor PORTS_IMPL */
+#define AHCI_FLAG_IGN_SERR_INTERNAL       (1 << 27) /* ignore SERR_INTERNAL */
+#define AHCI_FLAG_32BIT_ONLY              (1 << 28) /* force 32bit */
+
+#define ATA_SRST                          (1 << 2)  /* software reset */
+
+#define STATE_RUN                         0
+#define STATE_RESET                       1
+
+#define SATA_SCR_SSTATUS_DET_NODEV        0x0
+#define SATA_SCR_SSTATUS_DET_DEV_PRESENT_PHY_UP 0x3
+
+#define SATA_SCR_SSTATUS_SPD_NODEV        0x00
+#define SATA_SCR_SSTATUS_SPD_GEN1         0x10
+
+#define SATA_SCR_SSTATUS_IPM_NODEV        0x000
+#define SATA_SCR_SSTATUS_IPM_ACTIVE       0X100
+
+#define AHCI_SCR_SCTL_DET                 0xf
+
+#define SATA_FIS_TYPE_REGISTER_H2D        0x27
+#define SATA_FIS_REG_H2D_UPDATE_COMMAND_REGISTER 0x80
+
+#define AHCI_CMD_HDR_CMD_FIS_LEN           0x1f
+#define AHCI_CMD_HDR_PRDT_LEN              16
+
+#define SATA_SIGNATURE_CDROM               0xeb140000
+#define SATA_SIGNATURE_DISK                0x00000101
+
+#define AHCI_GENERIC_HOST_CONTROL_REGS_MAX_ADDR 0x20
+                                            /* Shouldn't this be 0x2c? */
+
+#define SATA_PORTS                         4
+
+#define AHCI_PORT_REGS_START_ADDR          0x100
+#define AHCI_PORT_REGS_END_ADDR (AHCI_PORT_REGS_START_ADDR + SATA_PORTS * 0x80)
+#define AHCI_PORT_ADDR_OFFSET_MASK         0x7f
+
+#define AHCI_NUM_COMMAND_SLOTS             31
+#define AHCI_SUPPORTED_SPEED               20
+#define AHCI_SUPPORTED_SPEED_GEN1          1
+#define AHCI_VERSION_1_0                   0x10000
+
+#define AHCI_PROGMODE_MAJOR_REV_1          1
+
+#define AHCI_COMMAND_TABLE_ACMD            0x40
+
+#define IDE_FEATURE_DMA                    1
+
+#define READ_FPDMA_QUEUED                  0x60
+#define WRITE_FPDMA_QUEUED                 0x61
+
+#define RES_FIS_DSFIS                      0x00
+#define RES_FIS_PSFIS                      0x20
+#define RES_FIS_RFIS                       0x40
+#define RES_FIS_SDBFIS                     0x58
+#define RES_FIS_UFIS                       0x60
+
+typedef struct AHCIControlRegs {
+    uint32_t    cap;
+    uint32_t    ghc;
+    uint32_t    irqstatus;
+    uint32_t    impl;
+    uint32_t    version;
+} AHCIControlRegs;
+
+typedef struct AHCIPortRegs {
+    uint32_t    lst_addr;
+    uint32_t    lst_addr_hi;
+    uint32_t    fis_addr;
+    uint32_t    fis_addr_hi;
+    uint32_t    irq_stat;
+    uint32_t    irq_mask;
+    uint32_t    cmd;
+    uint32_t    unused0;
+    uint32_t    tfdata;
+    uint32_t    sig;
+    uint32_t    scr_stat;
+    uint32_t    scr_ctl;
+    uint32_t    scr_err;
+    uint32_t    scr_act;
+    uint32_t    cmd_issue;
+    uint32_t    reserved;
+} AHCIPortRegs;
+
+typedef struct AHCICmdHdr {
+    uint32_t    opts;
+    uint32_t    status;
+    uint64_t    tbl_addr;
+    uint32_t    reserved[4];
+} __attribute__ ((packed)) AHCICmdHdr;
+
+typedef struct AHCI_SG {
+    uint64_t    addr;
+    uint32_t    reserved;
+    uint32_t    flags_size;
+} __attribute__ ((packed)) AHCI_SG;
+
+typedef struct AHCIDevice AHCIDevice;
+
+typedef struct NCQTransferState {
+    AHCIDevice *drive;
+    QEMUSGList sglist;
+    int is_read;
+    uint16_t sector_count;
+    uint64_t lba;
+    uint8_t tag;
+    int slot;
+    int used;
+} NCQTransferState;
+
+struct AHCIDevice {
+    IDEBus port;
+    int port_no;
+    uint32_t port_state;
+    uint32_t finished;
+    AHCIPortRegs port_regs;
+    struct AHCIState *hba;
+    uint8_t *lst;
+    uint8_t *res_fis;
+    uint8_t *cmd_fis;
+    int cmd_fis_len;
+    int dma_status;
+    BlockDriverCompletionFunc *dma_cb;
+    AHCICmdHdr *cur_cmd;
+    NCQTransferState ncq_tfs[AHCI_MAX_CMDS];
+};
+
+typedef struct AHCIState {
+    AHCIDevice dev[SATA_PORTS];
+    AHCIControlRegs control_regs;
+    int mem;
+    qemu_irq irq;
+} AHCIState;
+
+typedef struct AHCIPCIState {
+    PCIDevice card;
+    AHCIState ahci;
+} AHCIPCIState;
+
+typedef struct NCQFrame {
+    uint8_t fis_type;
+    uint8_t c;
+    uint8_t command;
+    uint8_t sector_count_low;
+    uint8_t lba0;
+    uint8_t lba1;
+    uint8_t lba2;
+    uint8_t fua;
+    uint8_t lba3;
+    uint8_t lba4;
+    uint8_t lba5;
+    uint8_t sector_count_high;
+    uint8_t tag;
+    uint8_t reserved5;
+    uint8_t reserved6;
+    uint8_t control;
+    uint8_t reserved7;
+    uint8_t reserved8;
+    uint8_t reserved9;
+    uint8_t reserved10;
+} __attribute__ ((packed)) NCQFrame;
+
+static void check_cmd(AHCIState *s, int port);
+static int handle_cmd(AHCIState *s,int port,int slot);
+static void ahci_reset_port(AHCIState *s, int port);
+static void ahci_write_fis_d2h(AHCIState *s, int port, uint8_t *cmd_fis);
+
+static uint32_t  ahci_port_read(AHCIState *s, int port, int offset)
+{
+    uint32_t val;
+    AHCIPortRegs *pr;
+    pr = &s->dev[port].port_regs;
+
+    switch (offset) {
+    case PORT_LST_ADDR:
+        val = pr->lst_addr;
+        break;
+    case PORT_LST_ADDR_HI:
+        val = pr->lst_addr_hi;
+        break;
+    case PORT_FIS_ADDR:
+        val = pr->fis_addr;
+        break;
+    case PORT_FIS_ADDR_HI:
+        val = pr->fis_addr_hi;
+        break;
+    case PORT_IRQ_STAT:
+        val = pr->irq_stat;
+        break;
+    case PORT_IRQ_MASK:
+        val = pr->irq_mask;
+        break;
+    case PORT_CMD:
+        val = pr->cmd;
+        break;
+    case PORT_TFDATA:
+        val = ((uint16_t)s->dev[port].port.ifs[0].error << 8) |
+              s->dev[port].port.ifs[0].status;
+        break;
+    case PORT_SIG:
+        val = pr->sig;
+        break;
+    case PORT_SCR_STAT:
+        if (s->dev[port].port.ifs[0].bs) {
+            val = SATA_SCR_SSTATUS_DET_DEV_PRESENT_PHY_UP |
+                  SATA_SCR_SSTATUS_SPD_GEN1 | SATA_SCR_SSTATUS_IPM_ACTIVE;
+        } else {
+            val = SATA_SCR_SSTATUS_DET_NODEV;
+        }
+        break;
+    case PORT_SCR_CTL:
+        val = pr->scr_ctl;
+        break;
+    case PORT_SCR_ERR:
+        val = pr->scr_err;
+        break;
+    case PORT_SCR_ACT:
+        pr->scr_act &= ~s->dev[port].finished;
+        s->dev[port].finished = 0;
+        val = pr->scr_act;
+        break;
+    case PORT_CMD_ISSUE:
+        val = pr->cmd_issue;
+        break;
+    case PORT_RESERVED:
+    default:
+        val = 0;
+    }
+    DPRINTF(port, "offset: 0x%x val: 0x%x\n", offset, val);
+    return val;
+
+}
+
+static void ahci_irq_raise(AHCIState *s, AHCIDevice *dev)
+{
+    struct AHCIPCIState *d = container_of(s, AHCIPCIState, ahci);
+
+    DPRINTF(0, "raise irq\n");
+
+    if (msi_enabled(&d->card)) {
+        msi_notify(&d->card, 0);
+    } else {
+        qemu_irq_raise(s->irq);
+    }
+}
+
+static void ahci_irq_lower(AHCIState *s, AHCIDevice *dev)
+{
+    struct AHCIPCIState *d = container_of(s, AHCIPCIState, ahci);
+
+    DPRINTF(0, "lower irq\n");
+
+    if (!msi_enabled(&d->card)) {
+        qemu_irq_lower(s->irq);
+    }
+}
+
+static void ahci_check_irq(AHCIState *s)
+{
+    int i;
+
+    DPRINTF(-1, "check irq %#x\n", s->control_regs.irqstatus);
+
+    for (i = 0; i < SATA_PORTS; i++) {
+        AHCIPortRegs *pr = &s->dev[i].port_regs;
+        if (pr->irq_stat & pr->irq_mask) {
+            s->control_regs.irqstatus |= (1 << i);
+        }
+    }
+
+    if (s->control_regs.irqstatus &&
+        (s->control_regs.ghc & HOST_CTL_IRQ_EN)) {
+            ahci_irq_raise(s, NULL);
+    } else {
+        ahci_irq_lower(s, NULL);
+    }
+}
+
+static void ahci_trigger_irq(AHCIState *s, AHCIDevice *d,
+                             int irq_type)
+{
+    DPRINTF(d->port_no, "trigger irq %#x -> %x\n",
+            irq_type, d->port_regs.irq_mask & irq_type);
+
+    d->port_regs.irq_stat |= irq_type;
+    ahci_check_irq(s);
+}
+
+static void map_page(uint8_t **ptr, uint64_t addr, uint32_t wanted)
+{
+    target_phys_addr_t len = wanted;
+
+    if (*ptr) {
+        cpu_physical_memory_unmap(*ptr, 1, len, len);
+    }
+
+    *ptr = cpu_physical_memory_map(addr, &len, 1);
+    if (len < wanted) {
+        cpu_physical_memory_unmap(*ptr, 1, len, len);
+    }
+}
+
+static void  ahci_port_write(AHCIState *s, int port, int offset, uint32_t val)
+{
+    AHCIPortRegs *pr = &s->dev[port].port_regs;
+
+    DPRINTF(port, "offset: 0x%x val: 0x%x\n", offset, val);
+    switch (offset) {
+        case PORT_LST_ADDR:
+            pr->lst_addr = val;
+            map_page(&s->dev[port].lst,
+                     ((uint64_t)pr->lst_addr_hi << 32) | pr->lst_addr, 1024);
+            break;
+        case PORT_LST_ADDR_HI:
+            pr->lst_addr_hi = val;
+            map_page(&s->dev[port].lst,
+                     ((uint64_t)pr->lst_addr_hi << 32) | pr->lst_addr, 1024);
+            break;
+        case PORT_FIS_ADDR:
+            pr->fis_addr = val;
+            map_page(&s->dev[port].res_fis,
+                     ((uint64_t)pr->fis_addr_hi << 32) | pr->fis_addr, 256);
+            break;
+        case PORT_FIS_ADDR_HI:
+            pr->fis_addr_hi = val;
+            map_page(&s->dev[port].res_fis,
+                     ((uint64_t)pr->fis_addr_hi << 32) | pr->fis_addr, 256);
+            break;
+        case PORT_IRQ_STAT:
+            pr->irq_stat &= ~val;
+            break;
+        case PORT_IRQ_MASK:
+            pr->irq_mask = val & 0xfdc000ff;
+            ahci_check_irq(s);
+            break;
+        case PORT_CMD:
+            pr->cmd = val & ~(PORT_CMD_LIST_ON | PORT_CMD_FIS_ON);
+
+            if (pr->cmd & PORT_CMD_START) {
+                pr->cmd |= PORT_CMD_LIST_ON;
+            }
+
+            if (pr->cmd & PORT_CMD_FIS_RX) {
+                pr->cmd |= PORT_CMD_FIS_ON;
+            }
+
+            check_cmd(s, port);
+            break;
+        case PORT_TFDATA:
+            s->dev[port].port.ifs[0].error = (val >> 8) & 0xff;
+            s->dev[port].port.ifs[0].status = val & 0xff;
+            break;
+        case PORT_SIG:
+            pr->sig = val;
+            break;
+        case PORT_SCR_STAT:
+            pr->scr_stat = val;
+            break;
+        case PORT_SCR_CTL:
+            if (((pr->scr_ctl & AHCI_SCR_SCTL_DET) == 1) &&
+                ((val & AHCI_SCR_SCTL_DET) == 0)) {
+                ahci_reset_port(s, port);
+            }
+            pr->scr_ctl = val;
+            break;
+        case PORT_SCR_ERR:
+            pr->scr_err &= ~val;
+            break;
+        case PORT_SCR_ACT:
+            /* RW1 */
+            pr->scr_act |= val;
+            break;
+        case PORT_CMD_ISSUE:
+            pr->cmd_issue |= val;
+            check_cmd(s, port);
+            break;
+        default:
+            break;
+    }
+}
+
+static uint32_t ahci_mem_readl(void *ptr, target_phys_addr_t addr)
+{
+    AHCIState *s = ptr;
+    uint32_t val = 0;
+
+    addr = addr & 0xfff;
+    if (addr < AHCI_GENERIC_HOST_CONTROL_REGS_MAX_ADDR) {
+        switch (addr) {
+        case HOST_CAP:
+            val = s->control_regs.cap;
+            break;
+        case HOST_CTL:
+            val = s->control_regs.ghc;
+            break;
+        case HOST_IRQ_STAT:
+            val = s->control_regs.irqstatus;
+            break;
+        case HOST_PORTS_IMPL:
+            val = s->control_regs.impl;
+            break;
+        case HOST_VERSION:
+            val = s->control_regs.version;
+            break;
+        }
+
+        DPRINTF(-1, "(addr 0x%08X), val 0x%08X\n", (unsigned) addr, val);
+    } else if ((addr >= AHCI_PORT_REGS_START_ADDR) &&
+               (addr < AHCI_PORT_REGS_END_ADDR)) {
+        val = ahci_port_read(s, (addr - AHCI_PORT_REGS_START_ADDR) >> 7,
+                             addr & AHCI_PORT_ADDR_OFFSET_MASK);
+    }
+
+    return val;
+}
+
+
+
+static void ahci_mem_writel(void *ptr, target_phys_addr_t addr, uint32_t val)
+{
+    AHCIState *s = ptr;
+    addr = addr & 0xfff;
+
+    /* Only aligned reads are allowed on AHCI */
+    if (addr & 3) {
+        fprintf(stderr, "ahci: Mis-aligned write to addr 0x"
+                TARGET_FMT_plx "\n", addr);
+        return;
+    }
+
+    if (addr < AHCI_GENERIC_HOST_CONTROL_REGS_MAX_ADDR) {
+        DPRINTF(-1, "(addr 0x%08X), val 0x%08X\n", (unsigned) addr, val);
+
+        switch (addr) {
+            case HOST_CAP: /* R/WO, RO */
+                /* FIXME handle R/WO */
+                break;
+            case HOST_CTL: /* R/W */
+                if (val & HOST_CTL_RESET) {
+                    DPRINTF(-1, "HBA Reset\n");
+                    /* FIXME reset? */
+                } else {
+                    s->control_regs.ghc = (val & 0x3) | HOST_CTL_AHCI_EN;
+                    ahci_check_irq(s);
+                }
+                break;
+            case HOST_IRQ_STAT: /* R/WC, RO */
+                s->control_regs.irqstatus &= ~val;
+                ahci_check_irq(s);
+                break;
+            case HOST_PORTS_IMPL: /* R/WO, RO */
+                /* FIXME handle R/WO */
+                break;
+            case HOST_VERSION: /* RO */
+                /* FIXME report write? */
+                break;
+            default:
+                DPRINTF(-1, "write to unknown register 0x%x\n", (unsigned)addr);
+        }
+    } else if ((addr >= AHCI_PORT_REGS_START_ADDR) &&
+               (addr < AHCI_PORT_REGS_END_ADDR)) {
+        ahci_port_write(s, (addr - AHCI_PORT_REGS_START_ADDR) >> 7,
+                        addr & AHCI_PORT_ADDR_OFFSET_MASK, val);
+    }
+
+}
+
+static CPUReadMemoryFunc * const ahci_readfn[3]={
+    ahci_mem_readl,
+    ahci_mem_readl,
+    ahci_mem_readl
+};
+
+static CPUWriteMemoryFunc * const ahci_writefn[3]={
+    ahci_mem_writel,
+    ahci_mem_writel,
+    ahci_mem_writel
+};
+
+static void ahci_reg_init(AHCIState *s)
+{
+    int i;
+
+    s->control_regs.cap = (SATA_PORTS - 1) |
+                          (AHCI_NUM_COMMAND_SLOTS << 8) |
+                          (AHCI_SUPPORTED_SPEED_GEN1 << AHCI_SUPPORTED_SPEED) |
+                          HOST_CAP_NCQ | HOST_CAP_AHCI;
+
+    s->control_regs.impl = (1 << SATA_PORTS) - 1;
+
+    s->control_regs.version = AHCI_VERSION_1_0;
+
+    for (i = 0; i < SATA_PORTS; i++) {
+        s->dev[i].port_state = STATE_RUN;
+    }
+}
+
+static uint32_t read_from_sglist(uint8_t *buffer, uint32_t len,
+                                 QEMUSGList *sglist)
+{
+    uint32_t i = 0;
+    uint32_t total = 0, once;
+    ScatterGatherEntry *cur_prd;
+    uint32_t sgcount;
+
+    cur_prd = sglist->sg;
+    sgcount = sglist->nsg;
+    for (i = 0; len && sgcount; i++) {
+        once = MIN(cur_prd->len + 1, len);
+        cpu_physical_memory_read(cur_prd->base, buffer, once);
+        cur_prd++;
+        sgcount--;
+        len -= once;
+        buffer += once;
+        total += once;
+    }
+
+    return total;
+}
+
+static uint32_t write_to_sglist(uint8_t *buffer, uint32_t len,
+                                QEMUSGList *sglist)
+{
+    uint32_t i = 0;
+    uint32_t total = 0, once;
+    ScatterGatherEntry *cur_prd;
+    uint32_t sgcount;
+
+    cur_prd = sglist->sg;
+    sgcount = sglist->nsg;
+    for (i = 0; len && sgcount; i++) {
+        once = MIN(cur_prd->len + 1, len);
+        cpu_physical_memory_write(cur_prd->base, buffer, once);
+        cur_prd++;
+        sgcount--;
+        len -= once;
+        buffer += once;
+        total += once;
+    }
+
+    return total;
+}
+
+static void check_cmd(AHCIState *s, int port)
+{
+    AHCIPortRegs *pr = &s->dev[port].port_regs;
+    int slot;
+
+    if (pr->cmd & PORT_CMD_START) {
+        for (slot = 0; (slot < 32) && pr->cmd_issue; slot++) {
+            if ((pr->cmd_issue & (1 << slot)) &&
+                !handle_cmd(s, port, slot)) {
+                pr->cmd_issue &= ~(1 << slot);
+            }
+        }
+    }
+}
+
+static void ahci_reset_port(AHCIState *s, int port)
+{
+    AHCIDevice *d = &s->dev[port];
+    AHCIPortRegs *pr = &d->port_regs;
+    IDEState *ide_state = &d->port.ifs[0];
+    uint8_t init_fis[0x20];
+    uint32_t tfd;
+
+    DPRINTF(port, "reset port\n");
+
+    ide_bus_reset(&d->port);
+    ide_state->ncq_queues = AHCI_MAX_CMDS;
+
+    pr->irq_stat = 0;
+    pr->irq_mask = 0;
+    pr->scr_stat = 0;
+    pr->scr_ctl = 0;
+    pr->scr_err = 0;
+    pr->scr_act = 0;
+
+    ide_state = &s->dev[port].port.ifs[0];
+    if (!ide_state->bs) {
+        return;
+    }
+
+    memset(init_fis, 0, sizeof(init_fis));
+    s->dev[port].port_state = STATE_RUN;
+    if (!ide_state->bs) {
+        s->dev[port].port_regs.sig = 0;
+        tfd = (1 << 8) | SEEK_STAT | WRERR_STAT;
+    } else if (ide_state->drive_kind == IDE_CD) {
+        s->dev[port].port_regs.sig = SATA_SIGNATURE_CDROM;
+        ide_state->lcyl = 0x14;
+        ide_state->hcyl = 0xeb;
+        DPRINTF(port, "set lcyl = %d\n", ide_state->lcyl);
+        init_fis[5] = ide_state->lcyl;
+        init_fis[6] = ide_state->hcyl;
+        ide_state->status = SEEK_STAT | WRERR_STAT | READY_STAT;
+    } else {
+        s->dev[port].port_regs.sig = SATA_SIGNATURE_DISK;
+        ide_state->status = SEEK_STAT | WRERR_STAT;
+    }
+
+    ide_state->error = 1;
+    init_fis[4] = 1;
+    init_fis[12] = 1;
+    ahci_write_fis_d2h(s, port, init_fis);
+}
+
+static void debug_print_fis(uint8_t *fis, int cmd_len)
+{
+#ifdef DEBUG_AHCI
+    int i;
+
+    fprintf(stderr, "fis:");
+    for (i = 0; i < cmd_len; i++) {
+        if ((i & 0xf) == 0) {
+            fprintf(stderr, "\n%02x:",i);
+        }
+        fprintf(stderr, "%02x ",fis[i]);
+    }
+    fprintf(stderr, "\n");
+#endif
+}
+
+static void ahci_write_fis_sdb(AHCIState *s, int port, uint32_t finished)
+{
+    AHCIPortRegs *pr = &s->dev[port].port_regs;
+    IDEState *ide_state;
+    uint8_t *sdb_fis;
+
+    if (!s->dev[port].res_fis ||
+        !(pr->cmd & PORT_CMD_FIS_RX)) {
+        return;
+    }
+
+    sdb_fis = &s->dev[port].res_fis[RES_FIS_SDBFIS];
+    ide_state = &s->dev[port].port.ifs[0];
+
+    /* clear memory */
+    *(uint32_t*)sdb_fis = 0;
+
+    /* write values */
+    sdb_fis[0] = ide_state->error;
+    sdb_fis[2] = ide_state->status & 0x77;
+    s->dev[port].finished |= finished;
+    *(uint32_t*)(sdb_fis + 4) = cpu_to_le32(s->dev[port].finished);
+
+    ahci_trigger_irq(s, &s->dev[port], PORT_IRQ_STAT_SDBS);
+}
+
+static void ahci_write_fis_d2h(AHCIState *s, int port, uint8_t *cmd_fis)
+{
+    AHCIPortRegs *pr = &s->dev[port].port_regs;
+    uint8_t *d2h_fis;
+    int i;
+
+    if (!s->dev[port].res_fis ||
+        !(pr->cmd & PORT_CMD_FIS_RX)) {
+        return;
+    }
+
+    d2h_fis = &s->dev[port].res_fis[RES_FIS_RFIS];
+
+    d2h_fis[0] = 0x34;
+    d2h_fis[1] = (s->control_regs.irqstatus ? (1 << 6) : 0);
+    d2h_fis[2] = s->dev[port].port.ifs[0].status;
+    d2h_fis[3] = s->dev[port].port.ifs[0].error;
+
+    d2h_fis[4] = cmd_fis[4];
+    d2h_fis[5] = cmd_fis[5];
+    d2h_fis[6] = cmd_fis[6];
+    d2h_fis[7] = cmd_fis[7];
+    d2h_fis[8] = cmd_fis[8];
+    d2h_fis[9] = cmd_fis[9];
+    d2h_fis[10] = cmd_fis[10];
+    d2h_fis[11] = cmd_fis[11];
+    d2h_fis[12] = cmd_fis[12];
+    d2h_fis[13] = cmd_fis[13];
+    for (i = 14; i < 0x20; i++) {
+        d2h_fis[i] = 0;
+    }
+
+    if (d2h_fis[2] & ERR_STAT) {
+        ahci_trigger_irq(s, &s->dev[port], PORT_IRQ_STAT_TFES);
+    }
+
+    ahci_trigger_irq(s, &s->dev[port], PORT_IRQ_D2H_REG_FIS);
+}
+
+static void ncq_cb(void *opaque, int ret)
+{
+    NCQTransferState *ncq_tfs = (NCQTransferState *)opaque;
+    IDEState *ide_state;
+
+    if (ret < 0) {
+        /* XXX error */
+    }
+
+    /* Clear bit for this tag in SActive */
+    ncq_tfs->drive->port_regs.scr_act &= ~(1 << ncq_tfs->tag);
+
+    ide_state = &ncq_tfs->drive->port.ifs[0];
+    ide_state->status = READY_STAT | SEEK_STAT;
+
+    /* XXX do we send a d2h fis here? */
+    ahci_write_fis_d2h(ncq_tfs->drive->hba, ncq_tfs->drive->port_no,
+                       ncq_tfs->drive->cmd_fis);
+
+    ahci_write_fis_sdb(ncq_tfs->drive->hba, ncq_tfs->drive->port_no,
+                       (1 << ncq_tfs->tag));
+
+    DPRINTF(ncq_tfs->drive->port_no, "NCQ transfer tag %d finished\n",
+            ncq_tfs->tag);
+
+    qemu_sglist_destroy(&ncq_tfs->sglist);
+    cpu_physical_memory_unmap(ncq_tfs->drive->cmd_fis, 1,
+                              ncq_tfs->drive->cmd_fis_len,
+                              ncq_tfs->drive->cmd_fis_len);
+
+    ncq_tfs->used = 0;
+}
+
+static void process_ncq_command(AHCIState *s, int port, uint8_t *cmd_fis,
+                                int slot, QEMUSGList *sg)
+{
+    NCQFrame *ncq_fis = (NCQFrame*)cmd_fis;
+    uint8_t tag = ncq_fis->tag >> 3;
+    NCQTransferState *ncq_tfs = &s->dev[port].ncq_tfs[tag];
+
+    if (ncq_tfs->used) {
+        /* error - already in use */
+        fprintf(stderr, "%s: tag %d already used\n", __FUNCTION__, tag);
+        return;
+    }
+
+    ncq_tfs->used = 1;
+    ncq_tfs->drive = &s->dev[port];
+    ncq_tfs->drive->cmd_fis = cmd_fis;
+    ncq_tfs->drive->cmd_fis_len = 0x20;
+    ncq_tfs->slot = slot;
+    ncq_tfs->lba = ((uint64_t)ncq_fis->lba5 << 40) |
+                   ((uint64_t)ncq_fis->lba4 << 32) |
+                   ((uint64_t)ncq_fis->lba3 << 24) |
+                   ((uint64_t)ncq_fis->lba2 << 16) |
+                   ((uint64_t)ncq_fis->lba1 << 8) |
+                   (uint64_t)ncq_fis->lba0;
+
+    /* Note: We calculate the sector count, but don't currently rely on it.
+     * The total size of the DMA buffer tells us the transfer size instead. */
+    ncq_tfs->sector_count = ((uint16_t)ncq_fis->sector_count_high << 8) |
+                                ncq_fis->sector_count_low;
+
+    DPRINTF(port, "NCQ transfer LBA from %ld to %ld, drive max %ld\n",
+            ncq_tfs->lba, ncq_tfs->lba + ncq_tfs->sector_count - 2,
+            s->dev[port].port.ifs[0].nb_sectors - 1);
+
+    ncq_tfs->sglist = *sg;
+    ncq_tfs->tag = tag;
+
+    switch(ncq_fis->command) {
+        case READ_FPDMA_QUEUED:
+            DPRINTF(port, "NCQ reading %d sectors from LBA %ld, tag %d\n",
+                    ncq_tfs->sector_count-1, ncq_tfs->lba, ncq_tfs->tag);
+            ncq_tfs->is_read = 1;
+
+            /* XXX: The specification is unclear about whether the DMA Setup
+             * FIS here should have the I bit set, but it suggest that it should
+             * not. Linux works without this interrupt, so I disabled it.
+             * If someone knows if it is needed, please tell me, or fix this. */
+
+            /* ahci_trigger_irq(s,s->dev[port],PORT_IRQ_STAT_DSS); */
+            DPRINTF(port, "tag %d aio read %ld\n", ncq_tfs->tag, ncq_tfs->lba);
+            dma_bdrv_read(ncq_tfs->drive->port.ifs[0].bs, &ncq_tfs->sglist,
+                          ncq_tfs->lba, ncq_cb, ncq_tfs);
+            break;
+        case WRITE_FPDMA_QUEUED:
+            DPRINTF(port, "NCQ writing %d sectors to LBA %ld, tag %d\n",
+                    ncq_tfs->sector_count-1, ncq_tfs->lba, ncq_tfs->tag);
+            ncq_tfs->is_read = 0;
+            /* ahci_trigger_irq(s,s->dev[port],PORT_IRQ_STAT_DSS); */
+            DPRINTF(port, "tag %d aio write %ld\n", ncq_tfs->tag, ncq_tfs->lba);
+            dma_bdrv_write(ncq_tfs->drive->port.ifs[0].bs, &ncq_tfs->sglist,
+                           ncq_tfs->lba, ncq_cb, ncq_tfs);
+            break;
+        default:
+            hw_error("ahci: tried to process non-NCQ command as NCQ\n");
+            break;
+    }
+}
+
+static int handle_cmd(AHCIState *s, int port, int slot)
+{
+    IDEState *ide_state;
+
+    int sglist_alloc_hint;
+    QEMUSGList sglist;
+    int atapi_packet_len = 0;
+    AHCIPortRegs *pr;
+    uint32_t opts;
+    uint64_t tbl_addr;
+    AHCICmdHdr *cmd;
+    uint8_t *cmd_fis;
+
+    target_phys_addr_t cmd_len;
+    int i;
+
+    if (s->dev[port].port.ifs[0].status & (BUSY_STAT|DRQ_STAT)) {
+        /* Engine currently busy, try again later */
+        DPRINTF(port, "engine busy\n");
+        return -1;
+    }
+
+    pr = &s->dev[port].port_regs;
+    cmd = &((AHCICmdHdr *)s->dev[port].lst)[slot];
+
+    if (!s->dev[port].lst) {
+        hw_error("%s: lst not given but cmd handled", __FUNCTION__);
+    }
+
+    opts = le32_to_cpu(cmd->opts);
+    tbl_addr = le64_to_cpu(cmd->tbl_addr);
+
+    sglist_alloc_hint = opts >> AHCI_CMD_HDR_PRDT_LEN;
+    cmd_len = 0x80 + (sglist_alloc_hint * sizeof(AHCI_SG));
+    cmd_fis = cpu_physical_memory_map(tbl_addr, &cmd_len, 1);
+
+    /* The device we are working for */
+    ide_state = &s->dev[port].port.ifs[0];
+
+    if (!ide_state->bs) {
+        hw_error("%s: guest accessed unused port", __FUNCTION__);
+    }
+
+    /* Get number of entries in the PRDT, init a qemu sglist accordingly */
+    memset(&sglist, 0, sizeof(sglist));
+
+    if (sglist_alloc_hint > 0) {
+        AHCI_SG *tbl = (AHCI_SG *)(&cmd_fis[0x80]);
+
+        qemu_sglist_init(&sglist, sglist_alloc_hint);
+        /* Parse the PRDs and create qemu sglist entries accordingly */
+        for (i = 0; i < sglist_alloc_hint; i++) {
+            /* flags_size is zero-based */
+            qemu_sglist_add(&sglist, le64_to_cpu(tbl[i].addr),
+                            le32_to_cpu(tbl[i].flags_size) + 1);
+        }
+    }
+
+    debug_print_fis(cmd_fis, (opts & AHCI_CMD_HDR_CMD_FIS_LEN) * 4);
+
+    switch (cmd_fis[0]) {
+        case SATA_FIS_TYPE_REGISTER_H2D:
+            break;
+        default:
+            hw_error("unknown command cmd_fis[0]=%02x cmd_fis[1]=%02x cmd_fis[2]=%02x\n",
+                     cmd_fis[0], cmd_fis[1], cmd_fis[2]);
+            break;
+    }
+
+    switch (cmd_fis[1]) {
+        case SATA_FIS_REG_H2D_UPDATE_COMMAND_REGISTER:
+            break;
+        case 0:
+            break;
+        default:
+            hw_error("unknown command cmd_fis[0]=%02x cmd_fis[1]=%02x cmd_fis[2]=%02x\n",
+                     cmd_fis[0], cmd_fis[1], cmd_fis[2]);
+            break;
+    }
+
+    switch (s->dev[port].port_state) {
+        case STATE_RUN:
+            if (cmd_fis[15] & ATA_SRST) {
+                s->dev[port].port_state = STATE_RESET;
+            }
+            break;
+        case STATE_RESET:
+            if (!(cmd_fis[15] & ATA_SRST)) {
+                ahci_reset_port(s, port);
+            }
+            break;
+    }
+
+    if (cmd_fis[1] == SATA_FIS_REG_H2D_UPDATE_COMMAND_REGISTER) {
+
+        /* Check for NCQ command */
+        if ((cmd_fis[2] == READ_FPDMA_QUEUED) ||
+            (cmd_fis[2] == WRITE_FPDMA_QUEUED)) {
+            process_ncq_command(s, port, cmd_fis, slot, &sglist);
+            goto out;
+        }
+
+        /* If the command is not NCQ, the sglist is needed in the core */
+        ide_state->sg = sglist;
+
+        /* Decompose the FIS  */
+        ide_state->nsector = (int64_t)((cmd_fis[13] << 8) | cmd_fis[12]);
+        ide_state->feature = cmd_fis[3];
+        if (!ide_state->nsector) {
+            ide_state->nsector = 256;
+        }
+
+        if (ide_state->drive_kind != IDE_CD) {
+            ide_set_sector(ide_state, (cmd_fis[6] << 16) | (cmd_fis[5] << 8) |
+                           cmd_fis[4]);
+        }
+
+        /* Copy the ACMD field (ATAPI packet, if any) from the AHCI command
+         * table to ide_state->io_buffer
+         */
+        if (opts & AHCI_CMD_ATAPI) {
+            atapi_packet_len = ((ide_state->hcyl) << 8) + ide_state->lcyl;
+            memcpy(ide_state->io_buffer, &cmd_fis[AHCI_COMMAND_TABLE_ACMD], 0x10);
+            ide_state->feature = IDE_FEATURE_DMA;
+        }
+
+        ide_state->error = 0;
+        s->dev[port].cur_cmd = cmd;
+
+        /* We're ready to process the command in FIS byte 2. */
+        ide_exec_cmd(&s->dev[port].port, cmd_fis[2]);
+
+        /* we're DMA'ing, so we're not ready yet, postpone cleanup to later */
+        if (s->dev[port].dma_status & BM_STATUS_DMAING) {
+            cmd->status = 0;
+            s->dev[port].cmd_fis = cmd_fis;
+            s->dev[port].cmd_fis_len = cmd_len;
+            return 0;
+        }
+
+        ahci_write_fis_d2h(s, port, cmd_fis);
+    }
+
+out:
+    cpu_physical_memory_unmap(cmd_fis, 1, cmd_len, cmd_len);
+
+    return 0;
+}
+
+/* DMA dev -> ram */
+static int ahci_start_transfer(void *opaque)
+{
+    AHCIDevice *ad = opaque;
+    IDEState *s = &ad->port.ifs[0];
+    uint32_t size = (uint32_t)(s->data_end - s->data_ptr);
+
+    DPRINTF(ad->port_no, "writing %d bytes\n", size);
+    write_to_sglist(s->data_ptr, size, &s->sg);
+
+    /* update number of transferred bytes */
+    ad->cur_cmd->status = cpu_to_le32(le32_to_cpu(ad->cur_cmd->status) + size);
+    /* declare that we processed everything */
+    s->data_ptr = s->data_end;
+    s->end_transfer_func(s);
+
+    if (!(s->status & DRQ_STAT)) {
+        /* done with DMA */
+        ahci_trigger_irq(ad->hba, ad, PORT_IRQ_STAT_DSS);
+    }
+
+    return 0;
+}
+
+static void ahci_start_dma(void *opaque, IDEState *s,
+                           BlockDriverCompletionFunc *dma_cb)
+{
+    AHCIDevice *ad = opaque;
+
+    DPRINTF(ad->port_no, "\n");
+    ad->dma_cb = dma_cb;
+    ad->dma_status |= BM_STATUS_DMAING;
+    dma_cb(s, 0);
+}
+
+static int ahci_dma_prepare_buf(void *opaque, int is_write)
+{
+    AHCIDevice *ad = opaque;
+    IDEState *s = &ad->port.ifs[0];
+    int i;
+
+    s->io_buffer_size = 0;
+    for (i = 0; i < s->sg.nsg; i++) {
+        s->io_buffer_size += s->sg.sg[i].len;
+    }
+
+    DPRINTF(ad->port_no, "len=%#x\n", s->io_buffer_size);
+    return s->io_buffer_size != 0;
+}
+
+static int ahci_dma_rw_buf(void *opaque, int is_write)
+{
+    AHCIDevice *ad = opaque;
+    IDEState *s = &ad->port.ifs[0];
+    uint8_t *p = s->io_buffer + s->io_buffer_index;
+    int l = s->io_buffer_size - s->io_buffer_index;
+
+    if (is_write) {
+        write_to_sglist(p, l, &s->sg);
+    } else {
+        read_from_sglist(p, l, &s->sg);
+    }
+
+    s->io_buffer_index += l;
+    DPRINTF(ad->port_no, "len=%#x\n", l);
+
+    return 1;
+}
+
+static int ahci_dma_set_unit(void *opaque, int unit)
+{
+    /* only a single unit per link */
+    return 0;
+}
+
+static int ahci_dma_set_status(void *opaque, int status)
+{
+    AHCIDevice *ad = opaque;
+    ad->dma_status |= status;
+    DPRINTF(ad->port_no, "set status: %x\n", status);
+
+    if (status & BM_STATUS_INT) {
+        ahci_trigger_irq(ad->hba, ad, PORT_IRQ_STAT_DSS);
+    }
+
+    return 0;
+}
+
+static int ahci_dma_set_inactive(void *opaque)
+{
+    AHCIDevice *ad = opaque;
+
+    DPRINTF(ad->port_no, "dma done\n");
+
+    /* update d2h status */
+    if (ad->cmd_fis) {
+        ahci_write_fis_d2h(ad->hba, ad->port_no, ad->cmd_fis);
+        cpu_physical_memory_unmap(ad->cmd_fis, 1, ad->cmd_fis_len, ad->cmd_fis_len);
+        ad->cmd_fis = NULL;
+    }
+
+    ad->dma_cb = NULL;
+
+    return 0;
+}
+
+static void ahci_irq_set(void *opaque, int n, int level)
+{
+}
+
+static void ahci_dma_restart_cb(void *opaque, int running, int reason)
+{
+}
+
+static int ahci_dma_reset(void *opaque)
+{
+    return 0;
+}
+
+static const IDEDMAOps ahci_dma_ops = {
+    .start_dma = ahci_start_dma,
+    .start_transfer = ahci_start_transfer,
+    .prepare_buf = ahci_dma_prepare_buf,
+    .rw_buf = ahci_dma_rw_buf,
+    .set_unit = ahci_dma_set_unit,
+    .set_status = ahci_dma_set_status,
+    .set_inactive = ahci_dma_set_inactive,
+    .restart_cb = ahci_dma_restart_cb,
+    .reset = ahci_dma_reset,
+};
+
+static void ahci_init(AHCIState *s, DeviceState *qdev)
+{
+    qemu_irq *irqs;
+    int i;
+
+    ahci_reg_init(s);
+    s->mem = cpu_register_io_memory(ahci_readfn, ahci_writefn, s);
+    irqs = qemu_allocate_irqs(ahci_irq_set, s, SATA_PORTS);
+
+    for (i = 0; i < SATA_PORTS; i++) {
+        AHCIDevice *ad = &s->dev[i];
+
+        ide_bus_new(&ad->port, qdev);
+        ide_init2(&ad->port, irqs[i]);
+
+        ad->hba = s;
+        ad->port_no = i;
+        ad->port.dma.ops = &ahci_dma_ops;
+        ad->port.dma.opaque = ad;
+        ad->port_regs.cmd = PORT_CMD_SPIN_UP | PORT_CMD_POWER_ON;
+    }
+}
+
+static void ahci_pci_map(PCIDevice *pci_dev, int region_num,
+        pcibus_t addr, pcibus_t size, int type)
+{
+    struct AHCIPCIState *d = (struct AHCIPCIState *)pci_dev;
+    AHCIState *s = &d->ahci;
+
+    cpu_register_physical_memory(addr, size, s->mem);
+}
+
+static void ahci_reset(void *opaque)
+{
+    struct AHCIPCIState *d = opaque;
+    int i;
+
+    for (i = 0; i < SATA_PORTS; i++) {
+        ahci_reset_port(&d->ahci, i);
+    }
+}
+
+static int pci_ahci_init(PCIDevice *dev)
+{
+    struct AHCIPCIState *d;
+    d = DO_UPCAST(struct AHCIPCIState, card, dev);
+
+    pci_config_set_vendor_id(d->card.config, PCI_VENDOR_ID_INTEL);
+    pci_config_set_device_id(d->card.config,
+                             PCI_DEVICE_ID_INTEL_ICH7_AHCI);
+
+    pci_config_set_class(d->card.config, PCI_CLASS_STORAGE_SATA);
+    pci_config_set_prog_interface(d->card.config, AHCI_PROGMODE_MAJOR_REV_1);
+
+    d->card.config[PCI_CACHE_LINE_SIZE] = 0x08;  /* Cache line size */
+    d->card.config[PCI_LATENCY_TIMER]   = 0x00;  /* Latency timer */
+    pci_config_set_interrupt_pin(d->card.config, 1);
+
+    qemu_register_reset(ahci_reset, d);
+
+    /* XXX BAR size should be 1k, but that breaks, so bump it to 4k for now */
+    pci_register_bar(&d->card, 5, 0x1000, PCI_BASE_ADDRESS_SPACE_MEMORY,
+                     ahci_pci_map);
+
+    msi_init(dev, 0x50, 1, true, false);
+
+    ahci_init(&d->ahci, &dev->qdev);
+    d->ahci.irq = d->card.irq[0];
+
+    return 0;
+}
+
+static int pci_ahci_uninit(PCIDevice *dev)
+{
+    if (msi_enabled(dev)) {
+        msi_uninit(dev);
+    }
+
+    return 0;
+}
+
+static void pci_ahci_write_config(PCIDevice *pci, uint32_t addr,
+                                  uint32_t val, int len)
+{
+    pci_default_write_config(pci, addr, val, len);
+    msi_write_config(pci, addr, val, len);
+}
+
+static PCIDeviceInfo ahci_info = {
+    .qdev.name  = "ahci",
+    .qdev.size  = sizeof(AHCIPCIState),
+    .init       = pci_ahci_init,
+    .exit       = pci_ahci_uninit,
+    .config_write = pci_ahci_write_config,
+};
+
+static void ahci_pci_register_devices(void)
+{
+    pci_qdev_register(&ahci_info);
+}
+
+device_init(ahci_pci_register_devices)