| Message ID | 1418087585-27601-5-git-send-email-lersek@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 9 December 2014 at 01:13, Laszlo Ersek <lersek@redhat.com> wrote: > fw_cfg already supports exposure over MMIO (used in ppc/mac_newworld.c, > ppc/mac_oldworld.c, sparc/sun4m.c); we can easily add it to the "virt" > board. > > Because MMIO access is slow on ARM KVM, we enable the guest, with > fw_cfg_init_data_memwidth(), to transfer up to 8 bytes with a single > access. This has been measured to speed up transfers up to 7.5-fold, > relative to single byte data access, on both ARM KVM and x86_64 TCG. > > The mmio register block of fw_cfg is advertized in the device tree. As > base address we pick 0x09020000, which conforms to the comment preceding > "a15memmap": it falls in the miscellaneous device I/O range 128MB..256MB, > and it is aligned at 64KB. The DTB properties follow the documentation in > the Linux source file "Documentation/devicetree/bindings/arm/fw-cfg.txt". > > fw_cfg automatically exports a number of files to the guest; for example, > "bootorder" (see fw_cfg_machine_reset()). > > Signed-off-by: Laszlo Ersek <lersek@redhat.com> > --- > > Notes: > v3: > - enable 8-byte wide access to fw_cfg MMIO data port [Drew] > - expose the exact size of the fused region in the DTB [Peter] > - reorder data register and control register so that we can keep the > region contiguous and still conform to alignment requirements [Laszlo] > > hw/arm/virt.c | 21 +++++++++++++++++++++ > 1 file changed, 21 insertions(+) > > diff --git a/hw/arm/virt.c b/hw/arm/virt.c > index 314e55b..274aaae 100644 > --- a/hw/arm/virt.c > +++ b/hw/arm/virt.c > @@ -67,8 +67,9 @@ enum { > VIRT_GIC_CPU, > VIRT_UART, > VIRT_MMIO, > VIRT_RTC, > + VIRT_FW_CFG, > }; > > typedef struct MemMapEntry { > hwaddr base; > @@ -106,8 +107,9 @@ static const MemMapEntry a15memmap[] = { > [VIRT_GIC_DIST] = { 0x08000000, 0x00010000 }, > [VIRT_GIC_CPU] = { 0x08010000, 0x00010000 }, > [VIRT_UART] = { 0x09000000, 0x00001000 }, > [VIRT_RTC] = { 0x09010000, 0x00001000 }, > + [VIRT_FW_CFG] = { 0x09020000, 0x0000000a }, > [VIRT_MMIO] = { 0x0a000000, 0x00000200 }, > /* ...repeating for a total of NUM_VIRTIO_TRANSPORTS, each of that size */ > /* 0x10000000 .. 0x40000000 reserved for PCI */ > [VIRT_MEM] = { 0x40000000, 30ULL * 1024 * 1024 * 1024 }, > @@ -518,8 +520,25 @@ static void create_flash(const VirtBoardInfo *vbi) > qemu_fdt_setprop_cell(vbi->fdt, nodename, "bank-width", 4); > g_free(nodename); > } > > +static void create_fw_cfg(const VirtBoardInfo *vbi) > +{ > + hwaddr base = vbi->memmap[VIRT_FW_CFG].base; > + hwaddr size = vbi->memmap[VIRT_FW_CFG].size; > + char *nodename; > + > + fw_cfg_init_data_memwidth(0, 0, base + 8, base, 8); fw_cfg_init_data_memwidth() adds a bunch of FW_CFG keys (bootsplash stuff, reboot timeouts, etc). Are you happy that they all make sense to export on ARM? (I guess we're already doing that on the other non-x86 fw_cfg users.) Assuming so, Reviewed-by: Peter Maydell <peter.maydell@linaro.org> -- PMM
On 12/12/14 13:55, Peter Maydell wrote: > On 9 December 2014 at 01:13, Laszlo Ersek <lersek@redhat.com> wrote: >> fw_cfg already supports exposure over MMIO (used in ppc/mac_newworld.c, >> ppc/mac_oldworld.c, sparc/sun4m.c); we can easily add it to the "virt" >> board. >> >> Because MMIO access is slow on ARM KVM, we enable the guest, with >> fw_cfg_init_data_memwidth(), to transfer up to 8 bytes with a single >> access. This has been measured to speed up transfers up to 7.5-fold, >> relative to single byte data access, on both ARM KVM and x86_64 TCG. >> >> The mmio register block of fw_cfg is advertized in the device tree. As >> base address we pick 0x09020000, which conforms to the comment preceding >> "a15memmap": it falls in the miscellaneous device I/O range 128MB..256MB, >> and it is aligned at 64KB. The DTB properties follow the documentation in >> the Linux source file "Documentation/devicetree/bindings/arm/fw-cfg.txt". >> >> fw_cfg automatically exports a number of files to the guest; for example, >> "bootorder" (see fw_cfg_machine_reset()). >> >> Signed-off-by: Laszlo Ersek <lersek@redhat.com> >> --- >> >> Notes: >> v3: >> - enable 8-byte wide access to fw_cfg MMIO data port [Drew] >> - expose the exact size of the fused region in the DTB [Peter] >> - reorder data register and control register so that we can keep the >> region contiguous and still conform to alignment requirements [Laszlo] >> >> hw/arm/virt.c | 21 +++++++++++++++++++++ >> 1 file changed, 21 insertions(+) >> >> diff --git a/hw/arm/virt.c b/hw/arm/virt.c >> index 314e55b..274aaae 100644 >> --- a/hw/arm/virt.c >> +++ b/hw/arm/virt.c >> @@ -67,8 +67,9 @@ enum { >> VIRT_GIC_CPU, >> VIRT_UART, >> VIRT_MMIO, >> VIRT_RTC, >> + VIRT_FW_CFG, >> }; >> >> typedef struct MemMapEntry { >> hwaddr base; >> @@ -106,8 +107,9 @@ static const MemMapEntry a15memmap[] = { >> [VIRT_GIC_DIST] = { 0x08000000, 0x00010000 }, >> [VIRT_GIC_CPU] = { 0x08010000, 0x00010000 }, >> [VIRT_UART] = { 0x09000000, 0x00001000 }, >> [VIRT_RTC] = { 0x09010000, 0x00001000 }, >> + [VIRT_FW_CFG] = { 0x09020000, 0x0000000a }, >> [VIRT_MMIO] = { 0x0a000000, 0x00000200 }, >> /* ...repeating for a total of NUM_VIRTIO_TRANSPORTS, each of that size */ >> /* 0x10000000 .. 0x40000000 reserved for PCI */ >> [VIRT_MEM] = { 0x40000000, 30ULL * 1024 * 1024 * 1024 }, >> @@ -518,8 +520,25 @@ static void create_flash(const VirtBoardInfo *vbi) >> qemu_fdt_setprop_cell(vbi->fdt, nodename, "bank-width", 4); >> g_free(nodename); >> } >> >> +static void create_fw_cfg(const VirtBoardInfo *vbi) >> +{ >> + hwaddr base = vbi->memmap[VIRT_FW_CFG].base; >> + hwaddr size = vbi->memmap[VIRT_FW_CFG].size; >> + char *nodename; >> + >> + fw_cfg_init_data_memwidth(0, 0, base + 8, base, 8); > > fw_cfg_init_data_memwidth() adds a bunch of FW_CFG keys > (bootsplash stuff, reboot timeouts, etc). Are you happy that > they all make sense to export on ARM? (I guess we're already doing > that on the other non-x86 fw_cfg users.) Yes, some of those I'm actually happy about (because I can immediately retrieve them in the firmware, without doing more qemu work); and the rest doesn't hurt (I might utilize them later on). > > Assuming so, > Reviewed-by: Peter Maydell <peter.maydell@linaro.org> > > -- PMM > Thanks! Laszlo
diff --git a/hw/arm/virt.c b/hw/arm/virt.c index 314e55b..274aaae 100644 --- a/hw/arm/virt.c +++ b/hw/arm/virt.c @@ -67,8 +67,9 @@ enum { VIRT_GIC_CPU, VIRT_UART, VIRT_MMIO, VIRT_RTC, + VIRT_FW_CFG, }; typedef struct MemMapEntry { hwaddr base; @@ -106,8 +107,9 @@ static const MemMapEntry a15memmap[] = { [VIRT_GIC_DIST] = { 0x08000000, 0x00010000 }, [VIRT_GIC_CPU] = { 0x08010000, 0x00010000 }, [VIRT_UART] = { 0x09000000, 0x00001000 }, [VIRT_RTC] = { 0x09010000, 0x00001000 }, + [VIRT_FW_CFG] = { 0x09020000, 0x0000000a }, [VIRT_MMIO] = { 0x0a000000, 0x00000200 }, /* ...repeating for a total of NUM_VIRTIO_TRANSPORTS, each of that size */ /* 0x10000000 .. 0x40000000 reserved for PCI */ [VIRT_MEM] = { 0x40000000, 30ULL * 1024 * 1024 * 1024 }, @@ -518,8 +520,25 @@ static void create_flash(const VirtBoardInfo *vbi) qemu_fdt_setprop_cell(vbi->fdt, nodename, "bank-width", 4); g_free(nodename); } +static void create_fw_cfg(const VirtBoardInfo *vbi) +{ + hwaddr base = vbi->memmap[VIRT_FW_CFG].base; + hwaddr size = vbi->memmap[VIRT_FW_CFG].size; + char *nodename; + + fw_cfg_init_data_memwidth(0, 0, base + 8, base, 8); + + nodename = g_strdup_printf("/fw-cfg@%" PRIx64, base); + qemu_fdt_add_subnode(vbi->fdt, nodename); + qemu_fdt_setprop_string(vbi->fdt, nodename, + "compatible", "qemu,fw-cfg-mmio"); + qemu_fdt_setprop_sized_cells(vbi->fdt, nodename, "reg", + 2, base, 2, size); + g_free(nodename); +} + static void *machvirt_dtb(const struct arm_boot_info *binfo, int *fdt_size) { const VirtBoardInfo *board = (const VirtBoardInfo *)binfo; @@ -603,8 +622,10 @@ static void machvirt_init(MachineState *machine) * no backend is created the transport will just sit harmlessly idle. */ create_virtio_devices(vbi, pic); + create_fw_cfg(vbi); + vbi->bootinfo.ram_size = machine->ram_size; vbi->bootinfo.kernel_filename = machine->kernel_filename; vbi->bootinfo.kernel_cmdline = machine->kernel_cmdline; vbi->bootinfo.initrd_filename = machine->initrd_filename;
fw_cfg already supports exposure over MMIO (used in ppc/mac_newworld.c, ppc/mac_oldworld.c, sparc/sun4m.c); we can easily add it to the "virt" board. Because MMIO access is slow on ARM KVM, we enable the guest, with fw_cfg_init_data_memwidth(), to transfer up to 8 bytes with a single access. This has been measured to speed up transfers up to 7.5-fold, relative to single byte data access, on both ARM KVM and x86_64 TCG. The mmio register block of fw_cfg is advertized in the device tree. As base address we pick 0x09020000, which conforms to the comment preceding "a15memmap": it falls in the miscellaneous device I/O range 128MB..256MB, and it is aligned at 64KB. The DTB properties follow the documentation in the Linux source file "Documentation/devicetree/bindings/arm/fw-cfg.txt". fw_cfg automatically exports a number of files to the guest; for example, "bootorder" (see fw_cfg_machine_reset()). Signed-off-by: Laszlo Ersek <lersek@redhat.com> --- Notes: v3: - enable 8-byte wide access to fw_cfg MMIO data port [Drew] - expose the exact size of the fused region in the DTB [Peter] - reorder data register and control register so that we can keep the region contiguous and still conform to alignment requirements [Laszlo] hw/arm/virt.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+)