[v3,5/6] block/nvme: add support for write zeros
diff mbox series

Message ID 20190703155944.9637-6-mlevitsk@redhat.com
State New
Headers show
Series
  • Few fixes for userspace NVME driver
Related show

Commit Message

Maxim Levitsky July 3, 2019, 3:59 p.m. UTC
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
---
 block/nvme.c         | 69 +++++++++++++++++++++++++++++++++++++++++++-
 block/trace-events   |  1 +
 include/block/nvme.h | 19 +++++++++++-
 3 files changed, 87 insertions(+), 2 deletions(-)

Comments

Max Reitz July 5, 2019, 1:33 p.m. UTC | #1
On 03.07.19 17:59, Maxim Levitsky wrote:
> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
> ---
>  block/nvme.c         | 69 +++++++++++++++++++++++++++++++++++++++++++-
>  block/trace-events   |  1 +
>  include/block/nvme.h | 19 +++++++++++-
>  3 files changed, 87 insertions(+), 2 deletions(-)
> 
> diff --git a/block/nvme.c b/block/nvme.c
> index 152d27b07f..02e0846643 100644
> --- a/block/nvme.c
> +++ b/block/nvme.c

[...]

> @@ -469,6 +473,11 @@ static void nvme_identify(BlockDriverState *bs, int namespace, Error **errp)
>      s->nsze = le64_to_cpu(idns->nsze);
>      lbaf = &idns->lbaf[NVME_ID_NS_FLBAS_INDEX(idns->flbas)];
>  
> +    if (NVME_ID_NS_DLFEAT_WRITE_ZEROS(idns->dlfeat) &&
> +            NVME_ID_NS_DLFEAT_READ_BEHAVIOR(idns->dlfeat) ==
> +                    NVME_ID_NS_DLFEAT_READ_BEHAVIOR_ZEROS)
> +        bs->supported_write_flags |= BDRV_REQ_MAY_UNMAP;
> +

This violates the coding style, there should be curly brackets here.

>      if (lbaf->ms) {
>          error_setg(errp, "Namespaces with metadata are not yet supported");
>          goto out;
> @@ -763,6 +772,8 @@ static int nvme_file_open(BlockDriverState *bs, QDict *options, int flags,
>      int ret;
>      BDRVNVMeState *s = bs->opaque;
>  
> +    bs->supported_write_flags = BDRV_REQ_FUA;
> +
>      opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
>      qemu_opts_absorb_qdict(opts, options, &error_abort);
>      device = qemu_opt_get(opts, NVME_BLOCK_OPT_DEVICE);
> @@ -791,7 +802,6 @@ static int nvme_file_open(BlockDriverState *bs, QDict *options, int flags,
>              goto fail;
>          }
>      }
> -    bs->supported_write_flags = BDRV_REQ_FUA;

Any reason for this movement?

>      return 0;
>  fail:
>      nvme_close(bs);
> @@ -1085,6 +1095,60 @@ static coroutine_fn int nvme_co_flush(BlockDriverState *bs)
>  }
>  
>  
> +static coroutine_fn int nvme_co_pwrite_zeroes(BlockDriverState *bs,
> +                                              int64_t offset,
> +                                              int bytes,
> +                                              BdrvRequestFlags flags)
> +{
> +    BDRVNVMeState *s = bs->opaque;
> +    NVMeQueuePair *ioq = s->queues[1];
> +    NVMeRequest *req;
> +
> +    if (!s->supports_write_zeros) {
> +        return -ENOTSUP;
> +    }
> +
> +    uint32_t cdw12 = ((bytes >> s->blkshift) - 1) & 0xFFFF;

Another coding style violation: Variable declarations and other code may
not be mixed.

> +
> +    NvmeCmd cmd = {
> +        .opcode = NVME_CMD_WRITE_ZEROS,
> +        .nsid = cpu_to_le32(s->nsid),
> +        .cdw10 = cpu_to_le32((offset >> s->blkshift) & 0xFFFFFFFF),
> +        .cdw11 = cpu_to_le32(((offset >> s->blkshift) >> 32) & 0xFFFFFFFF),
> +    };
> +
> +    NVMeCoData data = {
> +        .ctx = bdrv_get_aio_context(bs),
> +        .ret = -EINPROGRESS,
> +    };

[...]

> diff --git a/include/block/nvme.h b/include/block/nvme.h
> index 3ec8efcc43..65eb65c740 100644
> --- a/include/block/nvme.h
> +++ b/include/block/nvme.h
> @@ -653,12 +653,29 @@ typedef struct NvmeIdNs {
>      uint8_t     mc;
>      uint8_t     dpc;
>      uint8_t     dps;
> -    uint8_t     res30[98];
> +
> +    uint8_t     nmic;
> +    uint8_t     rescap;
> +    uint8_t     fpi;
> +    uint8_t     dlfeat;
> +
> +    uint8_t     res30[94];
>      NvmeLBAF    lbaf[16];
>      uint8_t     res192[192];
>      uint8_t     vs[3712];
>  } NvmeIdNs;
>  
> +
> +/*Deallocate Logical Block Features*/
> +#define NVME_ID_NS_DLFEAT_GUARD_CRC(dlfeat)       ((dlfeat) & 0x10)
> +#define NVME_ID_NS_DLFEAT_WRITE_ZEROS(dlfeat)     ((dlfeat) & 0x04)

Isn’t it bit 3, i.e. 0x08?

Max

> +
> +#define NVME_ID_NS_DLFEAT_READ_BEHAVIOR(dlfeat)     ((dlfeat) & 0x3)
> +#define NVME_ID_NS_DLFEAT_READ_BEHAVIOR_UNDEFINED   0
> +#define NVME_ID_NS_DLFEAT_READ_BEHAVIOR_ZEROS       1
> +#define NVME_ID_NS_DLFEAT_READ_BEHAVIOR_ONES        2
> +
> +
>  #define NVME_ID_NS_NSFEAT_THIN(nsfeat)      ((nsfeat & 0x1))
>  #define NVME_ID_NS_FLBAS_EXTENDED(flbas)    ((flbas >> 4) & 0x1)
>  #define NVME_ID_NS_FLBAS_INDEX(flbas)       ((flbas & 0xf))
>
Maxim Levitsky July 7, 2019, 9:19 a.m. UTC | #2
On Fri, 2019-07-05 at 15:33 +0200, Max Reitz wrote:
> On 03.07.19 17:59, Maxim Levitsky wrote:
> > Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
> > ---
> >  block/nvme.c         | 69 +++++++++++++++++++++++++++++++++++++++++++-
> >  block/trace-events   |  1 +
> >  include/block/nvme.h | 19 +++++++++++-
> >  3 files changed, 87 insertions(+), 2 deletions(-)
> > 
> > diff --git a/block/nvme.c b/block/nvme.c
> > index 152d27b07f..02e0846643 100644
> > --- a/block/nvme.c
> > +++ b/block/nvme.c
> 
> [...]
> 
> > @@ -469,6 +473,11 @@ static void nvme_identify(BlockDriverState *bs, int namespace, Error **errp)
> >      s->nsze = le64_to_cpu(idns->nsze);
> >      lbaf = &idns->lbaf[NVME_ID_NS_FLBAS_INDEX(idns->flbas)];
> >  
> > +    if (NVME_ID_NS_DLFEAT_WRITE_ZEROS(idns->dlfeat) &&
> > +            NVME_ID_NS_DLFEAT_READ_BEHAVIOR(idns->dlfeat) ==
> > +                    NVME_ID_NS_DLFEAT_READ_BEHAVIOR_ZEROS)
> > +        bs->supported_write_flags |= BDRV_REQ_MAY_UNMAP;
> > +
> 
> This violates the coding style, there should be curly brackets here.
100% agree + I need to see if we can update the checkpatch.pl to catch this.


> 
> >      if (lbaf->ms) {
> >          error_setg(errp, "Namespaces with metadata are not yet supported");
> >          goto out;
> > @@ -763,6 +772,8 @@ static int nvme_file_open(BlockDriverState *bs, QDict *options, int flags,
> >      int ret;
> >      BDRVNVMeState *s = bs->opaque;
> >  
> > +    bs->supported_write_flags = BDRV_REQ_FUA;
> > +
> >      opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
> >      qemu_opts_absorb_qdict(opts, options, &error_abort);
> >      device = qemu_opt_get(opts, NVME_BLOCK_OPT_DEVICE);
> > @@ -791,7 +802,6 @@ static int nvme_file_open(BlockDriverState *bs, QDict *options, int flags,
> >              goto fail;
> >          }
> >      }
> > -    bs->supported_write_flags = BDRV_REQ_FUA;
> 
> Any reason for this movement?

This is because the nvme_identify checks if the underlying namespace
supports 'discarded data reads back as zeros', and in which case it sets the
BDRV_REQ_MAY_UNMAP in bs->supported_write_flags which later allow me to set
'deallocate' bit in the write zeros command which hints the controller
to discard the area.

This was moved to avoid overwriting the value. I could have instead just ored the value,
but this way I think is cleaner a bit.



> 
> >      return 0;
> >  fail:
> >      nvme_close(bs);
> > @@ -1085,6 +1095,60 @@ static coroutine_fn int nvme_co_flush(BlockDriverState *bs)
> >  }
> >  
> >  
> > +static coroutine_fn int nvme_co_pwrite_zeroes(BlockDriverState *bs,
> > +                                              int64_t offset,
> > +                                              int bytes,
> > +                                              BdrvRequestFlags flags)
> > +{
> > +    BDRVNVMeState *s = bs->opaque;
> > +    NVMeQueuePair *ioq = s->queues[1];
> > +    NVMeRequest *req;
> > +
> > +    if (!s->supports_write_zeros) {
> > +        return -ENOTSUP;
> > +    }
> > +
> > +    uint32_t cdw12 = ((bytes >> s->blkshift) - 1) & 0xFFFF;
> 
> Another coding style violation: Variable declarations and other code may
> not be mixed.
Another bug in checkpatch.pl :-)

> 
> > +
> > +    NvmeCmd cmd = {
> > +        .opcode = NVME_CMD_WRITE_ZEROS,
> > +        .nsid = cpu_to_le32(s->nsid),
> > +        .cdw10 = cpu_to_le32((offset >> s->blkshift) & 0xFFFFFFFF),
> > +        .cdw11 = cpu_to_le32(((offset >> s->blkshift) >> 32) & 0xFFFFFFFF),
> > +    };
> > +
> > +    NVMeCoData data = {
> > +        .ctx = bdrv_get_aio_context(bs),
> > +        .ret = -EINPROGRESS,
> > +    };
> 
> [...]
> 
> > diff --git a/include/block/nvme.h b/include/block/nvme.h
> > index 3ec8efcc43..65eb65c740 100644
> > --- a/include/block/nvme.h
> > +++ b/include/block/nvme.h
> > @@ -653,12 +653,29 @@ typedef struct NvmeIdNs {
> >      uint8_t     mc;
> >      uint8_t     dpc;
> >      uint8_t     dps;
> > -    uint8_t     res30[98];
> > +
> > +    uint8_t     nmic;
> > +    uint8_t     rescap;
> > +    uint8_t     fpi;
> > +    uint8_t     dlfeat;
> > +
> > +    uint8_t     res30[94];
> >      NvmeLBAF    lbaf[16];
> >      uint8_t     res192[192];
> >      uint8_t     vs[3712];
> >  } NvmeIdNs;
> >  
> > +
> > +/*Deallocate Logical Block Features*/
> > +#define NVME_ID_NS_DLFEAT_GUARD_CRC(dlfeat)       ((dlfeat) & 0x10)
> > +#define NVME_ID_NS_DLFEAT_WRITE_ZEROS(dlfeat)     ((dlfeat) & 0x04)
> 
> Isn’t it bit 3, i.e. 0x08?
Oops, I haven't noticed that 'read behavier' field is 3 bits and not 2!
Thank you very much. I haven't caught this since my device I tested on doesn't support this anyway (dlfeat == 0)

> 
> Max
> 
> > +
> > +#define NVME_ID_NS_DLFEAT_READ_BEHAVIOR(dlfeat)     ((dlfeat) & 0x3)
> > +#define NVME_ID_NS_DLFEAT_READ_BEHAVIOR_UNDEFINED   0
> > +#define NVME_ID_NS_DLFEAT_READ_BEHAVIOR_ZEROS       1
> > +#define NVME_ID_NS_DLFEAT_READ_BEHAVIOR_ONES        2
> > +
> > +
> >  #define NVME_ID_NS_NSFEAT_THIN(nsfeat)      ((nsfeat & 0x1))
> >  #define NVME_ID_NS_FLBAS_EXTENDED(flbas)    ((flbas >> 4) & 0x1)
> >  #define NVME_ID_NS_FLBAS_INDEX(flbas)       ((flbas & 0xf))
> > 
> 


Thank you very very much for the review,
	Best regards,
		Maxim Levitsky

Patch
diff mbox series

diff --git a/block/nvme.c b/block/nvme.c
index 152d27b07f..02e0846643 100644
--- a/block/nvme.c
+++ b/block/nvme.c
@@ -110,6 +110,8 @@  typedef struct {
     uint64_t max_transfer;
     bool plugged;
 
+    bool supports_write_zeros;
+
     CoMutex dma_map_lock;
     CoQueue dma_flush_queue;
 
@@ -457,6 +459,8 @@  static void nvme_identify(BlockDriverState *bs, int namespace, Error **errp)
     s->max_transfer = MIN_NON_ZERO(s->max_transfer,
                           s->page_size / sizeof(uint64_t) * s->page_size);
 
+    s->supports_write_zeros = (idctrl->oncs & NVME_ONCS_WRITE_ZEROS) != 0;
+
     memset(resp, 0, 4096);
 
     cmd.cdw10 = 0;
@@ -469,6 +473,11 @@  static void nvme_identify(BlockDriverState *bs, int namespace, Error **errp)
     s->nsze = le64_to_cpu(idns->nsze);
     lbaf = &idns->lbaf[NVME_ID_NS_FLBAS_INDEX(idns->flbas)];
 
+    if (NVME_ID_NS_DLFEAT_WRITE_ZEROS(idns->dlfeat) &&
+            NVME_ID_NS_DLFEAT_READ_BEHAVIOR(idns->dlfeat) ==
+                    NVME_ID_NS_DLFEAT_READ_BEHAVIOR_ZEROS)
+        bs->supported_write_flags |= BDRV_REQ_MAY_UNMAP;
+
     if (lbaf->ms) {
         error_setg(errp, "Namespaces with metadata are not yet supported");
         goto out;
@@ -763,6 +772,8 @@  static int nvme_file_open(BlockDriverState *bs, QDict *options, int flags,
     int ret;
     BDRVNVMeState *s = bs->opaque;
 
+    bs->supported_write_flags = BDRV_REQ_FUA;
+
     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
     qemu_opts_absorb_qdict(opts, options, &error_abort);
     device = qemu_opt_get(opts, NVME_BLOCK_OPT_DEVICE);
@@ -791,7 +802,6 @@  static int nvme_file_open(BlockDriverState *bs, QDict *options, int flags,
             goto fail;
         }
     }
-    bs->supported_write_flags = BDRV_REQ_FUA;
     return 0;
 fail:
     nvme_close(bs);
@@ -1085,6 +1095,60 @@  static coroutine_fn int nvme_co_flush(BlockDriverState *bs)
 }
 
 
+static coroutine_fn int nvme_co_pwrite_zeroes(BlockDriverState *bs,
+                                              int64_t offset,
+                                              int bytes,
+                                              BdrvRequestFlags flags)
+{
+    BDRVNVMeState *s = bs->opaque;
+    NVMeQueuePair *ioq = s->queues[1];
+    NVMeRequest *req;
+
+    if (!s->supports_write_zeros) {
+        return -ENOTSUP;
+    }
+
+    uint32_t cdw12 = ((bytes >> s->blkshift) - 1) & 0xFFFF;
+
+    NvmeCmd cmd = {
+        .opcode = NVME_CMD_WRITE_ZEROS,
+        .nsid = cpu_to_le32(s->nsid),
+        .cdw10 = cpu_to_le32((offset >> s->blkshift) & 0xFFFFFFFF),
+        .cdw11 = cpu_to_le32(((offset >> s->blkshift) >> 32) & 0xFFFFFFFF),
+    };
+
+    NVMeCoData data = {
+        .ctx = bdrv_get_aio_context(bs),
+        .ret = -EINPROGRESS,
+    };
+
+    if (flags & BDRV_REQ_MAY_UNMAP) {
+        cdw12 |= (1 << 25);
+    }
+
+    if (flags & BDRV_REQ_FUA) {
+        cdw12 |= (1 << 30);
+    }
+
+    cmd.cdw12 = cpu_to_le32(cdw12);
+
+    trace_nvme_write_zeros(s, offset, bytes, flags);
+    assert(s->nr_queues > 1);
+    req = nvme_get_free_req(ioq);
+    assert(req);
+
+    nvme_submit_command(s, ioq, req, &cmd, nvme_rw_cb, &data);
+
+    data.co = qemu_coroutine_self();
+    while (data.ret == -EINPROGRESS) {
+        qemu_coroutine_yield();
+    }
+
+    trace_nvme_rw_done(s, true, offset, bytes, data.ret);
+    return data.ret;
+}
+
+
 static int nvme_reopen_prepare(BDRVReopenState *reopen_state,
                                BlockReopenQueue *queue, Error **errp)
 {
@@ -1297,6 +1361,9 @@  static BlockDriver bdrv_nvme = {
 
     .bdrv_co_preadv           = nvme_co_preadv,
     .bdrv_co_pwritev          = nvme_co_pwritev,
+
+    .bdrv_co_pwrite_zeroes    = nvme_co_pwrite_zeroes,
+
     .bdrv_co_flush_to_disk    = nvme_co_flush,
     .bdrv_reopen_prepare      = nvme_reopen_prepare,
 
diff --git a/block/trace-events b/block/trace-events
index 9ccea755da..12f363bb44 100644
--- a/block/trace-events
+++ b/block/trace-events
@@ -148,6 +148,7 @@  nvme_submit_command_raw(int c0, int c1, int c2, int c3, int c4, int c5, int c6,
 nvme_handle_event(void *s) "s %p"
 nvme_poll_cb(void *s) "s %p"
 nvme_prw_aligned(void *s, int is_write, uint64_t offset, uint64_t bytes, int flags, int niov) "s %p is_write %d offset %"PRId64" bytes %"PRId64" flags %d niov %d"
+nvme_write_zeros(void *s, uint64_t offset, uint64_t bytes, int flags) "s %p offset %"PRId64" bytes %"PRId64" flags %d"
 nvme_qiov_unaligned(const void *qiov, int n, void *base, size_t size, int align) "qiov %p n %d base %p size 0x%zx align 0x%x"
 nvme_prw_buffered(void *s, uint64_t offset, uint64_t bytes, int niov, int is_write) "s %p offset %"PRId64" bytes %"PRId64" niov %d is_write %d"
 nvme_rw_done(void *s, int is_write, uint64_t offset, uint64_t bytes, int ret) "s %p is_write %d offset %"PRId64" bytes %"PRId64" ret %d"
diff --git a/include/block/nvme.h b/include/block/nvme.h
index 3ec8efcc43..65eb65c740 100644
--- a/include/block/nvme.h
+++ b/include/block/nvme.h
@@ -653,12 +653,29 @@  typedef struct NvmeIdNs {
     uint8_t     mc;
     uint8_t     dpc;
     uint8_t     dps;
-    uint8_t     res30[98];
+
+    uint8_t     nmic;
+    uint8_t     rescap;
+    uint8_t     fpi;
+    uint8_t     dlfeat;
+
+    uint8_t     res30[94];
     NvmeLBAF    lbaf[16];
     uint8_t     res192[192];
     uint8_t     vs[3712];
 } NvmeIdNs;
 
+
+/*Deallocate Logical Block Features*/
+#define NVME_ID_NS_DLFEAT_GUARD_CRC(dlfeat)       ((dlfeat) & 0x10)
+#define NVME_ID_NS_DLFEAT_WRITE_ZEROS(dlfeat)     ((dlfeat) & 0x04)
+
+#define NVME_ID_NS_DLFEAT_READ_BEHAVIOR(dlfeat)     ((dlfeat) & 0x3)
+#define NVME_ID_NS_DLFEAT_READ_BEHAVIOR_UNDEFINED   0
+#define NVME_ID_NS_DLFEAT_READ_BEHAVIOR_ZEROS       1
+#define NVME_ID_NS_DLFEAT_READ_BEHAVIOR_ONES        2
+
+
 #define NVME_ID_NS_NSFEAT_THIN(nsfeat)      ((nsfeat & 0x1))
 #define NVME_ID_NS_FLBAS_EXTENDED(flbas)    ((flbas >> 4) & 0x1)
 #define NVME_ID_NS_FLBAS_INDEX(flbas)       ((flbas & 0xf))