[PATCH 21/25] block/nvme: Change size and alignment of IDENTIFY response buffer

Philippe Mathieu-Daudé posted 25 patches 5 years ago
There is a newer version of this series
[PATCH 21/25] block/nvme: Change size and alignment of IDENTIFY response buffer
Posted by Philippe Mathieu-Daudé 5 years ago
From: Eric Auger <eric.auger@redhat.com>

In preparation of 64kB host page support, let's change the size
and alignment of the IDENTIFY command response buffer so that
the VFIO DMA MAP succeeds. We align on the host page size.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 block/nvme.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/block/nvme.c b/block/nvme.c
index d2d57a287cc..ad70303c5c1 100644
--- a/block/nvme.c
+++ b/block/nvme.c
@@ -521,19 +521,20 @@ static bool nvme_identify(BlockDriverState *bs, int namespace, Error **errp)
         .opcode = NVME_ADM_CMD_IDENTIFY,
         .cdw10 = cpu_to_le32(0x1),
     };
+    size_t id_size = QEMU_ALIGN_UP(sizeof(*id), qemu_real_host_page_size);
 
-    id = qemu_try_memalign(s->page_size, sizeof(*id));
+    id = qemu_try_memalign(qemu_real_host_page_size, id_size);
     if (!id) {
         error_setg(errp, "Cannot allocate buffer for identify response");
         goto out;
     }
-    r = qemu_vfio_dma_map(s->vfio, id, sizeof(*id), true, &iova);
+    r = qemu_vfio_dma_map(s->vfio, id, id_size, true, &iova);
     if (r) {
         error_setg(errp, "Cannot map buffer for DMA");
         goto out;
     }
 
-    memset(id, 0, sizeof(*id));
+    memset(id, 0, id_size);
     cmd.dptr.prp1 = cpu_to_le64(iova);
     if (nvme_cmd_sync(bs, &cmd)) {
         error_setg(errp, "Failed to identify controller");
@@ -555,7 +556,7 @@ static bool nvme_identify(BlockDriverState *bs, int namespace, Error **errp)
     s->supports_write_zeroes = !!(oncs & NVME_ONCS_WRITE_ZEROES);
     s->supports_discard = !!(oncs & NVME_ONCS_DSM);
 
-    memset(id, 0, sizeof(*id));
+    memset(id, 0, id_size);
     cmd.cdw10 = 0;
     cmd.nsid = cpu_to_le32(namespace);
     if (nvme_cmd_sync(bs, &cmd)) {
-- 
2.26.2

Re: [PATCH 21/25] block/nvme: Change size and alignment of IDENTIFY response buffer
Posted by Stefan Hajnoczi 5 years ago
On Tue, Oct 27, 2020 at 02:55:43PM +0100, Philippe Mathieu-Daudé wrote:
> From: Eric Auger <eric.auger@redhat.com>
> 
> In preparation of 64kB host page support, let's change the size
> and alignment of the IDENTIFY command response buffer so that
> the VFIO DMA MAP succeeds. We align on the host page size.
> 
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>  block/nvme.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>