commit 0aecd06049ced6c0f863e99510b7a7cbff54aa56
author Eric Auger <eric.auger@redhat.com> Thu Oct 29 10:33:00 2020 +0100
committer Stefan Hajnoczi <stefanha@redhat.com> Tue Nov 03 19:06:22 2020 +0000
tree 86b0053deee84c7f56537cf645e353e34344f047
parent a652a3ec697d5b4cfce44599d3540aae535b9545

block/nvme: Change size and alignment of IDENTIFY response buffer

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>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20201029093306.1063879-20-philmd@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>

block/nvme.c

diff --git a/block/nvme.c b/block/nvme.c
index bd3860a..7628623 100644
--- a/block/nvme.c
+++ b/block/nvme.c
@@ -522,19 +522,20 @@
         .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_admin_cmd_sync(bs, &cmd)) {
         error_setg(errp, "Failed to identify controller");
@@ -556,7 +557,7 @@
     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_admin_cmd_sync(bs, &cmd)) {