vhost: secure vhost shared log files using argv paremeter

Commit Message

Rafael Tinoco Oct. 22, 2016, 9:46 p.m. UTC

Commit 31190ed7 added a migration blocker in vhost_dev_init() to
check if memfd would succeed. It is better if this blocker first
checks if vhost backend requires shared log. This will avoid a
situation where a blocker is added inappropriately (e.g. shared
log allocation fails when vhost backend doesn't support it).
---
 hw/virtio/vhost.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Marc-André Lureau Oct. 23, 2016, 3:19 p.m. UTC | #1

----- Original Message -----
> Commit 31190ed7 added a migration blocker in vhost_dev_init() to
> check if memfd would succeed. It is better if this blocker first
> checks if vhost backend requires shared log. This will avoid a
> situation where a blocker is added inappropriately (e.g. shared
> log allocation fails when vhost backend doesn't support it).
> ---
>  hw/virtio/vhost.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index bd051ab..742d0aa 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -1122,7 +1122,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void
> *opaque,
>          if (!(hdev->features & (0x1ULL << VHOST_F_LOG_ALL))) {
>              error_setg(&hdev->migration_blocker,
>                         "Migration disabled: vhost lacks VHOST_F_LOG_ALL
>                         feature.");
> -        } else if (!qemu_memfd_check()) {
> +        } else if (vhost_dev_log_is_shared(hdev) && !qemu_memfd_check()) {
>              error_setg(&hdev->migration_blocker,
>                         "Migration disabled: failed to allocate shared
>                         memory");
>          }

You should update the patch title/summary,

Reviewed-by: Marc-André Lureau <[e-mail]>

Patch

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index bd051ab..742d0aa 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -1122,7 +1122,7 @@  int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
         if (!(hdev->features & (0x1ULL << VHOST_F_LOG_ALL))) {
             error_setg(&hdev->migration_blocker,
                        "Migration disabled: vhost lacks VHOST_F_LOG_ALL feature.");
-        } else if (!qemu_memfd_check()) {
+        } else if (vhost_dev_log_is_shared(hdev) && !qemu_memfd_check()) {
             error_setg(&hdev->migration_blocker,
                        "Migration disabled: failed to allocate shared memory");
         }