We should advertise to the guest only the features supported by vhost
and kvmtool. Then we should set in vhost only the features acked by the
guest. Move vhost feature query to get_host_features(), and vhost
feature setting to device start (after the guest has acked features).
This fixes scsi because we used to enable all vhost features including
VIRTIO_SCSI_F_T10_PI which changes the request layout and caused
inconsistency between guest and vhost.
Signed-off-by: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
---
virtio/scsi.c | 33 +++++++++++++++++++--------------
1 file changed, 19 insertions(+), 14 deletions(-)
diff --git a/virtio/scsi.c b/virtio/scsi.c
index fc1c2ad9..5f392814 100644
--- a/virtio/scsi.c
+++ b/virtio/scsi.c
@@ -46,18 +46,34 @@ static size_t get_config_size(struct kvm *kvm, void *dev)
static u64 get_host_features(struct kvm *kvm, void *dev)
{
- return 1UL << VIRTIO_RING_F_EVENT_IDX |
- 1UL << VIRTIO_RING_F_INDIRECT_DESC;
+ int r;
+ u64 features;
+ struct scsi_dev *sdev = dev;
+
+ r = ioctl(sdev->vhost_fd, VHOST_GET_FEATURES, &features);
+ if (r != 0)
+ die_perror("VHOST_GET_FEATURES failed");
+
+ return features &
+ (1ULL << VIRTIO_RING_F_EVENT_IDX | \
+ 1ULL << VIRTIO_RING_F_INDIRECT_DESC | \
+ 1ULL << VIRTIO_F_ANY_LAYOUT);
}
static void notify_status(struct kvm *kvm, void *dev, u32 status)
{
+ int r;
struct scsi_dev *sdev = dev;
struct virtio_device *vdev = &sdev->vdev;
struct virtio_scsi_config *conf = &sdev->config;
if (status & VIRTIO__STATUS_START) {
- int r = ioctl(sdev->vhost_fd, VHOST_SCSI_SET_ENDPOINT,
+ r = ioctl(sdev->vhost_fd, VHOST_SET_FEATURES,
+ &sdev->vdev.features);
+ if (r != 0)
+ die_perror("VHOST_SET_FEATURES failed");
+
+ r = ioctl(sdev->vhost_fd, VHOST_SCSI_SET_ENDPOINT,
&sdev->target);
if (r != 0)
die("VHOST_SCSI_SET_ENDPOINT failed %d", errno);
@@ -163,23 +179,12 @@ static struct virtio_ops scsi_dev_virtio_ops = {
static void virtio_scsi_vhost_init(struct kvm *kvm, struct scsi_dev *sdev)
{
- u64 features;
- int r;
-
sdev->vhost_fd = open("/dev/vhost-scsi", O_RDWR);
if (sdev->vhost_fd < 0)
die_perror("Failed openning vhost-scsi device");
virtio_vhost_init(kvm, sdev->vhost_fd);
- r = ioctl(sdev->vhost_fd, VHOST_GET_FEATURES, &features);
- if (r != 0)
- die_perror("VHOST_GET_FEATURES failed");
-
- r = ioctl(sdev->vhost_fd, VHOST_SET_FEATURES, &features);
- if (r != 0)
- die_perror("VHOST_SET_FEATURES failed");
-
sdev->vdev.use_vhost = true;
}
--
2.40.0
