diff options
| author | Jean-Philippe Brucker <jean-philippe.brucker@arm.com> | 2019-04-04 14:20:43 +0100 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2019-04-26 14:57:59 +0100 |
| commit | 5c5cae758a726ac073b68c8b0072c877d901589f (patch) | |
| tree | eb5596d07fb488d7ff10e2a17ca87578b645e049 | |
| parent | ca14d9eded5aa786675b28ba1d9c06bde33182f6 (diff) | |
| download | kvmtool-5c5cae758a726ac073b68c8b0072c877d901589f.tar.gz | |
virtio/blk: Set VIRTIO_BLK_F_RO when the disk is read-only
Since we don't currently tell the guest when the disk backend is
read-only, it will report any inconsistent read after write as an error.
An image may be read-only either because user requested it on the
command-line, or because write support isn't implemented. Pass the
read-only attribute using the VIRTIO_BLK_F_RO feature.
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
| -rw-r--r-- | disk/core.c | 9 | ||||
| -rw-r--r-- | include/kvm/disk-image.h | 1 | ||||
| -rw-r--r-- | virtio/blk.c | 5 |
3 files changed, 12 insertions, 3 deletions
diff --git a/disk/core.c b/disk/core.c index dd2f258b..4c7c4f03 100644 --- a/disk/core.c +++ b/disk/core.c @@ -139,8 +139,10 @@ static struct disk_image *disk_image__open(const char *filename, bool readonly, /* blk device ?*/ disk = blkdev__probe(filename, flags, &st); - if (!IS_ERR_OR_NULL(disk)) + if (!IS_ERR_OR_NULL(disk)) { + disk->readonly = readonly; return disk; + } fd = open(filename, flags); if (fd < 0) @@ -150,13 +152,16 @@ static struct disk_image *disk_image__open(const char *filename, bool readonly, disk = qcow_probe(fd, true); if (!IS_ERR_OR_NULL(disk)) { pr_warning("Forcing read-only support for QCOW"); + disk->readonly = true; return disk; } /* raw image ?*/ disk = raw_image__probe(fd, &st, readonly); - if (!IS_ERR_OR_NULL(disk)) + if (!IS_ERR_OR_NULL(disk)) { + disk->readonly = readonly; return disk; + } if (close(fd) < 0) pr_warning("close() failed"); diff --git a/include/kvm/disk-image.h b/include/kvm/disk-image.h index b7280524..4746e88c 100644 --- a/include/kvm/disk-image.h +++ b/include/kvm/disk-image.h @@ -59,6 +59,7 @@ struct disk_image { void *priv; void *disk_req_cb_param; void (*disk_req_cb)(void *param, long len); + bool readonly; bool async; int evt; #ifdef CONFIG_HAS_AIO diff --git a/virtio/blk.c b/virtio/blk.c index a57df2e9..6e7a1ee3 100644 --- a/virtio/blk.c +++ b/virtio/blk.c @@ -148,10 +148,13 @@ static u8 *get_config(struct kvm *kvm, void *dev) static u32 get_host_features(struct kvm *kvm, void *dev) { + struct blk_dev *bdev = dev; + return 1UL << VIRTIO_BLK_F_SEG_MAX | 1UL << VIRTIO_BLK_F_FLUSH | 1UL << VIRTIO_RING_F_EVENT_IDX - | 1UL << VIRTIO_RING_F_INDIRECT_DESC; + | 1UL << VIRTIO_RING_F_INDIRECT_DESC + | (bdev->disk->readonly ? 1UL << VIRTIO_BLK_F_RO : 0); } static void set_guest_features(struct kvm *kvm, void *dev, u32 features) |