| Message ID | 20190218130702.32575-3-jean-philippe.brucker@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Disk fixes and AIO reset | expand |
On Mon, 18 Feb 2019 13:06:55 +0000 Jean-Philippe Brucker <jean-philippe.brucker@arm.com> wrote: > 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. > > Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> Reviewed-by: Andre Przywara <andre.przywara@arm.com> Cheers, Andre > --- > disk/core.c | 9 +++++++-- > include/kvm/disk-image.h | 1 + > virtio/blk.c | 5 ++++- > 3 files changed, 12 insertions(+), 3 deletions(-) > > diff --git a/disk/core.c b/disk/core.c > index dd2f258b0..4c7c4f030 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 b72805242..4746e88c9 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 a57df2e96..6e7a1ee36 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)
diff --git a/disk/core.c b/disk/core.c index dd2f258b0..4c7c4f030 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 b72805242..4746e88c9 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 a57df2e96..6e7a1ee36 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)
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. Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> --- disk/core.c | 9 +++++++-- include/kvm/disk-image.h | 1 + virtio/blk.c | 5 ++++- 3 files changed, 12 insertions(+), 3 deletions(-)