virtio-blk: add discard request support - #6142
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Extend the virtio-blk config space through the discard limit fields so the device can report discard capability details when the feature is enabled. [jackabt@amazon.com: rebased onto main and reconciled with the read-only config space test] Signed-off-by: Jonas Savulionis <jonas@esnet.lt> Signed-off-by: Jack Thomson <jackabt@amazon.com>
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Codecov Report❌ Patch coverage is Additional details and impacted files@@ Coverage Diff @@
## main #6142 +/- ##
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- Coverage 82.98% 82.91% -0.07%
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Files 277 277
Lines 30885 31010 +125
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+ Hits 25630 25713 +83
- Misses 5255 5297 +42
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Add opt-in virtio-blk discard support for sync file-backed drives. The device advertises VIRTIO_BLK_F_DISCARD only when enabled, validates guest discard ranges once during request parsing, and executes discard through BLKDISCARD for block devices or fallocate hole punching for regular files. Reject discard for read-only drives and the async IO engine for now, and return UNSUPP if a guest submits discard without negotiating the feature. [jackabt@amazon.com: rebased onto main, updated the config round-trip expectations for the normalised discard field in test_block_config, resources, and the two device manager persistence tests, and moved the changelog entry to the unreleased section] Signed-off-by: Jonas Savulionis <jonas@esnet.lt> Signed-off-by: Rekas <aure369@gmail.com> Signed-off-by: Jack Thomson <jackabt@amazon.com>
Allow the sync virtio-blk discard path to punch holes in regular files and issue BLKDISCARD for block-device backed drives. [jackabt@amazon.com: rebased onto main] Signed-off-by: Jonas Savulionis <jonas@esnet.lt> Signed-off-by: Rekas <aure369@gmail.com> Signed-off-by: Jack Thomson <jackabt@amazon.com>
Cover the discard drive API by validating successful configuration, guest-visible discard granularity, and rejection of unsupported read-only or async combinations. Add a guest functional test that writes data to a file-backed drive, issues blkdiscard, and verifies host block allocation decreases. [jackabt@amazon.com: rebased onto main] Signed-off-by: Jonas Savulionis <jonas@esnet.lt> Signed-off-by: Rekas <aure369@gmail.com> Signed-off-by: Jack Thomson <jackabt@amazon.com>
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Changes
Update of the PR: #5908
To fix a few warning and update against main
Also fixed a bug in which the config space was no longer calling
.to_le()Reason
...
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