[libvirt] [PATCH 21/21] qemu: caps: Add capability for dynamic 'auto-read-only' support for files

Initial implementation of 'auto-read-only' didn't reopen the backing files when needed. For '-blockdev' to work we need to be able to tel qemu to open a file read-only and change it during blockjobs as we label backing chains with a sVirt label which does not allow writing. The dynamic auto-read-only supports this as it reopens files when writing is demanded. Add a capability to detect that the posix file based backends support the dynamic part. --- src/qemu/qemu_capabilities.c | 4 ++++ src/qemu/qemu_capabilities.h | 3 +++ tests/qemucapabilitiesdata/caps_4.0.0.x86_64.xml | 1 + 3 files changed, 8 insertions(+) diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c index da90cd666e..4b851a6e89 100644 --- a/src/qemu/qemu_capabilities.c +++ b/src/qemu/qemu_capabilities.c @@ -526,6 +526,9 @@ VIR_ENUM_IMPL(virQEMUCaps, "scsi-disk.device_id", "virtio-pci-non-transitional", "overcommit", + + /* 330 */ + "blockdev-file-dynamic-auto-read-only", ); @@ -1265,6 +1268,7 @@ static struct virQEMUCapsStringFlags virQEMUCapsQMPSchemaQueries[] = { { "block-commit/arg-type/*top", QEMU_CAPS_ACTIVE_COMMIT }, { "query-iothreads/ret-type/poll-max-ns", QEMU_CAPS_IOTHREAD_POLLING }, { "query-display-options/ret-type/+egl-headless/rendernode", QEMU_CAPS_EGL_HEADLESS_RENDERNODE }, + { "blockdev-add/arg-type/+file/$dynamic-auto-read-only", QEMU_CAPS_BLOCK_FILE_AUTO_READONLY_DYNAMIC }, }; typedef struct _virQEMUCapsObjectTypeProps virQEMUCapsObjectTypeProps; diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h index fd7bec7589..b207142fdb 100644 --- a/src/qemu/qemu_capabilities.h +++ b/src/qemu/qemu_capabilities.h @@ -509,6 +509,9 @@ typedef enum { /* virQEMUCapsFlags grouping marker for syntax-check */ QEMU_CAPS_VIRTIO_PCI_TRANSITIONAL, /* virtio *-pci-{non-}transitional devices */ QEMU_CAPS_OVERCOMMIT, /* -overcommit */ + /* 330 */ + QEMU_CAPS_BLOCK_FILE_AUTO_READONLY_DYNAMIC, /* the auto-read-only property of block backends for files is dynamic */ + QEMU_CAPS_LAST /* this must always be the last item */ } virQEMUCapsFlags; diff --git a/tests/qemucapabilitiesdata/caps_4.0.0.x86_64.xml b/tests/qemucapabilitiesdata/caps_4.0.0.x86_64.xml index 00f2a1cb55..dd77b67456 100644 --- a/tests/qemucapabilitiesdata/caps_4.0.0.x86_64.xml +++ b/tests/qemucapabilitiesdata/caps_4.0.0.x86_64.xml @@ -201,6 +201,7 @@ <flag name='scsi-disk.device_id'/> <flag name='virtio-pci-non-transitional'/> <flag name='overcommit'/> + <flag name='blockdev-file-dynamic-auto-read-only'/> <version>3001092</version> <kvmVersion>0</kvmVersion> <microcodeVersion>43100758</microcodeVersion> -- 2.20.1