[libvirt] [PATCH 15/24] qemu_command: Use canonical names of CPU features

[Jiri Denemark]

On Wed, Jun 19, 2019 at 14:08:58 +0200, Ján Tomko wrote:
> On Wed, Jun 19, 2019 at 11:38:12AM +0200, Jiri Denemark wrote:
> >When building QEMU command line, we should use the preferred spelling of
> >each CPU feature without relying on compatibility aliases (which may be
> >removed at some point).
> >
> >The "unavailable-features" CPU property is used as a witness for the
> >correct names of the features in our translation table.
> >
> >Signed-off-by: Jiri Denemark <jdenemar at redhat.com>
> >---
> > src/qemu/qemu_capabilities.c                              | 8 +++++++-
> > src/qemu/qemu_capabilities.h                              | 1 +
> > src/qemu/qemu_command.c                                   | 2 ++
> > tests/qemucapabilitiesdata/caps_4.1.0.x86_64.xml          | 1 +
> > tests/qemuxml2argvdata/cpu-translation.x86_64-latest.args | 6 +++---
> > tests/qemuxml2argvdata/eoi-disabled.x86_64-latest.args    | 2 +-
> > tests/qemuxml2argvdata/eoi-enabled.x86_64-latest.args     | 2 +-
> > .../kvmclock+eoi-disabled.x86_64-latest.args              | 2 +-
> > .../pv-spinlock-disabled.x86_64-latest.args               | 2 +-
> > .../pv-spinlock-enabled.x86_64-latest.args                | 2 +-
> > 10 files changed, 19 insertions(+), 9 deletions(-)
> >
> >diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
> >index 3af6923e6f..c742838383 100644
> >--- a/src/qemu/qemu_capabilities.c
> >+++ b/src/qemu/qemu_capabilities.c
> >@@ -532,6 +532,7 @@ VIR_ENUM_IMPL(virQEMUCaps,
> >               "nbd-bitmap",
> >               "x86-max-cpu",
> >               "cpu-unavailable-features",
> >+              "canonical-cpu-features",
> >     );
> >
> >
> >@@ -2892,7 +2893,9 @@ virQEMUCapsCPUFeatureTranslate(virQEMUCapsPtr qemuCaps,
> >     if (ARCH_IS_X86(qemuCaps->arch))
> >         table = virQEMUCapsCPUFeaturesX86;
> >
> >-    if (!table || !feature)
> >+    if (!table ||
> >+        !feature ||
> >+        !virQEMUCapsGet(qemuCaps, QEMU_CAPS_CANONICAL_CPU_FEATURES))
> >         return feature;
> >
> >     for (entry = table; entry->libvirt; entry++) {
> >@@ -4398,6 +4401,9 @@ virQEMUCapsInitProcessCaps(virQEMUCapsPtr qemuCaps)
> >      * we are able to pass the custom 'device_id' for SCSI disks and cdroms. */
> >     if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_SCSI_DISK_DEVICE_ID))
> >         virQEMUCapsClear(qemuCaps, QEMU_CAPS_BLOCKDEV);
> >+
> >+    if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_CPU_UNAVAILABLE_FEATURES))
> >+        virQEMUCapsSet(qemuCaps, QEMU_CAPS_CANONICAL_CPU_FEATURES);
> > }
> 
> Do we need an alias for the QEMU_CAPS_CPU_UNAVAILABLE_FEATURES
> capability?
> 
> I think virQEMUCapsCPUFeatureTranslate can use QEMU_CAPS_CPU_UNAVAILABLE_FEATURES directly

Both virQEMUCapsProbeQMPHostCPU and virQEMUCapsCPUFeatureTranslate could
use QEMU_CAPS_CPU_UNAVAILABLE_FEATURES directly, but I felt the alias
will make it clear what's going on in there since "unavailable-features"
property serves just as a witness and we'd likely need to add a comment
about this to every usage which is not doing anything with the new
property.

Jirka