[libvirt] [PATCH v2 7/7] qemu: Drop MSR features from host-model with old QEMU

[Jiri Denemark]

With QEMU versions which lack "unavailable-features" we use CPUID based
detection of features which were enabled or disabled once QEMU starts.
Thus using MSR features with host-model would result in all of them
being marked as disabled in the active domain definition even though
QEMU did not actually disable them.

Let's make sure we add MSR features to host-model only when
"unavailable-features" property is supported by QEMU.

Signed-off-by: Jiri Denemark <jdenemar at redhat.com>
---
 src/qemu/qemu_capabilities.c                     | 16 ++++++++++++++++
 tests/domaincapsschemadata/qemu_3.1.0.x86_64.xml |  1 -
 tests/domaincapsschemadata/qemu_4.0.0.x86_64.xml |  1 -
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index 4134f319ac..b7c20f3e3e 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -3193,6 +3193,22 @@ virQEMUCapsInitHostCPUModel(virQEMUCapsPtr qemuCaps,
             goto error;
     }
 
+    if (ARCH_IS_X86(qemuCaps->arch) &&
+        !virQEMUCapsGet(qemuCaps, QEMU_CAPS_CPU_UNAVAILABLE_FEATURES)) {
+        bool selecting = false;
+        if (cpu &&
+            virCPUDefFilterFeatures(cpu, virCPUx86FeatureIsMSR, &selecting) < 0)
+            goto error;
+
+        if (migCPU &&
+            virCPUDefFilterFeatures(migCPU, virCPUx86FeatureIsMSR, &selecting) < 0)
+            goto error;
+
+        if (fullCPU &&
+            virCPUDefFilterFeatures(fullCPU, virCPUx86FeatureIsMSR, &selecting) < 0)
+            goto error;
+    }
+
     virQEMUCapsSetHostModel(qemuCaps, type, cpu, migCPU, fullCPU);
 
  cleanup:
diff --git a/tests/domaincapsschemadata/qemu_3.1.0.x86_64.xml b/tests/domaincapsschemadata/qemu_3.1.0.x86_64.xml
index dfd186afba..ca3baab88c 100644
--- a/tests/domaincapsschemadata/qemu_3.1.0.x86_64.xml
+++ b/tests/domaincapsschemadata/qemu_3.1.0.x86_64.xml
@@ -42,7 +42,6 @@
       <feature policy='require' name='xsaves'/>
       <feature policy='require' name='pdpe1gb'/>
       <feature policy='require' name='invtsc'/>
-      <feature policy='require' name='skip-l1dfl-vmentry'/>
     </mode>
     <mode name='custom' supported='yes'>
       <model usable='yes'>qemu64</model>
diff --git a/tests/domaincapsschemadata/qemu_4.0.0.x86_64.xml b/tests/domaincapsschemadata/qemu_4.0.0.x86_64.xml
index 36f6f1e94d..cba841d844 100644
--- a/tests/domaincapsschemadata/qemu_4.0.0.x86_64.xml
+++ b/tests/domaincapsschemadata/qemu_4.0.0.x86_64.xml
@@ -42,7 +42,6 @@
       <feature policy='require' name='xsaves'/>
       <feature policy='require' name='pdpe1gb'/>
       <feature policy='require' name='invtsc'/>
-      <feature policy='require' name='skip-l1dfl-vmentry'/>
     </mode>
     <mode name='custom' supported='yes'>
       <model usable='yes'>qemu64</model>
-- 
2.22.0