From: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
Commit 96193c22a "target-i386: Move xsave component mask to features array"
leverages features array to handle XCR0 processor state component bits,
however, it introduces a regression:
warning: host doesn't support requested feature: CPUID.0DH:EAX [bit 0]
warning: host doesn't support requested feature: CPUID.0DH:EAX [bit 1]
warning: host doesn't support requested feature: CPUID.0DH:EAX [bit 2]
My desktop doesn't have enough advance features, so just X87,SSE,AVX
warnings are splat when I boot a guest.
The get migratable flags logic in x86_cpu_filter_features() path will
filter out the feature flags which are unsupported and unmigratable.
However, the bits of XCR0 processor state component featureword don't
have feat_names, and some features like SSE/AVX etc have feat_names in
CPUID.01H:EDX, CPUID.01H:ECX, so they are treated as unsupported.
This patch fix it by don't filter out XCR0 processor state components
bits though they don't have feat_names just as before commit 96193c22ab3.
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Richard Henderson <rth@xxxxxxxxxxx>
Cc: Eduardo Habkost <ehabkost@xxxxxxxxxx>
Cc: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
---
v1 -> v2:
* move the check to x86_cpu_get_migratable_flags()
target-i386/cpu.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index 333309b..cc929ca 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -602,7 +602,10 @@ static uint32_t x86_cpu_get_migratable_flags(FeatureWord w)
uint32_t f = 1U << i;
/* If the feature name is unknown, it is not supported by QEMU yet */
if (!wi->feat_names[i]) {
- continue;
+ if (w != FEAT_XSAVE_COMP_LO &&
+ w != FEAT_XSAVE_COMP_HI) {
+ continue;
+ }
}
/* Skip features known to QEMU, but explicitly marked as unmigratable */
if (wi->unmigratable_flags & f) {
--
1.9.1
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