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authorJing Liu <[email protected]>2022-01-05 04:35:14 -0800
committerPaolo Bonzini <[email protected]>2022-01-07 13:33:04 -0500
commitcc04b6a21d431359eceeec0d812b492088b04af5 (patch)
tree39bd997cf64cc983f1efe5553ebd833a8befb501
parent36487e6228c4cb04257c92266a04078a384bc4ec (diff)
kvm: x86: Fix xstate_required_size() to follow XSTATE alignment rule
CPUID.0xD.1.EBX enumerates the size of the XSAVE area (in compacted format) required by XSAVES. If CPUID.0xD.i.ECX[1] is set for a state component (i), this state component should be located on the next 64-bytes boundary following the preceding state component in the compacted layout. Fix xstate_required_size() to follow the alignment rule. AMX is the first state component with 64-bytes alignment to catch this bug. Signed-off-by: Jing Liu <[email protected]> Signed-off-by: Yang Zhong <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
-rw-r--r--arch/x86/kvm/cpuid.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 0b920e12bb6d..f3e6fda6b858 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -42,7 +42,11 @@ static u32 xstate_required_size(u64 xstate_bv, bool compacted)
if (xstate_bv & 0x1) {
u32 eax, ebx, ecx, edx, offset;
cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx);
- offset = compacted ? ret : ebx;
+ /* ECX[1]: 64B alignment in compacted form */
+ if (compacted)
+ offset = (ecx & 0x2) ? ALIGN(ret, 64) : ret;
+ else
+ offset = ebx;
ret = max(ret, offset + eax);
}