[PATCH] KVM: x86: Enable AVX for guest

[PATCH] KVM: x86: Enable AVX for guest

[Sheng Yang]

Enable Intel(R) Advanced Vector Extension(AVX) for guest.

The detection of AVX feature includes OSXSAVE bit testing. When OSXSAVE bit is
not set, even if AVX is supported, the AVX instruction would result in UD as
well. So we're safe to expose AVX bits to guest directly.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
---
 arch/x86/kvm/x86.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d3d008e..8e90289 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1963,13 +1963,13 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 		0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW);
 	/* cpuid 1.ecx */
 	const u32 kvm_supported_word4_x86_features =
-		F(XMM3) | 0 /* Reserved, DTES64, MONITOR */ |
+		F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ |
 		0 /* DS-CPL, VMX, SMX, EST */ |
 		0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
 		0 /* Reserved */ | F(CX16) | 0 /* xTPR Update, PDCM */ |
 		0 /* Reserved, DCA */ | F(XMM4_1) |
 		F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) |
-		0 /* Reserved, AES */ | F(XSAVE) | 0 /* OSXSAVE */;
+		0 /* Reserved, AES */ | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX);
 	/* cpuid 0x80000001.ecx */
 	const u32 kvm_supported_word6_x86_features =
 		F(LAHF_LM) | F(CMP_LEGACY) | F(SVM) | 0 /* ExtApicSpace */ |
-- 
1.7.0.1

Re: [PATCH] KVM: x86: Enable AVX for guest

[Avi Kivity]

On 06/22/2010 08:49 AM, Sheng Yang wrote:
> Enable Intel(R) Advanced Vector Extension(AVX) for guest.
>
> The detection of AVX feature includes OSXSAVE bit testing. When OSXSAVE bit is
> not set, even if AVX is supported, the AVX instruction would result in UD as
> well. So we're safe to expose AVX bits to guest directly.
>    

Applied, thanks.

-- 
error compiling committee.c: too many arguments to function