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| author | Liang Li <liang.z.li@intel.com> | 2015-05-21 04:41:25 +0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2015-05-20 12:30:26 +0200 |
| commit | c447e76b4cabb49ddae8e49c5758f031f35d55fb (patch) | |
| tree | d19c11fe52ca9c9078676902fbf893517fe5c626 /arch/x86/kvm/cpuid.c | |
| parent | 0fdd74f7784b5cdff7075736992bbb149b1ae49c (diff) | |
| download | lwn-c447e76b4cabb49ddae8e49c5758f031f35d55fb.tar.gz lwn-c447e76b4cabb49ddae8e49c5758f031f35d55fb.zip | |
kvm/fpu: Enable eager restore kvm FPU for MPX
The MPX feature requires eager KVM FPU restore support. We have verified
that MPX cannot work correctly with the current lazy KVM FPU restore
mechanism. Eager KVM FPU restore should be enabled if the MPX feature is
exposed to VM.
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Signed-off-by: Liang Li <liang.z.li@intel.com>
[Also activate the FPU on AMD processors. - Paolo]
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/cpuid.c')
| -rw-r--r-- | arch/x86/kvm/cpuid.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 59b69f6a2844..1d08ad3582d0 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -16,6 +16,8 @@ #include <linux/module.h> #include <linux/vmalloc.h> #include <linux/uaccess.h> +#include <asm/i387.h> /* For use_eager_fpu. Ugh! */ +#include <asm/fpu-internal.h> /* For use_eager_fpu. Ugh! */ #include <asm/user.h> #include <asm/xsave.h> #include "cpuid.h" @@ -95,6 +97,8 @@ int kvm_update_cpuid(struct kvm_vcpu *vcpu) if (best && (best->eax & (F(XSAVES) | F(XSAVEC)))) best->ebx = xstate_required_size(vcpu->arch.xcr0, true); + vcpu->arch.eager_fpu = guest_cpuid_has_mpx(vcpu); + /* * The existing code assumes virtual address is 48-bit in the canonical * address checks; exit if it is ever changed. |