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| author | Avi Kivity <avi@redhat.com> | 2010-05-03 16:05:44 +0300 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2010-08-01 10:35:28 +0300 |
| commit | 1c11e713576edf33b95669be9c2dc0ff1e0c90d3 (patch) | |
| tree | 9d7cde9a08747e4e633302b418de4b8eedaf1c2b /arch/x86/kvm/x86.c | |
| parent | 08acfa187117046f8b5044b4a4cdc910f3ceeeb5 (diff) | |
| download | lwn-1c11e713576edf33b95669be9c2dc0ff1e0c90d3.tar.gz lwn-1c11e713576edf33b95669be9c2dc0ff1e0c90d3.zip | |
KVM: VMX: Avoid writing HOST_CR0 every entry
cr0.ts may change between entries, so we copy cr0 to HOST_CR0 before each
entry. That is slow, so instead, set HOST_CR0 to have TS set unconditionally
(which is a safe value), and issue a clts() just before exiting vcpu context
if the task indeed owns the fpu.
Saves ~50 cycles/exit.
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 1b270fd60634..801afc6461ed 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1731,8 +1731,8 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) { - kvm_put_guest_fpu(vcpu); kvm_x86_ops->vcpu_put(vcpu); + kvm_put_guest_fpu(vcpu); } static int is_efer_nx(void) |