diff options
| author | Gleb Natapov <gleb@redhat.com> | 2009-04-21 17:45:06 +0300 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2009-06-10 11:48:47 +0300 |
| commit | 0a5fff192388d2a74aa9ab5e0d394b745df9f225 (patch) | |
| tree | 7d837d9673b746b3e869089b3753cf62361096dc /arch/x86/kvm/svm.c | |
| parent | 615d5193055880d44db92b72403b7549251ac2a6 (diff) | |
KVM: Do not report TPR write to userspace if new value bigger or equal to a previous one.
Saves many exits to userspace in a case of IRQ chip in userspace.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86/kvm/svm.c')
| -rw-r--r-- | arch/x86/kvm/svm.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 143818eff52..e283a63b2bc 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1862,9 +1862,13 @@ static int emulate_on_interception(struct vcpu_svm *svm, static int cr8_write_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run) { + u8 cr8_prev = kvm_get_cr8(&svm->vcpu); + /* instruction emulation calls kvm_set_cr8() */ emulate_instruction(&svm->vcpu, NULL, 0, 0, 0); if (irqchip_in_kernel(svm->vcpu.kvm)) return 1; + if (cr8_prev <= kvm_get_cr8(&svm->vcpu)) + return 1; kvm_run->exit_reason = KVM_EXIT_SET_TPR; return 0; } |