Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-07 20:51:47 +00:00
Code Issues Packages Projects Releases Wiki Activity

KVM: Do not report TPR write to userspace if new value bigger or equal to a previous one.

Browse Source 
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>
This commit is contained in:
Gleb Natapov 2009-04-21 17:45:06 +03:00 committed by Avi Kivity
parent 615d519305
commit 0a5fff1923
2 changed files with 16 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
arch/x86/kvm/svm.c
View File

@ -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) 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); emulate_instruction(&svm->vcpu, NULL, 0, 0, 0);
if (irqchip_in_kernel(svm->vcpu.kvm)) if (irqchip_in_kernel(svm->vcpu.kvm))
return 1; return 1;
if (cr8_prev <= kvm_get_cr8(&svm->vcpu))
return 1;
kvm_run->exit_reason = KVM_EXIT_SET_TPR; kvm_run->exit_reason = KVM_EXIT_SET_TPR;
return 0; return 0;
} }

19
arch/x86/kvm/vmx.c
View File

@ -2724,13 +2724,18 @@ static int handle_cr(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
kvm_set_cr4(vcpu, kvm_register_read(vcpu, reg)); kvm_set_cr4(vcpu, kvm_register_read(vcpu, reg));
skip_emulated_instruction(vcpu); skip_emulated_instruction(vcpu);
return 1; return 1;
case 8: case 8: {
kvm_set_cr8(vcpu, kvm_register_read(vcpu, reg)); u8 cr8_prev = kvm_get_cr8(vcpu);
skip_emulated_instruction(vcpu); u8 cr8 = kvm_register_read(vcpu, reg);
if (irqchip_in_kernel(vcpu->kvm)) kvm_set_cr8(vcpu, cr8);
return 1; skip_emulated_instruction(vcpu);
kvm_run->exit_reason = KVM_EXIT_SET_TPR; if (irqchip_in_kernel(vcpu->kvm))
return 0; return 1;
if (cr8_prev <= cr8)
return 1;
kvm_run->exit_reason = KVM_EXIT_SET_TPR;
return 0;
}
}; };
break; break;
case 2: /* clts */ case 2: /* clts */