[PATCH 52/54] KVM: SVM: Exit to userspace if write to cr8 and not using in-kernel apic

From: Avi Kivity
Date: Tue Jan 01 2008 - 10:51:48 EST


From: Joerg Roedel <joerg.roedel@xxxxxxx>

With this patch KVM on SVM will exit to userspace if the guest writes to CR8
and the in-kernel APIC is disabled.

Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
Signed-off-by: Markus Rechberger <markus.rechberger@xxxxxxx>
Signed-off-by: Avi Kivity <avi@xxxxxxxxxxxx>
---
drivers/kvm/svm.c | 11 ++++++++++-
1 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c
index 677b525..9f8564a 100644
--- a/drivers/kvm/svm.c
+++ b/drivers/kvm/svm.c
@@ -1048,6 +1048,15 @@ static int emulate_on_interception(struct vcpu_svm *svm,
return 1;
}

+static int cr8_write_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
+{
+ emulate_instruction(&svm->vcpu, NULL, 0, 0, 0);
+ if (irqchip_in_kernel(svm->vcpu.kvm))
+ return 1;
+ kvm_run->exit_reason = KVM_EXIT_SET_TPR;
+ return 0;
+}
+
static int svm_get_msr(struct kvm_vcpu *vcpu, unsigned ecx, u64 *data)
{
struct vcpu_svm *svm = to_svm(vcpu);
@@ -1202,7 +1211,7 @@ static int (*svm_exit_handlers[])(struct vcpu_svm *svm,
[SVM_EXIT_WRITE_CR0] = emulate_on_interception,
[SVM_EXIT_WRITE_CR3] = emulate_on_interception,
[SVM_EXIT_WRITE_CR4] = emulate_on_interception,
- [SVM_EXIT_WRITE_CR8] = emulate_on_interception,
+ [SVM_EXIT_WRITE_CR8] = cr8_write_interception,
[SVM_EXIT_READ_DR0] = emulate_on_interception,
[SVM_EXIT_READ_DR1] = emulate_on_interception,
[SVM_EXIT_READ_DR2] = emulate_on_interception,
--
1.5.3.7

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