[PATCH] x86: svm: use cr_interception for SVM_EXIT_CR0_SEL_WRITE

From: Joel Schopp
Date: Fri Mar 06 2015 - 15:35:24 EST


From: David Kaplan <david.kaplan@xxxxxxx>

Another patch in my war on emulate_on_interception() use as a svm exit handler.

These were pulled out of a larger patch at the suggestion of Radim Krcmar, see
https://lkml.org/lkml/2015/2/25/559

Signed-off-by: David Kaplan <david.kaplan@xxxxxxx>
[separated out just cr_interception part from larger removal of
INTERCEPT_CR0_WRITE, forward ported, tested]
Signed-off-by: Joel Schopp <joel.schopp@xxxxxxx>
---
arch/x86/kvm/svm.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index d319e0c..57f0240 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2940,7 +2940,10 @@ static int cr_interception(struct vcpu_svm *svm)
return emulate_on_interception(svm);

reg = svm->vmcb->control.exit_info_1 & SVM_EXITINFO_REG_MASK;
- cr = svm->vmcb->control.exit_code - SVM_EXIT_READ_CR0;
+ if (svm->vmcb->control.exit_code == SVM_EXIT_SEL_CR0_WRITE)
+ cr = SVM_EXIT_WRITE_CR0 - SVM_EXIT_READ_CR0;
+ else
+ cr = svm->vmcb->control.exit_code - SVM_EXIT_READ_CR0;

err = 0;
if (cr >= 16) { /* mov to cr */
@@ -3325,7 +3328,7 @@ static int (*const svm_exit_handlers[])(struct vcpu_svm *svm) = {
[SVM_EXIT_READ_CR3] = cr_interception,
[SVM_EXIT_READ_CR4] = cr_interception,
[SVM_EXIT_READ_CR8] = cr_interception,
- [SVM_EXIT_CR0_SEL_WRITE] = emulate_on_interception,
+ [SVM_EXIT_CR0_SEL_WRITE] = cr_interception,
[SVM_EXIT_WRITE_CR0] = cr_interception,
[SVM_EXIT_WRITE_CR3] = cr_interception,
[SVM_EXIT_WRITE_CR4] = cr_interception,

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