KVM: SVM: Add intercept check for emulated cr accesses
This patch adds all necessary intercept checks for
instructions that access the crX registers.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 798ebe6..ff4ed36 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -3868,11 +3868,90 @@
update_cr0_intercept(svm);
}
+#define POST_EX(exit) { .exit_code = (exit), \
+ .stage = X86_ICPT_POST_EXCEPT, \
+ .valid = true }
+
+static struct __x86_intercept {
+ u32 exit_code;
+ enum x86_intercept_stage stage;
+ bool valid;
+} x86_intercept_map[] = {
+ [x86_intercept_cr_read] = POST_EX(SVM_EXIT_READ_CR0),
+ [x86_intercept_cr_write] = POST_EX(SVM_EXIT_WRITE_CR0),
+ [x86_intercept_clts] = POST_EX(SVM_EXIT_WRITE_CR0),
+ [x86_intercept_lmsw] = POST_EX(SVM_EXIT_WRITE_CR0),
+ [x86_intercept_smsw] = POST_EX(SVM_EXIT_READ_CR0),
+};
+
+#undef POST_EX
+
static int svm_check_intercept(struct kvm_vcpu *vcpu,
struct x86_instruction_info *info,
enum x86_intercept_stage stage)
{
- return X86EMUL_CONTINUE;
+ struct vcpu_svm *svm = to_svm(vcpu);
+ int vmexit, ret = X86EMUL_CONTINUE;
+ struct __x86_intercept icpt_info;
+ struct vmcb *vmcb = svm->vmcb;
+
+ if (info->intercept >= ARRAY_SIZE(x86_intercept_map))
+ goto out;
+
+ icpt_info = x86_intercept_map[info->intercept];
+
+ if (!icpt_info.valid || stage != icpt_info.stage)
+ goto out;
+
+ switch (icpt_info.exit_code) {
+ case SVM_EXIT_READ_CR0:
+ if (info->intercept == x86_intercept_cr_read)
+ icpt_info.exit_code += info->modrm_reg;
+ break;
+ case SVM_EXIT_WRITE_CR0: {
+ unsigned long cr0, val;
+ u64 intercept;
+
+ if (info->intercept == x86_intercept_cr_write)
+ icpt_info.exit_code += info->modrm_reg;
+
+ if (icpt_info.exit_code != SVM_EXIT_WRITE_CR0)
+ break;
+
+ intercept = svm->nested.intercept;
+
+ if (!(intercept & (1ULL << INTERCEPT_SELECTIVE_CR0)))
+ break;
+
+ cr0 = vcpu->arch.cr0 & ~SVM_CR0_SELECTIVE_MASK;
+ val = info->src_val & ~SVM_CR0_SELECTIVE_MASK;
+
+ if (info->intercept == x86_intercept_lmsw) {
+ cr0 &= 0xfUL;
+ val &= 0xfUL;
+ /* lmsw can't clear PE - catch this here */
+ if (cr0 & X86_CR0_PE)
+ val |= X86_CR0_PE;
+ }
+
+ if (cr0 ^ val)
+ icpt_info.exit_code = SVM_EXIT_CR0_SEL_WRITE;
+
+ break;
+ }
+ default:
+ break;
+ }
+
+ vmcb->control.next_rip = info->next_rip;
+ vmcb->control.exit_code = icpt_info.exit_code;
+ vmexit = nested_svm_exit_handled(svm);
+
+ ret = (vmexit == NESTED_EXIT_DONE) ? X86EMUL_INTERCEPTED
+ : X86EMUL_CONTINUE;
+
+out:
+ return ret;
}
static struct kvm_x86_ops svm_x86_ops = {