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KVM: SVM: Add intercept check for emulated cr accesses

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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>
This commit is contained in:
Joerg Roedel
2011-04-04 12:39:28 +02:00
committed by Avi Kivity
parent 8a76d7f25f
commit cfec82cb7d
5 changed files with 192 additions and 25 deletions
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81
arch/x86/kvm/svm.c
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@@ -3868,11 +3868,90 @@ static void svm_fpu_deactivate(struct kvm_vcpu *vcpu)
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 = {