[PATCH 7/9] KVM: SVM: Add intercept checks for one-byte instructions

[Joerg Roedel]

This patch add intercept checks for emulated one-byte
instructions to the KVM instruction emulation path.

Signed-off-by: Joerg Roedel <joerg.roe...@amd.com>
---
 arch/x86/kvm/svm.c |   36 +++++++++++++++++++++++++++++++++---
 1 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 77b344e..2a30b5b 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -3668,6 +3668,35 @@ static void svm_check_group7(struct vmcb *vmcb, struct 
x86_emulate_ctxt *ctxt)
        }
 }
 
+static void svm_check_onebyte(struct vmcb *vmcb, struct x86_emulate_ctxt *ctxt)
+{
+       struct decode_cache *c = &ctxt->decode;
+
+       switch (c->b) {
+       case 0x90: /* PAUSE */
+               if (c->rep_prefix == REPE_PREFIX)
+                       vmcb->control.exit_code = SVM_EXIT_PAUSE;
+               break;
+       case 0x9c: /* PUSHF */
+               break;
+       case 0x9d: /* POPF */
+               vmcb->control.exit_code = SVM_EXIT_POPF;
+               break;
+       case 0xcd: /* INTn */
+               vmcb->control.exit_code = SVM_EXIT_SWINT;
+               break;
+       case 0xcf: /* IRET */
+               vmcb->control.exit_code = SVM_EXIT_IRET;
+               break;
+       case 0xf1: /* ICEBP */
+               vmcb->control.exit_code = SVM_EXIT_ICEBP;
+               break;
+       case 0xf4: /* HLT */
+               vmcb->control.exit_code = SVM_EXIT_HLT;
+               break;
+       }
+}
+
 static int svm_insn_intercepted(struct kvm_vcpu *vcpu,
                                struct x86_emulate_ctxt *ctxt)
 {
@@ -3681,8 +3710,10 @@ static int svm_insn_intercepted(struct kvm_vcpu *vcpu,
 
        ret = X86EMUL_CONTINUE;
 
-       if (!c->twobyte)
+       if (!c->twobyte) {
+               svm_check_onebyte(vmcb, ctxt);
                goto out;
+       }
 
        switch (c->b) {
        case 0x00:
@@ -3799,14 +3830,13 @@ static int svm_insn_intercepted(struct kvm_vcpu *vcpu,
                break;
        }
 
+out:
        vmcb->control.next_rip = ctxt->eip;
        vmexit = nested_svm_exit_handled(svm);
 
        ret = (vmexit == NESTED_EXIT_DONE) ? X86EMUL_INTERCEPTED
                                           : X86EMUL_CONTINUE;
 
-out:
-
        return ret;
 }
 
-- 
1.7.1


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