KVM: X86: Kill off ctxt->ud

ctxt->ud is consumed only by x86_decode_insn(), we can kill it off by
passing emulation_type to x86_decode_insn() and dropping ctxt->ud
altogether. Tracking that info in ctxt for literally one call is silly.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <1622160097-37633-2-git-send-email-wanpengli@tencent.com>

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 8a0ccdb560766e7edb1e17f846c4e254f379827a..5e5de05a8fbfaf91e424c70b9f65c3efec4c3bba 100644 (file)
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -5111,7 +5111,7 @@ done:
        return rc;
 }
 
-int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
+int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len, int emulation_type)
 {
        int rc = X86EMUL_CONTINUE;
        int mode = ctxt->mode;
@@ -5322,7 +5322,8 @@ done_prefixes:
 
        ctxt->execute = opcode.u.execute;
 
-       if (unlikely(ctxt->ud) && likely(!(ctxt->d & EmulateOnUD)))
+       if (unlikely(emulation_type & EMULTYPE_TRAP_UD) &&
+           likely(!(ctxt->d & EmulateOnUD)))
                return EMULATION_FAILED;
 
        if (unlikely(ctxt->d &

diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h
index f016838faedd6c616b00007fa9ac59c46c47466d..3e870bf9ca4d59941aead4ace432634f3b56067f 100644 (file)
--- a/arch/x86/kvm/kvm_emulate.h
+++ b/arch/x86/kvm/kvm_emulate.h
@@ -314,7 +314,6 @@ struct x86_emulate_ctxt {
        int interruptibility;
 
        bool perm_ok; /* do not check permissions if true */
-       bool ud;        /* inject an #UD if host doesn't support insn */
        bool tf;        /* TF value before instruction (after for syscall/sysret) */
 
        bool have_exception;
@@ -491,7 +490,7 @@ enum x86_intercept {
 #define X86EMUL_MODE_HOST X86EMUL_MODE_PROT64
 #endif
 
-int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len);
+int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len, int emulation_type);
 bool x86_page_table_writing_insn(struct x86_emulate_ctxt *ctxt);
 #define EMULATION_FAILED -1
 #define EMULATION_OK 0

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 622cba2ed6997cc5bf0ce22803dda9232ca5c017..1cd6d4685932affeba8eead21a3df792d6536a56 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7568,9 +7568,7 @@ int x86_decode_emulated_instruction(struct kvm_vcpu *vcpu, int emulation_type,
            kvm_vcpu_check_breakpoint(vcpu, &r))
                return r;
 
-       ctxt->ud = emulation_type & EMULTYPE_TRAP_UD;
-
-       r = x86_decode_insn(ctxt, insn, insn_len);
+       r = x86_decode_insn(ctxt, insn, insn_len, emulation_type);
 
        trace_kvm_emulate_insn_start(vcpu);
        ++vcpu->stat.insn_emulation;