Commit b35491e6 authored by Wanpeng Li's avatar Wanpeng Li Committed by Paolo Bonzini
Browse files

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: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarWanpeng Li <wanpengli@tencent.com>
Reviewed-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <1622160097-37633-2-git-send-email-wanpengli@tencent.com>
parent da6393cd

arch/x86/kvm/emulate.c

+3 −2
Original line number Diff line number Diff line
@@ -5111,7 +5111,7 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op, 
	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 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len) 


	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 &

arch/x86/kvm/kvm_emulate.h

+1 −2
Original line number Diff line number Diff line
@@ -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

arch/x86/kvm/x86.c

+1 −3
Original line number Diff line number Diff line
@@ -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;