[v2,3/8] KVM: x86: Invert emulation re-execute behavior to make it opt-in
diff mbox series

Message ID 20180823205653.3264-4-sean.j.christopherson@intel.com
State New
Headers show
Series
  • KVM: x86: Fix the emulation type mess
Related show

Commit Message

Sean Christopherson Aug. 23, 2018, 8:56 p.m. UTC
Re-execution of an instruction after emulation decode failure is
intended to be used only when emulating shadow page accesses.  Invert
the flag to make allowing re-execution opt-in since that behavior is
by far in the minority.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/include/asm/kvm_host.h | 8 +++-----
 arch/x86/kvm/mmu.c              | 2 +-
 arch/x86/kvm/x86.c              | 2 +-
 3 files changed, 5 insertions(+), 7 deletions(-)

Patch
diff mbox series

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 3b220b86c8e4..a69ea11f3bab 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1238,7 +1238,7 @@  enum emulation_result {
 #define EMULTYPE_TRAP_UD	    (1 << 1)
 #define EMULTYPE_SKIP		    (1 << 2)
 #define EMULTYPE_RETRY		    (1 << 3)
-#define EMULTYPE_NO_REEXECUTE	    (1 << 4)
+#define EMULTYPE_ALLOW_REEXECUTE    (1 << 4)
 #define EMULTYPE_NO_UD_ON_FAIL	    (1 << 5)
 #define EMULTYPE_VMWARE		    (1 << 6)
 int x86_emulate_instruction(struct kvm_vcpu *vcpu, unsigned long cr2,
@@ -1247,15 +1247,13 @@  int x86_emulate_instruction(struct kvm_vcpu *vcpu, unsigned long cr2,
 static inline int emulate_instruction(struct kvm_vcpu *vcpu,
 			int emulation_type)
 {
-	return x86_emulate_instruction(vcpu, 0,
-			emulation_type | EMULTYPE_NO_REEXECUTE, NULL, 0);
+	return x86_emulate_instruction(vcpu, 0, emulation_type, NULL, 0);
 }
 
 static inline int kvm_emulate_instruction_from_buffer(struct kvm_vcpu *vcpu,
 						      void *insn, int insn_len)
 {
-	return x86_emulate_instruction(vcpu, 0, EMULTYPE_NO_REEXECUTE,
-				       insn, insn_len);
+	return x86_emulate_instruction(vcpu, 0, 0, insn, insn_len);
 }
 
 void kvm_enable_efer_bits(u64);
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index a282321329b5..4508c34eef20 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -5217,7 +5217,7 @@  static int make_mmu_pages_available(struct kvm_vcpu *vcpu)
 int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u64 error_code,
 		       void *insn, int insn_len)
 {
-	int r, emulation_type = EMULTYPE_RETRY;
+	int r, emulation_type = EMULTYPE_RETRY | EMULTYPE_ALLOW_REEXECUTE;
 	enum emulation_result er;
 	bool direct = vcpu->arch.mmu.direct_map;
 
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 14ee9a814888..c858703e1f26 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5870,7 +5870,7 @@  static bool reexecute_instruction(struct kvm_vcpu *vcpu, gva_t cr2,
 	gpa_t gpa = cr2;
 	kvm_pfn_t pfn;
 
-	if (emulation_type & EMULTYPE_NO_REEXECUTE)
+	if (!(emulation_type & EMULTYPE_ALLOW_REEXECUTE))
 		return false;
 
 	if (!vcpu->arch.mmu.direct_map) {