KVM: x86: Move #GP injection for VMware into x86_emulate_instruction()

Immediately inject a #GP when VMware emulation fails and return
EMULATE_DONE instead of propagating EMULATE_FAIL up the stack.  This
helps pave the way for removing EMULATE_FAIL altogether.

Rename EMULTYPE_VMWARE to EMULTYPE_VMWARE_GP to document that the x86
emulator is called to handle VMware #GP interception, e.g. why a #GP
is injected on emulation failure for EMULTYPE_VMWARE_GP.

Drop EMULTYPE_NO_UD_ON_FAIL as a standalone type.  The "no #UD on fail"
is used only in the VMWare case and is obsoleted by having the emulator
itself reinject #GP.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 13b35f9..80071d0 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1325,8 +1325,7 @@ enum emulation_result {
 #define EMULTYPE_TRAP_UD           (1 << 1)
 #define EMULTYPE_SKIP              (1 << 2)
 #define EMULTYPE_ALLOW_RETRY       (1 << 3)
-#define EMULTYPE_NO_UD_ON_FAIL     (1 << 4)
-#define EMULTYPE_VMWARE                    (1 << 5)
+#define EMULTYPE_VMWARE_GP         (1 << 5)
 int kvm_emulate_instruction(struct kvm_vcpu *vcpu, int emulation_type);
 int kvm_emulate_instruction_from_buffer(struct kvm_vcpu *vcpu,
                                        void *insn, int insn_len);

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 00ec27b..c7aa55e 100644 (file)
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2768,7 +2768,6 @@ static int gp_interception(struct vcpu_svm *svm)
 {
        struct kvm_vcpu *vcpu = &svm->vcpu;
        u32 error_code = svm->vmcb->control.exit_info_1;
-       int er;
 
        WARN_ON_ONCE(!enable_vmware_backdoor);
 
@@ -2780,13 +2779,8 @@ static int gp_interception(struct vcpu_svm *svm)
                kvm_queue_exception_e(vcpu, GP_VECTOR, error_code);
                return 1;
        }
-       er = kvm_emulate_instruction(vcpu,
-               EMULTYPE_VMWARE | EMULTYPE_NO_UD_ON_FAIL);
-       if (er == EMULATE_USER_EXIT)
-               return 0;
-       else if (er != EMULATE_DONE)
-               kvm_queue_exception_e(vcpu, GP_VECTOR, 0);
-       return 1;
+       return kvm_emulate_instruction(vcpu, EMULTYPE_VMWARE_GP) !=
+                                               EMULATE_USER_EXIT;
 }
 
 static bool is_erratum_383(void)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index d1bac3c..d437159 100644 (file)
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4522,7 +4522,6 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu)
        u32 intr_info, ex_no, error_code;
        unsigned long cr2, rip, dr6;
        u32 vect_info;
-       enum emulation_result er;
 
        vect_info = vmx->idt_vectoring_info;
        intr_info = vmx->exit_intr_info;
@@ -4549,13 +4548,8 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu)
                        kvm_queue_exception_e(vcpu, GP_VECTOR, error_code);
                        return 1;
                }
-               er = kvm_emulate_instruction(vcpu,
-                       EMULTYPE_VMWARE | EMULTYPE_NO_UD_ON_FAIL);
-               if (er == EMULATE_USER_EXIT)
-                       return 0;
-               else if (er != EMULATE_DONE)
-                       kvm_queue_exception_e(vcpu, GP_VECTOR, 0);
-               return 1;
+               return kvm_emulate_instruction(vcpu, EMULTYPE_VMWARE_GP) !=
+                                                       EMULATE_USER_EXIT;
        }
 
        /*

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index e6063f2..09753b6 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6307,8 +6307,10 @@ static int handle_emulation_failure(struct kvm_vcpu *vcpu, int emulation_type)
        ++vcpu->stat.insn_emulation_fail;
        trace_kvm_emulate_insn_failed(vcpu);
 
-       if (emulation_type & EMULTYPE_NO_UD_ON_FAIL)
-               return EMULATE_FAIL;
+       if (emulation_type & EMULTYPE_VMWARE_GP) {
+               kvm_queue_exception_e(vcpu, GP_VECTOR, 0);
+               return EMULATE_DONE;
+       }
 
        kvm_queue_exception(vcpu, UD_VECTOR);
 
@@ -6648,9 +6650,11 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu,
                }
        }
 
-       if ((emulation_type & EMULTYPE_VMWARE) &&
-           !is_vmware_backdoor_opcode(ctxt))
-               return EMULATE_FAIL;
+       if ((emulation_type & EMULTYPE_VMWARE_GP) &&
+           !is_vmware_backdoor_opcode(ctxt)) {
+               kvm_queue_exception_e(vcpu, GP_VECTOR, 0);
+               return EMULATE_DONE;
+       }
 
        if (emulation_type & EMULTYPE_SKIP) {
                kvm_rip_write(vcpu, ctxt->_eip);