KVM: SVM: limit kvm_handle_page_fault to #PF handling

It has always annoyed me a bit how SVM_EXIT_NPF is handled by
pf_interception.  This is also the only reason behind the
under-documented need_unprotect argument to kvm_handle_page_fault.
Let NPF go straight to kvm_mmu_page_fault, just like VMX
does in handle_ept_violation and handle_ept_misconfig.

Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index d7a7eaf..e4fb82c 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3820,8 +3820,7 @@ static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn,
 }
 
 int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
-                               u64 fault_address, char *insn, int insn_len,
-                               bool need_unprotect)
+                               u64 fault_address, char *insn, int insn_len)
 {
        int r = 1;
 
@@ -3829,7 +3828,7 @@ int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
        default:
                trace_kvm_page_fault(fault_address, error_code);
 
-               if (need_unprotect && kvm_event_needs_reinjection(vcpu))
+               if (kvm_event_needs_reinjection(vcpu))
                        kvm_mmu_unprotect_page_virt(vcpu, fault_address);
                r = kvm_mmu_page_fault(vcpu, fault_address, error_code, insn,
                                insn_len);

diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 64a2dbd..1092302 100644 (file)
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -65,8 +65,7 @@ void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly,
                             bool accessed_dirty);
 bool kvm_can_do_async_pf(struct kvm_vcpu *vcpu);
 int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
-                               u64 fault_address, char *insn, int insn_len,
-                               bool need_unprotect);
+                               u64 fault_address, char *insn, int insn_len);
 
 static inline unsigned int kvm_mmu_available_pages(struct kvm *kvm)
 {

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 3e4337e..84f1863 100644 (file)
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2141,7 +2141,18 @@ static int pf_interception(struct vcpu_svm *svm)
 
        return kvm_handle_page_fault(&svm->vcpu, error_code, fault_address,
                        svm->vmcb->control.insn_bytes,
-                       svm->vmcb->control.insn_len, !npt_enabled);
+                       svm->vmcb->control.insn_len);
+}
+
+static int npf_interception(struct vcpu_svm *svm)
+{
+       u64 fault_address = svm->vmcb->control.exit_info_2;
+       u64 error_code = svm->vmcb->control.exit_info_1;
+
+       trace_kvm_page_fault(fault_address, error_code);
+       return kvm_mmu_page_fault(&svm->vcpu, fault_address, error_code,
+                       svm->vmcb->control.insn_bytes,
+                       svm->vmcb->control.insn_len);
 }
 
 static int db_interception(struct vcpu_svm *svm)
@@ -4128,7 +4139,7 @@ static int (*const svm_exit_handlers[])(struct vcpu_svm *svm) = {
        [SVM_EXIT_MONITOR]                      = monitor_interception,
        [SVM_EXIT_MWAIT]                        = mwait_interception,
        [SVM_EXIT_XSETBV]                       = xsetbv_interception,
-       [SVM_EXIT_NPF]                          = pf_interception,
+       [SVM_EXIT_NPF]                          = npf_interception,
        [SVM_EXIT_RSM]                          = emulate_on_interception,
        [SVM_EXIT_AVIC_INCOMPLETE_IPI]          = avic_incomplete_ipi_interception,
        [SVM_EXIT_AVIC_UNACCELERATED_ACCESS]    = avic_unaccelerated_access_interception,

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 7458237..c9214e3 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5894,8 +5894,7 @@ static int handle_exception(struct kvm_vcpu *vcpu)
                cr2 = vmcs_readl(EXIT_QUALIFICATION);
                /* EPT won't cause page fault directly */
                WARN_ON_ONCE(!vcpu->arch.apf.host_apf_reason && enable_ept);
-               return kvm_handle_page_fault(vcpu, error_code, cr2, NULL, 0,
-                               true);
+               return kvm_handle_page_fault(vcpu, error_code, cr2, NULL, 0);
        }
 
        ex_no = intr_info & INTR_INFO_VECTOR_MASK;