KVM: async_pf: Add L1 guest async_pf #PF vmexit handler

This patch adds the L1 guest async page fault #PF vmexit handler, such
by L1 similar to ordinary async page fault.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
[Passed insn parameters to kvm_mmu_page_fault().]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 8d11ddcb0dbfd9371de4de807e6829a20de0d389..4f20ee6c79a169ebb5f78eb550e6753833e76bb2 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -650,6 +650,7 @@ struct kvm_vcpu_arch {
                u64 msr_val;
                u32 id;
                bool send_user_only;
+               u32 host_apf_reason;
        } apf;
 
        /* OSVW MSRs (AMD only) */

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index aafd399cf8c6f3d3e219ec636a73b19ee1e9d20d..3825a35cd7524e38235d40eeb19db230892f19b4 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -46,6 +46,7 @@
 #include <asm/io.h>
 #include <asm/vmx.h>
 #include <asm/kvm_page_track.h>
+#include "trace.h"
 
 /*
  * When setting this variable to true it enables Two-Dimensional-Paging
@@ -3780,6 +3781,38 @@ static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn,
        return false;
 }
 
+int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
+                               u64 fault_address, char *insn, int insn_len,
+                               bool need_unprotect)
+{
+       int r = 1;
+
+       switch (vcpu->arch.apf.host_apf_reason) {
+       default:
+               trace_kvm_page_fault(fault_address, error_code);
+
+               if (need_unprotect && 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);
+               break;
+       case KVM_PV_REASON_PAGE_NOT_PRESENT:
+               vcpu->arch.apf.host_apf_reason = 0;
+               local_irq_disable();
+               kvm_async_pf_task_wait(fault_address);
+               local_irq_enable();
+               break;
+       case KVM_PV_REASON_PAGE_READY:
+               vcpu->arch.apf.host_apf_reason = 0;
+               local_irq_disable();
+               kvm_async_pf_task_wake(fault_address);
+               local_irq_enable();
+               break;
+       }
+       return r;
+}
+EXPORT_SYMBOL_GPL(kvm_handle_page_fault);
+
 static bool
 check_hugepage_cache_consistency(struct kvm_vcpu *vcpu, gfn_t gfn, int level)
 {

diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index a276834950c14a15681c9d125ddde8e9b9dc6af8..d7d248a000dd6772681f3f5541e344f9677a2d1d 100644 (file)
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -77,6 +77,9 @@ void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu);
 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);
 
 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 cde756a02b1aa374bedc08238cb4474b55f83d61..fb23497cf91574dcba962b3a7f5cb533619a3db5 100644 (file)
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -194,7 +194,6 @@ struct vcpu_svm {
 
        unsigned int3_injected;
        unsigned long int3_rip;
-       u32 apf_reason;
 
        /* cached guest cpuid flags for faster access */
        bool nrips_enabled      : 1;
@@ -2122,34 +2121,11 @@ static void svm_set_dr7(struct kvm_vcpu *vcpu, unsigned long value)
 static int pf_interception(struct vcpu_svm *svm)
 {
        u64 fault_address = svm->vmcb->control.exit_info_2;
-       u64 error_code;
-       int r = 1;
+       u64 error_code = svm->vmcb->control.exit_info_1;
 
-       switch (svm->apf_reason) {
-       default:
-               error_code = svm->vmcb->control.exit_info_1;
-
-               trace_kvm_page_fault(fault_address, error_code);
-               if (!npt_enabled && kvm_event_needs_reinjection(&svm->vcpu))
-                       kvm_mmu_unprotect_page_virt(&svm->vcpu, fault_address);
-               r = kvm_mmu_page_fault(&svm->vcpu, fault_address, error_code,
+       return kvm_handle_page_fault(&svm->vcpu, error_code, fault_address,
                        svm->vmcb->control.insn_bytes,
-                       svm->vmcb->control.insn_len);
-               break;
-       case KVM_PV_REASON_PAGE_NOT_PRESENT:
-               svm->apf_reason = 0;
-               local_irq_disable();
-               kvm_async_pf_task_wait(fault_address);
-               local_irq_enable();
-               break;
-       case KVM_PV_REASON_PAGE_READY:
-               svm->apf_reason = 0;
-               local_irq_disable();
-               kvm_async_pf_task_wake(fault_address);
-               local_irq_enable();
-               break;
-       }
-       return r;
+                       svm->vmcb->control.insn_len, !npt_enabled);
 }
 
 static int db_interception(struct vcpu_svm *svm)
@@ -2630,7 +2606,7 @@ static int nested_svm_exit_special(struct vcpu_svm *svm)
                break;
        case SVM_EXIT_EXCP_BASE + PF_VECTOR:
                /* When we're shadowing, trap PFs, but not async PF */
-               if (!npt_enabled && svm->apf_reason == 0)
+               if (!npt_enabled && svm->vcpu.arch.apf.host_apf_reason == 0)
                        return NESTED_EXIT_HOST;
                break;
        default:
@@ -2677,7 +2653,7 @@ static int nested_svm_intercept(struct vcpu_svm *svm)
                }
                /* async page fault always cause vmexit */
                else if ((exit_code == SVM_EXIT_EXCP_BASE + PF_VECTOR) &&
-                        svm->apf_reason != 0)
+                        svm->vcpu.arch.apf.host_apf_reason != 0)
                        vmexit = NESTED_EXIT_DONE;
                break;
        }
@@ -4998,7 +4974,7 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu)
 
        /* if exit due to PF check for async PF */
        if (svm->vmcb->control.exit_code == SVM_EXIT_EXCP_BASE + PF_VECTOR)
-               svm->apf_reason = kvm_read_and_reset_pf_reason();
+               svm->vcpu.arch.apf.host_apf_reason = kvm_read_and_reset_pf_reason();
 
        if (npt_enabled) {
                vcpu->arch.regs_avail &= ~(1 << VCPU_EXREG_PDPTR);

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 69cc228436ea65921da8fe41eeb20d42545969f5..c9c46e63f744ed75d15fb48941e5a2fffc8747c3 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5698,14 +5698,11 @@ static int handle_exception(struct kvm_vcpu *vcpu)
        }
 
        if (is_page_fault(intr_info)) {
-               /* EPT won't cause page fault directly */
-               BUG_ON(enable_ept);
                cr2 = vmcs_readl(EXIT_QUALIFICATION);
-               trace_kvm_page_fault(cr2, error_code);
-
-               if (kvm_event_needs_reinjection(vcpu))
-                       kvm_mmu_unprotect_page_virt(vcpu, cr2);
-               return kvm_mmu_page_fault(vcpu, cr2, error_code, NULL, 0);
+               /* 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);
        }
 
        ex_no = intr_info & INTR_INFO_VECTOR_MASK;
@@ -8643,6 +8640,10 @@ static void vmx_complete_atomic_exit(struct vcpu_vmx *vmx)
                exit_intr_info = vmcs_read32(VM_EXIT_INTR_INFO);
        vmx->exit_intr_info = exit_intr_info;
 
+       /* if exit due to PF check for async PF */
+       if (is_page_fault(exit_intr_info))
+               vmx->vcpu.arch.apf.host_apf_reason = kvm_read_and_reset_pf_reason();
+
        /* Handle machine checks before interrupts are enabled */
        if (basic_exit_reason == EXIT_REASON_MCE_DURING_VMENTRY ||
            is_machine_check(exit_intr_info))