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Message-Id: <1499995842-92976-3-git-send-email-wanpeng.li@hotmail.com>
Date: Thu, 13 Jul 2017 18:30:40 -0700
From: Wanpeng Li <kernellwp@...il.com>
To: linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc: Paolo Bonzini <pbonzini@...hat.com>,
Radim Krčmář <rkrcmar@...hat.com>,
Wanpeng Li <wanpeng.li@...mail.com>
Subject: [PATCH v8 2/4] KVM: async_pf: Add L1 guest async_pf #PF vmexit handler
From: Wanpeng Li <wanpeng.li@...mail.com>
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@...hat.com>
Cc: Radim Krčmář <rkrcmar@...hat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@...mail.com>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/mmu.c | 32 ++++++++++++++++++++++++++++++++
arch/x86/kvm/mmu.h | 3 +++
arch/x86/kvm/svm.c | 36 ++++++------------------------------
arch/x86/kvm/vmx.c | 15 ++++++++-------
5 files changed, 50 insertions(+), 37 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 8d11ddc..4f20ee6 100644
--- 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 aafd399..338cb4c 100644
--- 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 +3781,37 @@ 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, NULL, 0);
+ 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 a276834..d7d248a 100644
--- 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 cde756a..fb23497 100644
--- 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 69cc228..c9c46e6 100644
--- 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))
--
2.7.4
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