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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>
This commit is contained in:
Wanpeng Li 2017-07-13 18:30:40 -07:00 committed by Radim Krčmář
parent cfcd20e5ca
commit 1261bfa326
5 changed files with 51 additions and 37 deletions
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1
arch/x86/include/asm/kvm_host.h
View File

@ -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) */

33
arch/x86/kvm/mmu.c
View File

@ -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)
{

3
arch/x86/kvm/mmu.h
View File

@ -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)
{

36
arch/x86/kvm/svm.c
View File

@ -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);

15
arch/x86/kvm/vmx.c
View File

@ -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))