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Commit 1261bfa3 authored by Wanpeng Li's avatar Wanpeng Li Committed by Radim Krčmář
Browse files

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: default avatarWanpeng Li <wanpeng.li@hotmail.com>
[Passed insn parameters to kvm_mmu_page_fault().]
Signed-off-by: default avatarRadim Krčmář <rkrcmar@redhat.com>
parent cfcd20e5

arch/x86/include/asm/kvm_host.h

+1 −0
Original line number Diff line number Diff line
@@ -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) */

arch/x86/kvm/mmu.c

+33 −0
Original line number Diff line number Diff line
@@ -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)

{

arch/x86/kvm/mmu.h

+3 −0
Original line number Diff line number Diff line
@@ -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)

{

arch/x86/kvm/svm.c

+6 −30
Original line number Diff line number Diff line
@@ -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);

arch/x86/kvm/vmx.c

+8 −7
Original line number Diff line number Diff line
@@ -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))