Commit fb67e14f authored by Xiao Guangrong's avatar Xiao Guangrong Committed by Avi Kivity
Browse files

KVM: MMU: retry #PF for softmmu 



Retry #PF for softmmu only when the current vcpu has the same cr3 as the time
when #PF occurs

Signed-off-by: default avatarXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 2ec4739d

arch/x86/include/asm/kvm_host.h

+1 −0
Original line number Diff line number Diff line
@@ -593,6 +593,7 @@ struct kvm_x86_ops { 
struct kvm_arch_async_pf {

	u32 token;

	gfn_t gfn;

	unsigned long cr3;

	bool direct_map;

};

arch/x86/kvm/mmu.c

+2 −0
Original line number Diff line number Diff line
@@ -2608,9 +2608,11 @@ static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva, 
static int kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn)

{

	struct kvm_arch_async_pf arch;



	arch.token = (vcpu->arch.apf.id++ << 12) | vcpu->vcpu_id;

	arch.gfn = gfn;

	arch.direct_map = vcpu->arch.mmu.direct_map;

	arch.cr3 = vcpu->arch.mmu.get_cr3(vcpu);



	return kvm_setup_async_pf(vcpu, gva, gfn, &arch);

}

arch/x86/kvm/paging_tmpl.h

+9 −5
Original line number Diff line number Diff line
@@ -438,7 +438,8 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw, 
static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,

			 struct guest_walker *gw,

			 int user_fault, int write_fault, int hlevel,

			 int *ptwrite, pfn_t pfn, bool map_writable)

			 int *ptwrite, pfn_t pfn, bool map_writable,

			 bool prefault)

{

	unsigned access = gw->pt_access;

	struct kvm_mmu_page *sp = NULL;
@@ -512,7 +513,7 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, 


	mmu_set_spte(vcpu, it.sptep, access, gw->pte_access & access,

		     user_fault, write_fault, dirty, ptwrite, it.level,

		     gw->gfn, pfn, false, map_writable);

		     gw->gfn, pfn, prefault, map_writable);

	FNAME(pte_prefetch)(vcpu, gw, it.sptep);



	return it.sptep;
@@ -568,8 +569,11 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code, 
	 */

	if (!r) {

		pgprintk("%s: guest page fault\n", __func__);

		if (!prefault) {

			inject_page_fault(vcpu, &walker.fault);

		vcpu->arch.last_pt_write_count = 0; /* reset fork detector */

			/* reset fork detector */

			vcpu->arch.last_pt_write_count = 0;

		}

		return 0;

	}
@@ -599,7 +603,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code, 
	trace_kvm_mmu_audit(vcpu, AUDIT_PRE_PAGE_FAULT);

	kvm_mmu_free_some_pages(vcpu);

	sptep = FNAME(fetch)(vcpu, addr, &walker, user_fault, write_fault,

			     level, &write_pt, pfn, map_writable);

			     level, &write_pt, pfn, map_writable, prefault);

	(void)sptep;

	pgprintk("%s: shadow pte %p %llx ptwrite %d\n", __func__,

		 sptep, *sptep, write_pt);

arch/x86/kvm/x86.c

+5 −1
Original line number Diff line number Diff line
@@ -6182,7 +6182,7 @@ void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work) 
{

	int r;



	if (!vcpu->arch.mmu.direct_map || !work->arch.direct_map ||

	if ((vcpu->arch.mmu.direct_map != work->arch.direct_map) ||

	      is_error_page(work->page))

		return;
@@ -6190,6 +6190,10 @@ void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work) 
	if (unlikely(r))

		return;



	if (!vcpu->arch.mmu.direct_map &&

	      work->arch.cr3 != vcpu->arch.mmu.get_cr3(vcpu))

		return;



	vcpu->arch.mmu.page_fault(vcpu, work->gva, 0, true);

}