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Commit bd6360cc authored by Xiao Guangrong's avatar Xiao Guangrong Committed by Avi Kivity
Browse files

KVM: MMU: introduce FNAME(prefetch_gpte) 



The only difference between FNAME(update_pte) and FNAME(pte_prefetch)
is that the former is allowed to prefetch gfn from dirty logged slot,
so introduce a common function to prefetch spte

Signed-off-by: default avatarXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent a052b42b

arch/x86/kvm/paging_tmpl.h

+24 −31
Original line number Diff line number Diff line
@@ -305,31 +305,43 @@ static int FNAME(walk_addr_nested)(struct guest_walker *walker, 
					addr, access);

}



static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,

			      u64 *spte, const void *pte)

static bool

FNAME(prefetch_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,

		     u64 *spte, pt_element_t gpte, bool no_dirty_log)

{

	pt_element_t gpte;

	unsigned pte_access;

	gfn_t gfn;

	pfn_t pfn;



	gpte = *(const pt_element_t *)pte;

	if (prefetch_invalid_gpte(vcpu, sp, spte, gpte))

		return;

		return false;



	pgprintk("%s: gpte %llx spte %p\n", __func__, (u64)gpte, spte);



	gfn = gpte_to_gfn(gpte);

	pte_access = sp->role.access & gpte_access(vcpu, gpte);

	protect_clean_gpte(&pte_access, gpte);

	pfn = gfn_to_pfn_atomic(vcpu->kvm, gpte_to_gfn(gpte));

	pfn = pte_prefetch_gfn_to_pfn(vcpu, gfn,

			no_dirty_log && (pte_access & ACC_WRITE_MASK));

	if (is_invalid_pfn(pfn))

		return;

		return false;



	/*

	 * we call mmu_set_spte() with host_writable = true because that

	 * vcpu->arch.update_pte.pfn was fetched from get_user_pages(write = 1).

	 * we call mmu_set_spte() with host_writable = true because

	 * pte_prefetch_gfn_to_pfn always gets a writable pfn.

	 */

	mmu_set_spte(vcpu, spte, sp->role.access, pte_access, 0, 0,

		     NULL, PT_PAGE_TABLE_LEVEL,

		     gpte_to_gfn(gpte), pfn, true, true);

		     NULL, PT_PAGE_TABLE_LEVEL, gfn, pfn, true, true);



	return true;

}



static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,

			      u64 *spte, const void *pte)

{

	pt_element_t gpte = *(const pt_element_t *)pte;



	FNAME(prefetch_gpte)(vcpu, sp, spte, gpte, false);

}



static bool FNAME(gpte_changed)(struct kvm_vcpu *vcpu,
@@ -375,33 +387,14 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw, 
	spte = sp->spt + i;



	for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) {

		pt_element_t gpte;

		unsigned pte_access;

		gfn_t gfn;

		pfn_t pfn;



		if (spte == sptep)

			continue;



		if (is_shadow_present_pte(*spte))

			continue;



		gpte = gptep[i];



		if (prefetch_invalid_gpte(vcpu, sp, spte, gpte))

			continue;



		pte_access = sp->role.access & gpte_access(vcpu, gpte);

		protect_clean_gpte(&pte_access, gpte);

		gfn = gpte_to_gfn(gpte);

		pfn = pte_prefetch_gfn_to_pfn(vcpu, gfn,

				      pte_access & ACC_WRITE_MASK);

		if (is_invalid_pfn(pfn))

		if (!FNAME(prefetch_gpte)(vcpu, sp, spte, gptep[i], true))

			break;



		mmu_set_spte(vcpu, spte, sp->role.access, pte_access, 0, 0,

			     NULL, PT_PAGE_TABLE_LEVEL, gfn,

			     pfn, true, true);

	}

}