Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit e8bc217a authored by Marcelo Tosatti's avatar Marcelo Tosatti Committed by Avi Kivity
Browse files

KVM: MMU: mode specific sync_page



Examine guest pagetable and bring the shadow back in sync. Caller is responsible
for local TLB flush before re-entering guest mode.

Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 38187c83
Loading
Loading
Loading
Loading
+10 −0
Original line number Diff line number Diff line
@@ -871,6 +871,12 @@ static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu,
		sp->spt[i] = shadow_trap_nonpresent_pte;
}

static int nonpaging_sync_page(struct kvm_vcpu *vcpu,
			       struct kvm_mmu_page *sp)
{
	return 1;
}

static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn)
{
	unsigned index;
@@ -1547,6 +1553,7 @@ static int nonpaging_init_context(struct kvm_vcpu *vcpu)
	context->gva_to_gpa = nonpaging_gva_to_gpa;
	context->free = nonpaging_free;
	context->prefetch_page = nonpaging_prefetch_page;
	context->sync_page = nonpaging_sync_page;
	context->root_level = 0;
	context->shadow_root_level = PT32E_ROOT_LEVEL;
	context->root_hpa = INVALID_PAGE;
@@ -1594,6 +1601,7 @@ static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level)
	context->page_fault = paging64_page_fault;
	context->gva_to_gpa = paging64_gva_to_gpa;
	context->prefetch_page = paging64_prefetch_page;
	context->sync_page = paging64_sync_page;
	context->free = paging_free;
	context->root_level = level;
	context->shadow_root_level = level;
@@ -1615,6 +1623,7 @@ static int paging32_init_context(struct kvm_vcpu *vcpu)
	context->gva_to_gpa = paging32_gva_to_gpa;
	context->free = paging_free;
	context->prefetch_page = paging32_prefetch_page;
	context->sync_page = paging32_sync_page;
	context->root_level = PT32_ROOT_LEVEL;
	context->shadow_root_level = PT32E_ROOT_LEVEL;
	context->root_hpa = INVALID_PAGE;
@@ -1634,6 +1643,7 @@ static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
	context->page_fault = tdp_page_fault;
	context->free = nonpaging_free;
	context->prefetch_page = nonpaging_prefetch_page;
	context->sync_page = nonpaging_sync_page;
	context->shadow_root_level = kvm_x86_ops->get_tdp_level();
	context->root_hpa = INVALID_PAGE;

+54 −0
Original line number Diff line number Diff line
@@ -507,6 +507,60 @@ static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu,
	}
}

/*
 * Using the cached information from sp->gfns is safe because:
 * - The spte has a reference to the struct page, so the pfn for a given gfn
 *   can't change unless all sptes pointing to it are nuked first.
 * - Alias changes zap the entire shadow cache.
 */
static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
{
	int i, offset, nr_present;

	offset = nr_present = 0;

	if (PTTYPE == 32)
		offset = sp->role.quadrant << PT64_LEVEL_BITS;

	for (i = 0; i < PT64_ENT_PER_PAGE; i++) {
		unsigned pte_access;
		pt_element_t gpte;
		gpa_t pte_gpa;
		gfn_t gfn = sp->gfns[i];

		if (!is_shadow_present_pte(sp->spt[i]))
			continue;

		pte_gpa = gfn_to_gpa(sp->gfn);
		pte_gpa += (i+offset) * sizeof(pt_element_t);

		if (kvm_read_guest_atomic(vcpu->kvm, pte_gpa, &gpte,
					  sizeof(pt_element_t)))
			return -EINVAL;

		if (gpte_to_gfn(gpte) != gfn || !is_present_pte(gpte) ||
		    !(gpte & PT_ACCESSED_MASK)) {
			u64 nonpresent;

			rmap_remove(vcpu->kvm, &sp->spt[i]);
			if (is_present_pte(gpte))
				nonpresent = shadow_trap_nonpresent_pte;
			else
				nonpresent = shadow_notrap_nonpresent_pte;
			set_shadow_pte(&sp->spt[i], nonpresent);
			continue;
		}

		nr_present++;
		pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte);
		set_spte(vcpu, &sp->spt[i], pte_access, 0, 0,
			 is_dirty_pte(gpte), 0, gfn,
			 spte_to_pfn(sp->spt[i]), true);
	}

	return !nr_present;
}

#undef pt_element_t
#undef guest_walker
#undef shadow_walker
+2 −0
Original line number Diff line number Diff line
@@ -220,6 +220,8 @@ struct kvm_mmu {
	gpa_t (*gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t gva);
	void (*prefetch_page)(struct kvm_vcpu *vcpu,
			      struct kvm_mmu_page *page);
	int (*sync_page)(struct kvm_vcpu *vcpu,
			 struct kvm_mmu_page *sp);
	hpa_t root_hpa;
	int root_level;
	int shadow_root_level;