KVM: MMU: Store shadow page tables as kernel virtual addresses, not physical

Simpifies things a bit.

Signed-off-by: Avi Kivity <avi@qumranet.com>

3 files changed, 17 insertions, 19 deletions

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 5e6dac5a3c00..fc4a6c1235f0 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -139,7 +139,7 @@ struct kvm_mmu_page {
         gfn_t gfn;
         union kvm_mmu_page_role role;
 
-        hpa_t page_hpa;
+        u64 *spt;
         unsigned long slot_bitmap; /* One bit set per slot which has memory
                                     * in this shadow page.
                                     */
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index a96c9ae54f3c..c85c6649280e 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -439,13 +439,12 @@ static void rmap_write_protect(struct kvm_vcpu *vcpu, u64 gfn)
 }
 
 #ifdef MMU_DEBUG
-static int is_empty_shadow_page(hpa_t page_hpa)
+static int is_empty_shadow_page(u64 *spt)
 {
         u64 *pos;
         u64 *end;
 
-        for (pos = __va(page_hpa), end = pos + PAGE_SIZE / sizeof(u64);
-                      pos != end; pos++)
+        for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++)
                 if (*pos != 0) {
                         printk(KERN_ERR "%s: %p %llx\n", __FUNCTION__,
                                pos, *pos);
@@ -458,7 +457,7 @@ static int is_empty_shadow_page(hpa_t page_hpa)
 static void kvm_mmu_free_page(struct kvm_vcpu *vcpu,
                               struct kvm_mmu_page *page_head)
 {
-        ASSERT(is_empty_shadow_page(page_head->page_hpa));
+        ASSERT(is_empty_shadow_page(page_head->spt));
         list_move(&page_head->link, &vcpu->free_pages);
         ++vcpu->kvm->n_free_mmu_pages;
 }
@@ -478,7 +477,7 @@ static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
 
         page = list_entry(vcpu->free_pages.next, struct kvm_mmu_page, link);
         list_move(&page->link, &vcpu->kvm->active_mmu_pages);
-        ASSERT(is_empty_shadow_page(page->page_hpa));
+        ASSERT(is_empty_shadow_page(page->spt));
         page->slot_bitmap = 0;
         page->multimapped = 0;
         page->parent_pte = parent_pte;
@@ -636,7 +635,7 @@ static void kvm_mmu_page_unlink_children(struct kvm_vcpu *vcpu,
         u64 *pt;
         u64 ent;
 
-        pt = __va(page->page_hpa);
+        pt = page->spt;
 
         if (page->role.level == PT_PAGE_TABLE_LEVEL) {
                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
@@ -803,7 +802,7 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, hpa_t p)
                                 return -ENOMEM;
                         }
 
-                        table[index] = new_table->page_hpa | PT_PRESENT_MASK
+                        table[index] = __pa(new_table->spt) | PT_PRESENT_MASK
                                 | PT_WRITABLE_MASK | PT_USER_MASK;
                 }
                 table_addr = table[index] & PT64_BASE_ADDR_MASK;
@@ -855,7 +854,7 @@ static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
                 ASSERT(!VALID_PAGE(root));
                 page = kvm_mmu_get_page(vcpu, root_gfn, 0,
                                         PT64_ROOT_LEVEL, 0, 0, NULL);
-                root = page->page_hpa;
+                root = __pa(page->spt);
                 ++page->root_count;
                 vcpu->mmu.root_hpa = root;
                 return;
@@ -876,7 +875,7 @@ static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
                 page = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
                                         PT32_ROOT_LEVEL, !is_paging(vcpu),
                                         0, NULL);
-                root = page->page_hpa;
+                root = __pa(page->spt);
                 ++page->root_count;
                 vcpu->mmu.pae_root[i] = root | PT_PRESENT_MASK;
         }
@@ -1220,8 +1219,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
                         if (quadrant != page->role.quadrant)
                                 continue;
                 }
-                spte = __va(page->page_hpa);
-                spte += page_offset / sizeof(*spte);
+                spte = &page->spt[page_offset / sizeof(*spte)];
                 while (npte--) {
                         mmu_pte_write_zap_pte(vcpu, page, spte);
                         mmu_pte_write_new_pte(vcpu, page, spte, new, bytes);
@@ -1262,8 +1260,8 @@ static void free_mmu_pages(struct kvm_vcpu *vcpu)
                 page = list_entry(vcpu->free_pages.next,
                                   struct kvm_mmu_page, link);
                 list_del(&page->link);
-                __free_page(pfn_to_page(page->page_hpa >> PAGE_SHIFT));
-                page->page_hpa = INVALID_PAGE;
+                free_page((unsigned long)page->spt);
+                page->spt = NULL;
         }
         free_page((unsigned long)vcpu->mmu.pae_root);
 }
@@ -1282,8 +1280,8 @@ static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
                 if ((page = alloc_page(GFP_KERNEL)) == NULL)
                         goto error_1;
                 set_page_private(page, (unsigned long)page_header);
-                page_header->page_hpa = (hpa_t)page_to_pfn(page) << PAGE_SHIFT;
-                memset(__va(page_header->page_hpa), 0, PAGE_SIZE);
+                page_header->spt = page_address(page);
+                memset(page_header->spt, 0, PAGE_SIZE);
                 list_add(&page_header->link, &vcpu->free_pages);
                 ++vcpu->kvm->n_free_mmu_pages;
         }
@@ -1346,7 +1344,7 @@ void kvm_mmu_slot_remove_write_access(struct kvm_vcpu *vcpu, int slot)
                 if (!test_bit(slot, &page->slot_bitmap))
                         continue;
 
-                pt = __va(page->page_hpa);
+                pt = page->spt;
                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
                         /* avoid RMW */
                         if (pt[i] & PT_WRITABLE_MASK) {
@@ -1497,7 +1495,7 @@ static int count_writable_mappings(struct kvm_vcpu *vcpu)
         int i;
 
         list_for_each_entry(page, &vcpu->kvm->active_mmu_pages, link) {
-                u64 *pt = __va(page->page_hpa);
+                u64 *pt = page->spt;
 
                 if (page->role.level != PT_PAGE_TABLE_LEVEL)
                         continue;
diff --git a/drivers/kvm/paging_tmpl.h b/drivers/kvm/paging_tmpl.h
index 10ba0a80ce59..6dd0da9a5d15 100644
--- a/drivers/kvm/paging_tmpl.h
+++ b/drivers/kvm/paging_tmpl.h
@@ -304,7 +304,7 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
                 shadow_page = kvm_mmu_get_page(vcpu, table_gfn, addr, level-1,
                                                metaphysical, hugepage_access,
                                                shadow_ent);
-                shadow_addr = shadow_page->page_hpa;
+                shadow_addr = __pa(shadow_page->spt);
                 shadow_pte = shadow_addr | PT_PRESENT_MASK | PT_ACCESSED_MASK
                         | PT_WRITABLE_MASK | PT_USER_MASK;
                 *shadow_ent = shadow_pte;