[PATCH 8/33] KVM: MMU: Make kvm_mmu_alloc_page() return a kvm_mmu_page pointer

Avi Kivity
2007-01-04T15:57:06Z

This allows further manipulation on the shadow page table.

Signed-off-by: Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>

Index: linux-2.6/drivers/kvm/mmu.c
===================================================================
--- linux-2.6.orig/drivers/kvm/mmu.c
+++ linux-2.6/drivers/kvm/mmu.c
@@ -292,12 +292,13 @@ static int is_empty_shadow_page(hpa_t pa
return 1;
}

-static hpa_t kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, u64 *parent_pte)
+static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
+ u64 *parent_pte)
{
struct kvm_mmu_page *page;

if (list_empty(&vcpu->free_pages))
- return INVALID_PAGE;
+ return NULL;

page = list_entry(vcpu->free_pages.next, struct kvm_mmu_page, link);
list_del(&page->link);
@@ -306,7 +307,7 @@ static hpa_t kvm_mmu_alloc_page(struct k
page->slot_bitmap = 0;
page->global = 1;
page->parent_pte = parent_pte;
- return page->page_hpa;
+ return page;
}

static void page_header_update_slot(struct kvm *kvm, void *pte, gpa_t gpa)
@@ -402,19 +403,16 @@ static int nonpaging_map(struct kvm_vcpu
}

if (table[index] == 0) {
- hpa_t new_table = kvm_mmu_alloc_page(vcpu,
- &table[index]);
+ struct kvm_mmu_page *new_table;

- if (!VALID_PAGE(new_table)) {
+ new_table = kvm_mmu_alloc_page(vcpu, &table[index]);
+ if (!new_table) {
pgprintk("nonpaging_map: ENOMEM\n");
return -ENOMEM;
}

- if (level == PT32E_ROOT_LEVEL)
- table[index] = new_table | PT_PRESENT_MASK;
- else
- table[index] = new_table | PT_PRESENT_MASK |
- PT_WRITABLE_MASK | PT_USER_MASK;
+ table[index] = new_table->page_hpa | PT_PRESENT_MASK
+ | PT_WRITABLE_MASK | PT_USER_MASK;
}
table_addr = table[index] & PT64_BASE_ADDR_MASK;
}
@@ -454,7 +452,7 @@ static void mmu_alloc_roots(struct kvm_v
hpa_t root = vcpu->mmu.root_hpa;

ASSERT(!VALID_PAGE(root));
- root = kvm_mmu_alloc_page(vcpu, NULL);
+ root = kvm_mmu_alloc_page(vcpu, NULL)->page_hpa;
vcpu->mmu.root_hpa = root;
return;
}
@@ -463,7 +461,7 @@ static void mmu_alloc_roots(struct kvm_v
hpa_t root = vcpu->mmu.pae_root[i];

ASSERT(!VALID_PAGE(root));
- root = kvm_mmu_alloc_page(vcpu, NULL);
+ root = kvm_mmu_alloc_page(vcpu, NULL)->page_hpa;
vcpu->mmu.pae_root[i] = root | PT_PRESENT_MASK;
}
vcpu->mmu.root_hpa = __pa(vcpu->mmu.pae_root);
Index: linux-2.6/drivers/kvm/paging_tmpl.h
===================================================================
--- linux-2.6.orig/drivers/kvm/paging_tmpl.h
+++ linux-2.6/drivers/kvm/paging_tmpl.h
@@ -179,6 +179,7 @@ static u64 *FNAME(fetch)(struct kvm_vcpu
for (; ; level--) {
u32 index = SHADOW_PT_INDEX(addr, level);
u64 *shadow_ent = ((u64 *)__va(shadow_addr)) + index;
+ struct kvm_mmu_page *shadow_page;
u64 shadow_pte;

if (is_present_pte(*shadow_ent) || is_io_pte(*shadow_ent)) {
@@ -204,9 +205,10 @@ static u64 *FNAME(fetch)(struct kvm_vcpu
return shadow_ent;
}

- shadow_addr = kvm_mmu_alloc_page(vcpu, shadow_ent);
- if (!VALID_PAGE(shadow_addr))
+ shadow_page = kvm_mmu_alloc_page(vcpu, shadow_ent);
+ if (!shadow_page)
return ERR_PTR(-ENOMEM);
+ shadow_addr = shadow_page->page_hpa;
shadow_pte = shadow_addr | PT_PRESENT_MASK | PT_ACCESSED_MASK
| PT_WRITABLE_MASK | PT_USER_MASK;
*shadow_ent = shadow_pte;