[patch 57/88] KVM: MMU: Extend kvm_mmu_page->slot_bitmap size

Greg KH
2009-04-30T17:33:25Z

[-- Attachment #1: kvm-mmu-extend-kvm_mmu_page-slot_bitmap-size.patch --]
[-- Type: text/plain, Size: 2180 bytes --]

2.6.28-stable review patch. If anyone has any objections, please let us know.

------------------

From: Sheng Yang <sheng@linux.intel.com>

(cherry picked from 291f26bc0f89518ad7ee3207c09eb8a743ac8fcc)

Otherwise set_bit() for private memory slot(above KVM_MEMORY_SLOTS) would
corrupted memory in 32bit host.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
arch/x86/include/asm/kvm_host.h | 8 +++++---
arch/x86/kvm/mmu.c | 6 +++---
2 files changed, 8 insertions(+), 6 deletions(-)

--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -190,9 +190,11 @@ struct kvm_mmu_page {
u64 *spt;
/* hold the gfn of each spte inside spt */
gfn_t *gfns;
- unsigned long slot_bitmap; /* One bit set per slot which has memory
- * in this shadow page.
- */
+ /*
+ * One bit set per slot which has memory
+ * in this shadow page.
+ */
+ DECLARE_BITMAP(slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS);
int multimapped; /* More than one parent_pte? */
int root_count; /* Currently serving as active root */
bool unsync;
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -787,7 +787,7 @@ static struct kvm_mmu_page *kvm_mmu_allo
set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
ASSERT(is_empty_shadow_page(sp->spt));
- sp->slot_bitmap = 0;
+ bitmap_zero(sp->slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS);
sp->multimapped = 0;
sp->parent_pte = parent_pte;
--vcpu->kvm->arch.n_free_mmu_pages;
@@ -1362,7 +1362,7 @@ static void page_header_update_slot(stru
int slot = memslot_id(kvm, gfn_to_memslot(kvm, gfn));
struct kvm_mmu_page *sp = page_header(__pa(pte));

- __set_bit(slot, &sp->slot_bitmap);
+ __set_bit(slot, sp->slot_bitmap);
}

static void mmu_convert_notrap(struct kvm_mmu_page *sp)
@@ -2451,7 +2451,7 @@ void kvm_mmu_slot_remove_write_access(st
int i;
u64 *pt;

- if (!test_bit(slot, &sp->slot_bitmap))
+ if (!test_bit(slot, sp->slot_bitmap))
continue;

pt = sp->spt;