[patch 70/88] KVM: MMU: handle large host sptes on invlpg/resync

Greg KH
2009-04-30T17:39:49Z

[-- Attachment #1: kvm-mmu-handle-large-host-sptes-on-invlpg-resync.patch --]
[-- Type: text/plain, Size: 1571 bytes --]

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

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

(cherry picked from 87917239204d67a316cb89751750f86c9ed3640b)

The invlpg and sync walkers lack knowledge of large host sptes,
descending to non-existant pagetable level.

Stop at directory level in such case.

Fixes SMP Windows XP with hugepages.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
arch/x86/kvm/mmu.c | 2 +-
arch/x86/kvm/paging_tmpl.h | 8 ++++++--
2 files changed, 7 insertions(+), 3 deletions(-)

--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -981,7 +981,7 @@ static int mmu_unsync_walk(struct kvm_mm
for_each_unsync_children(sp->unsync_child_bitmap, i) {
u64 ent = sp->spt[i];

- if (is_shadow_present_pte(ent)) {
+ if (is_shadow_present_pte(ent) && !is_large_pte(ent)) {
struct kvm_mmu_page *child;
child = page_header(ent & PT64_BASE_ADDR_MASK);

--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -467,9 +467,13 @@ static int FNAME(shadow_invlpg_entry)(st
u64 *sptep, int level)
{

- if (level == PT_PAGE_TABLE_LEVEL) {
- if (is_shadow_present_pte(*sptep))
+ if (level == PT_PAGE_TABLE_LEVEL ||
+ ((level == PT_DIRECTORY_LEVEL) && is_large_pte(*sptep))) {
+ if (is_shadow_present_pte(*sptep)) {
rmap_remove(vcpu->kvm, sptep);
+ if (is_large_pte(*sptep))
+ --vcpu->kvm->stat.lpages;
+ }
set_shadow_pte(sptep, shadow_trap_nonpresent_pte);
return 1;
}