[PATCH v2 6/7] KVM: MMU: traverse sp hlish safely

Xiao Guangrong
2010-06-04T13:56:11Z

Now, we can safely to traverse sp hlish

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
---
arch/x86/kvm/mmu.c | 51 +++++++++++++++++++++++----------------------------
1 files changed, 23 insertions(+), 28 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 6544d8e..845cba2 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1205,13 +1205,13 @@ static int kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp,
static void kvm_mmu_commit_zap_page(struct kvm *kvm,
struct list_head *invalid_list);

-#define for_each_gfn_sp(kvm, sp, gfn, pos, n) \
- hlist_for_each_entry_safe(sp, pos, n, \
+#define for_each_gfn_sp(kvm, sp, gfn, pos) \
+ hlist_for_each_entry(sp, pos, \
&(kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)], hash_link) \
if ((sp)->gfn != (gfn)) {} else

-#define for_each_gfn_indirect_valid_sp(kvm, sp, gfn, pos, n) \
- hlist_for_each_entry_safe(sp, pos, n, \
+#define for_each_gfn_indirect_valid_sp(kvm, sp, gfn, pos) \
+ hlist_for_each_entry(sp, pos, \
&(kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)], hash_link) \
if ((sp)->gfn != (gfn) || (sp)->role.direct || \
(sp)->role.invalid) {} else
@@ -1265,11 +1265,11 @@ static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
static void kvm_sync_pages(struct kvm_vcpu *vcpu, gfn_t gfn)
{
struct kvm_mmu_page *s;
- struct hlist_node *node, *n;
+ struct hlist_node *node;
LIST_HEAD(invalid_list);
bool flush = false;

- for_each_gfn_indirect_valid_sp(vcpu->kvm, s, gfn, node, n) {
+ for_each_gfn_indirect_valid_sp(vcpu->kvm, s, gfn, node) {
if (!s->unsync)
continue;

@@ -1387,7 +1387,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
union kvm_mmu_page_role role;
unsigned quadrant;
struct kvm_mmu_page *sp;
- struct hlist_node *node, *tmp;
+ struct hlist_node *node;
bool need_sync = false;

role = vcpu->arch.mmu.base_role;
@@ -1401,7 +1401,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
role.quadrant = quadrant;
}
- for_each_gfn_sp(vcpu->kvm, sp, gfn, node, tmp) {
+ for_each_gfn_sp(vcpu->kvm, sp, gfn, node) {
if (!need_sync && sp->unsync)
need_sync = true;

@@ -1656,19 +1656,18 @@ void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int kvm_nr_mmu_pages)
static int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn)
{
struct kvm_mmu_page *sp;
- struct hlist_node *node, *n;
+ struct hlist_node *node;
LIST_HEAD(invalid_list);
int r;

pgprintk("%s: looking for gfn %lx\n", __func__, gfn);
r = 0;
-restart:
- for_each_gfn_indirect_valid_sp(kvm, sp, gfn, node, n) {
+
+ for_each_gfn_indirect_valid_sp(kvm, sp, gfn, node) {
pgprintk("%s: gfn %lx role %x\n", __func__, gfn,
sp->role.word);
r = 1;
- if (kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list))
- goto restart;
+ kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list);
}
kvm_mmu_commit_zap_page(kvm, &invalid_list);
return r;
@@ -1677,15 +1676,13 @@ restart:
static void mmu_unshadow(struct kvm *kvm, gfn_t gfn)
{
struct kvm_mmu_page *sp;
- struct hlist_node *node, *nn;
+ struct hlist_node *node;
LIST_HEAD(invalid_list);

-restart:
- for_each_gfn_indirect_valid_sp(kvm, sp, gfn, node, nn) {
+ for_each_gfn_indirect_valid_sp(kvm, sp, gfn, node) {
pgprintk("%s: zap %lx %x\n",
__func__, gfn, sp->role.word);
- if (kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list))
- goto restart;
+ kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list);
}
kvm_mmu_commit_zap_page(kvm, &invalid_list);
}
@@ -1830,9 +1827,9 @@ static void __kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
static void kvm_unsync_pages(struct kvm_vcpu *vcpu, gfn_t gfn)
{
struct kvm_mmu_page *s;
- struct hlist_node *node, *n;
+ struct hlist_node *node;

- for_each_gfn_indirect_valid_sp(vcpu->kvm, s, gfn, node, n) {
+ for_each_gfn_indirect_valid_sp(vcpu->kvm, s, gfn, node) {
if (s->unsync)
continue;
WARN_ON(s->role.level != PT_PAGE_TABLE_LEVEL);
@@ -1844,10 +1841,10 @@ static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
bool can_unsync)
{
struct kvm_mmu_page *s;
- struct hlist_node *node, *n;
+ struct hlist_node *node;
bool need_unsync = false;

- for_each_gfn_indirect_valid_sp(vcpu->kvm, s, gfn, node, n) {
+ for_each_gfn_indirect_valid_sp(vcpu->kvm, s, gfn, node) {
if (s->role.level != PT_PAGE_TABLE_LEVEL)
return 1;

@@ -2722,7 +2719,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
{
gfn_t gfn = gpa >> PAGE_SHIFT;
struct kvm_mmu_page *sp;
- struct hlist_node *node, *n;
+ struct hlist_node *node;
LIST_HEAD(invalid_list);
u64 entry, gentry;
u64 *spte;
@@ -2792,8 +2789,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
}
}

-restart:
- for_each_gfn_indirect_valid_sp(vcpu->kvm, sp, gfn, node, n) {
+ for_each_gfn_indirect_valid_sp(vcpu->kvm, sp, gfn, node) {
pte_size = sp->role.cr4_pae ? 8 : 4;
misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1);
misaligned |= bytes < 4;
@@ -2810,9 +2806,8 @@ restart:
*/
pgprintk("misaligned: gpa %llx bytes %d role %x\n",
gpa, bytes, sp->role.word);
- if (kvm_mmu_prepare_zap_page(vcpu->kvm, sp,
- &invalid_list))
- goto restart;
+ kvm_mmu_prepare_zap_page(vcpu->kvm, sp,
+ &invalid_list);
++vcpu->kvm->stat.mmu_flooded;
continue;
}
--
1.6.1.2