This is a preparation for moving hlist_del(&sp->hash_link) from
kvm_mmu_isolate_page() to kvm_mmu_prepare_zap_page().
All for_each_gfn_indirect_valid_sp's whose bodies contain a function
call which will reach kvm_mmu_prepare_zap_page(), and not break the
loop right after the call, are converted to this new one.
Note: ignored the following checkpatch report:
ERROR: Macros with complex values should be enclosed in parenthesis
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@xxxxxxxxxxxxx>
---
arch/x86/kvm/mmu.c | 27 +++++++++++++++++++++------
1 files changed, 21 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 2a48533..d5bf373 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1677,6 +1677,18 @@ static void kvm_mmu_commit_zap_page(struct kvm *kvm,
for_each_gfn_sp(_kvm, _sp, _gfn, _pos) \
if (!(_sp)->role.direct && !(_sp)->role.invalid)
+/*
+ * Used for zapping mmu pages while traversing the mmu page hash list.
+ * Users must update @_n so that it points to the new next node after deleting
+ * any entries in such a way that can make the value prepared by
+ * hlist_for_each_entry_safe invalid.
+ */
+#define for_each_gfn_indirect_valid_sp_safe(_kvm, _sp, _gfn, _pos, _n) \
+ hlist_for_each_entry_safe(_sp, _pos, _n, \
+ &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)], hash_link) \
+ if (((_sp)->gfn == (_gfn)) && \
+ !(_sp)->role.direct && !(_sp)->role.invalid)
+
/* @sp->gfn should be write-protected at the call site */
static int __kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
struct list_head *invalid_list, bool clear_unsync)
@@ -1729,10 +1741,11 @@ static void kvm_sync_pages(struct kvm_vcpu *vcpu, gfn_t gfn)
{
struct kvm_mmu_page *s;
struct hlist_node *node;
+ struct sp_next_pos npos;
LIST_HEAD(invalid_list);
bool flush = false;
- for_each_gfn_indirect_valid_sp(vcpu->kvm, s, gfn, node) {
+ for_each_gfn_indirect_valid_sp_safe(vcpu->kvm, s, gfn, node, npos.hn) {
if (!s->unsync)
continue;
@@ -1741,7 +1754,7 @@ static void kvm_sync_pages(struct kvm_vcpu *vcpu, gfn_t gfn)
if ((s->role.cr4_pae != !!is_pae(vcpu)) ||
(vcpu->arch.mmu.sync_page(vcpu, s))) {
kvm_mmu_prepare_zap_page(vcpu->kvm, s,
- &invalid_list, NULL);
+ &invalid_list, &npos);
continue;
}
flush = true;
@@ -2176,17 +2189,18 @@ int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn)
{
struct kvm_mmu_page *sp;
struct hlist_node *node;
+ struct sp_next_pos npos;
LIST_HEAD(invalid_list);
int r;
pgprintk("%s: looking for gfn %llx\n", __func__, gfn);
r = 0;
spin_lock(&kvm->mmu_lock);
- for_each_gfn_indirect_valid_sp(kvm, sp, gfn, node) {
+ for_each_gfn_indirect_valid_sp_safe(kvm, sp, gfn, node, npos.hn) {
pgprintk("%s: gfn %llx role %x\n", __func__, gfn,
sp->role.word);
r = 1;
- kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, NULL);
+ kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, &npos);
}
kvm_mmu_commit_zap_page(kvm, &invalid_list);
spin_unlock(&kvm->mmu_lock);
@@ -3966,6 +3980,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
union kvm_mmu_page_role mask = { .word = 0 };
struct kvm_mmu_page *sp;
struct hlist_node *node;
+ struct sp_next_pos npos;
LIST_HEAD(invalid_list);
u64 entry, gentry, *spte;
int npte;
@@ -3996,11 +4011,11 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
kvm_mmu_audit(vcpu, AUDIT_PRE_PTE_WRITE);
mask.cr0_wp = mask.cr4_pae = mask.nxe = 1;
- for_each_gfn_indirect_valid_sp(vcpu->kvm, sp, gfn, node) {
+ for_each_gfn_indirect_valid_sp_safe(vcpu->kvm, sp, gfn, node, npos.hn) {
if (detect_write_misaligned(sp, gpa, bytes) ||
detect_write_flooding(sp)) {
zap_page |= !!kvm_mmu_prepare_zap_page(vcpu->kvm, sp,
- &invalid_list, NULL);
+ &invalid_list, &npos);
++vcpu->kvm->stat.mmu_flooded;
continue;
}
--
1.7.5.4
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