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authorXiao Guangrong <guangrong.xiao@linux.intel.com>2016-03-25 14:19:38 +0100
committerRadim Krčmář <rkrcmar@redhat.com>2016-04-20 15:29:17 +0200
commit46971a2f59f135341f8912f516540fef6890d4df (patch)
treea2489ff7acf6068bfcb1df35c16873b6abe8d840 /arch/x86
parentKVM: x86: optimize steal time calculation (diff)
downloadlinux-46971a2f59f135341f8912f516540fef6890d4df.tar.xz
linux-46971a2f59f135341f8912f516540fef6890d4df.zip
KVM: MMU: skip obsolete sp in for_each_gfn_*()
The obsolete sp should not be used on current vCPUs and should not hurt vCPU's running, so skip it from for_each_gfn_sp() and for_each_gfn_indirect_valid_sp() The side effort is we will double check role.invalid in kvm_mmu_get_page() but i think it is okay as role is well cached Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kvm/mmu.c28
1 files changed, 12 insertions, 16 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 1ff4dbb73fb7..850335a71d9f 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1909,18 +1909,17 @@ static void kvm_mmu_commit_zap_page(struct kvm *kvm,
* since it has been deleted from active_mmu_pages but still can be found
* at hast list.
*
- * for_each_gfn_indirect_valid_sp has skipped that kind of page and
- * kvm_mmu_get_page(), the only user of for_each_gfn_sp(), has skipped
- * all the obsolete pages.
+ * for_each_gfn_valid_sp() has skipped that kind of pages.
*/
-#define for_each_gfn_sp(_kvm, _sp, _gfn) \
+#define for_each_gfn_valid_sp(_kvm, _sp, _gfn) \
hlist_for_each_entry(_sp, \
&(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)], hash_link) \
- if ((_sp)->gfn != (_gfn)) {} else
+ if ((_sp)->gfn != (_gfn) || is_obsolete_sp((_kvm), (_sp)) \
+ || (_sp)->role.invalid) {} else
#define for_each_gfn_indirect_valid_sp(_kvm, _sp, _gfn) \
- for_each_gfn_sp(_kvm, _sp, _gfn) \
- if ((_sp)->role.direct || (_sp)->role.invalid) {} else
+ for_each_gfn_valid_sp(_kvm, _sp, _gfn) \
+ if ((_sp)->role.direct) {} else
/* @sp->gfn should be write-protected at the call site */
static bool __kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
@@ -1961,6 +1960,11 @@ static void kvm_mmu_audit(struct kvm_vcpu *vcpu, int point) { }
static void mmu_audit_disable(void) { }
#endif
+static bool is_obsolete_sp(struct kvm *kvm, struct kvm_mmu_page *sp)
+{
+ return unlikely(sp->mmu_valid_gen != kvm->arch.mmu_valid_gen);
+}
+
static bool kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
struct list_head *invalid_list)
{
@@ -2105,11 +2109,6 @@ static void clear_sp_write_flooding_count(u64 *spte)
__clear_sp_write_flooding_count(sp);
}
-static bool is_obsolete_sp(struct kvm *kvm, struct kvm_mmu_page *sp)
-{
- return unlikely(sp->mmu_valid_gen != kvm->arch.mmu_valid_gen);
-}
-
static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
gfn_t gfn,
gva_t gaddr,
@@ -2136,10 +2135,7 @@ 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) {
- if (is_obsolete_sp(vcpu->kvm, sp))
- continue;
-
+ for_each_gfn_valid_sp(vcpu->kvm, sp, gfn) {
if (!need_sync && sp->unsync)
need_sync = true;