korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-18 09:44:18 +08:00
Code Issues Packages Projects Releases Wiki Activity

KVM: MMU: skip obsolete sp in for_each_gfn_*()

Browse Source 
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>
This commit is contained in:
Xiao Guangrong 2016-03-25 21:19:38 +08:00 committed by Radim Krčmář
parent c54cdf141c
commit 46971a2f59
1 changed files with 12 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
arch/x86/kvm/mmu.c
View File

@ -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;