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| author | Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> | 2014-04-17 17:06:13 +0800 |
|---|---|---|
| committer | Marcelo Tosatti <mtosatti@redhat.com> | 2014-04-23 17:49:49 -0300 |
| commit | 92a476cbfc476c63ee982dd33d15a8c88b4d51b9 (patch) | |
| tree | 799bba57656b27699674a51381d489ffa62dcb2b /arch/x86/kvm/mmu.c | |
| parent | a086f6a1ebc9d8d2d028b99e779ce0dbd9691dea (diff) | |
| download | linux-stable-92a476cbfc476c63ee982dd33d15a8c88b4d51b9.tar.gz linux-stable-92a476cbfc476c63ee982dd33d15a8c88b4d51b9.tar.bz2 linux-stable-92a476cbfc476c63ee982dd33d15a8c88b4d51b9.zip | |
KVM: MMU: properly check last spte in fast_page_fault()
Using sp->role.level instead of @level since @level is not got from the
page table hierarchy
There is no issue in current code since the fast page fault currently only
fixes the fault caused by dirty-log that is always on the last level
(level = 1)
This patch makes the code more readable and avoids potential issue in the
further development
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch/x86/kvm/mmu.c')
| -rw-r--r-- | arch/x86/kvm/mmu.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 668ae5916de9..63107049249d 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2802,9 +2802,9 @@ static bool page_fault_can_be_fast(u32 error_code) } static bool -fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 spte) +fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, + u64 *sptep, u64 spte) { - struct kvm_mmu_page *sp = page_header(__pa(sptep)); gfn_t gfn; WARN_ON(!sp->role.direct); @@ -2830,6 +2830,7 @@ static bool fast_page_fault(struct kvm_vcpu *vcpu, gva_t gva, int level, u32 error_code) { struct kvm_shadow_walk_iterator iterator; + struct kvm_mmu_page *sp; bool ret = false; u64 spte = 0ull; @@ -2853,7 +2854,8 @@ static bool fast_page_fault(struct kvm_vcpu *vcpu, gva_t gva, int level, goto exit; } - if (!is_last_spte(spte, level)) + sp = page_header(__pa(iterator.sptep)); + if (!is_last_spte(spte, sp->role.level)) goto exit; /* @@ -2879,7 +2881,7 @@ static bool fast_page_fault(struct kvm_vcpu *vcpu, gva_t gva, int level, * the gfn is not stable for indirect shadow page. * See Documentation/virtual/kvm/locking.txt to get more detail. */ - ret = fast_pf_fix_direct_spte(vcpu, iterator.sptep, spte); + ret = fast_pf_fix_direct_spte(vcpu, sp, iterator.sptep, spte); exit: trace_fast_page_fault(vcpu, gva, error_code, iterator.sptep, spte, ret); |