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| author | Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> | 2015-10-19 15:13:29 +0900 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2015-10-19 11:36:05 +0200 |
| commit | 8c85ac1c0a1b41299370857765bc0950666ed5d9 (patch) | |
| tree | 5b3e8f77536dff0cc45186012bf675ec7dafdcb0 /arch/x86 | |
| parent | 5690891bcec5fcfda38da974ffa5488e36a59811 (diff) | |
| download | talos-op-linux-8c85ac1c0a1b41299370857765bc0950666ed5d9.tar.gz talos-op-linux-8c85ac1c0a1b41299370857765bc0950666ed5d9.zip | |
KVM: x86: MMU: Initialize force_pt_level before calling mapping_level()
Commit fd1369021878 ("KVM: x86: MMU: Move mapping_level_dirty_bitmap()
call in mapping_level()") forgot to initialize force_pt_level to false
in FNAME(page_fault)() before calling mapping_level() like
nonpaging_map() does. This can sometimes result in forcing page table
level mapping unnecessarily.
Fix this and move the first *force_pt_level check in mapping_level()
before kvm_vcpu_gfn_to_memslot() call to make it a bit clearer that
the variable must be initialized before mapping_level() gets called.
This change can also avoid calling kvm_vcpu_gfn_to_memslot() when
!check_hugepage_cache_consistency() check in tdp_page_fault() forces
page table level mapping.
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/mmu.c | 7 | ||||
| -rw-r--r-- | arch/x86/kvm/paging_tmpl.h | 2 |
2 files changed, 5 insertions, 4 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index dd2a7c6ec2ca..7d85bcae3332 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -886,10 +886,11 @@ static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn, int host_level, level, max_level; struct kvm_memory_slot *slot; - slot = kvm_vcpu_gfn_to_memslot(vcpu, large_gfn); + if (unlikely(*force_pt_level)) + return PT_PAGE_TABLE_LEVEL; - if (likely(!*force_pt_level)) - *force_pt_level = !memslot_valid_for_gpte(slot, true); + slot = kvm_vcpu_gfn_to_memslot(vcpu, large_gfn); + *force_pt_level = !memslot_valid_for_gpte(slot, true); if (unlikely(*force_pt_level)) return PT_PAGE_TABLE_LEVEL; diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index bf39d0f3efa9..b41faa91a6f9 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -698,7 +698,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code, int r; pfn_t pfn; int level = PT_PAGE_TABLE_LEVEL; - bool force_pt_level; + bool force_pt_level = false; unsigned long mmu_seq; bool map_writable, is_self_change_mapping; |
