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| author | Sean Christopherson <sean.j.christopherson@intel.com> | 2020-07-02 19:35:35 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-07-09 13:29:40 -0400 |
| commit | 9688088378d41d7918ee50fc89b6f884212aaa22 (patch) | |
| tree | 98040f36c440a243dbf9a50a690aba6358c87ec5 /arch | |
| parent | 5f6078f9f1e32b395a78c8d0c0f6598004c668de (diff) | |
| download | linux-stable-9688088378d41d7918ee50fc89b6f884212aaa22.tar.gz linux-stable-9688088378d41d7918ee50fc89b6f884212aaa22.tar.bz2 linux-stable-9688088378d41d7918ee50fc89b6f884212aaa22.zip | |
KVM: x86/mmu: Zero allocate shadow pages (outside of mmu_lock)
Set __GFP_ZERO for the shadow page memory cache and drop the explicit
clear_page() from kvm_mmu_get_page(). This moves the cost of zeroing a
page to the allocation time of the physical page, i.e. when topping up
the memory caches, and thus avoids having to zero out an entire page
while holding mmu_lock.
Cc: Peter Feiner <pfeiner@google.com>
Cc: Peter Shier <pshier@google.com>
Cc: Junaid Shahid <junaids@google.com>
Cc: Jim Mattson <jmattson@google.com>
Suggested-by: Ben Gardon <bgardon@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200703023545.8771-12-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/mmu/mmu.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 6e57044ae848..a9fb427107b2 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -2535,7 +2535,6 @@ trace_get_page: if (level > PG_LEVEL_4K && need_sync) flush |= kvm_sync_pages(vcpu, gfn, &invalid_list); } - clear_page(sp->spt); trace_kvm_mmu_get_page(sp, true); kvm_mmu_flush_or_zap(vcpu, &invalid_list, false, flush); @@ -5708,6 +5707,8 @@ int kvm_mmu_create(struct kvm_vcpu *vcpu) vcpu->arch.mmu_page_header_cache.kmem_cache = mmu_page_header_cache; vcpu->arch.mmu_page_header_cache.gfp_zero = __GFP_ZERO; + vcpu->arch.mmu_shadow_page_cache.gfp_zero = __GFP_ZERO; + vcpu->arch.mmu = &vcpu->arch.root_mmu; vcpu->arch.walk_mmu = &vcpu->arch.root_mmu; |