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authorSean Christopherson <[email protected]>2020-07-02 19:35:35 -0700
committerPaolo Bonzini <[email protected]>2020-07-09 13:29:40 -0400
commit9688088378d41d7918ee50fc89b6f884212aaa22 (patch)
tree98040f36c440a243dbf9a50a690aba6358c87ec5
parent5f6078f9f1e32b395a78c8d0c0f6598004c668de (diff)
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 <[email protected]> Cc: Peter Shier <[email protected]> Cc: Junaid Shahid <[email protected]> Cc: Jim Mattson <[email protected]> Suggested-by: Ben Gardon <[email protected]> Reviewed-by: Ben Gardon <[email protected]> Signed-off-by: Sean Christopherson <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
-rw-r--r--arch/x86/kvm/mmu/mmu.c3
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;