[PATCH 12/21] KVM: x86/mmu: Skip filling the gfn cache for guaranteed direct MMU topups
From: Sean Christopherson <hidden>
Date: 2020-06-05 21:39:37
Also in:
kvm, kvmarm, linux-mips, lkml
Subsystem:
kernel virtual machine for x86 (kvm/x86), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Sean Christopherson, Paolo Bonzini, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
Don't bother filling the gfn array cache when the caller is a fully direct MMU, i.e. won't need a gfn array for shadow pages. Signed-off-by: Sean Christopherson <redacted> --- arch/x86/kvm/mmu/mmu.c | 18 ++++++++++-------- arch/x86/kvm/mmu/paging_tmpl.h | 4 ++-- 2 files changed, 12 insertions(+), 10 deletions(-)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index a8f8eebf67df..8d66cf558f1b 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c@@ -1101,7 +1101,7 @@ static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc) } } -static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu) +static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu, bool maybe_indirect) { int r;
@@ -1114,10 +1114,12 @@ static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu) PT64_ROOT_MAX_LEVEL); if (r) return r; - r = mmu_topup_memory_cache(&vcpu->arch.mmu_gfn_array_cache, - PT64_ROOT_MAX_LEVEL); - if (r) - return r; + if (maybe_indirect) { + r = mmu_topup_memory_cache(&vcpu->arch.mmu_gfn_array_cache, + PT64_ROOT_MAX_LEVEL); + if (r) + return r; + } return mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache, PT64_ROOT_MAX_LEVEL); }
@@ -4107,7 +4109,7 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, if (fast_page_fault(vcpu, gpa, error_code)) return RET_PF_RETRY; - r = mmu_topup_memory_caches(vcpu); + r = mmu_topup_memory_caches(vcpu, false); if (r) return r;
@@ -5147,7 +5149,7 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu) { int r; - r = mmu_topup_memory_caches(vcpu); + r = mmu_topup_memory_caches(vcpu, !vcpu->arch.mmu->direct_map); if (r) goto out; r = mmu_alloc_roots(vcpu);
@@ -5341,7 +5343,7 @@ static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, * or not since pte prefetch is skiped if it does not have * enough objects in the cache. */ - mmu_topup_memory_caches(vcpu); + mmu_topup_memory_caches(vcpu, true); spin_lock(&vcpu->kvm->mmu_lock);
diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index 3de32122f601..ac39710d0594 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h@@ -818,7 +818,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code, return RET_PF_EMULATE; } - r = mmu_topup_memory_caches(vcpu); + r = mmu_topup_memory_caches(vcpu, true); if (r) return r;
@@ -905,7 +905,7 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva, hpa_t root_hpa) * No need to check return value here, rmap_can_add() can * help us to skip pte prefetch later. */ - mmu_topup_memory_caches(vcpu); + mmu_topup_memory_caches(vcpu, true); if (!VALID_PAGE(root_hpa)) { WARN_ON(1);
--
2.26.0
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