KVM: arm64: Use common code's approach for __GFP_ZERO with memory caches (e539451b) · Commits · 戴 / test

Add a "gfp_zero" member to arm64's 'struct kvm_mmu_memory_cache' to make the struct and its usage compatible with the common 'struct kvm_mmu_memory_cache' in linux/kvm_host.h. This will minimize code churn when arm64 moves to the common implementation in a future patch, at the cost of temporarily having somewhat silly code. Note, GFP_PGTABLE_USER is equivalent to GFP_KERNEL_ACCOUNT | GFP_ZERO: #define GFP_PGTABLE_USER (GFP_PGTABLE_KERNEL | __GFP_ACCOUNT) | -> #define GFP_PGTABLE_KERNEL (GFP_KERNEL | __GFP_ZERO) == GFP_KERNEL | __GFP_ACCOUNT | __GFP_ZERO versus #define GFP_KERNEL_ACCOUNT (GFP_KERNEL | __GFP_ACCOUNT) with __GFP_ZERO explicitly OR'd in == GFP_KERNEL | __GFP_ACCOUNT | __GFP_ZERO No functional change intended. Tested-by:

Marc Zyngier <maz@kernel.org> Signed-off-by:

Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200703023545.8771-18-sean.j.christopherson@intel.com> Signed-off-by:

Paolo Bonzini <pbonzini@redhat.com>

arch/arm64/include/asm/kvm_host.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -105,6 +105,7 @@ struct kvm_arch {
		*/
		struct kvm_mmu_memory_cache {
		int nobjs;
		gfp_t gfp_zero;
		void *objects[KVM_NR_MEM_OBJS];
		};

arch/arm64/kvm/arm.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -270,6 +270,8 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
		vcpu->arch.target = -1;
		bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES);

		vcpu->arch.mmu_page_cache.gfp_zero = __GFP_ZERO;

		/* Set up the timer */
		kvm_timer_vcpu_init(vcpu);

arch/arm64/kvm/mmu.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -131,7 +131,8 @@ static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache, int min)
		if (cache->nobjs >= min)
		return 0;
		while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
		page = (void *)__get_free_page(GFP_PGTABLE_USER);
		page = (void *)__get_free_page(GFP_KERNEL_ACCOUNT \|
		cache->gfp_zero);
		if (!page)
		return -ENOMEM;
		cache->objects[cache->nobjs++] = page;
		@@ -1467,7 +1468,7 @@ int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
		phys_addr_t addr, end;
		int ret = 0;
		unsigned long pfn;
		struct kvm_mmu_memory_cache cache = { 0, };
		struct kvm_mmu_memory_cache cache = { 0, __GFP_ZERO, };

		end = (guest_ipa + size + PAGE_SIZE - 1) & PAGE_MASK;
		pfn = __phys_to_pfn(pa);

Admin message