From 85f479308333c538ddb39ac8e0b009a03a1af066 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Tue, 6 Apr 2021 12:07:40 -0700 Subject: KVM: Explicitly use GFP_KERNEL_ACCOUNT for 'struct kvm_vcpu' allocations Use GFP_KERNEL_ACCOUNT when allocating vCPUs to make it more obvious that that the allocations are accounted, to make it easier to audit KVM's allocations in the future, and to be consistent with other cache usage in KVM. When using SLAB/SLUB, this is a nop as the cache itself is created with SLAB_ACCOUNT. When using SLOB, there are caveats within caveats. SLOB doesn't honor SLAB_ACCOUNT, so passing GFP_KERNEL_ACCOUNT will result in vCPU allocations now being accounted. But, even that depends on internal SLOB details as SLOB will only go to the page allocator when its cache is depleted. That just happens to be extremely likely for vCPUs because the size of kvm_vcpu is larger than the a page for almost all combinations of architecture and page size. Whether or not the SLOB behavior is by design is unknown; it's just as likely that no SLOB users care about accounding and so no one has bothered to implemented support in SLOB. Regardless, accounting vCPU allocations will not break SLOB+KVM+cgroup users, if any exist. Reviewed-by: Wanpeng Li Acked-by: David Rientjes Signed-off-by: Sean Christopherson Message-Id: <20210406190740.4055679-1-seanjc@google.com> Signed-off-by: Paolo Bonzini --- virt/kvm/kvm_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'virt/kvm') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index d1de843b7618..b299c0366320 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -3192,7 +3192,7 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id) if (r) goto vcpu_decrement; - vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL); + vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL_ACCOUNT); if (!vcpu) { r = -ENOMEM; goto vcpu_decrement; -- cgit v1.2.3