From f3747a5a9e5a26934da8c956ceef42639cbc623c Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 2 Jul 2020 19:35:31 -0700 Subject: [PATCH] KVM: x86/mmu: Topup memory caches after walking GVA->GPA Topup memory caches after walking the GVA->GPA translation during a shadow page fault, there is no need to ensure the caches are full when walking the GVA. As of commit f5a1e9f89504f ("KVM: MMU: remove call to kvm_mmu_pte_write from walk_addr"), the FNAME(walk_addr) flow no longer add rmaps via kvm_mmu_pte_write(). This avoids allocating memory in the case that the GVA is unmapped in the guest, and also provides a paper trail of why/when the memory caches need to be filled. Reviewed-by: Ben Gardon Signed-off-by: Sean Christopherson Message-Id: <20200703023545.8771-8-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu/paging_tmpl.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h index 0981b84c95e4..e3e9f9227372 100644 --- a/arch/x86/kvm/mmu/paging_tmpl.h +++ b/arch/x86/kvm/mmu/paging_tmpl.h @@ -789,10 +789,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code, pgprintk("%s: addr %lx err %x\n", __func__, addr, error_code); - r = mmu_topup_memory_caches(vcpu); - if (r) - return r; - /* * If PFEC.RSVD is set, this is a shadow page fault. * The bit needs to be cleared before walking guest page tables. @@ -820,6 +816,10 @@ 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); + if (r) + return r; + vcpu->arch.write_fault_to_shadow_pgtable = false; is_self_change_mapping = FNAME(is_self_change_mapping)(vcpu,