From: Sean Christopherson <sean.j.christopherson@intel.com> To: Marc Zyngier <maz@kernel.org>, Paolo Bonzini <pbonzini@redhat.com>, Arnd Bergmann <arnd@arndb.de> Cc: linux-arch@vger.kernel.org, Junaid Shahid <junaids@google.com>, Wanpeng Li <wanpengli@tencent.com>, kvm@vger.kernel.org, Joerg Roedel <joro@8bytes.org>, Peter Shier <pshier@google.com>, linux-mips@vger.kernel.org, Sean Christopherson <sean.j.christopherson@intel.com>, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Ben Gardon <bgardon@google.com>, Vitaly Kuznetsov <vkuznets@redhat.com>, Peter Feiner <pfeiner@google.com>, kvmarm@lists.cs.columbia.edu, Jim Mattson <jmattson@google.com> Subject: [PATCH v3 07/21] KVM: x86/mmu: Topup memory caches after walking GVA->GPA Date: Thu, 2 Jul 2020 19:35:31 -0700 [thread overview] Message-ID: <20200703023545.8771-8-sean.j.christopherson@intel.com> (raw) In-Reply-To: <20200703023545.8771-1-sean.j.christopherson@intel.com> 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 <bgardon@google.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> --- 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 58234bfaca07..451d7aa7d959 100644 --- a/arch/x86/kvm/mmu/paging_tmpl.h +++ b/arch/x86/kvm/mmu/paging_tmpl.h @@ -788,10 +788,6 @@ 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. @@ -819,6 +815,10 @@ 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, -- 2.26.0
WARNING: multiple messages have this Message-ID (diff)
From: Sean Christopherson <sean.j.christopherson@intel.com> To: Marc Zyngier <maz@kernel.org>, Paolo Bonzini <pbonzini@redhat.com>, Arnd Bergmann <arnd@arndb.de> Cc: James Morse <james.morse@arm.com>, Julien Thierry <julien.thierry.kdev@gmail.com>, Suzuki K Poulose <suzuki.poulose@arm.com>, Sean Christopherson <sean.j.christopherson@intel.com>, Vitaly Kuznetsov <vkuznets@redhat.com>, Wanpeng Li <wanpengli@tencent.com>, Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-mips@vger.kernel.org, kvm@vger.kernel.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Ben Gardon <bgardon@google.com>, Peter Feiner <pfeiner@google.com>, Peter Shier <pshier@google.com>, Junaid Shahid <junaids@google.com>, Christoffer Dall <christoffer.dall@arm.com> Subject: [PATCH v3 07/21] KVM: x86/mmu: Topup memory caches after walking GVA->GPA Date: Thu, 2 Jul 2020 19:35:31 -0700 [thread overview] Message-ID: <20200703023545.8771-8-sean.j.christopherson@intel.com> (raw) Message-ID: <20200703023531.z44j2tpKhOxOoK0RTTVRiSJJkL9EmSJShZmTyNqK4Cc@z> (raw) In-Reply-To: <20200703023545.8771-1-sean.j.christopherson@intel.com> 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 <bgardon@google.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> --- 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 58234bfaca07..451d7aa7d959 100644 --- a/arch/x86/kvm/mmu/paging_tmpl.h +++ b/arch/x86/kvm/mmu/paging_tmpl.h @@ -788,10 +788,6 @@ 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. @@ -819,6 +815,10 @@ 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, -- 2.26.0
next prev parent reply other threads:[~2020-07-03 2:35 UTC|newest] Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-07-03 2:35 [PATCH v3 00/21] KVM: Cleanup and unify kvm_mmu_memory_cache usage Sean Christopherson 2020-07-03 2:35 ` [PATCH v3 01/21] KVM: x86/mmu: Track the associated kmem_cache in the MMU caches Sean Christopherson 2020-07-03 2:35 ` Sean Christopherson 2020-07-03 2:35 ` [PATCH v3 02/21] KVM: x86/mmu: Consolidate "page" variant of memory cache helpers Sean Christopherson 2020-07-03 2:35 ` Sean Christopherson 2020-07-03 2:35 ` [PATCH v3 03/21] KVM: x86/mmu: Use consistent "mc" name for kvm_mmu_memory_cache locals Sean Christopherson 2020-07-03 2:35 ` Sean Christopherson 2020-07-03 2:35 ` [PATCH v3 04/21] KVM: x86/mmu: Remove superfluous gotos from mmu_topup_memory_caches() Sean Christopherson 2020-07-03 2:35 ` Sean Christopherson 2020-07-03 2:35 ` [PATCH v3 05/21] KVM: x86/mmu: Try to avoid crashing KVM if a MMU memory cache is empty Sean Christopherson 2020-07-03 2:35 ` Sean Christopherson 2020-07-03 2:35 ` [PATCH v3 06/21] KVM: x86/mmu: Move fast_page_fault() call above mmu_topup_memory_caches() Sean Christopherson 2020-07-03 2:35 ` Sean Christopherson 2020-07-03 2:35 ` Sean Christopherson [this message] 2020-07-03 2:35 ` [PATCH v3 07/21] KVM: x86/mmu: Topup memory caches after walking GVA->GPA Sean Christopherson 2020-07-03 2:35 ` [PATCH v3 08/21] KVM: x86/mmu: Clean up the gorilla math in mmu_topup_memory_caches() Sean Christopherson 2020-07-03 2:35 ` Sean Christopherson 2020-07-03 2:35 ` [PATCH v3 09/21] KVM: x86/mmu: Separate the memory caches for shadow pages and gfn arrays Sean Christopherson 2020-07-03 2:35 ` Sean Christopherson 2020-07-03 2:35 ` [PATCH v3 10/21] KVM: x86/mmu: Make __GFP_ZERO a property of the memory cache Sean Christopherson 2020-07-03 2:35 ` Sean Christopherson 2020-07-03 2:35 ` [PATCH v3 11/21] KVM: x86/mmu: Zero allocate shadow pages (outside of mmu_lock) Sean Christopherson 2020-07-03 2:35 ` Sean Christopherson 2020-07-03 2:35 ` [PATCH v3 12/21] KVM: x86/mmu: Skip filling the gfn cache for guaranteed direct MMU topups Sean Christopherson 2020-07-03 2:35 ` Sean Christopherson 2020-07-03 2:35 ` [PATCH v3 13/21] KVM: x86/mmu: Prepend "kvm_" to memory cache helpers that will be global Sean Christopherson 2020-07-03 2:35 ` [PATCH v3 14/21] KVM: Move x86's version of struct kvm_mmu_memory_cache to common code Sean Christopherson 2020-07-03 2:35 ` Sean Christopherson 2020-07-03 2:35 ` [PATCH v3 15/21] KVM: Move x86's MMU memory cache helpers to common KVM code Sean Christopherson 2020-07-03 2:35 ` Sean Christopherson 2020-07-03 2:35 ` [PATCH v3 16/21] KVM: arm64: Drop @max param from mmu_topup_memory_cache() Sean Christopherson 2020-07-03 2:35 ` Sean Christopherson 2020-07-03 2:35 ` [PATCH v3 17/21] KVM: arm64: Use common code's approach for __GFP_ZERO with memory caches Sean Christopherson 2020-07-03 2:35 ` Sean Christopherson 2020-07-03 2:35 ` [PATCH v3 18/21] KVM: arm64: Use common KVM implementation of MMU " Sean Christopherson 2020-07-03 2:35 ` Sean Christopherson 2020-07-03 2:35 ` [PATCH v3 19/21] KVM: MIPS: Drop @max param from mmu_topup_memory_cache() Sean Christopherson 2020-07-03 2:35 ` Sean Christopherson 2020-07-03 2:35 ` [PATCH v3 20/21] KVM: MIPS: Account pages used for GPA page tables Sean Christopherson 2020-07-03 2:35 ` Sean Christopherson 2020-07-03 2:35 ` [PATCH v3 21/21] KVM: MIPS: Use common KVM implementation of MMU memory caches Sean Christopherson 2020-07-03 2:35 ` Sean Christopherson 2020-07-09 12:14 ` [PATCH v3 00/21] KVM: Cleanup and unify kvm_mmu_memory_cache usage Paolo Bonzini
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