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[35.185.214.157]) by smtp.gmail.com with ESMTPSA id x71-20020a63864a000000b003c15f7f2914sm8650496pgd.24.2022.05.09.09.36.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 May 2022 09:36:47 -0700 (PDT) Date: Mon, 9 May 2022 16:36:43 +0000 From: Sean Christopherson To: David Matlack Subject: Re: [PATCH v4 18/20] KVM: x86/mmu: Refactor drop_large_spte() Message-ID: References: <20220422210546.458943-1-dmatlack@google.com> <20220422210546.458943-19-dmatlack@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220422210546.458943-19-dmatlack@google.com> Cc: Marc Zyngier , Albert Ou , "open list:KERNEL VIRTUAL MACHINE FOR MIPS \(KVM/mips\)" , Huacai Chen , "open list:KERNEL VIRTUAL MACHINE FOR MIPS \(KVM/mips\)" , Aleksandar Markovic , Palmer Dabbelt , "open list:KERNEL VIRTUAL MACHINE FOR RISC-V \(KVM/riscv\)" , Paul Walmsley , Ben Gardon , Paolo Bonzini , maciej.szmigiero@oracle.com, "moderated list:KERNEL VIRTUAL MACHINE FOR ARM64 \(KVM/arm64\)" , Peter Feiner X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On Fri, Apr 22, 2022, David Matlack wrote: > drop_large_spte() drops a large SPTE if it exists and then flushes TLBs. > Its helper function, __drop_large_spte(), does the drop without the > flush. > > In preparation for eager page splitting, which will need to sometimes > flush when dropping large SPTEs (and sometimes not), push the flushing > logic down into __drop_large_spte() and add a bool parameter to control > it. > > No functional change intended. > > Reviewed-by: Peter Xu > Signed-off-by: David Matlack > --- > arch/x86/kvm/mmu/mmu.c | 29 +++++++++++++++-------------- > 1 file changed, 15 insertions(+), 14 deletions(-) > > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > index 479c581e8a96..a5961c17eb36 100644 > --- a/arch/x86/kvm/mmu/mmu.c > +++ b/arch/x86/kvm/mmu/mmu.c > @@ -1183,28 +1183,29 @@ static void drop_spte(struct kvm *kvm, u64 *sptep) > rmap_remove(kvm, sptep); > } > > - > -static bool __drop_large_spte(struct kvm *kvm, u64 *sptep) > +static void __drop_large_spte(struct kvm *kvm, u64 *sptep, bool flush) > { > - if (is_large_pte(*sptep)) { > - WARN_ON(sptep_to_sp(sptep)->role.level == PG_LEVEL_4K); > - drop_spte(kvm, sptep); > - return true; > - } > + struct kvm_mmu_page *sp; > > - return false; > -} > + if (!is_large_pte(*sptep)) > + return; > > -static void drop_large_spte(struct kvm_vcpu *vcpu, u64 *sptep) > -{ > - if (__drop_large_spte(vcpu->kvm, sptep)) { > - struct kvm_mmu_page *sp = sptep_to_sp(sptep); > + sp = sptep_to_sp(sptep); > + WARN_ON(sp->role.level == PG_LEVEL_4K); > > - kvm_flush_remote_tlbs_with_address(vcpu->kvm, sp->gfn, > + drop_spte(kvm, sptep); > + > + if (flush) { Unnecessary curly braces. > + kvm_flush_remote_tlbs_with_address(kvm, sp->gfn, > KVM_PAGES_PER_HPAGE(sp->role.level)); > } > } > > +static void drop_large_spte(struct kvm_vcpu *vcpu, u64 *sptep) > +{ > + return __drop_large_spte(vcpu->kvm, sptep, true); > +} > + > /* > * Write-protect on the specified @sptep, @pt_protect indicates whether > * spte write-protection is caused by protecting shadow page table. > -- > 2.36.0.rc2.479.g8af0fa9b8e-goog > _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8AABEC433F5 for ; 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[35.185.214.157]) by smtp.gmail.com with ESMTPSA id x71-20020a63864a000000b003c15f7f2914sm8650496pgd.24.2022.05.09.09.36.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 May 2022 09:36:47 -0700 (PDT) Date: Mon, 9 May 2022 16:36:43 +0000 From: Sean Christopherson To: David Matlack Cc: Paolo Bonzini , Marc Zyngier , Huacai Chen , Aleksandar Markovic , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Andrew Jones , Ben Gardon , Peter Xu , maciej.szmigiero@oracle.com, "moderated list:KERNEL VIRTUAL MACHINE FOR ARM64 (KVM/arm64)" , "open list:KERNEL VIRTUAL MACHINE FOR MIPS (KVM/mips)" , "open list:KERNEL VIRTUAL MACHINE FOR MIPS (KVM/mips)" , "open list:KERNEL VIRTUAL MACHINE FOR RISC-V (KVM/riscv)" , Peter Feiner Subject: Re: [PATCH v4 18/20] KVM: x86/mmu: Refactor drop_large_spte() Message-ID: References: <20220422210546.458943-1-dmatlack@google.com> <20220422210546.458943-19-dmatlack@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220422210546.458943-19-dmatlack@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On Fri, Apr 22, 2022, David Matlack wrote: > drop_large_spte() drops a large SPTE if it exists and then flushes TLBs. > Its helper function, __drop_large_spte(), does the drop without the > flush. > > In preparation for eager page splitting, which will need to sometimes > flush when dropping large SPTEs (and sometimes not), push the flushing > logic down into __drop_large_spte() and add a bool parameter to control > it. > > No functional change intended. > > Reviewed-by: Peter Xu > Signed-off-by: David Matlack > --- > arch/x86/kvm/mmu/mmu.c | 29 +++++++++++++++-------------- > 1 file changed, 15 insertions(+), 14 deletions(-) > > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > index 479c581e8a96..a5961c17eb36 100644 > --- a/arch/x86/kvm/mmu/mmu.c > +++ b/arch/x86/kvm/mmu/mmu.c > @@ -1183,28 +1183,29 @@ static void drop_spte(struct kvm *kvm, u64 *sptep) > rmap_remove(kvm, sptep); > } > > - > -static bool __drop_large_spte(struct kvm *kvm, u64 *sptep) > +static void __drop_large_spte(struct kvm *kvm, u64 *sptep, bool flush) > { > - if (is_large_pte(*sptep)) { > - WARN_ON(sptep_to_sp(sptep)->role.level == PG_LEVEL_4K); > - drop_spte(kvm, sptep); > - return true; > - } > + struct kvm_mmu_page *sp; > > - return false; > -} > + if (!is_large_pte(*sptep)) > + return; > > -static void drop_large_spte(struct kvm_vcpu *vcpu, u64 *sptep) > -{ > - if (__drop_large_spte(vcpu->kvm, sptep)) { > - struct kvm_mmu_page *sp = sptep_to_sp(sptep); > + sp = sptep_to_sp(sptep); > + WARN_ON(sp->role.level == PG_LEVEL_4K); > > - kvm_flush_remote_tlbs_with_address(vcpu->kvm, sp->gfn, > + drop_spte(kvm, sptep); > + > + if (flush) { Unnecessary curly braces. > + kvm_flush_remote_tlbs_with_address(kvm, sp->gfn, > KVM_PAGES_PER_HPAGE(sp->role.level)); > } > } > > +static void drop_large_spte(struct kvm_vcpu *vcpu, u64 *sptep) > +{ > + return __drop_large_spte(vcpu->kvm, sptep, true); > +} > + > /* > * Write-protect on the specified @sptep, @pt_protect indicates whether > * spte write-protection is caused by protecting shadow page table. > -- > 2.36.0.rc2.479.g8af0fa9b8e-goog >