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AJvYcCWpr/hHZvuQ+5tszgwq989w2J20xPWhRbHMFkDqMPVBeQBxO/Oe3rO2PCx2FOPr5f5orNjm6043itVqrpzf6sLDJqcX X-Gm-Message-State: AOJu0Yx2zstQjtjdIe+m1mtDq7DNoz0KQnnPzp6BRR1o5R+cOwyJvTV1 DRn2pydW2pAfBE50kChbqlGKtxUXsV17ZaCeyhbnLUa8A2oPYF4rtg64+ntC7lDi3Edaz18uUx8 ajA== X-Google-Smtp-Source: AGHT+IGqNZ2BbD8cAo2AnWXa3Pi0tfvxVmoPgtWnywK5+NXQgcmpZ6RBn86fT+8nIYtd+ZPLip7+OZUjHdQ= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a05:6902:188e:b0:df7:8889:4795 with SMTP id 3f1490d57ef6-dfa5a407dc6mr54800276.0.1717019486318; Wed, 29 May 2024 14:51:26 -0700 (PDT) Date: Wed, 29 May 2024 14:51:24 -0700 In-Reply-To: <20240529180510.2295118-4-jthoughton@google.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240529180510.2295118-1-jthoughton@google.com> <20240529180510.2295118-4-jthoughton@google.com> Message-ID: Subject: Re: [PATCH v4 3/7] KVM: Add lockless memslot walk to KVM From: Sean Christopherson To: James Houghton Cc: Andrew Morton , Paolo Bonzini , Albert Ou , Ankit Agrawal , Anup Patel , Atish Patra , Axel Rasmussen , Bibo Mao , Catalin Marinas , David Matlack , David Rientjes , Huacai Chen , James Morse , Jonathan Corbet , Marc Zyngier , Michael Ellerman , Nicholas Piggin , Oliver Upton , Palmer Dabbelt , Paul Walmsley , Raghavendra Rao Ananta , Ryan Roberts , Shaoqin Huang , Shuah Khan , Suzuki K Poulose , Tianrui Zhao , Will Deacon , Yu Zhao , Zenghui Yu , kvm-riscv@lists.infradead.org, kvm@vger.kernel.org, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, loongarch@lists.linux.dev Content-Type: text/plain; charset="us-ascii" On Wed, May 29, 2024, James Houghton wrote: > @@ -686,10 +694,12 @@ static __always_inline int kvm_handle_hva_range(struct mmu_notifier *mn, > return __kvm_handle_hva_range(kvm, &range).ret; > } > > -static __always_inline int kvm_handle_hva_range_no_flush(struct mmu_notifier *mn, > - unsigned long start, > - unsigned long end, > - gfn_handler_t handler) > +static __always_inline int kvm_handle_hva_range_no_flush( > + struct mmu_notifier *mn, > + unsigned long start, > + unsigned long end, > + gfn_handler_t handler, > + bool lockless) Unnecessary and unwanted style change. > { > struct kvm *kvm = mmu_notifier_to_kvm(mn); > const struct kvm_mmu_notifier_range range = { > @@ -699,6 +709,7 @@ static __always_inline int kvm_handle_hva_range_no_flush(struct mmu_notifier *mn > .on_lock = (void *)kvm_null_fn, > .flush_on_ret = false, > .may_block = false, > + .lockless = lockless, Why add @lockess to kvm_handle_hva_range_no_flush()? Both callers immediately pass %false, and conceptually, locking is always optional for a "no flush" variant. > }; > > return __kvm_handle_hva_range(kvm, &range).ret; > @@ -889,7 +900,8 @@ static int kvm_mmu_notifier_clear_young(struct mmu_notifier *mn, > * cadence. If we find this inaccurate, we might come up with a > * more sophisticated heuristic later. > */ > - return kvm_handle_hva_range_no_flush(mn, start, end, kvm_age_gfn); > + return kvm_handle_hva_range_no_flush(mn, start, end, > + kvm_age_gfn, false); > } > > static int kvm_mmu_notifier_test_young(struct mmu_notifier *mn, > @@ -899,7 +911,7 @@ static int kvm_mmu_notifier_test_young(struct mmu_notifier *mn, > trace_kvm_test_age_hva(address); > > return kvm_handle_hva_range_no_flush(mn, address, address + 1, > - kvm_test_age_gfn); > + kvm_test_age_gfn, false); > } > > static void kvm_mmu_notifier_release(struct mmu_notifier *mn, > -- > 2.45.1.288.g0e0cd299f1-goog >