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Tue, 30 Jul 2024 03:41:34 -0700 (PDT) X-Google-Smtp-Source: AGHT+IEDPyYZQ8rptYaeG/QLRVtJLyqTXdGIvl8oYe7Os3i41TwtBzRWbRKhmb66UoorwOaLwZdqjQ== X-Received: by 2002:a50:a411:0:b0:5a1:7d68:62d8 with SMTP id 4fb4d7f45d1cf-5b022c81f43mr6159475a12.38.1722336093853; Tue, 30 Jul 2024 03:41:33 -0700 (PDT) Received: from [192.168.10.47] ([151.95.101.29]) by smtp.googlemail.com with ESMTPSA id 4fb4d7f45d1cf-5ac6377e06fsm7118734a12.28.2024.07.30.03.41.32 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 30 Jul 2024 03:41:33 -0700 (PDT) Message-ID: <63c41e25-2523-4397-96b4-557394281443@redhat.com> Date: Tue, 30 Jul 2024 12:41:31 +0200 Precedence: bulk X-Mailing-List: linux-mips@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v12 34/84] KVM: Add a helper to lookup a pfn without grabbing a reference To: Sean Christopherson , Marc Zyngier , Oliver Upton , Tianrui Zhao , Bibo Mao , Huacai Chen , Michael Ellerman , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Christian Borntraeger , Janosch Frank , Claudio Imbrenda Cc: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, David Matlack , David Stevens References: <20240726235234.228822-1-seanjc@google.com> <20240726235234.228822-35-seanjc@google.com> From: Paolo Bonzini Content-Language: en-US Autocrypt: addr=pbonzini@redhat.com; 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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 7/27/24 01:51, Sean Christopherson wrote: > Add a kvm_follow_pfn() wrapper, kvm_lookup_pfn(), to allow looking up a > gfn=>pfn mapping without the caller getting a reference to any underlying > page. The API will be used in flows that want to know if a gfn points at > a valid pfn, but don't actually need to do anything with the pfn. Can you rename the function kvm_gfn_has_pfn(), or kvm_gfn_can_be_mapped(), and make it return a bool? (As an aside, I wonder if reexecute_instruction() could just use kvm_is_error_hva(kvm_vcpu_gfn_to_hva(vcpu, gpa_to_gfn(gpa)) instead of going all the way to a pfn. But it's ok to be more restrictive). Paolo