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Wed, 14 Aug 2024 10:53:57 -0700 (PDT) X-Google-Smtp-Source: AGHT+IE0gtugkRTcQm7G8pkJF3tmkwxTEKg02g/XJX7ambB07oT/yEXqXmEM1X4Q43rWoTjJipEklw== X-Received: by 2002:adf:e3cf:0:b0:366:e9fa:17b with SMTP id ffacd0b85a97d-37186b85f8dmr478945f8f.1.1723658037010; Wed, 14 Aug 2024 10:53:57 -0700 (PDT) Received: from [192.168.10.47] ([151.95.101.29]) by smtp.googlemail.com with ESMTPSA id ffacd0b85a97d-36e4e51ea09sm13463097f8f.71.2024.08.14.10.53.54 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 14 Aug 2024 10:53:56 -0700 (PDT) Message-ID: Date: Wed, 14 Aug 2024 19:53:53 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 17/22] KVM: x86: Check EMULTYPE_WRITE_PF_TO_SP before unprotecting gfn To: Sean Christopherson Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Peter Gonda , Michael Roth , Vishal Annapurve , Ackerly Tng References: <20240809190319.1710470-1-seanjc@google.com> <20240809190319.1710470-18-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 8/9/24 21:03, Sean Christopherson wrote: > + * Retry even if _this_ vCPU didn't unprotect the gfn, as it's possible > + * all SPTEs were already zapped by a different task. The alternative > + * is to report the error to userspace and likely terminate the guest, > + * and the infinite loop detection logic will prevent retrying the page > + * fault indefinitely, i.e. there's nothing to lose by retrying. Putting myself in the shoes of someone unfamiliar with the code, I might prefer "the last_retry_eip/last_retry_addr checks" to "the infinite loop detection logic"; after all, you're saying in the same sentence that it's preventing an infinite loop. Thanks, Paolo