From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AAC5C199A8 for ; Mon, 30 Oct 2023 17:18:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="GEQsgL13" Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8E7E59C for ; Mon, 30 Oct 2023 10:18:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1698686337; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=Rk1z/nbke87TeFl+NzbMTW3BKeJ5hl7Q8glGeyBEAiE=; b=GEQsgL136iQdKEXxkTuxVFiEgMy8tMvuU/acg/4r1MxzdO7FcRtg2T/+nqd4xq8HUW76xh /RPAundhpcXMpVeXIjPIU3QcgdQB1IB6wRHHOsznWzGOAFs2qeh5omLqYNgq4dLHxhnpSY WSRJ2AwI/Nt4senKpHEugGV43VZvki4= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-472-h1NWMWnWOJOH1eSWLIsVng-1; Mon, 30 Oct 2023 13:18:56 -0400 X-MC-Unique: h1NWMWnWOJOH1eSWLIsVng-1 Received: by mail-wm1-f72.google.com with SMTP id 5b1f17b1804b1-408508aa81cso35228925e9.3 for ; Mon, 30 Oct 2023 10:18:55 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1698686315; x=1699291115; h=content-transfer-encoding:in-reply-to:autocrypt:from:references:cc :to:content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Rk1z/nbke87TeFl+NzbMTW3BKeJ5hl7Q8glGeyBEAiE=; b=v0a9F/0WmFHR0uvHanVcDbKlElHmalKmkGckW55OkgFsU2/eDXGKzuOkcL9Hrvwgg0 1nMbSjVC+6vMdYwrazdjiO4UW2Lb5BIebRea2DJdXdnYEJUGheoDnASjydWfSGvAaByI ZoGmpJbP/FNXNABwLPQPNC006mX+TnG7nTiqvebptFkNgcDrnGyUWO6LsAwaexv/dcTx 4Pt4wswikfolsUD3lJbtq7XAstzGKdqIgV2YJeFx12C/r6bM9L4RK1pmlJGsLUtQZ35I 7g7O83whEIXF5UubXuJ/R/lbk1A55XsQk68FdCiH80zIj2l/FS1IvlEdpJtnorKYW1k7 pv8A== X-Gm-Message-State: AOJu0YwHqhEbPfn1B5FM3OB084G+4KkdB3p5Us5b8bTAYB9R5kx2Rqm4 XDruFarZygw8Nj0YBSAWNQSABwx5xzHBSaZ3whypDJMeDekjDxKgd3CuWEU2Qc6HNjzsJvbnMmc 0+F1xDh6t04VJafwMKC9ZUkACMg== X-Received: by 2002:a05:600c:3512:b0:408:3e7a:82ea with SMTP id h18-20020a05600c351200b004083e7a82eamr9347575wmq.1.1698686315461; Mon, 30 Oct 2023 10:18:35 -0700 (PDT) X-Google-Smtp-Source: AGHT+IE2IYd31Kg1xsjAW7zrsQp03VV1LrLjkoWwzBfM1QTMJAHwovsXW/3FoijWAFrYv3Vz5FidRg== X-Received: by 2002:a05:600c:3512:b0:408:3e7a:82ea with SMTP id h18-20020a05600c351200b004083e7a82eamr9347545wmq.1.1698686315114; Mon, 30 Oct 2023 10:18:35 -0700 (PDT) Received: from [192.168.1.174] ([151.81.68.207]) by smtp.googlemail.com with ESMTPSA id l16-20020adffe90000000b003198a9d758dsm4171497wrr.78.2023.10.30.10.18.29 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 30 Oct 2023 10:18:34 -0700 (PDT) Message-ID: <22789e20-1a4a-48af-99ad-3e88c18dd231@redhat.com> Date: Mon, 30 Oct 2023 18:18:26 +0100 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v13 11/35] KVM: Drop .on_unlock() mmu_notifier hook Content-Language: en-US To: Sean Christopherson , Marc Zyngier , Oliver Upton , Huacai Chen , Michael Ellerman , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexander Viro , Christian Brauner , "Matthew Wilcox (Oracle)" , Andrew Morton Cc: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Xiaoyao Li , Xu Yilun , Chao Peng , Fuad Tabba , Jarkko Sakkinen , Anish Moorthy , David Matlack , Yu Zhang , Isaku Yamahata , =?UTF-8?B?TWlja2HDq2wgU2FsYcO8?= =?UTF-8?Q?n?= , Vlastimil Babka , Vishal Annapurve , Ackerley Tng , Maciej Szmigiero , David Hildenbrand , Quentin Perret , Michael Roth , Wang , Liam Merwick , Isaku Yamahata , "Kirill A . Shutemov" References: <20231027182217.3615211-1-seanjc@google.com> <20231027182217.3615211-12-seanjc@google.com> From: Paolo Bonzini Autocrypt: addr=pbonzini@redhat.com; keydata= xsEhBFRCcBIBDqDGsz4K0zZun3jh+U6Z9wNGLKQ0kSFyjN38gMqU1SfP+TUNQepFHb/Gc0E2 CxXPkIBTvYY+ZPkoTh5xF9oS1jqI8iRLzouzF8yXs3QjQIZ2SfuCxSVwlV65jotcjD2FTN04 hVopm9llFijNZpVIOGUTqzM4U55sdsCcZUluWM6x4HSOdw5F5Utxfp1wOjD/v92Lrax0hjiX DResHSt48q+8FrZzY+AUbkUS+Jm34qjswdrgsC5uxeVcLkBgWLmov2kMaMROT0YmFY6A3m1S P/kXmHDXxhe23gKb3dgwxUTpENDBGcfEzrzilWueOeUWiOcWuFOed/C3SyijBx3Av/lbCsHU Vx6pMycNTdzU1BuAroB+Y3mNEuW56Yd44jlInzG2UOwt9XjjdKkJZ1g0P9dwptwLEgTEd3Fo UdhAQyRXGYO8oROiuh+RZ1lXp6AQ4ZjoyH8WLfTLf5g1EKCTc4C1sy1vQSdzIRu3rBIjAvnC tGZADei1IExLqB3uzXKzZ1BZ+Z8hnt2og9hb7H0y8diYfEk2w3R7wEr+Ehk5NQsT2MPI2QBd wEv1/Aj1DgUHZAHzG1QN9S8wNWQ6K9DqHZTBnI1hUlkp22zCSHK/6FwUCuYp1zcAEQEAAc0j UGFvbG8gQm9uemluaSA8cGJvbnppbmlAcmVkaGF0LmNvbT7CwU0EEwECACMFAlRCcBICGwMH CwkIBwMCAQYVCAIJCgsEFgIDAQIeAQIXgAAKCRB+FRAMzTZpsbceDp9IIN6BIA0Ol7MoB15E 11kRz/ewzryFY54tQlMnd4xxfH8MTQ/mm9I482YoSwPMdcWFAKnUX6Yo30tbLiNB8hzaHeRj jx12K+ptqYbg+cevgOtbLAlL9kNgLLcsGqC2829jBCUTVeMSZDrzS97ole/YEez2qFpPnTV0 VrRWClWVfYh+JfzpXmgyhbkuwUxNFk421s4Ajp3d8nPPFUGgBG5HOxzkAm7xb1cjAuJ+oi/K CHfkuN+fLZl/u3E/fw7vvOESApLU5o0icVXeakfSz0LsygEnekDbxPnE5af/9FEkXJD5EoYG SEahaEtgNrR4qsyxyAGYgZlS70vkSSYJ+iT2rrwEiDlo31MzRo6Ba2FfHBSJ7lcYdPT7bbk9 AO3hlNMhNdUhoQv7M5HsnqZ6unvSHOKmReNaS9egAGdRN0/GPDWr9wroyJ65ZNQsHl9nXBqE AukZNr5oJO5vxrYiAuuTSd6UI/xFkjtkzltG3mw5ao2bBpk/V/YuePrJsnPFHG7NhizrxttB nTuOSCMo45pfHQ+XYd5K1+Cv/NzZFNWscm5htJ0HznY+oOsZvHTyGz3v91pn51dkRYN0otqr bQ4tlFFuVjArBZcapSIe6NV8C4cEiSTOwE0EVEJx7gEIAMeHcVzuv2bp9HlWDp6+RkZe+vtl KwAHplb/WH59j2wyG8V6i33+6MlSSJMOFnYUCCL77bucx9uImI5nX24PIlqT+zasVEEVGSRF m8dgkcJDB7Tps0IkNrUi4yof3B3shR+vMY3i3Ip0e41zKx0CvlAhMOo6otaHmcxr35sWq1Jk tLkbn3wG+fPQCVudJJECvVQ//UAthSSEklA50QtD2sBkmQ14ZryEyTHQ+E42K3j2IUmOLriF dNr9NvE1QGmGyIcbw2NIVEBOK/GWxkS5+dmxM2iD4Jdaf2nSn3jlHjEXoPwpMs0KZsgdU0pP JQzMUMwmB1wM8JxovFlPYrhNT9MAEQEAAcLBMwQYAQIACQUCVEJx7gIbDAAKCRB+FRAMzTZp sadRDqCctLmYICZu4GSnie4lKXl+HqlLanpVMOoFNnWs9oRP47MbE2wv8OaYh5pNR9VVgyhD OG0AU7oidG36OeUlrFDTfnPYYSF/mPCxHttosyt8O5kabxnIPv2URuAxDByz+iVbL+RjKaGM GDph56ZTswlx75nZVtIukqzLAQ5fa8OALSGum0cFi4ptZUOhDNz1onz61klD6z3MODi0sBZN Aj6guB2L/+2ZwElZEeRBERRd/uommlYuToAXfNRdUwrwl9gRMiA0WSyTb190zneRRDfpSK5d usXnM/O+kr3Dm+Ui+UioPf6wgbn3T0o6I5BhVhs4h4hWmIW7iNhPjX1iybXfmb1gAFfjtHfL xRUr64svXpyfJMScIQtBAm0ihWPltXkyITA92ngCmPdHa6M1hMh4RDX+Jf1fiWubzp1voAg0 JBrdmNZSQDz0iKmSrx8xkoXYfA3bgtFN8WJH2xgFL28XnqY4M6dLhJwV3z08tPSRqYFm4NMP dRsn0/7oymhneL8RthIvjDDQ5ktUjMe8LtHr70OZE/TT88qvEdhiIVUogHdo4qBrk41+gGQh b906Dudw5YhTJFU3nC6bbF2nrLlB4C/XSiH76ZvqzV0Z/cAMBo5NF/w= In-Reply-To: <20231027182217.3615211-12-seanjc@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 10/27/23 20:21, Sean Christopherson wrote: > Drop the .on_unlock() mmu_notifer hook now that it's no longer used for > notifying arch code that memory has been reclaimed. Adding .on_unlock() > and invoking it *after* dropping mmu_lock was a terrible idea, as doing so > resulted in .on_lock() and .on_unlock() having divergent and asymmetric > behavior, and set future developers up for failure, i.e. all but asked for > bugs where KVM relied on using .on_unlock() to try to run a callback while > holding mmu_lock. > > Opportunistically add a lockdep assertion in kvm_mmu_invalidate_end() to > guard against future bugs of this nature. This is what David suggested to do in patch 3, FWIW. Reviewed-by: Paolo Bonzini Paolo > Reported-by: Isaku Yamahata > Link: https://lore.kernel.org/all/20230802203119.GB2021422@ls.amr.corp.intel.com > Signed-off-by: Sean Christopherson > ---