From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 22EFE25179D for ; Mon, 12 May 2025 07:54:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747036460; cv=none; b=YZ2UTj3NfVl3+qf0Ugnll7PsLrEzDdqLXoIpLesi2q0PY6ZgPF/rA5/yUEAUQtdz6ovmXAA482/ypY4gtsFZW3Y3PXncbDh7peCaZPl5iKr9GOadoq18XFZwVF9EzeshrtBou4T7hcUDQzy+D2Ay6L8nRTpO1xFuGrWSi/JPN70= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747036460; c=relaxed/simple; bh=Xy1wN6Jh3sGiMfmqkMEIAg8iWiwBqQYnuPoE+RtUfM8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ilHHPr5s5JLntsYvsHOr6VPyBh3VqZjcKKJ6zo7Wi/oebk+IZu/f42p44vvFg1TUPcMR1aTnu6DCzLRaZBJU7TmhMQ6dljvBJcUelyI1TGYs46Mj3wloB5vW9OUX883HK+5QalX//7DiMWHfTItRuw5sODFdo4DXwERecKCRiI0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=cZ4WqNdk; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="cZ4WqNdk" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1747036453; 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=tejtTw+ujDY0fXNQwgGGe4XMZMbnZF0Fex+Sgc96/fk=; b=cZ4WqNdkSkuWjbgBaqD8xN/hDcQuCCgnUnBgQMqJ57IafVtrdbA/HmnRm7YAU+0hxhcDAd n9l8wKFxOTLnk3nO/KLv43asswiRjMZK0N8RjbizXntjFhQEdPyEXI5AUzGRXwQyhi4+D1 DxHHmwy16Czb14IFaomM8SAebzTi1Ao= Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-444-KCwFVtI9OSuQgk-CnR6uwQ-1; Mon, 12 May 2025 03:54:11 -0400 X-MC-Unique: KCwFVtI9OSuQgk-CnR6uwQ-1 X-Mimecast-MFC-AGG-ID: KCwFVtI9OSuQgk-CnR6uwQ_1747036450 Received: by mail-wr1-f72.google.com with SMTP id ffacd0b85a97d-3a202744565so487096f8f.0 for ; Mon, 12 May 2025 00:54:11 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1747036450; x=1747641250; h=content-transfer-encoding:in-reply-to:organization:autocrypt :content-language:from:references:cc:to:subject:user-agent :mime-version:date:message-id:x-gm-message-state:from:to:cc:subject :date:message-id:reply-to; bh=tejtTw+ujDY0fXNQwgGGe4XMZMbnZF0Fex+Sgc96/fk=; b=HWCL2Ubb2vBld2JEyomxn9cgFKpTgv//q9xok/0OuMwBnVtLWvanPBxH34iQuHRpaA EmR9kA8UtNsBYK18miuvDCRbAiBHGyF4BS8WAcRg8Wq01pyiwGB3jgrhFWAD7Slg2Rxg UT4y3MkqCpMeu+6cHfUnAo0QaHjOvshdXDH8jZBUmPK+baqwpxxxNHNcOuqAINOslBeH MafRAMjCGJ2dq87iJNq6S4l8RN46aHc73LjsHma2xdkmjK/ws4mtrQybRUXVYM3ely8r /sQFkp3i9FgBm+eVGbffhs5uiVFvn6OMQwUGzgMkESVfuB2LHUyR/s4ZeUR+1Y1t129e 5d+A== X-Forwarded-Encrypted: i=1; AJvYcCWFEog34FjlQ5raqOVo/NTU/yN8Z/yBqrSBmjGzXyneesa5TNvnFnBgrw7h6o/MUVmz9/M=@vger.kernel.org X-Gm-Message-State: AOJu0YwqzXqPxny7MlIMSt5NncdS7ysBgvYOJbLZx068bYZC7bY33+kw MA+t8m/txeCzihqL+dU96NauZecMMdGrUPCdOz76E+/YV1u2C3lDESIEA2B+fPyOM6UGHAGOkqi B0KmgCY8uRnOvM7GaBuWhE4wuQEQLhmJIh5FoQiHuAyhaERlLZA== X-Gm-Gg: ASbGncvhLH/uC+OwhdGJI4UxP5aJxy/TkNXVGe9TbHLwvCSUvLtFNoKK+3zcR/ThEUK oinI2m5ZdeNhYHJVs+JeWh9H+KF9HlBom1RP78TadyKJmpPu/Ptf34ASEWeEYnBH273u8Bgkrk5 z0Abhu6JguzTc6N27zaqSNJkmyNEpvnSYKdPHuxkQHg7lzkeamnziRGRawLD/DqhAb/KZiJSJT7 Ae+B1Ws40WUv4EVNgD5eHTHJ9ofOFgnHRcPA7MR5S4/eWc9w8UNP/khAhfY0WUxsRPySOZvAi+H C/Jb+dr9/4ET/zdVViYOgKZjU+/Oq51J4bHxSUyROcU= X-Received: by 2002:a05:6000:144f:b0:39c:30f7:b6ad with SMTP id ffacd0b85a97d-3a1f6c984a1mr10687456f8f.18.1747036450300; Mon, 12 May 2025 00:54:10 -0700 (PDT) X-Google-Smtp-Source: AGHT+IGJhOje2oJq6znmxvPYbUk0BcriQBCtS8TcM/2GHT8GIwEPu6EwA7/uRqITP4TGEjjdEkmbMQ== X-Received: by 2002:a05:6000:144f:b0:39c:30f7:b6ad with SMTP id ffacd0b85a97d-3a1f6c984a1mr10687433f8f.18.1747036449963; Mon, 12 May 2025 00:54:09 -0700 (PDT) Received: from [192.168.3.141] (p4fe0f9ab.dip0.t-ipconnect.de. [79.224.249.171]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3a1f5a4cc2esm11798364f8f.90.2025.05.12.00.54.08 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 12 May 2025 00:54:09 -0700 (PDT) Message-ID: Date: Mon, 12 May 2025 09:54:08 +0200 Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 10/13] memory: Change NotifyStateClear() definition to return the result To: Chenyi Qiang , Baolu Lu , Alexey Kardashevskiy , Peter Xu , Gupta Pankaj , Paolo Bonzini , =?UTF-8?Q?Philippe_Mathieu-Daud=C3=A9?= , Michael Roth Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org, Williams Dan J , Peng Chao P , Gao Chao , Xu Yilun , Li Xiaoyao References: <20250407074939.18657-1-chenyi.qiang@intel.com> <20250407074939.18657-11-chenyi.qiang@intel.com> <5fcf90b9-dff5-466c-9be5-2b6571a5de8a@linux.intel.com> <55547b18-be03-4684-9330-70fc2ba48954@intel.com> From: David Hildenbrand Content-Language: en-US Autocrypt: addr=david@redhat.com; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZgEEwEIAEICGwMGCwkIBwMCBhUIAgkKCwQW AgMBAh4BAheAAhkBFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAl8Ox4kFCRKpKXgACgkQTd4Q 9wD/g1oHcA//a6Tj7SBNjFNM1iNhWUo1lxAja0lpSodSnB2g4FCZ4R61SBR4l/psBL73xktp rDHrx4aSpwkRP6Epu6mLvhlfjmkRG4OynJ5HG1gfv7RJJfnUdUM1z5kdS8JBrOhMJS2c/gPf wv1TGRq2XdMPnfY2o0CxRqpcLkx4vBODvJGl2mQyJF/gPepdDfcT8/PY9BJ7FL6Hrq1gnAo4 3Iv9qV0JiT2wmZciNyYQhmA1V6dyTRiQ4YAc31zOo2IM+xisPzeSHgw3ONY/XhYvfZ9r7W1l pNQdc2G+o4Di9NPFHQQhDw3YTRR1opJaTlRDzxYxzU6ZnUUBghxt9cwUWTpfCktkMZiPSDGd KgQBjnweV2jw9UOTxjb4LXqDjmSNkjDdQUOU69jGMUXgihvo4zhYcMX8F5gWdRtMR7DzW/YE BgVcyxNkMIXoY1aYj6npHYiNQesQlqjU6azjbH70/SXKM5tNRplgW8TNprMDuntdvV9wNkFs 9TyM02V5aWxFfI42+aivc4KEw69SE9KXwC7FSf5wXzuTot97N9Phj/Z3+jx443jo2NR34XgF 89cct7wJMjOF7bBefo0fPPZQuIma0Zym71cP61OP/i11ahNye6HGKfxGCOcs5wW9kRQEk8P9 M/k2wt3mt/fCQnuP/mWutNPt95w9wSsUyATLmtNrwccz63XOwU0EVcufkQEQAOfX3n0g0fZz Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa N7eop7uh+6bezi+rugUI+w6DABEBAAHCwXwEGAEIACYCGwwWIQQb2cqtc1xMOkYN/MpN3hD3 AP+DWgUCXw7HsgUJEqkpoQAKCRBN3hD3AP+DWrrpD/4qS3dyVRxDcDHIlmguXjC1Q5tZTwNB boaBTPHSy/Nksu0eY7x6HfQJ3xajVH32Ms6t1trDQmPx2iP5+7iDsb7OKAb5eOS8h+BEBDeq 3ecsQDv0fFJOA9ag5O3LLNk+3x3q7e0uo06XMaY7UHS341ozXUUI7wC7iKfoUTv03iO9El5f XpNMx/YrIMduZ2+nd9Di7o5+KIwlb2mAB9sTNHdMrXesX8eBL6T9b+MZJk+mZuPxKNVfEQMQ a5SxUEADIPQTPNvBewdeI80yeOCrN+Zzwy/Mrx9EPeu59Y5vSJOx/z6OUImD/GhX7Xvkt3kq Er5KTrJz3++B6SH9pum9PuoE/k+nntJkNMmQpR4MCBaV/J9gIOPGodDKnjdng+mXliF3Ptu6 3oxc2RCyGzTlxyMwuc2U5Q7KtUNTdDe8T0uE+9b8BLMVQDDfJjqY0VVqSUwImzTDLX9S4g/8 kC4HRcclk8hpyhY2jKGluZO0awwTIMgVEzmTyBphDg/Gx7dZU1Xf8HFuE+UZ5UDHDTnwgv7E th6RC9+WrhDNspZ9fJjKWRbveQgUFCpe1sa77LAw+XFrKmBHXp9ZVIe90RMe2tRL06BGiRZr jPrnvUsUUsjRoRNJjKKA/REq+sAnhkNPPZ/NNMjaZ5b8Tovi8C0tmxiCHaQYqj7G2rgnT0kt WNyWQQ== Organization: Red Hat In-Reply-To: <55547b18-be03-4684-9330-70fc2ba48954@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 09.05.25 12:04, Chenyi Qiang wrote: > > > On 5/9/2025 4:22 PM, Baolu Lu wrote: >> On 4/27/2025 10:26 AM, Chenyi Qiang wrote: >>> Hi David, >>> >>> Any thought on patch 10-12, which is to move the change attribute into a >>> priority listener. A problem is how to handle the error handling of >>> private_to_shared failure. Previously, we thought it would never be able >>> to fail, but right now, it is possible in corner cases (e.g. -ENOMEM) in >>> set_attribute_private(). At present, I simply raise an assert instead of >>> adding any rollback work (see patch 11). >> >> Do the pages need to be pinned when converting them to a shared state >> and unpinned when converting to a private state? Or is this handled >> within the vfio_state_change_notify callbacks? > > I think it is handled in vfio_state_change_notify(). Just like the > device passthrough in legacy VM, the shared memory will be pinned during > vfio dma-map and unpin during unmap. We'll have to "unmap/unpin before shared->private" and "map/pin after private->shared" conversion. vfio cannot fail unmap/unpin, but guest_memfd will be able to "easily" fail shared->private. But in that case (temporary references) we'll likely have to retry the conversion until it works. guest_memfd cannot "easily" fail private->shared conversion, but vfio can fail map/pin, in which case we probably have to abort the conversion. Error handling/recovery will be a bit more tricky than it is today. -- Cheers, David / dhildenb