From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 4F954188733 for ; Tue, 25 Feb 2025 16:56:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740502561; cv=none; b=hvyobP6FF2kGLYn990kOA0LWmX1DbtZ4OqqOjj1GxA5R5bIqroBLukrwyJiKlTpy+zNYJ5h0nv6ZMolfaQ/Z8ij/C6t+hr5OTQ2hvZAk4/JDYgXHfjpf2r/KMR4v1eumJOQxjEg2oHVvEOkcFXMT4E+w4ZzJgsq94beyrYlo9Nw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740502561; c=relaxed/simple; bh=nQ44Bzpza4hhTa9otIjinjm0k/20MprTjt+HR8ATJQU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=uWVav7N88au3ni0K1MPy84VYPMGaJNTJm2/SUA5u+LsI4CDrqC4IhIOrLR0rVU9gKXKoprtOuEkWv5w9qRF9XJ42uvQJQahNSBQy6gjylQdiOSCUZ81K5ZN2OQxVLuu+fhurbzT76xgC4CB64bXi2Ey8A2AgcYo+3xmQ219bVyw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none 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=TRV4ZQYc; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none 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="TRV4ZQYc" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1740502559; 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=gc6nQtNUWZYE/MaGMWTUUIeNQ1kSqCMg8WjpiOLHoso=; b=TRV4ZQYcrNaRTgolF/UExLUgXwKYGtaGIe620OzT0Ph1weMaAZSQPiW6urDm3E/oBi3wk+ SDh7k1Ex70MzOCL7o0g/Ya0+PbaWYoFWpKXhBmNub0eugf1N8hblTksB65ZGLdWRXSSVIy WjJwNqdFLvDcAJHWv3asyspPRKL+isE= 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-615-GksYvmNZPVWl9tknKKdoMw-1; Tue, 25 Feb 2025 11:55:57 -0500 X-MC-Unique: GksYvmNZPVWl9tknKKdoMw-1 X-Mimecast-MFC-AGG-ID: GksYvmNZPVWl9tknKKdoMw_1740502557 Received: by mail-wm1-f72.google.com with SMTP id 5b1f17b1804b1-43947979ce8so25516265e9.0 for ; Tue, 25 Feb 2025 08:55:57 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1740502557; x=1741107357; 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=gc6nQtNUWZYE/MaGMWTUUIeNQ1kSqCMg8WjpiOLHoso=; b=IjgXZQY8x0D2IZ58Nyo5g+dMoLKudLDgk9R7ZU1hACMNAnStuyYIo4a/fkHAhJ/2v6 t7Bi8WmKPkj1uw9rkoVdHtBeXYvQocyw2rSwylC5pV3cqsvO6EzhR/0BlVTBTUAwK1AW OrlNa263tsv3pvwWLs6z6V22fD+9Xg4dCm/uT0fh59Tm+W5A6rUACSqS7gpMrDh+I5Eb Rm6Q4EVYeIomNxQOf0vh9guMiiY2P+DACM9MCeWE2Yw10DrCtgXnE1ZjpK708xrIDvOW xGyBA8+0csS/mJiSNQZws9RXuV5/Vm9zaRKxAjhg4BOLqDdN42Z5DPNmuxzOPLkPVL60 ELqQ== X-Forwarded-Encrypted: i=1; AJvYcCXnv2BJxYiCimO+8M41g/aquCsHh3FutgVhWC8+5y4OaxsJv4JDAtBSTettwwvcu+x4jbAu/gAJ23/8TBA=@vger.kernel.org X-Gm-Message-State: AOJu0Ywcg6+prtT1S+w9h070mCOQazEk1GOUT9VB4KOm6E7UfcawT8Nx oXCS3je72EwnOJTwYqKAXAB4FR0PyGQP4Fb8Ufv2HiakUZC5eXjLTDFl8WmySuyyYBXz49o72A4 w7Fz4WcfWY62ebOf5e9hCm8JnkIeEfshMN+f8JKWa26z7I1pUljhKcyxe+ZvK/w== X-Gm-Gg: ASbGncvg1fU85PpLZ3fDVID4NNZeHD64P/03JNg1Sg82CT96AjgtP0x61//eww5wgpp i2CahJ40WmmJeaey8BkrdPUe1+pYyOO6RD21GwCVVXHGSTweB3LnWFHpftYoXvy7kP/B7G9b0we LI3VX6Z+OBMLJjkNYUKEeZWuu8ctRZLu6HSDQ2SdH3hPZwO9p3N3bOfeoybmCsxLLAb3ZhxVBHK 6fW5GhtZaHVajYvlG4Cecz/vJ2fYAQrDy/+/klPfzouXTGS2RbnrBGNLmtqIJ/kRuX5CSqas+5A vimkZLF3mSF5UPOu4cnovyK4DN87WspXhG8vwZrb6ITL7nehkjrWw6r5E/faXGQySx3MVQ47rZz qrvktUO2E1/NcvVstaaZrJa4ITzu1irsx4Q8/azZC3PQ= X-Received: by 2002:a05:600c:1396:b0:439:88bb:d02d with SMTP id 5b1f17b1804b1-439ae1d9a2dmr164242615e9.2.1740502556780; Tue, 25 Feb 2025 08:55:56 -0800 (PST) X-Google-Smtp-Source: AGHT+IEzE/g/wzyX4nO+TszgBSun1B7uE43oREDnV0UH0oQHkzl3BhbsKqcoCLgqarg7oHx6lgcPEw== X-Received: by 2002:a05:600c:1396:b0:439:88bb:d02d with SMTP id 5b1f17b1804b1-439ae1d9a2dmr164242175e9.2.1740502556358; Tue, 25 Feb 2025 08:55:56 -0800 (PST) Received: from ?IPV6:2003:cb:c73e:aa00:c9db:441d:a65e:6999? (p200300cbc73eaa00c9db441da65e6999.dip0.t-ipconnect.de. [2003:cb:c73e:aa00:c9db:441d:a65e:6999]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-439b02ce60asm149821775e9.7.2025.02.25.08.55.54 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 25 Feb 2025 08:55:55 -0800 (PST) Message-ID: Date: Tue, 25 Feb 2025 17:55:53 +0100 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 v4 04/12] KVM: Add capability to discover KVM_GMEM_NO_DIRECT_MAP support To: Patrick Roy , rppt@kernel.org, seanjc@google.com Cc: pbonzini@redhat.com, corbet@lwn.net, willy@infradead.org, akpm@linux-foundation.org, song@kernel.org, jolsa@kernel.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, eddyz87@gmail.com, yonghong.song@linux.dev, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, Liam.Howlett@oracle.com, lorenzo.stoakes@oracle.com, vbabka@suse.cz, jannh@google.com, shuah@kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, tabba@google.com, jgowans@amazon.com, graf@amazon.com, kalyazin@amazon.com, xmarcalx@amazon.com, derekmn@amazon.com, jthoughton@google.com References: <20250221160728.1584559-1-roypat@amazon.co.uk> <20250221160728.1584559-5-roypat@amazon.co.uk> 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: <20250221160728.1584559-5-roypat@amazon.co.uk> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 21.02.25 17:07, Patrick Roy wrote: > Add a capability to let userspace discover whether guest_memfd supports > removing its folios from the direct map. Support depends on guest_memfd > itself being supported, but also on whether KVM can manipulate the > direct map at page granularity at all (possible most of the time, just > arm64 is a notable outlier where its impossible if the direct map has > been setup using hugepages, as arm64 cannot break these apart due to > break-before-make semantics). > > Signed-off-by: Patrick Roy > --- Not sure how KVM folks handle that, but I suspect we would just want to squash that into the previous commit, -- Cheers, David / dhildenb