From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793177951; b=XWERHlRUEwwB2Hm+AtvHDDY9l5ZRpLy9uTf0FNLosXndUbtQaI9gKEPElZGxLVD2KiDi G1Fc+H2u9M95IHRz3V8zyBj6njxWWyBiRjQlO+DCUp3toMDPduq+zHFthpshABoAjAnqc urehBVRUezvKGiZ/HJg3D8Zfq85SJ/rHGGnKoQcUfImj7Bi8O6lfzamtqLH51oZmcsfkW Kw48aotQqgQIblKmAcX3GQlESjCckVSE2M5u1etIZimflkALWtd9uZLJDTnCFDCpdy3aK 22rcDk+5xDnvTZ4N74/4iLcKP954Pz+fexuWFv4zUY78mSFUK1oXBx2UQ3tkte0bZpQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793177951; h=Received:DKIM-Signature:Message-ID:Date:MIME-Version:User-Agent: Subject:To:Cc:References:From:Content-Language:Autocrypt:In-Reply-To: Content-Type:Content-Transfer-Encoding; bh=i9qOtY7a0khzZp+2JUyiQcNdwBewsSehqHZrdYTNXPA=; b=ykOaqkMuZflWdplabZhceEISyqreZ4zCuihkAIQwd7BsEWHK7qJkEkUjFP6ia2ZSWUW+ hAOfqfZucAt74sKlQqz9G6vjHQ+ifPK0DKBPnWUgrOvoI/YiIGK6fTS4pUklq/lsAlauz dbd+9HJ0w9P7y+wQHNWPh3SOVkVGo6ezUrA/NqVlNQvirwCWXovKzXqgoIdy/en73cio1 V4IAf5/G0LUJQ3i4m9dB6/9um7mqU8IafEZ3MAQbS+GkswIetc7rzNxdnDt9ho1sGUVLx 8Pc4U6ej33/JvBiE+G+cKj+jIECreKQw5wrTmQjsy4VhssClLd/yFZ1DCnzv8rJjdkg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=n9uz2qBx; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ACB30606A31A; Wed, 28 Oct 2026 08:59:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=n9uz2qBx Received: by smtp.kernel.org (Postfix) with ESMTPSA id 95DD01F01825; Wed, 28 Oct 2026 08:59:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793177950; bh=i9qOtY7a0khzZp+2JUyiQcNdwBewsSehqHZrdYTNXPA=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=n9uz2qBxwkdOt+BBYDqcRYBsL0H4V2Ug9Ow5tu7fLk3/xzx2mxzf+HMTVGUiIJnbu UHfvtxmIjhY+xQ766vsmgwePsLiGx8kAmPZPlD4WCnC+4rJaxzKpjDf8l/PxSRuS7U ixLAvMeOxeiUvefXEFI/jfC9xp7ljf7OTppVYZjzY1dNcHcmh1NZWDF2vGHdc49hWv uTT0NSrtYNOYOcDppWH6dHgfZpTd171QUNIp7WpPs8lDGkcfpOKXPATlxU3qiH1ANx V+qfMdLsle8HqlqWD8gAGSfEwjudq/PMbS1R0zs9PPUAGsrYy40er4yK4lQU4aDgLA HllBmwshL59LQ== Message-ID: <2976bc2d-2642-4448-9c1f-ec13e67e45d5@kernel.org> Date: Wed, 28 Oct 2026 09:58:59 +0100 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 10/13] virtio_balloon: add higher-order page inflation To: Kevin Loughlin , "Michael S. Tsirkin" , Jason Wang , =?UTF-8?Q?Eugenio_P=C3=A9rez?= , Xuan Zhuo , Ard Biesheuvel , Kiryl Shutsemau , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Tom Lendacky , Ashish Kalra , Michael Roth , Rick Edgecombe , Andrew Morton , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Johannes Weiner , Zi Yan , Alexander Duyck Cc: virtualization@lists.linux.dev, linux-coco@lists.linux.dev, linux-efi@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Sidharth Telang , Punit Salian , Peter Gonda , Ackerley Tng , Jacky Li , Steve Rutherford , David Skidmore References: <20261027025616.1632690-1-kevinloughlin@google.com> <20261027025616.1632690-11-kevinloughlin@google.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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 B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: <20261027025616.1632690-11-kevinloughlin@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 10/27/26 03:56, Kevin Loughlin wrote: > In confidential computing guests requiring page state transitions, > unaccepted memory tracking operates at the EFI unaccepted memory unit > granularity (typically 2MB / order 9 on x86). Inflating the balloon > with 4KB pages would prevent unaccepting the backing 2MB unit. > > Inflate balloon pages at unaccepted_memory_order() when > virtballoon_cc_needs_state_transition() is true, while retaining > order-0 allocations for non-CoCo guests and CoCo guests that do not > use unaccepted memory transitions. When a higher-order balloon page > spans more 4KB balloon PFNs than VIRTIO_BALLOON_ARRAY_PFNS_MAX (256), > transmit its PFNs to the host in VIRTIO_BALLOON_ARRAY_PFNS_MAX chunks. > > Signed-off-by: Kevin Loughlin Sorry, not happening. There is no migration support for these (large) things, and there likely won't be any time soon. NAK -- Cheers, David