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 CD51528EA7E for ; Wed, 4 Jun 2025 12:26:55 +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=1749040017; cv=none; b=ksTeJD2vYs7yof45g0a6DMV4oOIM7aBUe1iqMJyDz1SOZtsEo1Yvsg0/P5gj12wYIeI8VgkWWW47bigV0hqjPvsCWP/gNOJNW3iwDNfU+yz1AvJDgFmE/RaA6bhTjmn0mDiEYhNI3LEQRKSQ/ohtCAoJhEWICpqDYK25YqvVx/E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749040017; c=relaxed/simple; bh=A7TqLIeJ5CLbMZAQ1Zg/O2PsiKyVkpr+YJ74zRbx7AY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=N2hx1UbbeXILa22qJDx8L4VeereHeh8lKqFX4JhM6psP3GDtjqfmrESkNWIedGitLAuXCDJYG7AAG3esJp71GDYC27/JXeNaz7XzJ2xqn9bQ//ma0/o82nIPMVlSWb+YnRi3XxzmV4QU174PeHmsdDanpgLFlOYwaI3jimYuf6A= 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=M3fNhg8s; 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="M3fNhg8s" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1749040014; 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=Q+aRfq2GW38vhFS2hoYFrz2Xx/pbsUYxa82R0G/kuMk=; b=M3fNhg8sXWV8i8Go4o4JU5Y+ISrEgEF1mozzOqYTfex/uzdu8j7TUuSJ81dw/Z+AKVFiGe 5gZtsZmrX7xyqo8/squPEonCnEklEASx8mXBeeBxWX39yBQQziLFKff64hxPovRw47DDWC JKn6aEKoNjA+6lbpM80wRFD79v+eS3M= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-622-c145iSlbNBqKi5wLaniuGg-1; Wed, 04 Jun 2025 08:26:53 -0400 X-MC-Unique: c145iSlbNBqKi5wLaniuGg-1 X-Mimecast-MFC-AGG-ID: c145iSlbNBqKi5wLaniuGg_1749040012 Received: by mail-wm1-f71.google.com with SMTP id 5b1f17b1804b1-450dada0f83so39817085e9.0 for ; Wed, 04 Jun 2025 05:26:53 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1749040012; x=1749644812; 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=Q+aRfq2GW38vhFS2hoYFrz2Xx/pbsUYxa82R0G/kuMk=; b=pAPV0PObUeoj5ydRSD9EBQtxAmFYocrXSTp71pu5FGePdj1AOyvFOrpTCvkalNe2gQ 8KdopF1D29V0d3F3y4Pueo2KnFa2QR+RR2SNexLNkyXOy457EEUQ4NuTJhQj7RXm+x6U 98fXHuSFwOnt7QSOiRDN+Bp7iy8XE/w1vqL/Bfn56xFm0++7iuQ9onMimqk7a7b1DyKc o5sID+APKIRo9axDc1gqimDSBdaQ1SEtenTBIcuoCuXmo0+BpF+WHtCRVMQ+VH7y9f8P cT83zFQN0x/g1xg3ftnyifUvBgeau3wpHMJGJQZXRLQ5ZslecbQpYRdBSbqSbNOE2D8c O1fA== X-Forwarded-Encrypted: i=1; AJvYcCU9fvMcQPiHY+3mnm0MwdKSb2m5JYlOWrFIWqGi+h+NuIAy9aah2k50pKGKnCAKQXUAr80=@vger.kernel.org X-Gm-Message-State: AOJu0Yx7ohTRyVtlJhm5HnfdVuW6oFvKaq8wYmfRyzeqHcOOewL6iFbx eG7+e2c3bh9KtVBSMe4dYcFhdzyoG8uHDfOKioXgzhXPhqxfxvAcRxhreeeyVLvs+BlMqc8a74r SkVyP6aCF3qWVZKF52OMFlwjwjvG+3jiMaa6iKoI7xasqbHlM9hkREw== X-Gm-Gg: ASbGnctEjJbfIgT/zeNriLVuZdalY2EgGXhK/kmvM/wfNwVlmvFfujayyxnQ9tEGdJR WTYKyyl/gajvWznLfF3eXhsGHVMBlbpgWSwYoZtY4d3VQma883Smgl2TneVbvOIYsS7se2O5Mt/ CNokfFhRMSZ5hO3uuJoDNGwCbERp6M6N0sqnE8rBZqDIohk9rYwbrfG8y5BF3xpE0HIjHi6lF2i GK/2b7bKFCcYg4kiCIkNU2NUM1Ae7G1/GhUCw8Cn6RSY8m401aBaLEz0b2lnD7yE74+UzO46KoP HcXu7T3cCGo7Zc8q//WvruXJCGKLP61Rus1nU1JoSnEFsAjS56/EW4n/sdEgDPpkZzuG05nTJkj Bmof6tZay6uh4WizHlcKqdiTfngXLy2oxi95cnac= X-Received: by 2002:a05:600c:870c:b0:43c:ee3f:2c3 with SMTP id 5b1f17b1804b1-451f0a636ebmr22965525e9.7.1749040012487; Wed, 04 Jun 2025 05:26:52 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFExWHzdiWQndGAxNRarobM5yA3gJhRQVXlyu2LxUdQOrlj9R1BVLaEKWqX19XbJI84tys7wA== X-Received: by 2002:a05:600c:870c:b0:43c:ee3f:2c3 with SMTP id 5b1f17b1804b1-451f0a636ebmr22965165e9.7.1749040012067; Wed, 04 Jun 2025 05:26:52 -0700 (PDT) Received: from ?IPV6:2003:d8:2f1b:b800:6fdb:1af2:4fbd:1fdf? (p200300d82f1bb8006fdb1af24fbd1fdf.dip0.t-ipconnect.de. [2003:d8:2f1b:b800:6fdb:1af2:4fbd:1fdf]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3a4efe5b92bsm21276266f8f.9.2025.06.04.05.26.49 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 04 Jun 2025 05:26:51 -0700 (PDT) Message-ID: Date: Wed, 4 Jun 2025 14:26:49 +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 v10 08/16] KVM: guest_memfd: Allow host to map guest_memfd pages To: Fuad Tabba , kvm@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-mm@kvack.org Cc: pbonzini@redhat.com, chenhuacai@kernel.org, mpe@ellerman.id.au, anup@brainfault.org, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, seanjc@google.com, viro@zeniv.linux.org.uk, brauner@kernel.org, willy@infradead.org, akpm@linux-foundation.org, xiaoyao.li@intel.com, yilun.xu@intel.com, chao.p.peng@linux.intel.com, jarkko@kernel.org, amoorthy@google.com, dmatlack@google.com, isaku.yamahata@intel.com, mic@digikod.net, vbabka@suse.cz, vannapurve@google.com, ackerleytng@google.com, mail@maciej.szmigiero.name, michael.roth@amd.com, wei.w.wang@intel.com, liam.merwick@oracle.com, isaku.yamahata@gmail.com, kirill.shutemov@linux.intel.com, suzuki.poulose@arm.com, steven.price@arm.com, quic_eberman@quicinc.com, quic_mnalajal@quicinc.com, quic_tsoni@quicinc.com, quic_svaddagi@quicinc.com, quic_cvanscha@quicinc.com, quic_pderrin@quicinc.com, quic_pheragu@quicinc.com, catalin.marinas@arm.com, james.morse@arm.com, yuzenghui@huawei.com, oliver.upton@linux.dev, maz@kernel.org, will@kernel.org, qperret@google.com, keirf@google.com, roypat@amazon.co.uk, shuah@kernel.org, hch@infradead.org, jgg@nvidia.com, rientjes@google.com, jhubbard@nvidia.com, fvdl@google.com, hughd@google.com, jthoughton@google.com, peterx@redhat.com, pankaj.gupta@amd.com, ira.weiny@intel.com References: <20250527180245.1413463-1-tabba@google.com> <20250527180245.1413463-9-tabba@google.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: <20250527180245.1413463-9-tabba@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 27.05.25 20:02, Fuad Tabba wrote: > This patch enables support for shared memory in guest_memfd, including > mapping that memory at the host userspace. This support is gated by the > configuration option KVM_GMEM_SHARED_MEM, and toggled by the guest_memfd > flag GUEST_MEMFD_FLAG_SUPPORT_SHARED, which can be set when creating a > guest_memfd instance. > > Co-developed-by: Ackerley Tng > Signed-off-by: Ackerley Tng > Signed-off-by: Fuad Tabba > --- > arch/x86/include/asm/kvm_host.h | 10 ++++ > arch/x86/kvm/x86.c | 3 +- Nit: I would split off the x86 bits. Meaning, this patch would only introduce the infrastructure and a x86 KVM patch would enable it for selected x86 VMs. -- Cheers, David / dhildenb