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 7402B2356C0 for ; Fri, 13 Jun 2025 21:18:20 +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=1749849502; cv=none; b=BDg80T6NuHIF2l6n5ihCEaZDZoiIbWlAeIAdORsyc3bPH0jyKNwpYxCOmRrDQhCd/xWVe/giNS5oVaw40ZZ/FNH6H6PahgwCScl6hLjVCkZP/Hej7+hQUilNDx20e8Ps/FGm6qS3HYiqJcXtqKTGiKZk4lYRpja2kqYZ8T3H0UQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749849502; c=relaxed/simple; bh=cjS1R/h5yYqj8F/QZF4nccCyoFcjDNQc4ZKgUarS9ts=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Ua7PkBjbMJJy2+RKcLt9OsiGgvSsWYLyCurB7Lm5WZHNrjkOzZDsrX9/WmeEyf6T9DvWhU4e5umA6ZTwl2AeNZcXnUYXfWr8FkN6BsInu7b8DAt0iQSTM8Nk9eAjhDlvbxN6cfd05iUFGSMpuHENJ6gcXMv2v2nXjXpLPmm+f6c= 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=FnwFW4yq; 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="FnwFW4yq" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1749849499; 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=ufscstiQHCbS9G1pdl0dbNIBD2ajGNOtHVKChNRSU3k=; b=FnwFW4yqajHp9CCUEdq2M8QVguhLJtgcgUz205/E76fRSVE6Cbj8G87fMl1bUahldefFtn vdMjjQJ9qwlobEAFf8KUHTYou59+QOgaOmtTLJbvDpzr8LdNNkG9dqeXWK36Wymi6qHGya WUvnUnQ4zGc1hg9ZnItlqjyqP8iZSKU= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-70-ooF2hkutOlu9fBJZ4bZaQg-1; Fri, 13 Jun 2025 17:18:18 -0400 X-MC-Unique: ooF2hkutOlu9fBJZ4bZaQg-1 X-Mimecast-MFC-AGG-ID: ooF2hkutOlu9fBJZ4bZaQg_1749849497 Received: by mail-wm1-f70.google.com with SMTP id 5b1f17b1804b1-450de98b28eso20174235e9.0 for ; Fri, 13 Jun 2025 14:18:18 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1749849497; x=1750454297; 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=ufscstiQHCbS9G1pdl0dbNIBD2ajGNOtHVKChNRSU3k=; b=twCX2dmZSmawxkt1aT4ELFW44L1WMkmxdtToziukvclS/5Zp6y74BWmcz5M4rmY6qr 9oE4s0gxRx8mI2bojHu4vhHCNsr344MXZkKV7PpgOoM6RKYLdL6O7O0rOPasjt7a7BFd aRZZD71f2VZTZSS/OEUn0ERAjIRqe5mU4E9WFjRAidrUH3Q6x1ZPZ+whjVwmeYrhsPuW Gv4ZbGR+MrIM4niDwP3FGWy6gIvY0P7cCLRHEXNOUPzTN1sE04auQH552henaD0Pj1aa YCVxa/MHN3Navex7QoWOd0GYtpT9VlmElWKHRMe+lh21tNZQHJmyd9pyLVI3OWSWCo+K y23w== X-Forwarded-Encrypted: i=1; AJvYcCVD0Gl8xkdS1m2FnpKD0frQHwcyAp14OlJrEKRq3YHqdFgQEX8GYBmVPUi5USnQ6jYiE05w0EE=@lists.linux.dev X-Gm-Message-State: AOJu0Yx1gvBbfTT7YNcbvhhahbWwMxRFRTWis85zDqsZRGQQhj9gkI4e mFcsVk1dWG1xYOeomEM+yC6KmTd+suFCJvOw4llS1DAyW463U0ZEjG1Sti1nwUBPRdesX6/dcpV C1mrsy/tj4z6xITTd+V8f/PYhykvObZMq8Zl0mD0NZFEOqnX13PxZGtvaJQ== X-Gm-Gg: ASbGncvwlByyP9KLTQT6f0ENjpjFqHgof+OL7apjIBorJagNiw2h+02d+2xPeunAkDU DL4082tlfKE75kn4+Fs1/roSnmMFk/gtF4c1CC2FvUENhJJxnIg7M2oAYqrQ0yOl7qPe0UM9fNA Nnj3jF8QFPFNsDBfbPzjGgPxOyxrVmBEB3Dx2AyCrTzaCK3zhI4DwDqm0lbsVk1dMbGm5gFTdYP CQIpCZi5bfmLdVc3rEQ5r0n0GOKKz8tay0D2i9Gs22VJIZ3BXeZoEVuKbW4514Nz0AZuuDTUJ0G 3NRwD4/vKdhBwXlWICH2Xow5UJBZ3YxffF8ZDSdZQYr+BhiReavjTgNXVwZmeVI+iYmuGq/dAfB XOobNBT67h5V3V8tHMpw3zr7LSqi2lhcqWKGRu7/egI23xCD/Lg== X-Received: by 2002:a05:600c:8b45:b0:43b:c6a7:ac60 with SMTP id 5b1f17b1804b1-4533c92e57bmr12391215e9.10.1749849496944; Fri, 13 Jun 2025 14:18:16 -0700 (PDT) X-Google-Smtp-Source: AGHT+IEOB0FovDmJMWiAczOt+st9w/YGQAhqOEOsMFMcs9zkOeNn6NLpFPp2mWC5LMWJqaHx++tm7w== X-Received: by 2002:a05:600c:8b45:b0:43b:c6a7:ac60 with SMTP id 5b1f17b1804b1-4533c92e57bmr12390675e9.10.1749849496527; Fri, 13 Jun 2025 14:18:16 -0700 (PDT) Received: from ?IPV6:2003:d8:2f1a:3700:2982:b5f7:a04e:4cb4? (p200300d82f1a37002982b5f7a04e4cb4.dip0.t-ipconnect.de. [2003:d8:2f1a:3700:2982:b5f7:a04e:4cb4]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4532e172b03sm63129605e9.36.2025.06.13.14.18.12 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 13 Jun 2025 14:18:15 -0700 (PDT) Message-ID: <09b66a3f-e7f9-43b2-be9a-bbf6310b3c43@redhat.com> Date: Fri, 13 Jun 2025 23:18:12 +0200 Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v12 08/18] KVM: guest_memfd: Allow host to map guest_memfd pages To: Sean Christopherson , Fuad Tabba Cc: kvm@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-mm@kvack.org, kvmarm@lists.linux.dev, pbonzini@redhat.com, chenhuacai@kernel.org, mpe@ellerman.id.au, anup@brainfault.org, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, 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: <20250611133330.1514028-1-tabba@google.com> <20250611133330.1514028-9-tabba@google.com> From: David Hildenbrand 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: X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: yoWtdDJ0bxX9dOJzeG_bhIRc_OGUmIpZFL6gNRlo4vs_1749849497 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 13.06.25 23:03, Sean Christopherson wrote: > On Wed, Jun 11, 2025, Fuad Tabba wrote: >> This patch enables support for shared memory in guest_memfd, including > > Please don't lead with with "This patch", simply state what changes are being > made as a command. Agrred. > >> mapping that memory from host userspace. > >> This functionality is gated by the KVM_GMEM_SHARED_MEM Kconfig option, >> and enabled for a given instance by the GUEST_MEMFD_FLAG_SUPPORT_SHARED >> flag at creation time. > > Why? I can see that from the patch. > > This changelog is way, way, waaay too light on details. Agreed. Sorry for jumping in at > the 11th hour, but we've spent what, 2 years working on this? It's late in Germany on a Friday, so I am probably grumpy, but most of what you raise (terminology ...) was been discussed plenty of times before either during review here or during the upstream calls ... :( Anyhow, happy for your review feedback on this series at this point, but this is just the perfect time to shutdown my computer on a Friday evening, knowing we will need another 2 years until this is finally upstream if we keep going like that. (again, sorry to be grumpy, but this is not the stuff I want to be reading at the 11th hour) -- Cheers, David / dhildenb