From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id CE44FC0219B for ; Tue, 11 Feb 2025 16:18:05 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 64D636B007B; Tue, 11 Feb 2025 11:18:05 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 5D6816B009D; Tue, 11 Feb 2025 11:18:05 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4502A280008; Tue, 11 Feb 2025 11:18:05 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 1FC396B007B for ; Tue, 11 Feb 2025 11:18:05 -0500 (EST) Received: from smtpin30.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id CC3B0A05DC for ; Tue, 11 Feb 2025 16:18:04 +0000 (UTC) X-FDA: 83108170488.30.5EE2019 Received: from mail-qt1-f182.google.com (mail-qt1-f182.google.com [209.85.160.182]) by imf11.hostedemail.com (Postfix) with ESMTP id 0995040019 for ; Tue, 11 Feb 2025 16:18:02 +0000 (UTC) Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=RZSmWfmb; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf11.hostedemail.com: domain of tabba@google.com designates 209.85.160.182 as permitted sender) smtp.mailfrom=tabba@google.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1739290683; a=rsa-sha256; cv=none; b=e9bxa8fYBh2EbrPPlcbzKjPbzp1cG7r6s9J8uEzNOnP1aez7Y43H06hnvNaO+bvSm6YwjJ P16hYBJZxq64UPF0i+ejeEe5xr+h6lCJjyjctN5wKIgbILy+BsrKqQJq+EitnRz5wX9LB3 kQFC03RubxDBa3CjSWj4L3Aggs6qLw8= ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=RZSmWfmb; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf11.hostedemail.com: domain of tabba@google.com designates 209.85.160.182 as permitted sender) smtp.mailfrom=tabba@google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1739290683; h=from:from:sender: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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=1P6rPw9a5wgRlWQeCB5ce6X5jA7i7I59rEFbE9TxC38=; b=xmkeASjm4OjWdYeY2qZxVuiK0CJOwSs6/R+jVVRrGK40wlE139Jsb/7Wj9BdFUYf1wH5Sj nPOBMcZl4GdbzBi8QINLb/TTmmm8zXxsLIANFobGlNgyf/+1KfdPDvKrrDnIaFCeS1Athj j5SY9Md/mLvoeglFXo0WsjfYtfMn9Gs= Received: by mail-qt1-f182.google.com with SMTP id d75a77b69052e-4718e224eb1so184281cf.1 for ; Tue, 11 Feb 2025 08:18:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1739290682; x=1739895482; darn=kvack.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=1P6rPw9a5wgRlWQeCB5ce6X5jA7i7I59rEFbE9TxC38=; b=RZSmWfmb0uVGW8Znx4CN/VdfJpGk4IMcuG+PazlRS7Tr6aGwymW/RIpgTi+kLEzNKT DAQZ+62MToFeXe6VMFrvzdlP5z6Vi+ZL/HIkdiuX/wQhn1LzGVJMwwisEQeyFfZRNc3X DulV10FzkQ63wL8XhJpg+o3HcGMqBXiMLW1/C/ninsBq6Ye+NJ4Z5wXP5lerLf19ryAN GrOHky2K54OTURKvLYjJLJxbsMHi8yPMLBVkZrPljOmPBzjNCcsJdk8dytKk8UQtFh+S aNiGoftxmAcJCLJ/3LoFJoSwtFldktZUO/MKNfuH89vTRuVAAuRosKWERFzGdwcHqnK3 MGDQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1739290682; x=1739895482; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=1P6rPw9a5wgRlWQeCB5ce6X5jA7i7I59rEFbE9TxC38=; b=FzIE4UgipWk/Uv1LAiCWhQBuv7yafQF4Nig0dlZxrNoBjMfrzcRefEa9rm8lSSChKI s/W1WukR/F58upgsFS/7vQEaaE2iipWRltWOKESt1NjT2nY/5hpZGh18NbP480sHHH+c JVJP+/YFijXI7s6pkLd0vqw5xdjV27MYTt6AC/VUpSgJgMjpeABBk+rwsdlVnNF9KWtT nrCQWagTQGgfEqCManVgyiQiYHweRqNWMEX6N/ixzVMb+X5z/Qn4XbqaEUfX4jHaMHo5 rO3JDJXwyzo5TaQe1QBt8uybeeNLqEmVaesXhkH/9j2spF65o3j0gldErllC7K95083q mp2A== X-Forwarded-Encrypted: i=1; AJvYcCWkl4twXU/npJd8/dWObUDlP+Tg2ALtnSwT8YKeN61YKCzW7pBe7jkcokt2WB0mmjt4Tc41+l1hbg==@kvack.org X-Gm-Message-State: AOJu0YxjelR+5TFWewlIod3H7w15duFTekC5F6HCcfkk1v8XbQzN/zQl tquxcoL/VsCtpQitdCmXL82wWrn/EXUqo2nS8YafZr0UP/RFKqwtdrX3o3jNvGdAmjYgD2j2tUM tWyDesctraCk9ESiXEK2gXriqTkxqp/jq9r6R X-Gm-Gg: ASbGncugq41G0gJDqkq+9eC/QSSAkF9g2mZ5beAw0CybEQBNTdOkLJ5i+HhIbw1/Yy0 3AtOD+GPBXvoDOIHowp41ObMTBQmmhCv1nZSGE46ujtxz0yVBpDKwKYXFZ5YnzfQajk+fCxc= X-Google-Smtp-Source: AGHT+IGRp/t/qyZgBNNs9uDbWDmGbv+wSRNshXJ/1B7IsIgm6NNprZWeBInojuq3Er9SgY46w7AA1qT4RgWppbOxFXI= X-Received: by 2002:a05:622a:1a8a:b0:465:18f3:79c8 with SMTP id d75a77b69052e-471a40eca3amr3647231cf.13.1739290681809; Tue, 11 Feb 2025 08:18:01 -0800 (PST) MIME-Version: 1.0 References: <20250211121128.703390-1-tabba@google.com> <20250211121128.703390-10-tabba@google.com> In-Reply-To: From: Fuad Tabba Date: Tue, 11 Feb 2025 16:17:25 +0000 X-Gm-Features: AWEUYZleK4-0g5_ZXLVnzOqYNfblXwrznWvqo5s0DcKLyDLPZbzlg5mmY8W_67k Message-ID: Subject: Re: [PATCH v3 09/11] KVM: arm64: Introduce KVM_VM_TYPE_ARM_SW_PROTECTED machine type To: Quentin Perret Cc: kvm@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-mm@kvack.org, 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, yu.c.zhang@linux.intel.com, isaku.yamahata@intel.com, mic@digikod.net, vbabka@suse.cz, vannapurve@google.com, ackerleytng@google.com, mail@maciej.szmigiero.name, david@redhat.com, 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, 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 Content-Type: text/plain; charset="UTF-8" X-Rspam-User: X-Rspamd-Queue-Id: 0995040019 X-Rspamd-Server: rspam12 X-Stat-Signature: 1m8444g9ikgye5m16eix9eaa8xq5r4k5 X-HE-Tag: 1739290682-111819 X-HE-Meta: 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 zQ8wAn/l u2QahMRSW5hhcJgeTleAn4dbayKJpbdXYXvgpoqvZdw+gfRAZfaYowPRQROZMd6+M/LFoxwvv9YoUAEHs6OGFBnYGQzpgNUePvmnTh4i4ajzQvBthrN5Eyk3OohzEYKckQvv33vkiCW4LC2tgSYlQbg8mkeNsxvjjakpxOomVDihm1hUjgyd8H5spNPiT1RVcVDNj1e5CB2UqkxrJy1IQSy+B8yKsLKtuZewtBWjzOvzgmXcUn+lX2rDUS025sEqRBplDXkxLgykfr6eqsxxDpaPKhP2CpIIm92MS94uug1lAczCUhpXBUQQFnyb5TDVMfRMxGpxDH/Sap1xWNkWkOf9ZbA== X-Bogosity: Ham, tests=bogofilter, spamicity=0.006999, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Hi Quentin, On Tue, 11 Feb 2025 at 16:12, Quentin Perret wrote: > > Hi Fuad, > > On Tuesday 11 Feb 2025 at 12:11:25 (+0000), Fuad Tabba wrote: > > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > > index 117937a895da..f155d3781e08 100644 > > --- a/include/uapi/linux/kvm.h > > +++ b/include/uapi/linux/kvm.h > > @@ -652,6 +652,12 @@ struct kvm_enable_cap { > > #define KVM_VM_TYPE_ARM_IPA_SIZE_MASK 0xffULL > > #define KVM_VM_TYPE_ARM_IPA_SIZE(x) \ > > ((x) & KVM_VM_TYPE_ARM_IPA_SIZE_MASK) > > + > > +#define KVM_VM_TYPE_ARM_SW_PROTECTED (1UL << 9) > > FWIW, the downstream Android code has used bit 31 since forever > for that. > > Although I very much believe that upstream should not care about the > downstream mess in general, in this particular instance bit 9 really > isn't superior in any way, and there's a bunch of existing userspace > code that uses bit 31 today as we speak. It is very much Android's > problem to update these userspace programs if we do go with bit 9 > upstream, but I don't really see how that would benefit upstream > either. > > So, given that there is no maintenance cost for upstream to use bit 31 > instead of 9, I'd vote for using bit 31 and ease the landing with > existing userspace code, unless folks are really opinionated with this > stuff :) My thinking is that this bit does _not_ mean pKVM. It means an experimental software VM that is similar to the x86 KVM_X86_SW_PROTECTED_VM. Hence why I didn't choose bit 31. >From Documentation/virt/kvm/api.rst (for x86): ''' Note, KVM_X86_SW_PROTECTED_VM is currently only for development and testing. Do not use KVM_X86_SW_PROTECTED_VM for "real" VMs, and especially not in production. The behavior and effective ABI for software-protected VMs is unstable. ''' which is similar to the documentation I added here. Cheers, /fuad > Thanks, > Quentin > > > +#define KVM_VM_TYPE_MASK (KVM_VM_TYPE_ARM_IPA_SIZE_MASK | \ > > + KVM_VM_TYPE_ARM_SW_PROTECTED) > > + > > /* > > * ioctls for /dev/kvm fds: > > */ > > -- > > 2.48.1.502.g6dc24dfdaf-goog > >