From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f44.google.com (mail-ej1-f44.google.com [209.85.218.44]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A923BD305 for ; Fri, 28 Jul 2023 09:25:28 +0000 (UTC) Received: by mail-ej1-f44.google.com with SMTP id a640c23a62f3a-99357737980so271150366b.2 for ; Fri, 28 Jul 2023 02:25:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1690536326; x=1691141126; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=MyDeksRVqGtJNd0fe/itajI8E9fXoiZCjVyZ7emrXms=; b=yZlBBa+QgG6A3izqrAvYrZmjNARnJqe9UVJDDaWeo1ngnmOt9VRY93kWsBg3OxlgJ6 BNgAnv6T/0ObsR7NeaCjk+WNJnmyD7Q59yeCq15kUZEqjsFvHdvXA60zH7S6F25/qIjt fm8Sg5o5MpunPrL/BqoXYGZy7msDjit8jc0wg2EmQ6Q8Th8F7S82AjrHRl+/FMq8bTJh sEoAOBkEqP29Krhf8xqYypp/joUWh9VUOF8DEcZIisv2V3iWTfC6qxmMhKHNjRW9HI9T TolK5KmZ7NzIlhfQCguxbwjQDJpXunGMqxws18N6XaE4FtdLuzrmk4BalRM99UvIXMiI LjuA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690536326; x=1691141126; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=MyDeksRVqGtJNd0fe/itajI8E9fXoiZCjVyZ7emrXms=; b=OeWq0hCGIhveWlZZb1WAbCMWCzRBLGurrF2Kpc4Z1T4RGhtKsNEfWqyOcdlY1wovOS 7xGs1YCVa2tzCnWK+zaGVfAy5LIdjRjBu4oY5Tz18SevdK9MCln9p6rD6nXK1XjGFIiY /f8xCUdC54uhWqrusMB8633Qdg9gM7q4HZGTKcNhamx09WSrUnwl0rZw4fnNR82r5qrT qqDQPfGolyBax3285LyPcb/gIcpcuawr0Hegi4/AGZgsbwgzu0ZJqvolb2aDHzZGbeZm bMJ9DTg/XfEcEDNdRtuE9iX1IlzUqtFoAU1uyO+k28WTigMi87ttKgc65z/5v0i3zxiM O1iw== X-Gm-Message-State: ABy/qLY7keBWal1nCABh3o84pzDwngnO6NkV6Zsv+MxpVMgt+HYQWEjy pQ74SvDK5Pvh/4llhcDq877xOQ== X-Google-Smtp-Source: APBJJlG4DNtaaix3llwTkCcLiQNG9ALlnJv6ynH+2HDeVn6HzB3Xx8i5ieUEd323eDEBkV9C48RmSw== X-Received: by 2002:a17:906:8454:b0:994:1fee:3065 with SMTP id e20-20020a170906845400b009941fee3065mr1975862ejy.15.1690536326590; Fri, 28 Jul 2023 02:25:26 -0700 (PDT) Received: from google.com (64.227.90.34.bc.googleusercontent.com. [34.90.227.64]) by smtp.gmail.com with ESMTPSA id n12-20020a170906688c00b00992c92af6f4sm1857653ejr.144.2023.07.28.02.25.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 28 Jul 2023 02:25:26 -0700 (PDT) Date: Fri, 28 Jul 2023 09:25:22 +0000 From: Quentin Perret To: Sean Christopherson Cc: Paolo Bonzini , Marc Zyngier , Oliver Upton , Huacai Chen , Michael Ellerman , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , "Matthew Wilcox (Oracle)" , Andrew Morton , Paul Moore , James Morris , "Serge E. Hallyn" , kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, Chao Peng , Fuad Tabba , Jarkko Sakkinen , Yu Zhang , Vishal Annapurve , Ackerley Tng , Maciej Szmigiero , Vlastimil Babka , David Hildenbrand , Michael Roth , Wang , Liam Merwick , Isaku Yamahata , "Kirill A . Shutemov" Subject: Re: [RFC PATCH v11 06/29] KVM: Introduce KVM_SET_USER_MEMORY_REGION2 Message-ID: References: <20230718234512.1690985-1-seanjc@google.com> <20230718234512.1690985-7-seanjc@google.com> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230718234512.1690985-7-seanjc@google.com> On Tuesday 18 Jul 2023 at 16:44:49 (-0700), Sean Christopherson wrote: > --- a/include/uapi/linux/kvm.h > +++ b/include/uapi/linux/kvm.h > @@ -95,6 +95,16 @@ struct kvm_userspace_memory_region { > __u64 userspace_addr; /* start of the userspace allocated memory */ > }; > > +/* for KVM_SET_USER_MEMORY_REGION2 */ > +struct kvm_userspace_memory_region2 { > + __u32 slot; > + __u32 flags; > + __u64 guest_phys_addr; > + __u64 memory_size; > + __u64 userspace_addr; > + __u64 pad[16]; Should we replace that pad[16] with: __u64 size; where 'size' is the size of the structure as seen by userspace? This is used in other UAPIs (see struct sched_attr for example) and is a bit more robust for future extensions (e.g. an 'old' kernel can correctly reject a newer version of the struct with additional fields it doesn't know about if that makes sense, etc).