From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Date: Wed, 28 Jul 2021 14:17:27 +0100 From: Christoph Hellwig Subject: Re: [PATCH 01/11] mm: Introduce a function to check for virtualization protection features Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Tom Lendacky Cc: linux-kernel@vger.kernel.org, x86@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, iommu@lists.linux-foundation.org, kvm@vger.kernel.org, linux-efi@vger.kernel.org, platform-driver-x86@vger.kernel.org, linux-graphics-maintainer@vmware.com, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, kexec@lists.infradead.org, linux-fsdevel@vger.kernel.org, Andi Kleen , Tianyu Lan , Borislav Petkov , Brijesh Singh On Tue, Jul 27, 2021 at 05:26:04PM -0500, Tom Lendacky via iommu wrote: > In prep for other protected virtualization technologies, introduce a > generic helper function, prot_guest_has(), that can be used to check > for specific protection attributes, like memory encryption. This is > intended to eliminate having to add multiple technology-specific checks > to the code (e.g. if (sev_active() || tdx_active())). So common checks obviously make sense, but I really hate the stupid multiplexer. Having one well-documented helper per feature is much easier to follow. > +#define PATTR_MEM_ENCRYPT 0 /* Encrypted memory */ > +#define PATTR_HOST_MEM_ENCRYPT 1 /* Host encrypted memory */ > +#define PATTR_GUEST_MEM_ENCRYPT 2 /* Guest encrypted memory */ > +#define PATTR_GUEST_PROT_STATE 3 /* Guest encrypted state */ The kerneldoc comments on these individual helpers will give you plenty of space to properly document what they indicate and what a (potential) caller should do based on them. Something the above comments completely fail to. _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec