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Wed, 27 May 2026 20:17:18 +0000 (UTC) Date: Wed, 27 May 2026 13:17:10 -0700 From: Borislav Petkov To: Ashish Kalra Cc: tglx@kernel.org, mingo@redhat.com, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, seanjc@google.com, peterz@infradead.org, thomas.lendacky@amd.com, herbert@gondor.apana.org.au, davem@davemloft.net, ardb@kernel.org, pbonzini@redhat.com, aik@amd.com, Michael.Roth@amd.com, KPrateek.Nayak@amd.com, Tycho.Andersen@amd.com, Nathan.Fontenot@amd.com, ackerleytng@google.com, jackyli@google.com, pgonda@google.com, rientjes@google.com, jacobhxu@google.com, xin@zytor.com, pawan.kumar.gupta@linux.intel.com, babu.moger@amd.com, dyoung@redhat.com, nikunj@amd.com, john.allen@amd.com, darwi@linutronix.de, linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org, kvm@vger.kernel.org, linux-coco@lists.linux.dev Subject: Re: [PATCH v5 1/7] x86/cpufeatures: Add X86_FEATURE_AMD_RMPOPT feature flag Message-ID: <20260527201710.GAahdRRoHFOor425im@fat_crate.local> References: <305b625c0528f16a95542001c66e643fbd3a2622.1779133590.git.ashish.kalra@amd.com> Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <305b625c0528f16a95542001c66e643fbd3a2622.1779133590.git.ashish.kalra@amd.com> Content-Transfer-Encoding: quoted-printable On Mon, May 18, 2026 at 09:41:53PM +0000, Ashish Kalra wrote: > From: Ashish Kalra >=20 > Add a flag indicating whether RMPOPT instruction is supported. >=20 > RMPOPT is a new instruction designed to minimize the performance > overhead of RMP checks on the hypervisor and on non-SNP guests by > allowing RMP checks to be skipped when 1G regions of memory are known > not to contain any SEV-SNP guest memory. Streamline: "RMPOPT is a new instruction that reduces the performance overhead of RMP checks for the hypervisor and non=E2=80=91SNP guests by allowing those ch= ecks to be skipped when 1=E2=80=91GB memory regions are known to contain no SEV=E2=80= =91SNP guest memory." --=20 Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette