From: K Prateek Nayak <kprateek.nayak@amd.com>
To: Borislav Petkov <bp@alien8.de>
Cc: Ashish Kalra <Ashish.Kalra@amd.com>, <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>, <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 v10 2/6] x86/sev: Initialize RMPOPT configuration MSRs
Date: Thu, 23 Jul 2026 11:28:47 +0530 [thread overview]
Message-ID: <70580cfc-8625-4f35-a77b-7154a52e10a5@amd.com> (raw)
In-Reply-To: <20260723051422.GGamGjLhlTqRDcFlee@fat_crate.local>
Hello Boris,
On 7/23/2026 10:44 AM, Borislav Petkov wrote:
> On Thu, Jul 23, 2026 at 10:23:56AM +0530, K Prateek Nayak wrote:
>> The offline cores will remain offline since hotplug is disabled. RMPOPT
>> is simply a performance optimization for RMP checks and leaving the
>> offline cores (that will never exit idle) unoptimized should be
>> acceptable.
>
> What happens if you boot with a subset of cores, the boot flow enables RMPOPT
> and then you online the rest?
RMPOPT happens at __sev_snp_init_locked() for all online cores. Until
then, SnpEn is still 0 and we don't need RMPOPT because RMP checks
haven't been enabled yet.
>
> Have we tried that?
That said, Ashish, should snp_rmptable_init() do a
snp_rmpopt_all_physmem() (or something equivalent) when it finds SNP_EN
set in MSR_AMD64_SYSCFG after a kexec?
--
Thanks and Regards,
Prateek
next prev parent reply other threads:[~2026-07-23 5:59 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-30 18:08 [PATCH v10 0/6] Add RMPOPT support Ashish Kalra
2026-06-30 18:09 ` [PATCH v10 1/6] x86/cpufeatures: Add X86_FEATURE_RMPOPT feature flag Ashish Kalra
2026-07-20 21:12 ` Borislav Petkov
2026-06-30 18:10 ` [PATCH v10 2/6] x86/sev: Initialize RMPOPT configuration MSRs Ashish Kalra
2026-07-20 22:17 ` Borislav Petkov
2026-07-20 22:38 ` Kalra, Ashish
2026-07-21 1:48 ` Borislav Petkov
2026-07-21 14:26 ` Kalra, Ashish
2026-07-21 14:57 ` K Prateek Nayak
2026-07-21 20:46 ` Kalra, Ashish
2026-07-22 2:46 ` K Prateek Nayak
2026-07-22 19:17 ` Kalra, Ashish
2026-07-21 15:32 ` Borislav Petkov
2026-07-23 1:10 ` Borislav Petkov
2026-07-23 4:53 ` K Prateek Nayak
2026-07-23 5:14 ` Borislav Petkov
2026-07-23 5:58 ` K Prateek Nayak [this message]
2026-07-23 7:03 ` Kalra, Ashish
2026-07-23 7:16 ` K Prateek Nayak
2026-07-23 8:00 ` Kalra, Ashish
2026-07-23 6:50 ` Kalra, Ashish
2026-07-23 13:24 ` Kalra, Ashish
2026-07-23 14:29 ` K Prateek Nayak
2026-07-23 18:32 ` Borislav Petkov
2026-06-30 18:11 ` [PATCH v10 3/6] x86/sev: Disable CPU hotplug while SNP is active Ashish Kalra
2026-07-01 9:40 ` Jethro Beekman
2026-07-01 16:39 ` K Prateek Nayak
2026-07-01 21:08 ` Kalra, Ashish
2026-07-01 21:25 ` Kalra, Ashish
2026-07-06 12:02 ` Jethro Beekman
2026-07-23 18:53 ` Borislav Petkov
2026-07-23 19:44 ` Kalra, Ashish
2026-07-23 20:00 ` Borislav Petkov
2026-07-23 20:39 ` Kalra, Ashish
2026-07-23 22:19 ` Kalra, Ashish
2026-06-30 18:11 ` [PATCH v10 4/6] x86/sev: Add support to perform RMP optimizations asynchronously Ashish Kalra
2026-07-21 15:06 ` K Prateek Nayak
2026-07-22 19:43 ` Kalra, Ashish
2026-06-30 18:11 ` [PATCH v10 5/6] x86/sev: Add interface to re-enable RMP optimizations Ashish Kalra
2026-06-30 18:12 ` [PATCH v10 6/6] KVM: SEV: Perform RMP optimizations on SNP guest shutdown Ashish Kalra
2026-07-20 20:17 ` [PATCH v10 0/6] Add RMPOPT support Kalra, Ashish
2026-07-20 20:28 ` Borislav Petkov
2026-07-20 20:39 ` Kalra, Ashish
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