From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To: "Nikunj A. Dadhania" <nikunj@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>,
linux-kernel@vger.kernel.org, x86@kernel.org,
kvm@vger.kernel.org, bp@alien8.de, mingo@redhat.com,
tglx@linutronix.de, dave.hansen@linux.intel.com,
dionnaglaze@google.com, pgonda@google.com, seanjc@google.com,
pbonzini@redhat.com
Subject: Re: [PATCH v5 09/14] x86/sev: Add Secure TSC support for SNP guests
Date: Mon, 6 Nov 2023 16:00:41 +0300 [thread overview]
Message-ID: <20231106130041.gqoqszdxrmdomsxl@box.shutemov.name> (raw)
In-Reply-To: <d419893f-3167-4a8f-aa4e-06e8ecd390d1@amd.com>
On Mon, Nov 06, 2023 at 04:15:59PM +0530, Nikunj A. Dadhania wrote:
> On 11/2/2023 4:06 PM, Kirill A. Shutemov wrote:
> > On Thu, Nov 02, 2023 at 11:11:52AM +0530, Nikunj A. Dadhania wrote:
> >> On 10/31/2023 1:56 AM, Tom Lendacky wrote:
> >>>> diff --git a/include/linux/cc_platform.h b/include/linux/cc_platform.h
> >>>> index cb0d6cd1c12f..e081ca4d5da2 100644
> >>>> --- a/include/linux/cc_platform.h
> >>>> +++ b/include/linux/cc_platform.h
> >>>> @@ -90,6 +90,14 @@ enum cc_attr {
> >>>> * Examples include TDX Guest.
> >>>> */
> >>>> CC_ATTR_HOTPLUG_DISABLED,
> >>>> +
> >>>> + /**
> >>>> + * @CC_ATTR_GUEST_SECURE_TSC: Secure TSC is active.
> >>>> + *
> >>>> + * The platform/OS is running as a guest/virtual machine and actively
> >>>> + * using AMD SEV-SNP Secure TSC feature.
> >>>
> >>> I think TDX also has a secure TSC like feature, so can this be generic?
> >>
> >> Yes, we can do that. In SNP case SecureTSC is an optional feature, not sure if that is the case for TDX as well.
> >>
> >> Kirill any inputs ?
> >
> > We have several X86_FEATURE_ flags to indicate quality of TSC. Do we
> > really need a CC_ATTR on top of that? Maybe SEV code could just set
> > X86_FEATURE_ according to what its TSC can do?
>
> For SEV-SNP, SEV_STATUS MSR has the information of various features
> that have been enabled by the hypervisor. We will need a CC_ATTR for
> these optional features.
If all users of the attribute is withing x86, I would rather add synthetic
X86_FEATURE_ flags than CC_ATTR_. We have better instrumentation around
features.
--
Kiryl Shutsemau / Kirill A. Shutemov
next prev parent reply other threads:[~2023-11-06 13:00 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-30 6:36 [PATCH v5 00/14] Add Secure TSC support for SNP guests Nikunj A Dadhania
2023-10-30 6:36 ` [PATCH v5 01/14] virt: sev-guest: Use AES GCM crypto library Nikunj A Dadhania
2023-10-30 17:51 ` Tom Lendacky
2023-11-02 3:33 ` Nikunj A. Dadhania
2023-10-30 6:36 ` [PATCH v5 02/14] virt: sev-guest: Move mutex to SNP guest device structure Nikunj A Dadhania
2023-10-30 6:36 ` [PATCH v5 03/14] virt: sev-guest: Replace dev_dbg with pr_debug Nikunj A Dadhania
2023-10-30 6:36 ` [PATCH v5 04/14] virt: sev-guest: Add SNP guest request structure Nikunj A Dadhania
2023-10-30 18:16 ` Tom Lendacky
2023-11-02 4:01 ` Nikunj A. Dadhania
2023-10-30 6:36 ` [PATCH v5 05/14] virt: sev-guest: Add vmpck_id to snp_guest_dev struct Nikunj A Dadhania
2023-10-30 16:16 ` Dionna Amalie Glaze
2023-10-30 17:12 ` Tom Lendacky
2023-11-02 4:03 ` Nikunj A. Dadhania
2023-10-30 18:26 ` Tom Lendacky
2023-10-30 6:36 ` [PATCH v5 06/14] x86/sev: Cache the secrets page address Nikunj A Dadhania
2023-10-30 6:36 ` [PATCH v5 07/14] x86/sev: Move and reorganize sev guest request api Nikunj A Dadhania
2023-10-30 19:16 ` Tom Lendacky
2023-11-02 4:28 ` Nikunj A. Dadhania
2023-11-02 14:17 ` Tom Lendacky
2023-10-30 6:36 ` [PATCH v5 08/14] x86/mm: Add generic guest initialization hook Nikunj A Dadhania
2023-10-30 17:23 ` Dave Hansen
2023-11-02 4:30 ` Nikunj A. Dadhania
2023-10-30 19:19 ` Tom Lendacky
2023-11-02 5:08 ` Nikunj A. Dadhania
2023-10-30 6:36 ` [PATCH v5 09/14] x86/sev: Add Secure TSC support for SNP guests Nikunj A Dadhania
2023-10-30 16:46 ` Dionna Amalie Glaze
2023-11-02 5:13 ` Nikunj A. Dadhania
2023-10-30 20:26 ` Tom Lendacky
2023-11-02 5:36 ` Nikunj A. Dadhania
2023-11-02 14:29 ` Tom Lendacky
2023-11-02 5:41 ` Nikunj A. Dadhania
2023-11-02 10:36 ` Kirill A. Shutemov
2023-11-06 10:45 ` Nikunj A. Dadhania
2023-11-06 13:00 ` Kirill A. Shutemov [this message]
2023-10-30 6:36 ` [PATCH v5 10/14] x86/sev: Change TSC MSR behavior for Secure TSC enabled guests Nikunj A Dadhania
2023-10-30 6:36 ` [PATCH v5 11/14] x86/sev: Prevent RDTSC/RDTSCP interception " Nikunj A Dadhania
2023-10-30 20:32 ` Tom Lendacky
2023-11-02 5:47 ` Nikunj A. Dadhania
2023-10-30 6:36 ` [PATCH v5 12/14] x86/kvmclock: Skip kvmclock when Secure TSC is available Nikunj A Dadhania
2023-10-30 21:00 ` Tom Lendacky
2023-11-02 5:39 ` Nikunj A. Dadhania
2023-10-30 6:36 ` [PATCH v5 13/14] x86/tsc: Mark Secure TSC as reliable clocksource Nikunj A Dadhania
2023-10-30 17:18 ` Dave Hansen
2023-11-02 5:53 ` Nikunj A. Dadhania
2023-11-02 10:33 ` Kirill A. Shutemov
2023-11-02 12:07 ` Nikunj A. Dadhania
2023-11-02 12:16 ` Nikunj A. Dadhania
2023-11-02 12:38 ` Kirill A. Shutemov
2023-11-06 11:53 ` Nikunj A. Dadhania
2023-11-06 13:03 ` Kirill A. Shutemov
2023-10-30 6:36 ` [PATCH v5 14/14] x86/sev: Enable Secure TSC for SNP guests Nikunj A Dadhania
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