From: "Nikunj A. Dadhania" <nikunj@amd.com>
To: Sean Christopherson <seanjc@google.com>, Borislav Petkov <bp@alien8.de>
Cc: linux-kernel@vger.kernel.org, thomas.lendacky@amd.com,
x86@kernel.org, kvm@vger.kernel.org, mingo@redhat.com,
tglx@linutronix.de, dave.hansen@linux.intel.com,
pgonda@google.com, pbonzini@redhat.com,
francescolavra.fl@gmail.com,
Alexey Makhalov <alexey.makhalov@broadcom.com>,
Juergen Gross <jgross@suse.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>
Subject: Re: [PATCH v16 12/13] x86/tsc: Switch to native sched clock
Date: Thu, 9 Jan 2025 12:02:14 +0530 [thread overview]
Message-ID: <4ab9dc76-4556-4a96-be0d-2c8ee942b113@amd.com> (raw)
In-Reply-To: <Z36vqqTgrZp5Y3ab@google.com>
On 1/8/2025 10:32 PM, Sean Christopherson wrote:
> On Wed, Jan 08, 2025, Borislav Petkov wrote:
>> On Wed, Jan 08, 2025 at 06:00:59AM -0800, Sean Christopherson wrote:
> For TDX guests, the TSC is _always_ "secure". So similar to singling out kvmclock,
> handling SNP's STSC but not the TDX case again leaves the kernel in an inconsistent
> state. Which is why I originally suggested[*] fixing the sched_clock mess in a
> generically;
> doing so would avoid the need to special case SNP or TDX in code> that doesn't/shouldn't care about SNP or TDX.
That is what I have attempted in this patch[1] where irrespective of SNP/TDX, whenever
TSC is picked up as a clock source, sched-clock will start using TSC instead of any
PV sched clock. This does not have any special case for STSC/SNP/TDX.
> [*] https://lore.kernel.org/all/ZurCbP7MesWXQbqZ@google.com
Regards
Nikunj
1. https://lore.kernel.org/kvm/20250106124633.1418972-13-nikunj@amd.com/
next prev parent reply other threads:[~2025-01-09 6:32 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-06 12:46 [PATCH v16 00/13] Add Secure TSC support for SNP guests Nikunj A Dadhania
2025-01-06 12:46 ` [PATCH v16 01/13] virt: sev-guest: Remove is_vmpck_empty() helper Nikunj A Dadhania
2025-01-07 18:38 ` Tom Lendacky
2025-01-09 9:43 ` [tip: x86/sev] " tip-bot2 for Nikunj A Dadhania
2025-01-06 12:46 ` [PATCH v16 02/13] virt: sev-guest: Replace GFP_KERNEL_ACCOUNT with GFP_KERNEL Nikunj A Dadhania
2025-01-07 18:40 ` Tom Lendacky
2025-01-09 9:43 ` [tip: x86/sev] " tip-bot2 for Nikunj A Dadhania
2025-01-06 12:46 ` [PATCH v16 03/13] x86/sev: Carve out and export SNP guest messaging init routines Nikunj A Dadhania
2025-01-09 9:43 ` [tip: x86/sev] " tip-bot2 for Nikunj A Dadhania
2025-01-06 12:46 ` [PATCH v16 04/13] x86/sev: Relocate SNP guest messaging routines to common code Nikunj A Dadhania
2025-01-09 9:43 ` [tip: x86/sev] " tip-bot2 for Nikunj A Dadhania
2025-01-06 12:46 ` [PATCH v16 05/13] x86/sev: Add Secure TSC support for SNP guests Nikunj A Dadhania
2025-01-07 10:42 ` Borislav Petkov
2025-01-07 11:43 ` Nikunj A. Dadhania
2025-01-07 12:37 ` Borislav Petkov
2025-01-07 18:53 ` Tom Lendacky
2025-01-07 19:18 ` Borislav Petkov
2025-01-08 7:47 ` Nikunj A. Dadhania
2025-01-08 8:05 ` Borislav Petkov
2025-01-08 8:37 ` Nikunj A. Dadhania
2025-01-08 8:43 ` Borislav Petkov
2025-01-07 19:46 ` Tom Lendacky
2025-01-07 19:53 ` Borislav Petkov
2025-01-09 9:43 ` [tip: x86/sev] " tip-bot2 for Nikunj A Dadhania
2025-01-06 12:46 ` [PATCH v16 06/13] x86/sev: Change TSC MSR behavior for Secure TSC enabled guests Nikunj A Dadhania
2025-01-07 20:09 ` Tom Lendacky
2025-01-09 9:43 ` [tip: x86/sev] " tip-bot2 for Nikunj A Dadhania
2025-01-06 12:46 ` [PATCH v16 07/13] x86/sev: Prevent GUEST_TSC_FREQ MSR interception " Nikunj A Dadhania
2025-01-09 9:43 ` [tip: x86/sev] " tip-bot2 for Nikunj A Dadhania
2025-01-06 12:46 ` [PATCH v16 08/13] x86/sev: Prevent RDTSC/RDTSCP " Nikunj A Dadhania
2025-01-09 9:43 ` [tip: x86/sev] " tip-bot2 for Nikunj A Dadhania
2025-01-06 12:46 ` [PATCH v16 09/13] x86/sev: Mark Secure TSC as reliable clocksource Nikunj A Dadhania
2025-01-09 9:43 ` [tip: x86/sev] x86/sev: Mark the TSC in a secure TSC guest as reliable tip-bot2 for Nikunj A Dadhania
2025-01-06 12:46 ` [PATCH v16 10/13] x86/tsc: Switch Secure TSC guests away from kvm-clock Nikunj A Dadhania
2025-01-07 15:16 ` Borislav Petkov
2025-01-08 10:45 ` Nikunj A. Dadhania
2025-01-09 9:43 ` [tip: x86/sev] x86/tsc: Init the TSC for Secure TSC guests tip-bot2 for Nikunj A Dadhania
2025-01-06 12:46 ` [PATCH v16 11/13] x86/tsc: Upgrade TSC clocksource rating for guests Nikunj A Dadhania
2025-01-07 17:51 ` Borislav Petkov
2025-01-06 12:46 ` [PATCH v16 12/13] x86/tsc: Switch to native sched clock Nikunj A Dadhania
2025-01-07 19:37 ` Borislav Petkov
2025-01-08 5:20 ` Nikunj A. Dadhania
2025-01-08 8:22 ` Borislav Petkov
2025-01-08 8:34 ` Nikunj A. Dadhania
2025-01-08 10:20 ` Nikunj A. Dadhania
2025-01-08 14:00 ` Sean Christopherson
2025-01-08 15:34 ` Borislav Petkov
2025-01-08 17:02 ` Sean Christopherson
2025-01-08 19:53 ` Borislav Petkov
2025-01-09 6:32 ` Nikunj A. Dadhania [this message]
2025-01-15 21:37 ` Sean Christopherson
2025-01-16 16:25 ` Borislav Petkov
2025-01-16 16:56 ` Sean Christopherson
2025-01-17 20:28 ` Borislav Petkov
2025-01-17 20:59 ` Sean Christopherson
2025-01-21 11:32 ` Borislav Petkov
2025-01-21 3:59 ` Nikunj A. Dadhania
2025-01-28 5:41 ` Nikunj A Dadhania
2025-01-06 12:46 ` [PATCH v16 13/13] x86/sev: Allow Secure TSC feature for SNP guests Nikunj A Dadhania
2025-01-09 9:43 ` [tip: x86/sev] x86/sev: Add the " tip-bot2 for Nikunj A Dadhania
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