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From: Sean Christopherson <seanjc@google.com>
To: sashiko-reviews@lists.linux.dev
Cc: kvm@vger.kernel.org
Subject: Re: [PATCH v8 07/17] KVM: x86: Move "no master clock" fallback from __get_kvmclock() to get_kvmclock()
Date: Wed, 5 Aug 2026 08:17:51 -0700	[thread overview]
Message-ID: <anNUHwk5JvUik6Ra@google.com> (raw)
In-Reply-To: <20260804235204.559041F00A3A@smtp.kernel.org>

On Tue, Aug 04, 2026, sashiko-bot@kernel.org wrote:
> commit cb25993776f1881f5ff66de261984bd8992ceece
> Author: Sean Christopherson <seanjc@google.com>
> 
> KVM: x86: Move "no master clock" fallback from __get_kvmclock() to get_kvmclock()
> 
> This commit refactors the kvmclock retrieval logic by extracting the master
> clock fallback out of the inner helper and changing it to return a boolean.
> 
> > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> > index b520928579129..7366d4602f89f 100644
> > --- a/arch/x86/kvm/x86.c
> > +++ b/arch/x86/kvm/x86.c
> 
> [ ... ]
> 
> > @@ -1667,8 +1673,6 @@ static void __get_kvmclock(struct kvm *kvm, struct kvm_clock_data *data)
> >  				   &hv_clock.tsc_shift,
> >  				   &hv_clock.tsc_to_system_mul);
> >  		data->clock = __pvclock_read_cycles(&hv_clock, data->host_tsc);
> > -	} else {
> > -		data->clock = get_kvmclock_base_ns() + ka->kvmclock_offset;
> >  	}
> >  }
> 
> [Severity: High]
> Does this function need to return true on the success path?

Doh, yes.  I botched the splitting and incorrectly added the "return true" in
"KVM: x86: Wrap all of __get_kvmclock_master_clock() with CONFIG_X86_64=y".  I'll
fix, and properly compile test all patches (I did that before splitting the patch,
but obviously not after).

  reply	other threads:[~2026-08-05 15:17 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-04 23:39 [PATCH v8 00/17] KVM: x86: Cleaning up the KVM clock mess, part 1 Sean Christopherson
2026-08-04 23:39 ` [PATCH v8 01/17] KVM: x86: Update "last guest TSC" snapshot prior to enabling IRQs/preemption Sean Christopherson
2026-08-04 23:39 ` [PATCH v8 02/17] KVM: x86: Improve accuracy of KVM clock when TSC scaling is in force Sean Christopherson
2026-08-04 23:39 ` [PATCH v8 03/17] KVM: x86: Explicitly disable TSC scaling without CONSTANT_TSC Sean Christopherson
2026-08-04 23:39 ` [PATCH v8 04/17] KVM: x86: Activate master clock immediately on vCPU creation Sean Christopherson
2026-08-05  0:06   ` sashiko-bot
2026-08-05  9:11     ` David Woodhouse
2026-08-05 15:02       ` Sean Christopherson
2026-08-04 23:39 ` [PATCH v8 05/17] KVM: x86: Avoid NTP frequency skew for KVM clock on 32-bit host Sean Christopherson
2026-08-05  0:02   ` sashiko-bot
2026-08-05 18:21     ` Sean Christopherson
2026-08-07  0:27       ` Sean Christopherson
2026-08-04 23:39 ` [PATCH v8 06/17] KVM: x86: Drop unnecessary CPU pinning when computing/getting kvmclock Sean Christopherson
2026-08-04 23:39 ` [PATCH v8 07/17] KVM: x86: Move "no master clock" fallback from __get_kvmclock() to get_kvmclock() Sean Christopherson
2026-08-04 23:52   ` sashiko-bot
2026-08-05 15:17     ` Sean Christopherson [this message]
2026-08-04 23:39 ` [PATCH v8 08/17] KVM: x86: Wrap all of __get_kvmclock_master_clock() with CONFIG_X86_64=y Sean Christopherson
2026-08-04 23:39 ` [PATCH v8 09/17] KVM: x86: Fall back to non-master-clock if clockread fails in get_kvmclock() Sean Christopherson
2026-08-04 23:39 ` [PATCH v8 10/17] KVM: x86: Fix KVM clock precision in get_kvmclock() with TSC scaling Sean Christopherson
2026-08-04 23:39 ` [PATCH v8 11/17] KVM: x86: Use get_kvmclock() in kvm_get_wall_clock_epoch() Sean Christopherson
2026-08-04 23:39 ` [PATCH v8 12/17] KVM: x86: Fix compute_guest_tsc() to handle negative time deltas Sean Christopherson
2026-08-04 23:39 ` [PATCH v8 13/17] KVM: x86: Disable preemption, not IRQs, when getting TSC+freq pair Sean Christopherson
2026-08-04 23:56   ` sashiko-bot
2026-08-05 15:16     ` Sean Christopherson
2026-08-05 15:55       ` David Woodhouse
2026-08-05 16:22         ` Sean Christopherson
2026-08-04 23:39 ` [PATCH v8 14/17] KVM: x86: Make master clock logic in guest PV clock updates 64-bit only Sean Christopherson
2026-08-04 23:39 ` [PATCH v8 15/17] KVM: x86: Upscale TSC to "now", not master clock when updating PV clocks Sean Christopherson
2026-08-04 23:39 ` [PATCH v8 16/17] KVM: x86: Simplify and comment kvm_get_time_scale() Sean Christopherson
2026-08-04 23:39 ` [PATCH v8 17/17] KVM: x86: Remove implicit rdtsc() from kvm_compute_l1_tsc_offset() Sean Christopherson

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