Re: [PATCH v6 13/51] x86/acrn: Mark TSC frequency as known when using ACRN for calibration
Sean Christopherson <[email protected]> Mon, 10 Aug 2026 06:56:31 -0700
| Newsgroups | org.kernel.vger.linux-hyperv,dev.linux.lists.linux-coco,dev.linux.lists.virtualization,org.kernel.vger.kvm,org.kernel.vger.linux-kernel,org.xenproject.lists.xen-devel |
|---|---|
| Message-ID | <[email protected]> |
On Sat, Aug 08, 2026, David Woodhouse wrote:
> On Thu, 2026-08-06 at 16:35 -0700, Sean Christopherson wrote:
> > Mark the TSC frequency as known when using ACRN's PV CPUID information.
> > Per commit 81a71f51b89e ("x86/acrn: Set up timekeeping") and common sense,
> > the TSC freq is explicitly provided by the hypervisor.
> >
> > Signed-off-by: Sean Christopherson <[email protected]>
>
> Huh... does this literally get reverted completely in the very *next*
> patch in the series? Kind of weird, but I guess in some ways it makes
> sense...
The literal code gets reverted, but the functional change does not. Before this
change, ACRN is the only guest-side PV code that doesn't set X86_FEATURE_TSC_KNOWN_FREQ
when the hypervisor provides the exact frequency. I.e. this patch allows for
making the "No functional change intended" claim in the next patch.