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Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Long Li , Ajay Kaher , Alexey Makhalov , Jan Kiszka , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Juergen Gross , Daniel Lezcano , Thomas Gleixner , John Stultz , Vitaly Kuznetsov , Broadcom internal kernel review list , Boris Ostrovsky , Stephen Boyd , Miroslav Lichvar , x86@kernel.org, linux-coco@lists.linux.dev, kvm@vger.kernel.org, linux-hyperv@vger.kernel.org, virtualization@lists.linux.dev, linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, Michael Kelley , Tom Lendacky , Nikunj A Dadhania , Thomas Gleixner Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable On Thu, Sep 10, 2026, David Woodhouse wrote: > On Thu, 2026-09-10 at 10:59 -0700, Sean Christopherson wrote: > > On Thu, Aug 06, 2026, Sean Christopherson wrote: > > > The primary goal of this series to fix flaws with SNP and TDX guests = where a > > > PV clock provided by the untrusted hypervisor is used instead of the = secure > > > TSC that is controlled by trusted firmware. > > >=20 > > > The secondary goal is modernize running under KVM.=C2=A0 Currently, K= VM guests will > > > use TSC for clocksource, but not sched_clock.=C2=A0 And Linux-as-a-KV= M-guest doesn't > > > support paravirt enumeration of the TSC/APIC frequencies, even though= QEMU > > > provides that information by default. > > >=20 > > > The tertiary goal is to clean up the PV clock code to deduplicate log= ic across > > > hypervisors, and to hopefully make it all easier to maintain going fo= rward. > > >=20 > > > The quaternary goal is to clean up the TSC calibration code, which wa= s made > > > stupidly hard to follow by hypervisor code mixing in with the native > > > calibration routines, instead of being implemented as a pure alternat= ive. > > >=20 > > > Note, the VMware and Xen changes still probably should get acks from = those > > > maintainers, as my understanding of what they're trying to do may be = flawed. > >=20 > > This (thankfully) still applies cleanly.=C2=A0 What can I do to help mo= ve this forward? >=20 > Nudge Thomas to spot that this is guest-side and we want him to pick it u= p, I guess? Amazingly, still applies cleanly on 7.4-rc1 and tip/master. I know we're s= hortly after the merge window, but this has been sitting idle for months and addre= sses issues that are impacting a variety of end users. Note, this also provides meaningful hardening for SNP and TDX. /me stares = intently in the direction of Dave and Boris.