linux-kernel - Re: [PATCH v2 13/15] KVM: x86: Kill cur_tsc

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Message-ID: <87bce8896d05c026647a957ad49de5c5582a766b.camel@infradead.org>
Date: Tue, 14 May 2024 14:17:16 +0100
From: David Woodhouse <dwmw2@...radead.org>
To: Chenyi Qiang <chenyi.qiang@...el.com>, kvm@...r.kernel.org
Cc: Paolo Bonzini <pbonzini@...hat.com>, Jonathan Corbet <corbet@....net>, 
 Sean Christopherson <seanjc@...gle.com>, Thomas Gleixner
 <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>, Borislav Petkov
 <bp@...en8.de>, Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
 "H. Peter Anvin" <hpa@...or.com>,  Paul Durrant <paul@....org>, Shuah Khan
 <shuah@...nel.org>, linux-doc@...r.kernel.org, 
 linux-kernel@...r.kernel.org, linux-kselftest@...r.kernel.org, Oliver Upton
 <oliver.upton@...ux.dev>, Marcelo Tosatti <mtosatti@...hat.com>, 
 jalliste@...zon.co.uk, sveith@...zon.de, zide.chen@...el.com, Dongli Zhang
 <dongli.zhang@...cle.com>
Subject: Re: [PATCH v2 13/15] KVM: x86: Kill cur_tsc_{nsec,offset,write}
 fields

On Fri, 2024-05-10 at 17:03 +0800, Chenyi Qiang wrote:
> 
> Do we need to track vcpu->arch.this_tsc_nsec/this_tsc_write? At least
> they are still used in compute_guest_tsc() to calculate the guest
> tsc.

Ah yes, that's true. Good catch; thanks.

That should be caught by a test case which runs the guest TSC at a
higher speed than the host, but *without* hardware TSC scaling.

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