On Fri, 2018-04-13 at 17:35 +0200, Paolo Bonzini wrote:
> On 13/04/2018 14:40, Raslan, KarimAllah wrote:
> >
> > >
> > >
> > > static void update_ia32_tsc_adjust_msr(struct kvm_vcpu *vcpu, s64 offset)
> > > {
> > > - u64 curr_offset = vcpu->arch.tsc_offset;
> > > + u64 curr_offset = kvm_x86_ops->read_l1_tsc_offset(vcpu);
> > I might be missing something but is this really strictly needed or is
> > it really a bug?
> >
> > I can see update_ia32_tsc_adjust_msr called from kvm_write_tsc only
> > which is called from a) vmx_set_msr or b) kvm_arch_vcpu_postcreate.
> > The adjust_msr would only be called if !host_initiated. So only
> > vmx_set_msr which is coming from an L1 write (or a restore but that
> > would not be !host_initiated). So the only that tsc_adjust is called is
> > !is_guest_mode.
>
> It can also be called from guest mode if the MSR bitmap says there's no
> L1 vmexit for that MSR; that's what the testcases do.
Apparently I will never wrap my head around this nested stuff :D
>
> Paolo
>
> >
> > >
> > > vcpu->arch.ia32_tsc_adjust_msr += offset - curr_offset;
>
>
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