Re: [PATCH 2/6] kvm: x86: drop read_tsc_offset()

From	Paolo Bonzini <pbonzini@redhat.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH 2/6] kvm: x86: drop read_tsc_offset()
Date	2016-09-19 17:40 +0200
Message-ID	<sj8PL-7bp-3@gated-at.bofh.it> (permalink)
References	<si2jn-5SZ-3@gated-at.bofh.it> <si2jp-5SZ-55@gated-at.bofh.it> <sj8PL-7bp-5@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On 19/09/2016 17:30, Jim Mattson wrote:
> vmx_read_tsc_offset has a bug when running nested VMs.  It should really be:
> 
>        if (is_guest_mode(vcpu))
>                return to_vmx(vcpu)->nested.vmcs01_tsc_offset;
>        else
>                return vmcs_read64(TSC_OFFSET);
> 
> Perhaps a better name woulf be "vmx_get_l1_tsc_offset."

I agree, but doesn't this patch fix the bug too?

Paolo

> In any case, this does not seem consistent with vcpu->arch.tsc_offset.

Thread

[PATCH v2 0/6] kvm: x86: export TSC information to user-space Luiz Capitulino <lcapitulino@redhat.com> - 2016-09-16 16:30 +0200
  [PATCH 1/6] kvm: x86: add tsc_offset field to struct kvm_vcpu_arch Luiz Capitulino <lcapitulino@redhat.com> - 2016-09-16 16:30 +0200
  [PATCH 3/6] kvm: kvm_destroy_vm_debugfs(): check debugfs_stat_data pointer Luiz Capitulino <lcapitulino@redhat.com> - 2016-09-16 16:30 +0200
  [PATCH 4/6] kvm: add stubs for arch specific debugfs support Luiz Capitulino <lcapitulino@redhat.com> - 2016-09-16 16:30 +0200
  [PATCH 2/6] kvm: x86: drop read_tsc_offset() Luiz Capitulino <lcapitulino@redhat.com> - 2016-09-16 16:30 +0200
    Re: [PATCH 2/6] kvm: x86: drop read_tsc_offset() Paolo Bonzini <pbonzini@redhat.com> - 2016-09-19 17:40 +0200
      Re: [PATCH 2/6] kvm: x86: drop read_tsc_offset() Jim Mattson <jmattson@google.com> - 2016-09-20 00:20 +0200
        Re: [PATCH 2/6] kvm: x86: drop read_tsc_offset() Paolo Bonzini <pbonzini@redhat.com> - 2016-09-20 07:40 +0200
          Re: [PATCH 2/6] kvm: x86: drop read_tsc_offset() Paolo Bonzini <pbonzini@redhat.com> - 2016-09-21 17:30 +0200
            Re: [PATCH 2/6] kvm: x86: drop read_tsc_offset() Jim Mattson <jmattson@google.com> - 2016-09-21 17:40 +0200
          Re: [PATCH 2/6] kvm: x86: drop read_tsc_offset() Jim Mattson <jmattson@google.com> - 2016-09-21 17:30 +0200
    Re: [PATCH 2/6] kvm: x86: drop read_tsc_offset() Jim Mattson <jmattson@google.com> - 2016-09-19 17:40 +0200
  Re: [PATCH v2 0/6] kvm: x86: export TSC information to user-space Paolo Bonzini <pbonzini@redhat.com> - 2016-09-16 17:00 +0200
    Re: [PATCH v2 0/6] kvm: x86: export TSC information to user-space Luiz Capitulino <lcapitulino@redhat.com> - 2016-09-16 17:00 +0200
      Re: [PATCH v2 0/6] kvm: x86: export TSC information to user-space Paolo Bonzini <pbonzini@redhat.com> - 2016-09-16 17:10 +0200
        Re: [PATCH v2 0/6] kvm: x86: export TSC information to user-space Luiz Capitulino <lcapitulino@redhat.com> - 2016-09-16 17:20 +0200

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