Re: [PATCH v2] KVM: hyperv: fix locking of struct kvm_hv fields

[Roman Kagan]

On Mon, Dec 12, 2016 at 10:12:53AM +0100, Paolo Bonzini wrote:
> Introduce a new mutex to avoid an AB-BA deadlock between kvm->lock and
> vcpu->mutex.  Protect accesses in kvm_hv_setup_tsc_page too, as suggested
> by Roman.
> 
> Reported-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
> Cc: Roman Kagan <rkagan@xxxxxxxxxxxxx>
> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> ---
>  Documentation/virtual/kvm/locking.txt |  8 ++++++--
>  arch/x86/include/asm/kvm_host.h       |  1 +
>  arch/x86/kvm/hyperv.c                 | 24 +++++++++++++++---------
>  arch/x86/kvm/x86.c                    |  1 +
>  4 files changed, 23 insertions(+), 11 deletions(-)

Reviewed-by: Roman Kagan <rkagan@xxxxxxxxxxxxx>