On Mon, Jun 12, 2017 at 10:08:16AM +0100, Marc Zyngier wrote:
> Nit: Please fix the time on your machine. It ended up in my Spam folder
> because it comes from the future...
>
> On 12/06/17 15:37, Hu Huajun wrote:
> > When reading the cntpct_el0 in guest with VHE (Virtual Host Extension)
> > enabled in host, the "Unsupported guest sys_reg access" error reported.
> > The reason is cnthctl_el2.EL1PCTEN is not enabled, which is expected
> > to be done in kvm_timer_init_vhe(). The problem is kvm_timer_init_vhe
> > is called by cpu_init_hyp_mode, and which is called when VHE is disabled.
> > This patch remove the incorrect call to kvm_timer_init_vhe() from
> > cpu_init_hyp_mode(), and calls kvm_timer_init_vhe() to enable
> > cnthctl_el2.EL1PCTEN in cpu_hyp_reinit().
> >
> > Changes from v1:
> > * According to Christoffer Dall's comment, remove the incocrrect call
> > to kvm_timer_init_vhe() in cpu_init_hyp_mode().
> >
> > Signed-off-by: Hu Huajun <huhuajun@xxxxxxxxxx>
> > ---
> > virt/kvm/arm/arm.c | 4 +---
> > 1 file changed, 1 insertion(+), 3 deletions(-)
> >
> > diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
> > index 3417e18..a430125 100644
> > --- a/virt/kvm/arm/arm.c
> > +++ b/virt/kvm/arm/arm.c
> > @@ -1115,9 +1115,6 @@ static void cpu_init_hyp_mode(void *dummy)
> > __cpu_init_hyp_mode(pgd_ptr, hyp_stack_ptr, vector_ptr);
> > __cpu_init_stage2();
> >
> > - if (is_kernel_in_hyp_mode())
> > - kvm_timer_init_vhe();
> > -
> > kvm_arm_init_debug();
> > }
> >
> > @@ -1137,6 +1134,7 @@ static void cpu_hyp_reinit(void)
> > * event was cancelled before the CPU was reset.
> > */
> > __cpu_init_stage2();
> > + kvm_timer_init_vhe();
> > } else {
> > cpu_init_hyp_mode(NULL);
> > }
> >
>
> How about:
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 488f94d7212b ("KVM: arm64: Access CNTHCTL_EL2 bit fields
> correctly on VHE systems")
Yes, definitely. I've added this.
>
> Otherwise:
>
> Acked-by: Marc Zyngier <marc.zyngier@xxxxxxx>
>
Thanks,
-Christoffer
