Re: [PATCH] KVM: PPC: Book3S HV: Fix guest time accounting with VIRT_CPU_ACCOUNTING_GEN

From: Paul Mackerras
Date: Sun Mar 04 2018 - 18:01:17 EST


On Fri, Mar 02, 2018 at 11:51:56AM +0100, Laurent Vivier wrote:
> Since commit 8b24e69fc47e ("KVM: PPC: Book3S HV: Close race with testing
> for signals on guest entry"), if CONFIG_VIRT_CPU_ACCOUNTING_GEN is set, the
> guest time is not accounted to guest time and user time, but instead to
> system time.
>
> This is because guest_enter()/guest_exit() are called while interrupts
> are disabled and the tick counter cannot be updated between them.
>
> To fix that, move guest_exit() after local_irq_enable(), and as
> guest_enter() is called with IRQ disabled, calls guest_enter_irqoff()
> instead.
>
> Fixes: 8b24e69fc47e
> ("KVM: PPC: Book3S HV: Close race with testing for signals on guest entry")
> Signed-off-by: Laurent Vivier <lvivier@xxxxxxxxxx>

Thanks, applied to my kvm-ppc-fixes branch.

Paul.