Re: [PATCH] kvm: ppc: booke: Restore SPRG3 when entering guest

Alexander Graf
2014-07-17T16:10:59Z

On 16.07.14 08:02, Bharat Bhushan wrote:
> SPRG3 is guest accessible and SPRG3 can be clobbered by host
> or another guest, So this need to be restored when loading
> guest state.
>
> Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
> ---
> arch/powerpc/kvm/booke_interrupts.S | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/powerpc/kvm/booke_interrupts.S b/arch/powerpc/kvm/booke_interrupts.S
> index 2c6deb5ef..0d3403f 100644
> --- a/arch/powerpc/kvm/booke_interrupts.S
> +++ b/arch/powerpc/kvm/booke_interrupts.S
> @@ -459,6 +459,8 @@ lightweight_exit:
> * written directly to the shared area, so we
> * need to reload them here with the guest's values.
> */
> + PPC_LD(r3, VCPU_SHARED_SPRG3, r5)
> + mtspr SPRN_SPRG3, r3

We also need to restore it when resuming the host, no?

Alex

> PPC_LD(r3, VCPU_SHARED_SPRG4, r5)
> mtspr SPRN_SPRG4W, r3
> PPC_LD(r3, VCPU_SHARED_SPRG5, r5)