On 17.04.2018 09:17, David Gibson wrote:
> cpu_ppc_set_papr() removes the EP and HV bits from the MSR mask. While
> removing the HV bit makes sense (a cpu in PAPR mode should never be
> emulated in hypervisor mode), the EP bit is just bizarre. Although it's
> true that a papr mode guest shouldn't be able to change the exception
> prefix, the MSR[EP] bit doesn't even exist on the cpus supported for PAPR
> mode, so it's pointless to do anything with it here.
>
> Signed-off-by: David Gibson <da...@gibson.dropbear.id.au>
> ---
> target/ppc/translate_init.c | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/target/ppc/translate_init.c b/target/ppc/translate_init.c
> index 5e89901149..bb5559d799 100644
> --- a/target/ppc/translate_init.c
> +++ b/target/ppc/translate_init.c
> @@ -8870,12 +8870,11 @@ void cpu_ppc_set_papr(PowerPCCPU *cpu,
> PPCVirtualHypervisor *vhyp)
>
> cpu->vhyp = vhyp;
>
> - /* PAPR always has exception vectors in RAM not ROM. To ensure this,
> - * MSR[IP] should never be set.
> - *
> - * We also disallow setting of MSR_HV
> + /*
> + * With a virtual hypervisor mode we never allow the CPU to go
> + * hypervisor mode itself
> */
> - env->msr_mask &= ~((1ull << MSR_EP) | MSR_HVB);
> + env->msr_mask &= ~MSR_HVB;
>
> /* Tell KVM that we're in PAPR mode */
> if (kvm_enabled()) {
Looks right.
Reviewed-by: Thomas Huth <th...@redhat.com>
