Re: [Qemu-devel] [PATCHv2 5/7] target-ppc: force update of msr bits in cpu_post_load

[Alexander Graf <agraf@suse.de>]

On 21.01.15 17:01, Mark Cave-Ayland wrote:
> Since env->msr has already been restored by the time cpu_post_load is called,
> make sure that ppc_store_msr() is explicitly called with all msr bits except
> MSR_TGPR marked as invalid.
> 
> This solves the issue where MSR flags aren't set correctly when restoring a VM
> snapshot, in particular the internal env->excp_prefix value when MSR_EP has
> been altered by a guest.
> 
> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> ---
>  target-ppc/machine.c |    8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/target-ppc/machine.c b/target-ppc/machine.c
> index c801b82..fc8ddcd 100644
> --- a/target-ppc/machine.c
> +++ b/target-ppc/machine.c
> @@ -159,6 +159,7 @@ static int cpu_post_load(void *opaque, int version_id)
>      PowerPCCPU *cpu = opaque;
>      CPUPPCState *env = &cpu->env;
>      int i;
> +    target_ulong msr;
>  
>      /*
>       * We always ignore the source PVR. The user or management
> @@ -190,7 +191,12 @@ static int cpu_post_load(void *opaque, int version_id)
>          /* Restore htab_base and htab_mask variables */
>          ppc_store_sdr1(env, env->spr[SPR_SDR1]);
>      }
> -    hreg_compute_hflags(env);
> +
> +    /* Mark msr bits except MSR_TGPR invalid before restoring */
> +    msr = env->msr;
> +    env->msr ^= ~(1 << MSR_TGPR);

Doesn't this need to be 1ULL?


Alex

> +    ppc_store_msr(env, msr);
> +
>      hreg_compute_mem_idx(env);
>  
>      return 0;
>