From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58248) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YDaJT-00062e-28 for qemu-devel@nongnu.org; Tue, 20 Jan 2015 10:01:52 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YDaJM-0006if-SM for qemu-devel@nongnu.org; Tue, 20 Jan 2015 10:01:51 -0500 Sender: Paolo Bonzini Message-ID: <54BE6DCC.5080609@redhat.com> Date: Tue, 20 Jan 2015 16:01:32 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <1419294981-17368-1-git-send-email-mark.cave-ayland@ilande.co.uk> <1419294981-17368-6-git-send-email-mark.cave-ayland@ilande.co.uk> In-Reply-To: <1419294981-17368-6-git-send-email-mark.cave-ayland@ilande.co.uk> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 5/7] ppc: force update of all msr bits in cpu_post_load List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Mark Cave-Ayland , qemu-ppc@nongnu.org, qemu-devel@nongnu.org, agraf@suse.de On 23/12/2014 01:36, 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 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 > --- > 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..9669063 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 all msr bits invalid before restoring */ > + msr = env->msr; > + env->msr = ~env->msr; > + ppc_store_msr(env, msr); > + > hreg_compute_mem_idx(env); > > return 0; > This is wrong for this line of hreg_store_msr: if (unlikely((env->flags & POWERPC_FLAG_TGPR) && ((value ^ env->msr) & (1 << MSR_TGPR)))) { /* Swap temporary saved registers with GPRs */ hreg_swap_gpr_tgpr(env); } I think you need to change the ~ with "^ ~(1 << MSR_TGPR)". Paolo