From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45950) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bAEYc-0006w2-15 for qemu-devel@nongnu.org; Tue, 07 Jun 2016 06:48:27 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bAEYW-00055F-Kw for qemu-devel@nongnu.org; Tue, 07 Jun 2016 06:48:25 -0400 From: David Gibson Date: Tue, 7 Jun 2016 20:47:59 +1000 Message-Id: <1465296493-10851-13-git-send-email-david@gibson.dropbear.id.au> In-Reply-To: <1465296493-10851-1-git-send-email-david@gibson.dropbear.id.au> References: <1465296493-10851-1-git-send-email-david@gibson.dropbear.id.au> Subject: [Qemu-devel] [PULL 12/26] ppc: Fix hreg_store_msr() so that non-HV mode cannot alter MSR:HV List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: peter.maydell@linaro.org Cc: agraf@suse.de, qemu-ppc@nongnu.org, qemu-devel@nongnu.org, Benjamin Herrenschmidt , David Gibson From: Benjamin Herrenschmidt This helper is only used by the various instructions that can alter MSR and not interrupts. Add a comment to that effect to the interrupt code as well in case somebody wants to change this Signed-off-by: Benjamin Herrenschmidt Reviewed-by: David Gibson Signed-off-by: David Gibson --- target-ppc/excp_helper.c | 8 ++++++-- target-ppc/helper_regs.h | 4 ++-- 2 files changed, 8 insertions(+), 4 deletions(-) diff --git a/target-ppc/excp_helper.c b/target-ppc/excp_helper.c index a37009e..30e960e 100644 --- a/target-ppc/excp_helper.c +++ b/target-ppc/excp_helper.c @@ -709,8 +709,12 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp) } } #endif - /* XXX: we don't use hreg_store_msr here as already have treated - * any special case that could occur. Just store MSR and update hflags + /* We don't use hreg_store_msr here as already have treated + * any special case that could occur. Just store MSR and update hflags + * + * Note: We *MUST* not use hreg_store_msr() as-is anyway because it + * will prevent setting of the HV bit which some exceptions might need + * to do. */ env->msr = new_msr & env->msr_mask; hreg_compute_hflags(env); diff --git a/target-ppc/helper_regs.h b/target-ppc/helper_regs.h index 57da931..12af61c 100644 --- a/target-ppc/helper_regs.h +++ b/target-ppc/helper_regs.h @@ -114,8 +114,8 @@ static inline int hreg_store_msr(CPUPPCState *env, target_ulong value, excp = 0; value &= env->msr_mask; #if !defined(CONFIG_USER_ONLY) - if (!alter_hv) { - /* mtmsr cannot alter the hypervisor state */ + /* Neither mtmsr nor guest state can alter HV */ + if (!alter_hv || !(env->msr & MSR_HVB)) { value &= ~MSR_HVB; value |= env->msr & MSR_HVB; } -- 2.5.5