From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48870) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b8ny4-0001rY-GZ for qemu-devel@nongnu.org; Fri, 03 Jun 2016 08:12:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b8nxw-0002ig-Os for qemu-devel@nongnu.org; Fri, 03 Jun 2016 08:12:47 -0400 Received: from 18.mo1.mail-out.ovh.net ([46.105.35.72]:45040) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b8nxw-0002iD-IL for qemu-devel@nongnu.org; Fri, 03 Jun 2016 08:12:40 -0400 Received: from player729.ha.ovh.net (b9.ovh.net [213.186.33.59]) by mo1.mail-out.ovh.net (Postfix) with ESMTP id B285C10F012A for ; Fri, 3 Jun 2016 14:12:39 +0200 (CEST) From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= Date: Fri, 3 Jun 2016 14:11:18 +0200 Message-Id: <1464955880-10176-2-git-send-email-clg@kaod.org> In-Reply-To: <1464955880-10176-1-git-send-email-clg@kaod.org> References: <1464955880-10176-1-git-send-email-clg@kaod.org> Subject: [Qemu-devel] [PATCH 1/3] 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: David Gibson Cc: Benjamin Herrenschmidt , Mark Cave-Ayland , qemu-devel@nongnu.org, qemu-ppc@nongnu.org, Cedric Le Goater 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 --- 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 a37009eb2560..30e960e30b63 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 57da931e3c4d..12af61cbf19b 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; } -- 2.1.4