From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35145) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xccfx-00076s-I3 for qemu-devel@nongnu.org; Fri, 10 Oct 2014 12:04:23 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Xccfq-00084P-VK for qemu-devel@nongnu.org; Fri, 10 Oct 2014 12:04:17 -0400 Received: from mail-oi0-f50.google.com ([209.85.218.50]:60614) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xccfq-00084K-P7 for qemu-devel@nongnu.org; Fri, 10 Oct 2014 12:04:10 -0400 Received: by mail-oi0-f50.google.com with SMTP id i138so7074042oig.37 for ; Fri, 10 Oct 2014 09:04:10 -0700 (PDT) From: Greg Bellows Date: Fri, 10 Oct 2014 11:03:27 -0500 Message-Id: <1412957023-11105-17-git-send-email-greg.bellows@linaro.org> In-Reply-To: <1412957023-11105-1-git-send-email-greg.bellows@linaro.org> References: <1412957023-11105-1-git-send-email-greg.bellows@linaro.org> Subject: [Qemu-devel] [PATCH v6 16/32] target-arm: respect SCR.FW, SCR.AW and SCTLR.NMFI List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, peter.maydell@linaro.org, serge.fdrv@gmail.com, edgar.iglesias@gmail.com, aggelerf@ethz.ch From: Fabian Aggeler bits when modifying CPSR. Signed-off-by: Fabian Aggeler Signed-off-by: Greg Bellows --------------- v3 -> v4 - Fixed up conditions for ignoring CPSR.A/F updates by isolating to v7 and checking for the existence of EL3 and non-existence of EL2. --- target-arm/helper.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 59 insertions(+), 3 deletions(-) diff --git a/target-arm/helper.c b/target-arm/helper.c index 760e3f9..6d0f3ec 100644 --- a/target-arm/helper.c +++ b/target-arm/helper.c @@ -3645,9 +3645,6 @@ void cpsr_write(CPUARMState *env, uint32_t val, uint32_t mask) env->GE = (val >> 16) & 0xf; } - env->daif &= ~(CPSR_AIF & mask); - env->daif |= val & CPSR_AIF & mask; - if ((env->uncached_cpsr ^ val) & mask & CPSR_M) { if (bad_mode_switch(env, val & CPSR_M)) { /* Attempt to switch to an invalid mode: this is UNPREDICTABLE. @@ -3659,6 +3656,65 @@ void cpsr_write(CPUARMState *env, uint32_t val, uint32_t mask) switch_mode(env, val & CPSR_M); } } + + /* In a V7 implementation that incldoes the security extensions but does + * not include Virtualization Extensions the SCR.FW and SCR.AW bits control + * whether non-secure software is allowed to change the CPSR_F and CPSR_A + * bits respectively. + * + * In a V8 implementation, it is permitted for privileged software to + * change the CPSR A/F bits regardless of the SCR.AW/FW bits. However, + * when the SPSR is copied to the CPSR, the SCR.AW/FW bits control whether + * the CPSR.A/F bits are copied. + */ + if (!arm_feature(env, ARM_FEATURE_V8)) { + if ((mask & CPSR_A) && + (val & CPSR_A) != (env->uncached_cpsr & CPSR_A) && + arm_feature(env, ARM_FEATURE_EL3) && + !arm_feature(env, ARM_FEATURE_EL2) && + !(env->cp15.scr_el3 & SCR_AW) && !arm_is_secure(env)) { + qemu_log_mask(LOG_GUEST_ERROR, + "Ignoring attempt to switch CPSR_A flag from " + "non-secure world with SCR.AW bit clear\n"); + mask &= ~CPSR_A; + } + + if ((mask & CPSR_F) && + (val & CPSR_F) != (env->uncached_cpsr & CPSR_F)) { + /* + * The existence of the security extension (EL3) and the + * non-existence of the virtualization extension affects whether + * the CPSR.F bit can be modified. + */ + if (arm_feature(env, ARM_FEATURE_EL3) && + !arm_feature(env, ARM_FEATURE_EL2)) { + /* CPSR.F cannot be changed in nonsecure with SCR.FW clear */ + if (!(env->cp15.scr_el3 & SCR_FW) && !arm_is_secure(env)) { + qemu_log_mask(LOG_GUEST_ERROR, + "Ignoring attempt to switch CPSR_F flag from " + "non-secure world with SCR.FW bit clear\n"); + mask &= ~CPSR_F; + } + + /* Check whether non-maskable FIQ (NMFI) support is enabled. + * If this bit is set software is not allowed to mask + * FIQs, but is allowed to set CPSR_F to 0. + */ + if ((A32_BANKED_CURRENT_REG_GET(env, sctlr) & SCTLR_NMFI) && + (val & CPSR_F)) { + qemu_log_mask(LOG_GUEST_ERROR, + "Ignoring attempt to enable CPSR_F flag " + "(non-maskable FIQ [NMFI] support " + "enabled)\n"); + mask &= ~CPSR_F; + } + } + } + } + + env->daif &= ~(CPSR_AIF & mask); + env->daif |= val & CPSR_AIF & mask; + mask &= ~CACHED_CPSR_BITS; env->uncached_cpsr = (env->uncached_cpsr & ~mask) | (val & mask); } -- 1.8.3.2