From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55418) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gAyeT-00086I-Re for qemu-devel@nongnu.org; Fri, 12 Oct 2018 10:42:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gAyeS-000364-U1 for qemu-devel@nongnu.org; Fri, 12 Oct 2018 10:42:53 -0400 From: Peter Maydell Date: Fri, 12 Oct 2018 15:42:34 +0100 Message-Id: <20181012144235.19646-10-peter.maydell@linaro.org> In-Reply-To: <20181012144235.19646-1-peter.maydell@linaro.org> References: <20181012144235.19646-1-peter.maydell@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: [Qemu-devel] [PATCH 09/10] target/arm: Get IL bit correct for v7 syndrome values List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-arm@nongnu.org, qemu-devel@nongnu.org Cc: patches@linaro.org For the v7 version of the Arm architecture, the IL bit in syndrome register values where the field is not valid was defined to be UNK/SBZP. In v8 this is RES1, which is what QEMU currently implements. Handle the desired v7 behaviour by squashing the IL bit for the affected cases: * EC == EC_UNCATEGORIZED * prefetch aborts * data aborts where ISV is 0 (The fourth case listed in the v8 Arm ARM DDI 0487C.a in section G7.2.70, "illegal state exception", can't happen on a v7 CPU.) This deals with a corner case noted in a comment. Signed-off-by: Peter Maydell --- target/arm/internals.h | 7 ++----- target/arm/helper.c | 14 ++++++++++++++ 2 files changed, 16 insertions(+), 5 deletions(-) diff --git a/target/arm/internals.h b/target/arm/internals.h index 516f9454e9b..cd8bc1ec3d4 100644 --- a/target/arm/internals.h +++ b/target/arm/internals.h @@ -286,11 +286,8 @@ static inline uint32_t syn_get_ec(uint32_t syn) /* Utility functions for constructing various kinds of syndrome value. * Note that in general we follow the AArch64 syndrome values; in a * few cases the value in HSR for exceptions taken to AArch32 Hyp - * mode differs slightly, so if we ever implemented Hyp mode then the - * syndrome value would need some massaging on exception entry. - * (One example of this is that AArch64 defaults to IL bit set for - * exceptions which don't specifically indicate information about the - * trapping instruction, whereas AArch32 defaults to IL bit clear.) + * mode differs slightly, and we fix this up when populating HSR in + * arm_cpu_do_interrupt_aarch32_hyp(). */ static inline uint32_t syn_uncategorized(void) { diff --git a/target/arm/helper.c b/target/arm/helper.c index 0b89804961b..0b659171b07 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -8299,6 +8299,20 @@ static void arm_cpu_do_interrupt_aarch32_hyp(CPUState *cs) } if (cs->exception_index != EXCP_IRQ && cs->exception_index != EXCP_FIQ) { + + if (!arm_feature(env, ARM_FEATURE_V8)) { + /* + * QEMU syndrome values are v8-style. v7 has the IL bit + * UNK/SBZP for "field not valid" cases, where v8 uses RES1. + * If this is a v7 CPU, squash the IL bit in those cases. + */ + if (cs->exception_index == EXCP_PREFETCH_ABORT || + (cs->exception_index == EXCP_DATA_ABORT && + !(env->exception.syndrome & ARM_EL_ISV)) || + syn_get_ec(env->exception.syndrome) == EC_UNCATEGORIZED) { + env->exception.syndrome &= ~ARM_EL_IL; + } + } env->cp15.esr_el[2] = env->exception.syndrome; } -- 2.19.0