[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH v9 14/26] target-arm: respect SCR.FW, SCR.AW and SCT
From: |
Greg Bellows |
Subject: |
[Qemu-devel] [PATCH v9 14/26] target-arm: respect SCR.FW, SCR.AW and SCTLR.NMFI |
Date: |
Wed, 5 Nov 2014 17:23:01 -0600 |
From: Fabian Aggeler <address@hidden>
Add checks of SCR AW/FW bits when performing writes of CPSR. These SCR bits
are used to control whether the CPSR masking bits can be adjusted from
non-secure state.
Signed-off-by: Fabian Aggeler <address@hidden>
Signed-off-by: Greg Bellows <address@hidden>
---
v8 -> v9
- Move cpsr_write mask filtering above mode switch.
- Replace conditional checks removed in v8.
v7 -> v8
- Fixed incorrect use of env->uncached_cpsr A/I/F to use env->daif instead.
- Removed incorrect statement about SPSR to CPSR copies being affected by
SCR.AW/FW.
- Fix typo in comment.
- Simpified cpsr_write logic
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 | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 57 insertions(+), 2 deletions(-)
diff --git a/target-arm/helper.c b/target-arm/helper.c
index 70ba884..1091e0b 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -3644,6 +3644,8 @@ uint32_t cpsr_read(CPUARMState *env)
void cpsr_write(CPUARMState *env, uint32_t val, uint32_t mask)
{
+ uint32_t changed_daif;
+
if (mask & CPSR_NZCV) {
env->ZF = (~val) & CPSR_Z;
env->NF = val;
@@ -3666,8 +3668,57 @@ 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;
+ /* In a V7 implementation that includes 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.
+ */
+ if (!arm_feature(env, ARM_FEATURE_V8) &&
+ arm_feature(env, ARM_FEATURE_EL3) &&
+ !arm_feature(env, ARM_FEATURE_EL2) &&
+ !arm_is_secure(env)) {
+
+ changed_daif = (env->daif ^ val) & mask;
+
+ if (changed_daif & CPSR_A) {
+ /* Check to see if we are allowed to change the masking of async
+ * abort exceptions from a non-secure state.
+ */
+ if (!(env->cp15.scr_el3 & SCR_AW)) {
+ 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 (changed_daif & CPSR_F) {
+ /* Check to see if we are allowed to change the masking of FIQ
+ * exceptions from a non-secure state.
+ */
+ if (!(env->cp15.scr_el3 & SCR_FW)) {
+ 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;
+ }
+ }
+ }
if ((env->uncached_cpsr ^ val) & mask & CPSR_M) {
if (bad_mode_switch(env, val & CPSR_M)) {
@@ -3680,6 +3731,10 @@ void cpsr_write(CPUARMState *env, uint32_t val, uint32_t
mask)
switch_mode(env, val & CPSR_M);
}
}
+
+ 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
- [Qemu-devel] [PATCH v9 02/26] target-arm: add async excp target_el function, (continued)
- [Qemu-devel] [PATCH v9 02/26] target-arm: add async excp target_el function, Greg Bellows, 2014/11/05
- [Qemu-devel] [PATCH v9 05/26] target-arm: add CPREG secure state support, Greg Bellows, 2014/11/05
- [Qemu-devel] [PATCH v9 06/26] target-arm: add secure state bit to CPREG hash, Greg Bellows, 2014/11/05
- [Qemu-devel] [PATCH v9 08/26] target-arm: move AArch32 SCR into security reglist, Greg Bellows, 2014/11/05
- [Qemu-devel] [PATCH v9 07/26] target-arm: insert AArch32 cpregs twice into hashtable, Greg Bellows, 2014/11/05
- [Qemu-devel] [PATCH v9 09/26] target-arm: implement IRQ/FIQ routing to Monitor mode, Greg Bellows, 2014/11/05
- [Qemu-devel] [PATCH v9 10/26] target-arm: add NSACR register, Greg Bellows, 2014/11/05
- [Qemu-devel] [PATCH v9 11/26] target-arm: add SDER definition, Greg Bellows, 2014/11/05
- [Qemu-devel] [PATCH v9 12/26] target-arm: add MVBAR support, Greg Bellows, 2014/11/05
- [Qemu-devel] [PATCH v9 13/26] target-arm: add SCTLR_EL3 and make SCTLR banked, Greg Bellows, 2014/11/05
- [Qemu-devel] [PATCH v9 14/26] target-arm: respect SCR.FW, SCR.AW and SCTLR.NMFI,
Greg Bellows <=
- [Qemu-devel] [PATCH v9 15/26] target-arm: make CSSELR banked, Greg Bellows, 2014/11/05
- [Qemu-devel] [PATCH v9 16/26] target-arm: make TTBR0/1 banked, Greg Bellows, 2014/11/05
- [Qemu-devel] [PATCH v9 17/26] target-arm: make TTBCR banked, Greg Bellows, 2014/11/05
- [Qemu-devel] [PATCH v9 18/26] target-arm: make DACR banked, Greg Bellows, 2014/11/05
- [Qemu-devel] [PATCH v9 19/26] target-arm: make IFSR banked, Greg Bellows, 2014/11/05
- [Qemu-devel] [PATCH v9 20/26] target-arm: make DFSR banked, Greg Bellows, 2014/11/05
- [Qemu-devel] [PATCH v9 21/26] target-arm: make IFAR/DFAR banked, Greg Bellows, 2014/11/05
- [Qemu-devel] [PATCH v9 22/26] target-arm: make PAR banked, Greg Bellows, 2014/11/05
- [Qemu-devel] [PATCH v9 23/26] target-arm: make VBAR banked, Greg Bellows, 2014/11/05
- [Qemu-devel] [PATCH v9 24/26] target-arm: make c13 cp regs banked (FCSEIDR, ...), Greg Bellows, 2014/11/05