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authorPeter Collingbourne <pcc@google.com>2021-06-16 12:56:14 -0700
committerPeter Maydell <peter.maydell@linaro.org>2021-06-21 17:12:52 +0100
commit80fd1f22fc3a95b69b5b25d47c9727e7659da2ff (patch)
treeabdf5aae6ca448686e05120bf98ab5fb7edfb9e7
parentd93a468d1302f29afcb1e368fb39da3fe024fc39 (diff)
downloadqemu-arm-80fd1f22fc3a95b69b5b25d47c9727e7659da2ff.tar.gz
target/arm: Implement MTE3
MTE3 introduces an asymmetric tag checking mode, in which loads are checked synchronously and stores are checked asynchronously. Add support for it. Signed-off-by: Peter Collingbourne <pcc@google.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20210616195614.11785-1-pcc@google.com [PMM: Add line to emulation.rst] Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
-rw-r--r--docs/system/arm/emulation.rst1
-rw-r--r--target/arm/cpu64.c2
-rw-r--r--target/arm/mte_helper.c82
3 files changed, 53 insertions, 32 deletions
diff --git a/docs/system/arm/emulation.rst b/docs/system/arm/emulation.rst
index 836c1ca845..144dc491d9 100644
--- a/docs/system/arm/emulation.rst
+++ b/docs/system/arm/emulation.rst
@@ -29,6 +29,7 @@ the following architecture extensions:
- FEAT_LSE (Large System Extensions)
- FEAT_MTE (Memory Tagging Extension)
- FEAT_MTE2 (Memory Tagging Extension)
+- FEAT_MTE3 (MTE Asymmetric Fault Handling)
- FEAT_PAN (Privileged access never)
- FEAT_PAN2 (AT S1E1R and AT S1E1W instruction variants affected by PSTATE.PAN)
- FEAT_PAuth (Pointer authentication)
diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
index 1c23187d1a..c7a1626bec 100644
--- a/target/arm/cpu64.c
+++ b/target/arm/cpu64.c
@@ -683,7 +683,7 @@ static void aarch64_max_initfn(Object *obj)
* during realize if the board provides no tag memory, much like
* we do for EL2 with the virtualization=on property.
*/
- t = FIELD_DP64(t, ID_AA64PFR1, MTE, 2);
+ t = FIELD_DP64(t, ID_AA64PFR1, MTE, 3);
cpu->isar.id_aa64pfr1 = t;
t = cpu->isar.id_aa64mmfr0;
diff --git a/target/arm/mte_helper.c b/target/arm/mte_helper.c
index 9e615cc513..724175210b 100644
--- a/target/arm/mte_helper.c
+++ b/target/arm/mte_helper.c
@@ -538,13 +538,50 @@ void HELPER(stzgm_tags)(CPUARMState *env, uint64_t ptr, uint64_t val)
}
}
+static void mte_sync_check_fail(CPUARMState *env, uint32_t desc,
+ uint64_t dirty_ptr, uintptr_t ra)
+{
+ int is_write, syn;
+
+ env->exception.vaddress = dirty_ptr;
+
+ is_write = FIELD_EX32(desc, MTEDESC, WRITE);
+ syn = syn_data_abort_no_iss(arm_current_el(env) != 0, 0, 0, 0, 0, is_write,
+ 0x11);
+ raise_exception_ra(env, EXCP_DATA_ABORT, syn, exception_target_el(env), ra);
+ g_assert_not_reached();
+}
+
+static void mte_async_check_fail(CPUARMState *env, uint64_t dirty_ptr,
+ uintptr_t ra, ARMMMUIdx arm_mmu_idx, int el)
+{
+ int select;
+
+ if (regime_has_2_ranges(arm_mmu_idx)) {
+ select = extract64(dirty_ptr, 55, 1);
+ } else {
+ select = 0;
+ }
+ env->cp15.tfsr_el[el] |= 1 << select;
+#ifdef CONFIG_USER_ONLY
+ /*
+ * Stand in for a timer irq, setting _TIF_MTE_ASYNC_FAULT,
+ * which then sends a SIGSEGV when the thread is next scheduled.
+ * This cpu will return to the main loop at the end of the TB,
+ * which is rather sooner than "normal". But the alternative
+ * is waiting until the next syscall.
+ */
+ qemu_cpu_kick(env_cpu(env));
+#endif
+}
+
/* Record a tag check failure. */
static void mte_check_fail(CPUARMState *env, uint32_t desc,
uint64_t dirty_ptr, uintptr_t ra)
{
int mmu_idx = FIELD_EX32(desc, MTEDESC, MIDX);
ARMMMUIdx arm_mmu_idx = core_to_aa64_mmu_idx(mmu_idx);
- int el, reg_el, tcf, select, is_write, syn;
+ int el, reg_el, tcf;
uint64_t sctlr;
reg_el = regime_el(env, arm_mmu_idx);
@@ -564,14 +601,8 @@ static void mte_check_fail(CPUARMState *env, uint32_t desc,
switch (tcf) {
case 1:
/* Tag check fail causes a synchronous exception. */
- env->exception.vaddress = dirty_ptr;
-
- is_write = FIELD_EX32(desc, MTEDESC, WRITE);
- syn = syn_data_abort_no_iss(arm_current_el(env) != 0, 0, 0, 0, 0,
- is_write, 0x11);
- raise_exception_ra(env, EXCP_DATA_ABORT, syn,
- exception_target_el(env), ra);
- /* noreturn, but fall through to the assert anyway */
+ mte_sync_check_fail(env, desc, dirty_ptr, ra);
+ break;
case 0:
/*
@@ -583,30 +614,19 @@ static void mte_check_fail(CPUARMState *env, uint32_t desc,
case 2:
/* Tag check fail causes asynchronous flag set. */
- if (regime_has_2_ranges(arm_mmu_idx)) {
- select = extract64(dirty_ptr, 55, 1);
- } else {
- select = 0;
- }
- env->cp15.tfsr_el[el] |= 1 << select;
-#ifdef CONFIG_USER_ONLY
- /*
- * Stand in for a timer irq, setting _TIF_MTE_ASYNC_FAULT,
- * which then sends a SIGSEGV when the thread is next scheduled.
- * This cpu will return to the main loop at the end of the TB,
- * which is rather sooner than "normal". But the alternative
- * is waiting until the next syscall.
- */
- qemu_cpu_kick(env_cpu(env));
-#endif
+ mte_async_check_fail(env, dirty_ptr, ra, arm_mmu_idx, el);
break;
- default:
- /* Case 3: Reserved. */
- qemu_log_mask(LOG_GUEST_ERROR,
- "Tag check failure with SCTLR_EL%d.TCF%s "
- "set to reserved value %d\n",
- reg_el, el ? "" : "0", tcf);
+ case 3:
+ /*
+ * Tag check fail causes asynchronous flag set for stores, or
+ * a synchronous exception for loads.
+ */
+ if (FIELD_EX32(desc, MTEDESC, WRITE)) {
+ mte_async_check_fail(env, dirty_ptr, ra, arm_mmu_idx, el);
+ } else {
+ mte_sync_check_fail(env, desc, dirty_ptr, ra);
+ }
break;
}
}