target/arm: Implement virtual SError exceptions

Virtual SError exceptions are raised by setting HCR_EL2.VSE,
and are routed to EL1 just like other virtual exceptions.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220506180242.216785-16-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 39 insertions, 1 deletions

diff --git a/target/arm/helper.c b/target/arm/helper.c
index b6faebf4a7..4857d2dbb8 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -1863,7 +1863,12 @@ static uint64_t isr_read(CPUARMState *env, const ARMCPRegInfo *ri)
         }
     }
 
-    /* External aborts are not possible in QEMU so A bit is always clear */
+    if (hcr_el2 & HCR_AMO) {
+        if (cs->interrupt_request & CPU_INTERRUPT_VSERR) {
+            ret |= CPSR_A;
+        }
+    }
+
     return ret;
 }
 
@@ -5175,6 +5180,7 @@ static void do_hcr_write(CPUARMState *env, uint64_t value, uint64_t valid_mask)
     g_assert(qemu_mutex_iothread_locked());
     arm_cpu_update_virq(cpu);
     arm_cpu_update_vfiq(cpu);
+    arm_cpu_update_vserr(cpu);
 }
 
 static void hcr_write(CPUARMState *env, const ARMCPRegInfo *ri, uint64_t value)
@@ -9331,6 +9337,7 @@ void arm_log_exception(CPUState *cs)
             [EXCP_LSERR] = "v8M LSERR UsageFault",
             [EXCP_UNALIGNED] = "v7M UNALIGNED UsageFault",
             [EXCP_DIVBYZERO] = "v7M DIVBYZERO UsageFault",
+            [EXCP_VSERR] = "Virtual SERR",
         };
 
         if (idx >= 0 && idx < ARRAY_SIZE(excnames)) {
@@ -9843,6 +9850,31 @@ static void arm_cpu_do_interrupt_aarch32(CPUState *cs)
         mask = CPSR_A | CPSR_I | CPSR_F;
         offset = 4;
         break;
+    case EXCP_VSERR:
+        {
+            /*
+             * Note that this is reported as a data abort, but the DFAR
+             * has an UNKNOWN value.  Construct the SError syndrome from
+             * AET and ExT fields.
+             */
+            ARMMMUFaultInfo fi = { .type = ARMFault_AsyncExternal, };
+
+            if (extended_addresses_enabled(env)) {
+                env->exception.fsr = arm_fi_to_lfsc(&fi);
+            } else {
+                env->exception.fsr = arm_fi_to_sfsc(&fi);
+            }
+            env->exception.fsr |= env->cp15.vsesr_el2 & 0xd000;
+            A32_BANKED_CURRENT_REG_SET(env, dfsr, env->exception.fsr);
+            qemu_log_mask(CPU_LOG_INT, "...with IFSR 0x%x\n",
+                          env->exception.fsr);
+
+            new_mode = ARM_CPU_MODE_ABT;
+            addr = 0x10;
+            mask = CPSR_A | CPSR_I;
+            offset = 8;
+        }
+        break;
     case EXCP_SMC:
         new_mode = ARM_CPU_MODE_MON;
         addr = 0x08;
@@ -10063,6 +10095,12 @@ static void arm_cpu_do_interrupt_aarch64(CPUState *cs)
     case EXCP_VFIQ:
         addr += 0x100;
         break;
+    case EXCP_VSERR:
+        addr += 0x180;
+        /* Construct the SError syndrome from IDS and ISS fields. */
+        env->exception.syndrome = syn_serror(env->cp15.vsesr_el2 & 0x1ffffff);
+        env->cp15.esr_el[new_el] = env->exception.syndrome;
+        break;
     default:
         cpu_abort(cs, "Unhandled exception 0x%x\n", cs->exception_index);
     }