Add IS and FS bit in ISR_EL1 and handle the read. With CPU_INTERRUPT_NMI or
CPU_INTERRUPT_VNMI, both CPSR_I and ISR_IS must be set. With
CPU_INTERRUPT_VFIQ and HCRX_EL2.VFNMI set, both CPSR_F and ISR_FS must be set.

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
v7:
- env->cp15.hcrx_el2 -> arm_hcrx_el2_eff().
- Add Reviewed-by.
v6:
- Verify that HCR_EL2.VF is set before checking VFNMI.
v4；
- Also handle VNMI.
v3:
- CPU_INTERRUPT_NMI do not set FIQ, so remove it.
- With CPU_INTERRUPT_NMI, both CPSR_I and ISR_IS must be set.
---
 target/arm/cpu.h    |  2 ++
 target/arm/helper.c | 14 ++++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index de9446c68c..97f276559f 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -1467,6 +1467,8 @@ FIELD(CPTR_EL3, TCPAC, 31, 1)
 #define CPSR_N (1U << 31)
 #define CPSR_NZCV (CPSR_N | CPSR_Z | CPSR_C | CPSR_V)
 #define CPSR_AIF (CPSR_A | CPSR_I | CPSR_F)
+#define ISR_FS (1U << 9)
+#define ISR_IS (1U << 10)
 
 #define CPSR_IT (CPSR_IT_0_1 | CPSR_IT_2_7)
 #define CACHED_CPSR_BITS (CPSR_T | CPSR_AIF | CPSR_GE | CPSR_IT | CPSR_Q \
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 7cdc90e9e3..15f72fa425 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -2018,15 +2018,29 @@ static uint64_t isr_read(CPUARMState *env, const ARMCPRegInfo *ri)
         if (cs->interrupt_request & CPU_INTERRUPT_VIRQ) {
             ret |= CPSR_I;
         }
+        if (cs->interrupt_request & CPU_INTERRUPT_VNMI) {
+            ret |= ISR_IS;
+            ret |= CPSR_I;
+        }
     } else {
         if (cs->interrupt_request & CPU_INTERRUPT_HARD) {
             ret |= CPSR_I;
         }
+
+        if (cs->interrupt_request & CPU_INTERRUPT_NMI) {
+            ret |= ISR_IS;
+            ret |= CPSR_I;
+        }
     }
 
     if (hcr_el2 & HCR_FMO) {
         if (cs->interrupt_request & CPU_INTERRUPT_VFIQ) {
             ret |= CPSR_F;
+
+            if ((arm_hcr_el2_eff(env) & HCR_VF) &&
+                (arm_hcrx_el2_eff(env) & HCRX_VFNMI)) {
+                ret |= ISR_FS;
+            }
         }
     } else {
         if (cs->interrupt_request & CPU_INTERRUPT_FIQ) {
-- 
2.34.1