target-arm: Add AArch64 ELR_EL1 register.

Add the AArch64 ELR_EL1 register.

Note that this does not live in env->cp15: for KVM migration
compatibility we need to migrate it separately rather than
as part of the system registers, because the KVM-to-userspace
interface puts it in the struct kvm_regs rather than making
them visible via the ONE_REG ioctls.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>

target-arm/cpu.h

@@ -162,6 +162,8 @@ typedef struct CPUARMState {
     uint32_t condexec_bits; /* IT bits.  cpsr[15:10,26:25].  */
     uint64_t daif; /* exception masks, in the bits they are in in PSTATE */
 
+    uint64_t elr_el1; /* AArch64 ELR_EL1 */
+
     /* System control coprocessor (cp15) */
     struct {
         uint32_t c0_cpuid;

target-arm/helper.c

@@ -1911,6 +1911,10 @@ static const ARMCPRegInfo v8_cp_reginfo[] = {
     { .name = "OSLAR_EL1", .state = ARM_CP_STATE_AA64,
       .opc0 = 2, .opc1 = 0, .crn = 1, .crm = 0, .opc2 = 4,
       .access = PL1_W, .type = ARM_CP_NOP },
+    { .name = "ELR_EL1", .state = ARM_CP_STATE_AA64,
+      .type = ARM_CP_NO_MIGRATE,
+      .opc0 = 3, .opc1 = 0, .crn = 4, .crm = 0, .opc2 = 1,
+      .access = PL1_RW, .fieldoffset = offsetof(CPUARMState, elr_el1) },
     REGINFO_SENTINEL
 };
 

target-arm/kvm64.c

@@ -144,9 +144,15 @@ int kvm_arch_put_registers(CPUState *cs, int level)
         return ret;
     }
 
+    reg.id = AARCH64_CORE_REG(elr_el1);
+    reg.addr = (uintptr_t) &env->elr_el1;
+    ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
+    if (ret) {
+        return ret;
+    }
+
     /* TODO:
      * SP_EL1
-     * ELR_EL1
      * SPSR[]
      * FP state
      * system registers
@@ -195,6 +201,13 @@ int kvm_arch_get_registers(CPUState *cs)
         return ret;
     }
 
+    reg.id = AARCH64_CORE_REG(elr_el1);
+    reg.addr = (uintptr_t) &env->elr_el1;
+    ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
+    if (ret) {
+        return ret;
+    }
+
     /* TODO: other registers */
     return ret;
 }

target-arm/machine.c

@@ -222,9 +222,9 @@ static int cpu_post_load(void *opaque, int version_id)
 
 const VMStateDescription vmstate_arm_cpu = {
     .name = "cpu",
-    .version_id = 14,
-    .minimum_version_id = 14,
-    .minimum_version_id_old = 14,
+    .version_id = 15,
+    .minimum_version_id = 15,
+    .minimum_version_id_old = 15,
     .pre_save = cpu_pre_save,
     .post_load = cpu_post_load,
     .fields = (VMStateField[]) {
@@ -243,6 +243,7 @@ const VMStateDescription vmstate_arm_cpu = {
         VMSTATE_UINT32_ARRAY(env.banked_r14, ARMCPU, 6),
         VMSTATE_UINT32_ARRAY(env.usr_regs, ARMCPU, 5),
         VMSTATE_UINT32_ARRAY(env.fiq_regs, ARMCPU, 5),
+        VMSTATE_UINT64(env.elr_el1, ARMCPU),
         /* The length-check must come before the arrays to avoid
          * incoming data possibly overflowing the array.
          */