target-arm: Implement AArch64 SPSR_EL1

Implement the AArch64 SPSR_EL1. For compatibility with how KVM
handles SPSRs and with the architectural mapping between AArch32
and AArch64, we put this in the banked_spsr[] array in the slot
that is used for SVC in AArch32. This means we need to extend the
array from uint32_t to uint64_t, which requires some reworking
of the 32 bit KVM save/restore code.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>

target-arm/cpu.h

@@ -143,7 +143,7 @@ typedef struct CPUARMState {
     uint32_t spsr;
 
     /* Banked registers.  */
-    uint32_t banked_spsr[6];
+    uint64_t banked_spsr[6];
     uint32_t banked_r13[6];
     uint32_t banked_r14[6];
 

target-arm/helper.c

@@ -1936,6 +1936,10 @@ static const ARMCPRegInfo v8_cp_reginfo[] = {
       .type = ARM_CP_NO_MIGRATE,
       .opc0 = 3, .opc1 = 0, .crn = 4, .crm = 0, .opc2 = 1,
       .access = PL1_RW, .fieldoffset = offsetof(CPUARMState, elr_el1) },
+    { .name = "SPSR_EL1", .state = ARM_CP_STATE_AA64,
+      .type = ARM_CP_NO_MIGRATE,
+      .opc0 = 3, .opc1 = 0, .crn = 4, .crm = 0, .opc2 = 0,
+      .access = PL1_RW, .fieldoffset = offsetof(CPUARMState, banked_spsr[0]) },
     /* We rely on the access checks not allowing the guest to write to the
      * state field when SPSel indicates that it's being used as the stack
      * pointer.

target-arm/kvm32.c

@@ -295,6 +295,14 @@ typedef struct Reg {
         offsetof(CPUARMState, vfp.xregs[ARM_VFP_##R])      \
     }
 
+/* Like COREREG, but handle fields which are in a uint64_t in CPUARMState. */
+#define COREREG64(KERNELNAME, QEMUFIELD)                     \
+    {                                                        \
+        KVM_REG_ARM | KVM_REG_SIZE_U32 |                     \
+        KVM_REG_ARM_CORE | KVM_REG_ARM_CORE_REG(KERNELNAME), \
+        offsetoflow32(CPUARMState, QEMUFIELD)                \
+    }
+
 static const Reg regs[] = {
     /* R0_usr .. R14_usr */
     COREREG(usr_regs.uregs[0], regs[0]),
@@ -315,16 +323,16 @@ static const Reg regs[] = {
     /* R13, R14, SPSR for SVC, ABT, UND, IRQ banks */
     COREREG(svc_regs[0], banked_r13[1]),
     COREREG(svc_regs[1], banked_r14[1]),
-    COREREG(svc_regs[2], banked_spsr[1]),
+    COREREG64(svc_regs[2], banked_spsr[1]),
     COREREG(abt_regs[0], banked_r13[2]),
     COREREG(abt_regs[1], banked_r14[2]),
-    COREREG(abt_regs[2], banked_spsr[2]),
+    COREREG64(abt_regs[2], banked_spsr[2]),
     COREREG(und_regs[0], banked_r13[3]),
     COREREG(und_regs[1], banked_r14[3]),
-    COREREG(und_regs[2], banked_spsr[3]),
+    COREREG64(und_regs[2], banked_spsr[3]),
     COREREG(irq_regs[0], banked_r13[4]),
     COREREG(irq_regs[1], banked_r14[4]),
-    COREREG(irq_regs[2], banked_spsr[4]),
+    COREREG64(irq_regs[2], banked_spsr[4]),
     /* R8_fiq .. R14_fiq and SPSR_fiq */
     COREREG(fiq_regs[0], fiq_regs[0]),
     COREREG(fiq_regs[1], fiq_regs[1]),
@@ -333,7 +341,7 @@ static const Reg regs[] = {
     COREREG(fiq_regs[4], fiq_regs[4]),
     COREREG(fiq_regs[5], banked_r13[5]),
     COREREG(fiq_regs[6], banked_r14[5]),
-    COREREG(fiq_regs[7], banked_spsr[5]),
+    COREREG64(fiq_regs[7], banked_spsr[5]),
     /* R15 */
     COREREG(usr_regs.uregs[15], regs[15]),
     /* VFP system registers */

target-arm/kvm64.c

@@ -167,8 +167,16 @@ int kvm_arch_put_registers(CPUState *cs, int level)
         return ret;
     }
 
+    for (i = 0; i < KVM_NR_SPSR; i++) {
+        reg.id = AARCH64_CORE_REG(spsr[i]);
+        reg.addr = (uintptr_t) &env->banked_spsr[i - 1];
+        ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
+        if (ret) {
+            return ret;
+        }
+    }
+
     /* TODO:
-     * SPSR[]
      * FP state
      * system registers
      */
@@ -239,6 +247,15 @@ int kvm_arch_get_registers(CPUState *cs)
         return ret;
     }
 
+    for (i = 0; i < KVM_NR_SPSR; i++) {
+        reg.id = AARCH64_CORE_REG(spsr[i]);
+        reg.addr = (uintptr_t) &env->banked_spsr[i - 1];
+        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 = 16,
+    .version_id = 17,
-    .minimum_version_id = 16,
+    .minimum_version_id = 17,
-    .minimum_version_id_old = 16,
+    .minimum_version_id_old = 17,
     .pre_save = cpu_pre_save,
     .post_load = cpu_post_load,
     .fields = (VMStateField[]) {
@@ -238,7 +238,7 @@ const VMStateDescription vmstate_arm_cpu = {
             .offset = 0,
         },
         VMSTATE_UINT32(env.spsr, ARMCPU),
-        VMSTATE_UINT32_ARRAY(env.banked_spsr, ARMCPU, 6),
+        VMSTATE_UINT64_ARRAY(env.banked_spsr, ARMCPU, 6),
         VMSTATE_UINT32_ARRAY(env.banked_r13, ARMCPU, 6),
         VMSTATE_UINT32_ARRAY(env.banked_r14, ARMCPU, 6),
         VMSTATE_UINT32_ARRAY(env.usr_regs, ARMCPU, 5),