This is needed for riscv based CPUs by MIPS since those may have
sparse hart-ID layouts. ACLINT and APLIC still assume a dense
range, and if a hart is missing, this causes NULL derefs.

Signed-off-by: Chao-ying Fu <cfu@mips.com>
Signed-off-by: Djordje Todorovic <djordje.todorovic@htecgroup.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 hw/intc/riscv_aclint.c | 18 ++++++++++++++++--
 hw/intc/riscv_aplic.c  | 13 ++++++++++---
 2 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/hw/intc/riscv_aclint.c b/hw/intc/riscv_aclint.c
index 4623cfa029..e3e019e605 100644
--- a/hw/intc/riscv_aclint.c
+++ b/hw/intc/riscv_aclint.c
@@ -297,7 +297,12 @@ static void riscv_aclint_mtimer_realize(DeviceState *dev, Error **errp)
     s->timecmp = g_new0(uint64_t, s->num_harts);
     /* Claim timer interrupt bits */
     for (i = 0; i < s->num_harts; i++) {
-        RISCVCPU *cpu = RISCV_CPU(cpu_by_arch_id(s->hartid_base + i));
+        CPUState *cpu_by_hartid = cpu_by_arch_id(s->hartid_base + i);
+        if (cpu_by_hartid == NULL) {
+            /* Valid for sparse hart layouts - skip this hart ID */
+            continue;
+        }
+        RISCVCPU *cpu = RISCV_CPU(cpu_by_hartid);
         if (riscv_cpu_claim_interrupts(cpu, MIP_MTIP) < 0) {
             error_report("MTIP already claimed");
             exit(1);
@@ -486,7 +491,12 @@ static void riscv_aclint_swi_realize(DeviceState *dev, Error **errp)
 
     /* Claim software interrupt bits */
     for (i = 0; i < swi->num_harts; i++) {
-        RISCVCPU *cpu = RISCV_CPU(qemu_get_cpu(swi->hartid_base + i));
+        CPUState *cpu_by_hartid = cpu_by_arch_id(swi->hartid_base + i);
+        if (cpu_by_hartid == NULL) {
+            /* Valid for sparse hart layouts - skip this hart ID */
+            continue;
+        }
+        RISCVCPU *cpu = RISCV_CPU(cpu_by_hartid);
         /* We don't claim mip.SSIP because it is writable by software */
         if (riscv_cpu_claim_interrupts(cpu, swi->sswi ? 0 : MIP_MSIP) < 0) {
             error_report("MSIP already claimed");
@@ -550,6 +560,10 @@ DeviceState *riscv_aclint_swi_create(hwaddr addr, uint32_t hartid_base,
 
     for (i = 0; i < num_harts; i++) {
         CPUState *cpu = cpu_by_arch_id(hartid_base + i);
+        if (cpu == NULL) {
+            /* Valid for sparse hart layouts - skip this hart ID */
+            continue;
+        }
         RISCVCPU *rvcpu = RISCV_CPU(cpu);
 
         qdev_connect_gpio_out(dev, i,
diff --git a/hw/intc/riscv_aplic.c b/hw/intc/riscv_aplic.c
index a1d9fa5085..77cec8ece9 100644
--- a/hw/intc/riscv_aplic.c
+++ b/hw/intc/riscv_aplic.c
@@ -903,9 +903,12 @@ static void riscv_aplic_realize(DeviceState *dev, Error **errp)
         if (!aplic->msimode) {
             /* Claim the CPU interrupt to be triggered by this APLIC */
             for (i = 0; i < aplic->num_harts; i++) {
-                RISCVCPU *cpu;
-
-                cpu = RISCV_CPU(cpu_by_arch_id(aplic->hartid_base + i));
+                CPUState *temp = cpu_by_arch_id(aplic->hartid_base + i);
+                if (temp == NULL) {
+                    /* Valid for sparse hart layouts - skip this hart ID */
+                    continue;
+                }
+                RISCVCPU *cpu = RISCV_CPU(temp);
                 if (riscv_cpu_claim_interrupts(cpu,
                     (aplic->mmode) ? MIP_MEIP : MIP_SEIP) < 0) {
                     error_report("%s already claimed",
@@ -1088,6 +1091,10 @@ DeviceState *riscv_aplic_create(hwaddr addr, hwaddr size,
         if (!msimode) {
             for (i = 0; i < num_harts; i++) {
                 CPUState *cpu = cpu_by_arch_id(hartid_base + i);
+                if (cpu == NULL) {
+                    /* Valid for sparse hart layouts - skip this hart ID */
+                    continue;
+                }
 
                 qdev_connect_gpio_out_named(dev, NULL, i,
                                             qdev_get_gpio_in(DEVICE(cpu),
-- 
2.34.1