hw/loongarch/virt: Set max 256 cpus support on loongarch virt machine

Add separate macro EXTIOI_CPUS for extioi interrupt controller, extioi
only supports 4 cpu. And set macro LOONGARCH_MAX_CPUS as 256 so that
loongarch virt machine supports more cpus.

Interrupts from external devices can only be routed cpu 0-3 because
of extioi limits, cpu internal interrupt such as timer/ipi can be
triggered on all cpus.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Song Gao <gaosong@loongson.cn>
Message-Id: <20230512100421.1867848-3-gaosong@loongson.cn>

hw/intc/loongarch_extioi.c

@@ -254,7 +254,7 @@ static const VMStateDescription vmstate_loongarch_extioi = {
     .minimum_version_id = 1,
     .fields = (VMStateField[]) {
         VMSTATE_UINT32_ARRAY(bounce, LoongArchExtIOI, EXTIOI_IRQS_GROUP_COUNT),
-        VMSTATE_UINT32_2DARRAY(coreisr, LoongArchExtIOI, LOONGARCH_MAX_VCPUS,
+        VMSTATE_UINT32_2DARRAY(coreisr, LoongArchExtIOI, EXTIOI_CPUS,
                                EXTIOI_IRQS_GROUP_COUNT),
         VMSTATE_UINT32_ARRAY(nodetype, LoongArchExtIOI,
                              EXTIOI_IRQS_NODETYPE_COUNT / 2),
@@ -281,7 +281,7 @@ static void loongarch_extioi_instance_init(Object *obj)
 
     qdev_init_gpio_in(DEVICE(obj), extioi_setirq, EXTIOI_IRQS);
 
-    for (cpu = 0; cpu < LOONGARCH_MAX_VCPUS; cpu++) {
+    for (cpu = 0; cpu < EXTIOI_CPUS; cpu++) {
         memory_region_init_io(&s->extioi_iocsr_mem[cpu], OBJECT(s), &extioi_ops,
                               s, "extioi_iocsr", 0x900);
         sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->extioi_iocsr_mem[cpu]);

hw/loongarch/virt.c

@@ -607,8 +607,13 @@ static void loongarch_irq_init(LoongArchMachineState *lams)
         memory_region_add_subregion(&env->system_iocsr, MAIL_SEND_ADDR,
                                     sysbus_mmio_get_region(SYS_BUS_DEVICE(ipi),
                                     1));
-        /* extioi iocsr memory region */
-        memory_region_add_subregion(&env->system_iocsr, APIC_BASE,
+        /*
+	 * extioi iocsr memory region
+	 * only one extioi is added on loongarch virt machine
+	 * external device interrupt can only be routed to cpu 0-3
+	 */
+	if (cpu < EXTIOI_CPUS)
+            memory_region_add_subregion(&env->system_iocsr, APIC_BASE,
                                 sysbus_mmio_get_region(SYS_BUS_DEVICE(extioi),
                                 cpu));
     }
@@ -617,7 +622,7 @@ static void loongarch_irq_init(LoongArchMachineState *lams)
      * connect ext irq to the cpu irq
      * cpu_pin[9:2] <= intc_pin[7:0]
      */
-    for (cpu = 0; cpu < ms->smp.cpus; cpu++) {
+    for (cpu = 0; cpu < MIN(ms->smp.cpus, EXTIOI_CPUS); cpu++) {
         cpudev = DEVICE(qemu_get_cpu(cpu));
         for (pin = 0; pin < LS3A_INTC_IP; pin++) {
             qdev_connect_gpio_out(extioi, (cpu * 8 + pin),
@@ -1026,7 +1031,7 @@ static void loongarch_class_init(ObjectClass *oc, void *data)
     mc->default_ram_size = 1 * GiB;
     mc->default_cpu_type = LOONGARCH_CPU_TYPE_NAME("la464");
     mc->default_ram_id = "loongarch.ram";
-    mc->max_cpus = LOONGARCH_MAX_VCPUS;
+    mc->max_cpus = LOONGARCH_MAX_CPUS;
     mc->is_default = 1;
     mc->default_kernel_irqchip_split = false;
     mc->block_default_type = IF_VIRTIO;

include/hw/intc/loongarch_extioi.h

@@ -14,6 +14,8 @@
 #define LS3A_INTC_IP               8
 #define EXTIOI_IRQS                (256)
 #define EXTIOI_IRQS_BITMAP_SIZE    (256 / 8)
+/* irq from EXTIOI is routed to no more than 4 cpus */
+#define EXTIOI_CPUS                (4)
 /* map to ipnum per 32 irqs */
 #define EXTIOI_IRQS_IPMAP_SIZE     (256 / 32)
 #define EXTIOI_IRQS_COREMAP_SIZE   256
@@ -46,17 +48,17 @@ struct LoongArchExtIOI {
     uint32_t nodetype[EXTIOI_IRQS_NODETYPE_COUNT / 2];
     uint32_t bounce[EXTIOI_IRQS_GROUP_COUNT];
     uint32_t isr[EXTIOI_IRQS / 32];
-    uint32_t coreisr[LOONGARCH_MAX_VCPUS][EXTIOI_IRQS_GROUP_COUNT];
+    uint32_t coreisr[EXTIOI_CPUS][EXTIOI_IRQS_GROUP_COUNT];
     uint32_t enable[EXTIOI_IRQS / 32];
     uint32_t ipmap[EXTIOI_IRQS_IPMAP_SIZE / 4];
     uint32_t coremap[EXTIOI_IRQS / 4];
     uint32_t sw_pending[EXTIOI_IRQS / 32];
-    DECLARE_BITMAP(sw_isr[LOONGARCH_MAX_VCPUS][LS3A_INTC_IP], EXTIOI_IRQS);
+    DECLARE_BITMAP(sw_isr[EXTIOI_CPUS][LS3A_INTC_IP], EXTIOI_IRQS);
     uint8_t  sw_ipmap[EXTIOI_IRQS_IPMAP_SIZE];
     uint8_t  sw_coremap[EXTIOI_IRQS];
-    qemu_irq parent_irq[LOONGARCH_MAX_VCPUS][LS3A_INTC_IP];
+    qemu_irq parent_irq[EXTIOI_CPUS][LS3A_INTC_IP];
     qemu_irq irq[EXTIOI_IRQS];
-    MemoryRegion extioi_iocsr_mem[LOONGARCH_MAX_VCPUS];
+    MemoryRegion extioi_iocsr_mem[EXTIOI_CPUS];
     MemoryRegion extioi_system_mem;
 };
 #endif /* LOONGARCH_EXTIOI_H */

include/hw/loongarch/virt.h

@@ -14,7 +14,7 @@
 #include "hw/intc/loongarch_ipi.h"
 #include "hw/block/flash.h"
 
-#define LOONGARCH_MAX_VCPUS     4
+#define LOONGARCH_MAX_CPUS      256
 
 #define VIRT_ISA_IO_BASE        0x18000000UL
 #define VIRT_ISA_IO_SIZE        0x0004000