hw/intc/loongarch_pch: Add kernel irqchip save and restore function

Add save and store funtction if kvm_irqchip_in_kernel() return true,
it is to get and set PCH PCI irqchip state from KVM kernel.

Reviewed-by: Song Gao <gaosong@loongson.cn>
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Message-ID: <20250606063033.2557365-9-maobibo@loongson.cn>
Signed-off-by: Song Gao <gaosong@loongson.cn>

hw/intc/loongarch_pch_pic.c

@@ -287,16 +287,38 @@ static void loongarch_pic_realize(DeviceState *dev, Error **errp)
     }
 }
 
+static int loongarch_pic_pre_save(LoongArchPICCommonState *opaque)
+{
+    if (kvm_irqchip_in_kernel()) {
+        return kvm_pic_get(opaque);
+    }
+
+    return 0;
+}
+
+static int loongarch_pic_post_load(LoongArchPICCommonState *opaque,
+                                   int version_id)
+{
+    if (kvm_irqchip_in_kernel()) {
+        return kvm_pic_put(opaque, version_id);
+    }
+
+    return 0;
+}
+
 static void loongarch_pic_class_init(ObjectClass *klass, const void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     LoongarchPICClass *lpc = LOONGARCH_PIC_CLASS(klass);
+    LoongArchPICCommonClass *lpcc = LOONGARCH_PIC_COMMON_CLASS(klass);
     ResettableClass *rc = RESETTABLE_CLASS(klass);
 
     resettable_class_set_parent_phases(rc, NULL, loongarch_pic_reset_hold,
                                        NULL, &lpc->parent_phases);
     device_class_set_parent_realize(dc, loongarch_pic_realize,
                                     &lpc->parent_realize);
+    lpcc->pre_save = loongarch_pic_pre_save;
+    lpcc->post_load = loongarch_pic_post_load;
 }
 
 static const TypeInfo loongarch_pic_types[] = {

hw/intc/loongarch_pic_kvm.c

@@ -13,6 +13,53 @@
 #include "hw/pci-host/ls7a.h"
 #include "system/kvm.h"
 
+static void kvm_pch_pic_access_reg(int fd, uint64_t addr, void *val, bool write)
+{
+    kvm_device_access(fd, KVM_DEV_LOONGARCH_PCH_PIC_GRP_REGS,
+                      addr, val, write, &error_abort);
+}
+
+static void kvm_pch_pic_access(void *opaque, bool write)
+{
+    LoongArchPICCommonState *s = LOONGARCH_PIC_COMMON(opaque);
+    LoongarchPICState *lps = LOONGARCH_PIC(opaque);
+    int fd = lps->dev_fd;
+    int addr, offset;
+
+    kvm_pch_pic_access_reg(fd, PCH_PIC_INT_MASK, &s->int_mask, write);
+    kvm_pch_pic_access_reg(fd, PCH_PIC_HTMSI_EN, &s->htmsi_en, write);
+    kvm_pch_pic_access_reg(fd, PCH_PIC_INT_EDGE, &s->intedge, write);
+    kvm_pch_pic_access_reg(fd, PCH_PIC_AUTO_CTRL0, &s->auto_crtl0, write);
+    kvm_pch_pic_access_reg(fd, PCH_PIC_AUTO_CTRL1, &s->auto_crtl1, write);
+
+    for (addr = PCH_PIC_ROUTE_ENTRY;
+        addr < PCH_PIC_ROUTE_ENTRY_END; addr++) {
+        offset = addr - PCH_PIC_ROUTE_ENTRY;
+        kvm_pch_pic_access_reg(fd, addr, &s->route_entry[offset], write);
+    }
+
+    for (addr = PCH_PIC_HTMSI_VEC; addr < PCH_PIC_HTMSI_VEC_END; addr++) {
+        offset = addr - PCH_PIC_HTMSI_VEC;
+        kvm_pch_pic_access_reg(fd, addr, &s->htmsi_vector[offset], write);
+    }
+
+    kvm_pch_pic_access_reg(fd, PCH_PIC_INT_REQUEST, &s->intirr, write);
+    kvm_pch_pic_access_reg(fd, PCH_PIC_INT_STATUS, &s->intisr, write);
+    kvm_pch_pic_access_reg(fd, PCH_PIC_INT_POL, &s->int_polarity, write);
+}
+
+int kvm_pic_get(void *opaque)
+{
+    kvm_pch_pic_access(opaque, false);
+    return 0;
+}
+
+int kvm_pic_put(void *opaque, int version_id)
+{
+    kvm_pch_pic_access(opaque, true);
+    return 0;
+}
+
 void kvm_pic_realize(DeviceState *dev, Error **errp)
 {
     LoongarchPICState *lps = LOONGARCH_PIC(dev);

include/hw/intc/loongarch_pch_pic.h

@@ -27,5 +27,7 @@ struct LoongarchPICClass {
 };
 
 void kvm_pic_realize(DeviceState *dev, Error **errp);
+int kvm_pic_get(void *opaque);
+int kvm_pic_put(void *opaque, int version_id);
 
 #endif /* HW_LOONGARCH_PCH_PIC_H */

include/hw/intc/loongarch_pic_common.h

@@ -23,6 +23,7 @@
 #define PCH_PIC_ROUTE_ENTRY_END         0x13f
 #define PCH_PIC_HTMSI_VEC               0x200
 #define PCH_PIC_HTMSI_VEC_END           0x23f
+#define PCH_PIC_INT_REQUEST             0x380
 #define PCH_PIC_INT_STATUS              0x3a0
 #define PCH_PIC_INT_POL                 0x3e0