hw/intc/loongarch_ipi: 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 IPI irqchip state from KVM kernel.

Reviewed-by: Song Gao <gaosong@loongson.cn>
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Message-ID: <20250606063033.2557365-6-maobibo@loongson.cn>
Signed-off-by: Song Gao <gaosong@loongson.cn>

3 files changed, 76 insertions, 0 deletions

diff --git a/hw/intc/loongarch_ipi.c b/hw/intc/loongarch_ipi.c
index 159ba91..0ea91ea 100644
--- a/hw/intc/loongarch_ipi.c
+++ b/hw/intc/loongarch_ipi.c
@@ -171,6 +171,24 @@ static void loongarch_ipi_cpu_unplug(HotplugHandler *hotplug_dev,
     core->cpu = NULL;
 }
 
+static int loongarch_ipi_pre_save(void *opaque)
+{
+    if (kvm_irqchip_in_kernel()) {
+        return kvm_ipi_get(opaque);
+    }
+
+    return 0;
+}
+
+static int loongarch_ipi_post_load(void *opaque, int version_id)
+{
+    if (kvm_irqchip_in_kernel()) {
+        return kvm_ipi_put(opaque, version_id);
+    }
+
+    return 0;
+}
+
 static void loongarch_ipi_class_init(ObjectClass *klass, const void *data)
 {
     LoongsonIPICommonClass *licc = LOONGSON_IPI_COMMON_CLASS(klass);
@@ -187,6 +205,8 @@ static void loongarch_ipi_class_init(ObjectClass *klass, const void *data)
     licc->cpu_by_arch_id = loongarch_cpu_by_arch_id;
     hc->plug = loongarch_ipi_cpu_plug;
     hc->unplug = loongarch_ipi_cpu_unplug;
+    licc->pre_save = loongarch_ipi_pre_save;
+    licc->post_load = loongarch_ipi_post_load;
 }
 
 static const TypeInfo loongarch_ipi_types[] = {
diff --git a/hw/intc/loongarch_ipi_kvm.c b/hw/intc/loongarch_ipi_kvm.c
index 51e9c7e..b615060 100644
--- a/hw/intc/loongarch_ipi_kvm.c
+++ b/hw/intc/loongarch_ipi_kvm.c
@@ -11,6 +11,60 @@
 #include "system/kvm.h"
 #include "target/loongarch/cpu.h"
 
+static void kvm_ipi_access_reg(int fd, uint64_t addr, uint32_t *val, bool write)
+{
+    kvm_device_access(fd, KVM_DEV_LOONGARCH_IPI_GRP_REGS,
+                      addr, val, write, &error_abort);
+}
+
+static void kvm_ipi_access_regs(void *opaque, bool write)
+{
+    LoongsonIPICommonState *ipi = (LoongsonIPICommonState *)opaque;
+    LoongarchIPIState *lis = LOONGARCH_IPI(opaque);
+    IPICore *core;
+    uint64_t attr;
+    int cpu, fd = lis->dev_fd;
+
+    for (cpu = 0; cpu < ipi->num_cpu; cpu++) {
+        core = &ipi->cpu[cpu];
+        attr = (cpu << 16) | CORE_STATUS_OFF;
+        kvm_ipi_access_reg(fd, attr, &core->status, write);
+
+        attr = (cpu << 16) | CORE_EN_OFF;
+        kvm_ipi_access_reg(fd, attr, &core->en, write);
+
+        attr = (cpu << 16) | CORE_SET_OFF;
+        kvm_ipi_access_reg(fd, attr, &core->set, write);
+
+        attr = (cpu << 16) | CORE_CLEAR_OFF;
+        kvm_ipi_access_reg(fd, attr, &core->clear, write);
+
+        attr = (cpu << 16) | CORE_BUF_20;
+        kvm_ipi_access_reg(fd, attr, &core->buf[0], write);
+
+        attr = (cpu << 16) | CORE_BUF_28;
+        kvm_ipi_access_reg(fd, attr, &core->buf[2], write);
+
+        attr = (cpu << 16) | CORE_BUF_30;
+        kvm_ipi_access_reg(fd, attr, &core->buf[4], write);
+
+        attr = (cpu << 16) | CORE_BUF_38;
+        kvm_ipi_access_reg(fd, attr, &core->buf[6], write);
+    }
+}
+
+int kvm_ipi_get(void *opaque)
+{
+    kvm_ipi_access_regs(opaque, false);
+    return 0;
+}
+
+int kvm_ipi_put(void *opaque, int version_id)
+{
+    kvm_ipi_access_regs(opaque, true);
+    return 0;
+}
+
 void kvm_ipi_realize(DeviceState *dev, Error **errp)
 {
     LoongarchIPIState *lis = LOONGARCH_IPI(dev);
diff --git a/include/hw/intc/loongarch_ipi.h b/include/hw/intc/loongarch_ipi.h
index 608cd09..5175a6b 100644
--- a/include/hw/intc/loongarch_ipi.h
+++ b/include/hw/intc/loongarch_ipi.h
@@ -26,5 +26,7 @@ struct LoongarchIPIClass {
 };
 
 void kvm_ipi_realize(DeviceState *dev, Error **errp);
+int kvm_ipi_get(void *opaque);
+int kvm_ipi_put(void *opaque, int version_id);
 
 #endif