Re: [PATCH v4 1/3] LongArch: KVM: Add DMSINTC device support
From: gaosong
Date: Thu Dec 25 2025 - 02:36:39 EST
在 2025/12/25 下午2:48, Bibo Mao 写道:
On 2025/12/18 下午7:18, Song Gao wrote:
Add device model for DMSINTC interrupt controller, implement basic
create/destroy/set_attr interfaces, and register device model to kvm
device table.
Reviewed-by: Bibo Mao <maobibo@xxxxxxxxxxx>
Signed-off-by: Song Gao <gaosong@xxxxxxxxxxx>
---
arch/loongarch/include/asm/kvm_dmsintc.h | 21 +++++
arch/loongarch/include/asm/kvm_host.h | 3 +
arch/loongarch/include/uapi/asm/kvm.h | 4 +
arch/loongarch/kvm/Makefile | 1 +
arch/loongarch/kvm/intc/dmsintc.c | 110 +++++++++++++++++++++++
arch/loongarch/kvm/main.c | 5 ++
include/uapi/linux/kvm.h | 2 +
7 files changed, 146 insertions(+)
create mode 100644 arch/loongarch/include/asm/kvm_dmsintc.h
create mode 100644 arch/loongarch/kvm/intc/dmsintc.c
diff --git a/arch/loongarch/include/asm/kvm_dmsintc.h
b/arch/loongarch/include/asm/kvm_dmsintc.h
new file mode 100644
index 000000000000..1d4f66996f3c
--- /dev/null
+++ b/arch/loongarch/include/asm/kvm_dmsintc.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2025 Loongson Technology Corporation Limited
+ */
+
+#ifndef __ASM_KVM_DMSINTC_H
+#define __ASM_KVM_DMSINTC_H
+
+
+struct loongarch_dmsintc {
+ struct kvm *kvm;
+ uint64_t msg_addr_base;
+ uint64_t msg_addr_size;
+};
+
+struct dmsintc_state {
+ atomic64_t vector_map[4];
+};
+
+int kvm_loongarch_register_dmsintc_device(void);
+#endif
diff --git a/arch/loongarch/include/asm/kvm_host.h
b/arch/loongarch/include/asm/kvm_host.h
index e4fe5b8e8149..5e9e2af7312f 100644
--- a/arch/loongarch/include/asm/kvm_host.h
+++ b/arch/loongarch/include/asm/kvm_host.h
@@ -22,6 +22,7 @@
#include <asm/kvm_ipi.h>
#include <asm/kvm_eiointc.h>
#include <asm/kvm_pch_pic.h>
+#include <asm/kvm_dmsintc.h>
#include <asm/loongarch.h>
#define __KVM_HAVE_ARCH_INTC_INITIALIZED
@@ -134,6 +135,7 @@ struct kvm_arch {
struct loongarch_ipi *ipi;
struct loongarch_eiointc *eiointc;
struct loongarch_pch_pic *pch_pic;
+ struct loongarch_dmsintc *dmsintc;
};
#define CSR_MAX_NUMS 0x800
@@ -244,6 +246,7 @@ struct kvm_vcpu_arch {
struct kvm_mp_state mp_state;
/* ipi state */
struct ipi_state ipi_state;
+ struct dmsintc_state dmsintc_state;
/* cpucfg */
u32 cpucfg[KVM_MAX_CPUCFG_REGS];
diff --git a/arch/loongarch/include/uapi/asm/kvm.h
b/arch/loongarch/include/uapi/asm/kvm.h
index de6c3f18e40a..0a370d018b08 100644
--- a/arch/loongarch/include/uapi/asm/kvm.h
+++ b/arch/loongarch/include/uapi/asm/kvm.h
@@ -154,4 +154,8 @@ struct kvm_iocsr_entry {
#define KVM_DEV_LOONGARCH_PCH_PIC_GRP_CTRL 0x40000006
#define KVM_DEV_LOONGARCH_PCH_PIC_CTRL_INIT 0
+#define KVM_DEV_LOONGARCH_DMSINTC_CTRL 0x40000007
+#define KVM_DEV_LOONGARCH_DMSINTC_MSG_ADDR_BASE 0x0
+#define KVM_DEV_LOONGARCH_DMSINTC_MSG_ADDR_SIZE 0x1
+
#endif /* __UAPI_ASM_LOONGARCH_KVM_H */
diff --git a/arch/loongarch/kvm/Makefile b/arch/loongarch/kvm/Makefile
index cb41d9265662..6e184e24443c 100644
--- a/arch/loongarch/kvm/Makefile
+++ b/arch/loongarch/kvm/Makefile
@@ -19,6 +19,7 @@ kvm-y += vm.o
kvm-y += intc/ipi.o
kvm-y += intc/eiointc.o
kvm-y += intc/pch_pic.o
+kvm-y += intc/dmsintc.o
kvm-y += irqfd.o
CFLAGS_exit.o += $(call cc-disable-warning, override-init)
diff --git a/arch/loongarch/kvm/intc/dmsintc.c
b/arch/loongarch/kvm/intc/dmsintc.c
new file mode 100644
index 000000000000..3fdea81a08c8
--- /dev/null
+++ b/arch/loongarch/kvm/intc/dmsintc.c
@@ -0,0 +1,110 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2025 Loongson Technology Corporation Limited
+ */
+
+#include <linux/kvm_host.h>
+#include <asm/kvm_dmsintc.h>
+#include <asm/kvm_vcpu.h>
+
+static int kvm_dmsintc_ctrl_access(struct kvm_device *dev,
+ struct kvm_device_attr *attr,
+ bool is_write)
+{
+ int addr = attr->attr;
+ void __user *data;
+ struct loongarch_dmsintc *s = dev->kvm->arch.dmsintc;
+ u64 tmp;
+
+ data = (void __user *)attr->addr;
+ switch (addr) {
+ case KVM_DEV_LOONGARCH_DMSINTC_MSG_ADDR_BASE:
+ if (is_write) {
+ if (copy_from_user(&tmp, data, sizeof(s->msg_addr_base)))
+ return -EFAULT;
+ if (s->msg_addr_base) {
+ /* Duplicate setting are not allowed. */
+ return -EFAULT;
+ }
+ if ((tmp & (BIT(AVEC_CPU_SHIFT) - 1)) == 0)
+ s->msg_addr_base = tmp;
+ else
+ return -EFAULT;
+ }
+ break;
+ case KVM_DEV_LOONGARCH_DMSINTC_MSG_ADDR_SIZE:
+ if (is_write) {
+ if (copy_from_user(&tmp, data, sizeof(s->msg_addr_size)))
+ return -EFAULT;
+ if (s->msg_addr_size) {
+ /*Duplicate setting are not allowed. */
+ return -EFAULT;
+ }
+ s->msg_addr_size = tmp;
+ }
+ break;
+ default:
+ kvm_err("%s: unknown dmsintc register, addr = %d\n",
__func__, addr);
+ return -ENXIO;
+ }
+
+ return 0;
+}
+
+static int kvm_dmsintc_set_attr(struct kvm_device *dev,
+ struct kvm_device_attr *attr)
+{
+ switch (attr->group) {
+ case KVM_DEV_LOONGARCH_DMSINTC_CTRL:
+ return kvm_dmsintc_ctrl_access(dev, attr, true);
+ default:
+ kvm_err("%s: unknown group (%d)\n", __func__, attr->group);
+ return -EINVAL;
+ }
+}
+
+static int kvm_dmsintc_create(struct kvm_device *dev, u32 type)
+{
+ struct kvm *kvm;
+ struct loongarch_dmsintc *s;
+
+ if (!dev) {
+ kvm_err("%s: kvm_device ptr is invalid!\n", __func__);
+ return -EINVAL;
+ }
+
+ kvm = dev->kvm;
+ if (kvm->arch.dmsintc) {
+ kvm_err("%s: LoongArch DMSINTC has already been created!\n",
__func__);
+ return -EINVAL;
+ }
+
+ s = kzalloc(sizeof(struct loongarch_dmsintc), GFP_KERNEL);
+ if (!s)
+ return -ENOMEM;
+
+ s->kvm = kvm;
+ kvm->arch.dmsintc = s;
+ return 0;
+}
+
+static void kvm_dmsintc_destroy(struct kvm_device *dev)
+{
+
+ if (!dev || !dev->kvm || !dev->kvm->arch.dmsintc)
+ return;
+
+ kfree(dev->kvm->arch.dmsintc);
+}
+
+static struct kvm_device_ops kvm_dmsintc_dev_ops = {
+ .name = "kvm-loongarch-dmsintc",
+ .create = kvm_dmsintc_create,
+ .destroy = kvm_dmsintc_destroy,
+ .set_attr = kvm_dmsintc_set_attr,
+};
+
+int kvm_loongarch_register_dmsintc_device(void)
+{
+ return kvm_register_device_ops(&kvm_dmsintc_dev_ops,
KVM_DEV_TYPE_LOONGARCH_DMSINTC);
+}
diff --git a/arch/loongarch/kvm/main.c b/arch/loongarch/kvm/main.c
index 80ea63d465b8..2e26d4fd9000 100644
--- a/arch/loongarch/kvm/main.c
+++ b/arch/loongarch/kvm/main.c
@@ -408,6 +408,11 @@ static int kvm_loongarch_env_init(void)
/* Register LoongArch PCH-PIC interrupt controller interface. */
ret = kvm_loongarch_register_pch_pic_device();
+ if (ret)
+ return ret;
+
+ /* Register LoongArch DMSINTC interrupt contrroller interface */
+ ret = kvm_loongarch_register_dmsintc_device();
I think it will be better if cpu_has_msgint() is added, in theory
dmsintc cannot be added on 3C5000 host machine, and KVM cannot prevent
VMM executing FUZZ ioctl commands.
I will add it on next version.
Thanks.
Song Gao
Regards
Bibo Mao
return ret;
}
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index dddb781b0507..7c56e7e36265 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1209,6 +1209,8 @@ enum kvm_device_type {
#define KVM_DEV_TYPE_LOONGARCH_EIOINTC KVM_DEV_TYPE_LOONGARCH_EIOINTC
KVM_DEV_TYPE_LOONGARCH_PCHPIC,
#define KVM_DEV_TYPE_LOONGARCH_PCHPIC KVM_DEV_TYPE_LOONGARCH_PCHPIC
+ KVM_DEV_TYPE_LOONGARCH_DMSINTC,
+#define KVM_DEV_TYPE_LOONGARCH_DMSINTC KVM_DEV_TYPE_LOONGARCH_DMSINTC
KVM_DEV_TYPE_MAX,