[PATCH V3 02/11] LoongArch: KVM: Add IPI device support

From: Xianglai Li
Date: Tue Sep 10 2024 - 07:59:29 EST


Added device model for IPI interrupt controller,
implemented basic create destroy interface,
and registered device model to kvm device table.

Signed-off-by: Tianrui Zhao <zhaotianrui@xxxxxxxxxxx>
Signed-off-by: Xianglai Li <lixianglai@xxxxxxxxxxx>
---
Cc: Bibo Mao <maobibo@xxxxxxxxxxx>
Cc: Huacai Chen <chenhuacai@xxxxxxxxxx>
Cc: kvm@xxxxxxxxxxxxxxx
Cc: loongarch@xxxxxxxxxxxxxxx
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Tianrui Zhao <zhaotianrui@xxxxxxxxxxx>
Cc: WANG Xuerui <kernel@xxxxxxxxxx>
Cc: Xianglai li <lixianglai@xxxxxxxxxxx>

arch/loongarch/include/asm/kvm_host.h | 4 +
arch/loongarch/include/asm/kvm_ipi.h | 36 +++++++
arch/loongarch/kvm/Makefile | 1 +
arch/loongarch/kvm/intc/ipi.c | 138 ++++++++++++++++++++++++++
arch/loongarch/kvm/main.c | 6 +-
arch/loongarch/kvm/vcpu.c | 3 +
include/uapi/linux/kvm.h | 4 +
7 files changed, 190 insertions(+), 2 deletions(-)
create mode 100644 arch/loongarch/include/asm/kvm_ipi.h
create mode 100644 arch/loongarch/kvm/intc/ipi.c

diff --git a/arch/loongarch/include/asm/kvm_host.h b/arch/loongarch/include/asm/kvm_host.h
index 5f0677e03817..2b65007503dc 100644
--- a/arch/loongarch/include/asm/kvm_host.h
+++ b/arch/loongarch/include/asm/kvm_host.h
@@ -19,6 +19,7 @@
#include <asm/inst.h>
#include <asm/kvm_mmu.h>
#include <asm/loongarch.h>
+#include <asm/kvm_ipi.h>

/* Loongarch KVM register ids */
#define KVM_GET_IOC_CSR_IDX(id) ((id & KVM_CSR_IDX_MASK) >> LOONGARCH_REG_SHIFT)
@@ -110,6 +111,7 @@ struct kvm_arch {

s64 time_offset;
struct kvm_context __percpu *vmcs;
+ struct loongarch_ipi *ipi;
};

#define CSR_MAX_NUMS 0x800
@@ -203,6 +205,8 @@ struct kvm_vcpu_arch {
int last_sched_cpu;
/* mp state */
struct kvm_mp_state mp_state;
+ /* ipi state */
+ struct ipi_state ipi_state;
/* cpucfg */
u32 cpucfg[KVM_MAX_CPUCFG_REGS];

diff --git a/arch/loongarch/include/asm/kvm_ipi.h b/arch/loongarch/include/asm/kvm_ipi.h
new file mode 100644
index 000000000000..3dacdf1781b8
--- /dev/null
+++ b/arch/loongarch/include/asm/kvm_ipi.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2024 Loongson Technology Corporation Limited
+ */
+
+#ifndef __ASM_KVM_IPI_H
+#define __ASM_KVM_IPI_H
+
+#include <kvm/iodev.h>
+
+#define LARCH_INT_IPI 12
+
+struct loongarch_ipi {
+ spinlock_t lock;
+ struct kvm *kvm;
+ struct kvm_io_device device;
+ struct kvm_io_device mail_dev;
+};
+
+struct ipi_state {
+ spinlock_t lock;
+ uint32_t status;
+ uint32_t en;
+ uint32_t set;
+ uint32_t clear;
+ uint64_t buf[4];
+};
+
+#define SMP_MAILBOX 0x1000
+#define KVM_IOCSR_IPI_ADDR_SIZE 0x48
+
+#define MAIL_SEND_ADDR (SMP_MAILBOX + IOCSR_MAIL_SEND)
+#define KVM_IOCSR_MAIL_ADDR_SIZE 0x118
+
+int kvm_loongarch_register_ipi_device(void);
+#endif
diff --git a/arch/loongarch/kvm/Makefile b/arch/loongarch/kvm/Makefile
index b2f4cbe01ae8..36c3009fe89c 100644
--- a/arch/loongarch/kvm/Makefile
+++ b/arch/loongarch/kvm/Makefile
@@ -18,5 +18,6 @@ kvm-y += timer.o
kvm-y += tlb.o
kvm-y += vcpu.o
kvm-y += vm.o
+kvm-y += intc/ipi.o

CFLAGS_exit.o += $(call cc-option,-Wno-override-init,)
diff --git a/arch/loongarch/kvm/intc/ipi.c b/arch/loongarch/kvm/intc/ipi.c
new file mode 100644
index 000000000000..5a19712185d5
--- /dev/null
+++ b/arch/loongarch/kvm/intc/ipi.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2024 Loongson Technology Corporation Limited
+ */
+
+#include <linux/kvm_host.h>
+#include <asm/kvm_ipi.h>
+#include <asm/kvm_vcpu.h>
+
+static int kvm_ipi_write(struct kvm_vcpu *vcpu,
+ struct kvm_io_device *dev,
+ gpa_t addr, int len, const void *val)
+{
+ return 0;
+}
+
+static int kvm_ipi_read(struct kvm_vcpu *vcpu,
+ struct kvm_io_device *dev,
+ gpa_t addr, int len, void *val)
+{
+ return 0;
+}
+
+static int kvm_loongarch_mail_write(struct kvm_vcpu *vcpu,
+ struct kvm_io_device *dev,
+ gpa_t addr, int len, const void *val)
+{
+ return 0;
+}
+
+static const struct kvm_io_device_ops kvm_ipi_ops = {
+ .read = kvm_ipi_read,
+ .write = kvm_ipi_write,
+};
+
+static const struct kvm_io_device_ops kvm_loongarch_mail_ops = {
+ .write = kvm_loongarch_mail_write,
+};
+
+static int kvm_ipi_get_attr(struct kvm_device *dev,
+ struct kvm_device_attr *attr)
+{
+ return 0;
+}
+
+static int kvm_ipi_set_attr(struct kvm_device *dev,
+ struct kvm_device_attr *attr)
+{
+ return 0;
+}
+
+static void kvm_ipi_destroy(struct kvm_device *dev)
+{
+ struct kvm *kvm;
+ struct loongarch_ipi *ipi;
+
+ if (!dev || !dev->kvm || !dev->kvm->arch.ipi)
+ return;
+ kvm = dev->kvm;
+ ipi = kvm->arch.ipi;
+ kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &ipi->device);
+ kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &ipi->mail_dev);
+ kfree(ipi);
+}
+
+static int kvm_ipi_create(struct kvm_device *dev, u32 type)
+{
+ struct kvm *kvm;
+ struct loongarch_ipi *s;
+ unsigned long addr;
+ struct kvm_io_device *device;
+ int ret;
+
+ kvm_debug("begin create loongarch ipi in kvm ...\n");
+ if (!dev) {
+ kvm_err("%s: kvm_device ptr is invalid!\n", __func__);
+ return -EINVAL;
+ }
+
+ kvm = dev->kvm;
+ if (kvm->arch.ipi) {
+ kvm_err("%s: loongarch ipi has been created!\n", __func__);
+ return -EINVAL;
+ }
+
+ s = kzalloc(sizeof(struct loongarch_ipi), GFP_KERNEL);
+ if (!s)
+ return -ENOMEM;
+ spin_lock_init(&s->lock);
+ s->kvm = kvm;
+
+ /*
+ * Initialize IOCSR device
+ */
+ device = &s->device;
+ kvm_iodevice_init(device, &kvm_ipi_ops);
+ addr = SMP_MAILBOX;
+ mutex_lock(&kvm->slots_lock);
+ ret = kvm_io_bus_register_dev(kvm, KVM_IOCSR_BUS, addr,
+ KVM_IOCSR_IPI_ADDR_SIZE, device);
+ mutex_unlock(&kvm->slots_lock);
+ if (ret < 0) {
+ kvm_err("%s: initialize IOCSR dev failed, ret = %d\n", __func__, ret);
+ goto err;
+ }
+
+ device = &s->mail_dev;
+ kvm_iodevice_init(device, &kvm_loongarch_mail_ops);
+ addr = MAIL_SEND_ADDR;
+ mutex_lock(&kvm->slots_lock);
+ ret = kvm_io_bus_register_dev(kvm, KVM_IOCSR_BUS, addr,
+ KVM_IOCSR_MAIL_ADDR_SIZE, device);
+ mutex_unlock(&kvm->slots_lock);
+ if (ret < 0) {
+ kvm_io_bus_unregister_dev(kvm, KVM_IOCSR_BUS, &s->device);
+ kvm_err("%s: initialize mail box dev failed, ret = %d\n", __func__, ret);
+ goto err;
+ }
+ kvm->arch.ipi = s;
+ return 0;
+err:
+ kfree(s);
+ return -EFAULT;
+}
+
+static struct kvm_device_ops kvm_ipi_dev_ops = {
+ .name = "kvm-loongarch-ipi",
+ .create = kvm_ipi_create,
+ .destroy = kvm_ipi_destroy,
+ .set_attr = kvm_ipi_set_attr,
+ .get_attr = kvm_ipi_get_attr,
+};
+
+int kvm_loongarch_register_ipi_device(void)
+{
+ return kvm_register_device_ops(&kvm_ipi_dev_ops,
+ KVM_DEV_TYPE_LOONGARCH_IPI);
+}
diff --git a/arch/loongarch/kvm/main.c b/arch/loongarch/kvm/main.c
index 844736b99d38..a1cec0b1fd7f 100644
--- a/arch/loongarch/kvm/main.c
+++ b/arch/loongarch/kvm/main.c
@@ -313,7 +313,7 @@ void kvm_arch_hardware_disable(void)

static int kvm_loongarch_env_init(void)
{
- int cpu, order;
+ int cpu, order, ret;
void *addr;
struct kvm_context *context;

@@ -368,7 +368,9 @@ static int kvm_loongarch_env_init(void)

kvm_init_gcsr_flag();

- return 0;
+ /* Register loongarch ipi interrupt controller interface. */
+ ret = kvm_loongarch_register_ipi_device();
+ return ret;
}

static void kvm_loongarch_env_exit(void)
diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c
index 6905283f535b..ad8e69344a56 100644
--- a/arch/loongarch/kvm/vcpu.c
+++ b/arch/loongarch/kvm/vcpu.c
@@ -1162,6 +1162,9 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
/* Init */
vcpu->arch.last_sched_cpu = -1;

+ /* Init ipi_state lock */
+ spin_lock_init(&vcpu->arch.ipi_state.lock);
+
/*
* Initialize guest register state to valid architectural reset state.
*/
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 637efc055145..9fff439c30ea 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1158,7 +1158,11 @@ enum kvm_device_type {
#define KVM_DEV_TYPE_ARM_PV_TIME KVM_DEV_TYPE_ARM_PV_TIME
KVM_DEV_TYPE_RISCV_AIA,
#define KVM_DEV_TYPE_RISCV_AIA KVM_DEV_TYPE_RISCV_AIA
+ KVM_DEV_TYPE_LOONGARCH_IPI,
+#define KVM_DEV_TYPE_LOONGARCH_IPI KVM_DEV_TYPE_LOONGARCH_IPI
+
KVM_DEV_TYPE_MAX,
+
};

struct kvm_vfio_spapr_tce {
--
2.39.1