[RFC PATCH v3 5/5] arm/arm64: vgic-new: Implement KVM_DEV_ARM_VGIC_GRP_LEVEL_INFO ioctl

[vijay.kilari@gmail.com (vijay.kilari at gmail.com)]

From: Vijaya Kumar K <Vijaya.Kumar@cavium.com>

Userspace requires to store and restore of line_level for
level triggered interrupts. For this ioctl KVM_DEV_ARM_VGIC_GRP_LEVEL_INFO
is defined.

Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@cavium.com>
---
 arch/arm64/include/uapi/asm/kvm.h   |  6 +++++
 virt/kvm/arm/vgic/vgic-kvm-device.c | 44 ++++++++++++++++++++++++++++++++++++-
 virt/kvm/arm/vgic/vgic-mmio-v3.c    | 19 ++++++++++++++++
 virt/kvm/arm/vgic/vgic-mmio.c       | 34 ++++++++++++++++++++++++++++
 virt/kvm/arm/vgic/vgic-mmio.h       |  6 +++++
 virt/kvm/arm/vgic/vgic.h            |  3 +++
 6 files changed, 111 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index b13c944..45c56d7 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -209,6 +209,12 @@ struct kvm_arch_memory_slot {
 #define KVM_DEV_ARM_VGIC_GRP_CTRL	4
 #define KVM_DEV_ARM_VGIC_GRP_REDIST_REGS 5
 #define KVM_DEV_ARM_VGIC_CPU_SYSREGS    6
+#define KVM_DEV_ARM_VGIC_GRP_LEVEL_INFO 7
+#define KVM_DEV_ARM_VGIC_LINE_LEVEL_INFO_SHIFT	9
+#define KVM_DEV_ARM_VGIC_LINE_LEVEL_INFO_MASK \
+			(0x7fffffULL << KVM_DEV_ARM_VGIC_LINE_LEVEL_INFO_SHIFT)
+#define KVM_DEV_ARM_VGIC_LINE_LEVEL_INTID_MASK	0x1ff
+#define KVM_DEV_ARM_VGIC_LINE_LEVEL_INFO_VAL	1
 
 #define   KVM_DEV_ARM_VGIC_CTRL_INIT	0
 #define   KVM_DEV_ARM_VGIC_SYSREG_MASK (KVM_REG_ARM64_SYSREG_OP0_MASK | \
diff --git a/virt/kvm/arm/vgic/vgic-kvm-device.c b/virt/kvm/arm/vgic/vgic-kvm-device.c
index 74e5c38..7e3bc49 100644
--- a/virt/kvm/arm/vgic/vgic-kvm-device.c
+++ b/virt/kvm/arm/vgic/vgic-kvm-device.c
@@ -509,6 +509,23 @@ static int vgic_attr_regs_access_v3(struct kvm_device *dev,
 						  regid, reg);
 		break;
 	}
+	case KVM_DEV_ARM_VGIC_GRP_LEVEL_INFO: {
+		unsigned int info, intid;
+
+		info = (attr->attr & KVM_DEV_ARM_VGIC_LINE_LEVEL_INFO_MASK) >>
+			KVM_DEV_ARM_VGIC_LINE_LEVEL_INFO_SHIFT;
+		if (info == KVM_DEV_ARM_VGIC_LINE_LEVEL_INFO_VAL) {
+			intid = attr->attr &
+				KVM_DEV_ARM_VGIC_LINE_LEVEL_INTID_MASK;
+			ret = vgic_v3_line_level_info_uaccess(vcpu, is_write,
+							      intid, &tmp32);
+			if (!is_write)
+				*reg = tmp32;
+		} else {
+			ret = -EINVAL;
+		}
+		break;
+	}
 	default:
 		ret = -EINVAL;
 		break;
@@ -551,6 +568,17 @@ static int vgic_v3_set_attr(struct kvm_device *dev,
 
 		return vgic_attr_regs_access_v3(dev, attr, &reg, true);
 	}
+	case KVM_DEV_ARM_VGIC_GRP_LEVEL_INFO: {
+		u32 __user *uaddr = (u32 __user *)(long)attr->addr;
+		u64 reg;
+		u32 tmp32;
+
+		if (get_user(tmp32, uaddr))
+			return -EFAULT;
+
+		reg = tmp32;
+		return vgic_attr_regs_access_v3(dev, attr, &reg, true);
+	}
 	}
 	return -ENXIO;
 }
@@ -588,8 +616,19 @@ static int vgic_v3_get_attr(struct kvm_device *dev,
 		ret = put_user(reg, uaddr);
 		return ret;
 	}
-	}
+	case KVM_DEV_ARM_VGIC_GRP_LEVEL_INFO: {
+		u32 __user *uaddr = (u32 __user *)(long)attr->addr;
+		u64 reg;
+		u32 tmp32;
 
+		ret = vgic_attr_regs_access_v3(dev, attr, &reg, false);
+		if (ret)
+			return ret;
+		tmp32 = reg;
+		ret = put_user(tmp32, uaddr);
+		return ret;
+	}
+	}
 	return -ENXIO;
 }
 
@@ -610,11 +649,14 @@ static int vgic_v3_has_attr(struct kvm_device *dev,
 		return vgic_v3_has_attr_regs(dev, attr);
 	case KVM_DEV_ARM_VGIC_GRP_NR_IRQS:
 		return 0;
+	case KVM_DEV_ARM_VGIC_GRP_LEVEL_INFO:
+		return 0;
 	case KVM_DEV_ARM_VGIC_GRP_CTRL:
 		switch (attr->attr) {
 		case KVM_DEV_ARM_VGIC_CTRL_INIT:
 			return 0;
 		}
+		break;
 	}
 	return -ENXIO;
 }
diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index 61abea0..fde1472 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
@@ -789,3 +789,22 @@ int vgic_v3_redist_uaccess(struct kvm_vcpu *vcpu, bool is_write,
 
 	return vgic_v3_uaccess(vcpu, dev, is_write, offset, val);
 }
+
+int vgic_v3_line_level_info_uaccess(struct kvm_vcpu *vcpu, bool is_write,
+				    u32 intid, u32 *val)
+{
+	unsigned int len = 4;
+	u8 buf[4];
+	int ret;
+
+	if (is_write) {
+		vgic_data_host_to_mmio_bus(buf, len, *val);
+		ret = vgic_write_irq_line_level_info(vcpu, intid, len, buf);
+	} else {
+		ret = vgic_read_irq_line_level_info(vcpu, intid, len, buf);
+		if (!ret)
+			*val = vgic_data_mmio_bus_to_host(buf, len);
+	}
+
+	return ret;
+}
diff --git a/virt/kvm/arm/vgic/vgic-mmio.c b/virt/kvm/arm/vgic/vgic-mmio.c
index 38f2c75..74d0449 100644
--- a/virt/kvm/arm/vgic/vgic-mmio.c
+++ b/virt/kvm/arm/vgic/vgic-mmio.c
@@ -391,6 +391,40 @@ void vgic_mmio_write_config(struct kvm_vcpu *vcpu,
 	}
 }
 
+int vgic_read_irq_line_level_info(struct kvm_vcpu *vcpu, u32 intid,
+				  unsigned int len, void *val)
+{
+	unsigned long data = 0;
+	int i;
+
+	for (i = 0; i < len * 8; i++) {
+		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+		if (irq->line_level)
+			data |= (1U << i);
+	}
+	vgic_data_host_to_mmio_bus(val, len, data);
+
+	return 0;
+}
+
+int vgic_write_irq_line_level_info(struct kvm_vcpu *vcpu, u32 intid,
+				   unsigned int len, const void *val)
+{
+	int i;
+	unsigned long data = vgic_data_mmio_bus_to_host(val, len);
+
+	for_each_set_bit(i, &data, len * 8) {
+		struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+		spin_lock(&irq->irq_lock);
+		irq->line_level = true;
+		spin_unlock(&irq->irq_lock);
+	}
+
+	return 0;
+}
+
 static int match_region(const void *key, const void *elt)
 {
 	const unsigned int offset = (unsigned long)key;
diff --git a/virt/kvm/arm/vgic/vgic-mmio.h b/virt/kvm/arm/vgic/vgic-mmio.h
index b97a97b..b03c4e7 100644
--- a/virt/kvm/arm/vgic/vgic-mmio.h
+++ b/virt/kvm/arm/vgic/vgic-mmio.h
@@ -183,6 +183,12 @@ int vgic_mmio_uaccess_read(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
 int vgic_mmio_uaccess_write(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
 			    gpa_t addr, int len, const void *val);
 
+int vgic_read_irq_line_level_info(struct kvm_vcpu *vcpu, u32 intid,
+				  unsigned int len, void *val);
+
+int vgic_write_irq_line_level_info(struct kvm_vcpu *vcpu, u32 intid,
+				   unsigned int len, const void *val);
+
 unsigned int vgic_v2_init_dist_iodev(struct vgic_io_device *dev);
 
 unsigned int vgic_v3_init_dist_iodev(struct vgic_io_device *dev);
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index 20eab36c..b8ee5b9 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -100,6 +100,9 @@ int vgic_v3_cpu_sysregs_uaccess(struct kvm_vcpu *vcpu, bool is_write,
 			 u64 id, u64 *val);
 int vgic_v3_has_cpu_sysregs_attr(struct kvm_vcpu *vcpu, bool is_write, u64 id,
 				u64 *reg);
+int vgic_v3_line_level_info_uaccess(struct kvm_vcpu *vcpu, bool is_write,
+				    u32 intid, u32 *val);
+
 #else
 static inline void vgic_v3_process_maintenance(struct kvm_vcpu *vcpu)
 {
-- 
1.9.1