diff --git a/Documentation/virt/kvm/devices/arm-vgic-v5.rst b/Documentation/virt/kvm/devices/arm-vgic-v5.rst
index 9904cb888277..29335ea823fc 100644
--- a/Documentation/virt/kvm/devices/arm-vgic-v5.rst
+++ b/Documentation/virt/kvm/devices/arm-vgic-v5.rst
@@ -25,6 +25,19 @@ Groups:
       request the initialization of the VGIC, no additional parameter in
       kvm_device_attr.addr. Must be called after all VCPUs have been created.
 
+   KVM_DEV_ARM_VGIC_USERPSPACE_PPIs
+      request the mask of userspace-drivable PPIs. Only a subset of the PPIs can
+      be directly driven from userspace with GICv5, and the returned mask
+      informs userspace of which it is allowed to drive via KVM_IRQ_LINE.
+
+      Userspace must allocate and point to __u64[2] of data in
+      kvm_device_attr.addr. When this call returns, the provided memory will be
+      populated with the userspace PPI mask. The lower __u64 contains the mask
+      for the lower 64 PPIS, with the remaining 64 being in the second __u64.
+
+      This is a read-only attribute, and cannot be set. Attempts to set it are
+      rejected.
+
   Errors:
 
     =======  ========================================================
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index a792a599b9d6..1c13bfa2d38a 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -428,6 +428,7 @@ enum {
 #define   KVM_DEV_ARM_ITS_RESTORE_TABLES        2
 #define   KVM_DEV_ARM_VGIC_SAVE_PENDING_TABLES	3
 #define   KVM_DEV_ARM_ITS_CTRL_RESET		4
+#define   KVM_DEV_ARM_VGIC_USERSPACE_PPIS	5
 
 /* Device Control API on vcpu fd */
 #define KVM_ARM_VCPU_PMU_V3_CTRL	0
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index cb22bed9c85d..36410f7cd2ad 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1449,10 +1449,11 @@ static int vcpu_interrupt_line(struct kvm_vcpu *vcpu, int number, bool level)
 int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level,
 			  bool line_status)
 {
-	u32 irq = irq_level->irq;
 	unsigned int irq_type, vcpu_id, irq_num;
 	struct kvm_vcpu *vcpu = NULL;
 	bool level = irq_level->level;
+	u32 irq = irq_level->irq;
+	unsigned long *mask;
 
 	irq_type = (irq >> KVM_ARM_IRQ_TYPE_SHIFT) & KVM_ARM_IRQ_TYPE_MASK;
 	vcpu_id = (irq >> KVM_ARM_IRQ_VCPU_SHIFT) & KVM_ARM_IRQ_VCPU_MASK;
@@ -1486,6 +1487,14 @@ int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level,
 			if (irq_num >= VGIC_V5_NR_PRIVATE_IRQS)
 				return -EINVAL;
 
+			/*
+			 * Only allow PPIs that are explicitly exposed to
+			 * usespace to be driven via KVM_IRQ_LINE
+			 */
+			mask = kvm->arch.vgic.gicv5_vm.userspace_ppis;
+			if (!test_bit(irq_num, mask))
+				return -EINVAL;
+
 			/* Build a GICv5-style IntID here */
 			irq_num = vgic_v5_make_ppi(irq_num);
 		} else if (irq_num < VGIC_NR_SGIS ||
diff --git a/arch/arm64/kvm/vgic/vgic-kvm-device.c b/arch/arm64/kvm/vgic/vgic-kvm-device.c
index 772da54c1518..a96c77dccf35 100644
--- a/arch/arm64/kvm/vgic/vgic-kvm-device.c
+++ b/arch/arm64/kvm/vgic/vgic-kvm-device.c
@@ -720,6 +720,32 @@ struct kvm_device_ops kvm_arm_vgic_v3_ops = {
 	.has_attr = vgic_v3_has_attr,
 };
 
+static int vgic_v5_get_userspace_ppis(struct kvm_device *dev,
+				      struct kvm_device_attr *attr)
+{
+	struct vgic_v5_vm *gicv5_vm = &dev->kvm->arch.vgic.gicv5_vm;
+	u64 __user *uaddr = (u64 __user *)(long)attr->addr;
+	int ret;
+
+	guard(mutex)(&dev->kvm->arch.config_lock);
+
+	/*
+	 * We either support 64 or 128 PPIs. In the former case, we need to
+	 * return 0s for the second 64 bits as we have no storage backing those.
+	 */
+	ret = put_user(bitmap_read(gicv5_vm->userspace_ppis, 0, 64), uaddr);
+	if (ret)
+		return ret;
+	uaddr++;
+
+	if (VGIC_V5_NR_PRIVATE_IRQS == 128)
+		ret = put_user(bitmap_read(gicv5_vm->userspace_ppis, 64, 128), uaddr);
+	else
+		ret = put_user(0, uaddr);
+
+	return ret;
+}
+
 static int vgic_v5_set_attr(struct kvm_device *dev,
 			    struct kvm_device_attr *attr)
 {
@@ -732,6 +758,7 @@ static int vgic_v5_set_attr(struct kvm_device *dev,
 		switch (attr->attr) {
 		case KVM_DEV_ARM_VGIC_CTRL_INIT:
 			return vgic_set_common_attr(dev, attr);
+		case KVM_DEV_ARM_VGIC_USERSPACE_PPIS:
 		default:
 			return -ENXIO;
 		}
@@ -753,6 +780,8 @@ static int vgic_v5_get_attr(struct kvm_device *dev,
 		switch (attr->attr) {
 		case KVM_DEV_ARM_VGIC_CTRL_INIT:
 			return vgic_get_common_attr(dev, attr);
+		case KVM_DEV_ARM_VGIC_USERSPACE_PPIS:
+			return vgic_v5_get_userspace_ppis(dev, attr);
 		default:
 			return -ENXIO;
 		}
@@ -773,6 +802,8 @@ static int vgic_v5_has_attr(struct kvm_device *dev,
 		switch (attr->attr) {
 		case KVM_DEV_ARM_VGIC_CTRL_INIT:
 			return 0;
+		case KVM_DEV_ARM_VGIC_USERSPACE_PPIS:
+			return 0;
 		default:
 			return -ENXIO;
 		}
diff --git a/arch/arm64/kvm/vgic/vgic-v5.c b/arch/arm64/kvm/vgic/vgic-v5.c
index f7a24ea6ad78..2b6cd5c3f9c2 100644
--- a/arch/arm64/kvm/vgic/vgic-v5.c
+++ b/arch/arm64/kvm/vgic/vgic-v5.c
@@ -143,6 +143,16 @@ int vgic_v5_init(struct kvm *kvm)
 		}
 	}
 
+	/* We only allow userspace to drive the SW_PPI, if it is implemented. */
+	bitmap_zero(kvm->arch.vgic.gicv5_vm.userspace_ppis,
+		    VGIC_V5_NR_PRIVATE_IRQS);
+	__assign_bit(GICV5_ARCH_PPI_SW_PPI,
+		     kvm->arch.vgic.gicv5_vm.userspace_ppis,
+		     VGIC_V5_NR_PRIVATE_IRQS);
+	bitmap_and(kvm->arch.vgic.gicv5_vm.userspace_ppis,
+		   kvm->arch.vgic.gicv5_vm.userspace_ppis,
+		   ppi_caps.impl_ppi_mask, VGIC_V5_NR_PRIVATE_IRQS);
+
 	return 0;
 }
 
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 8cc3a7b4d815..1388dc6028a9 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -350,6 +350,9 @@ struct vgic_v5_vm {
 	 */
 	DECLARE_BITMAP(vgic_ppi_mask, VGIC_V5_NR_PRIVATE_IRQS);
 
+	/* A mask of the PPIs that are exposed for userspace to drive. */
+	DECLARE_BITMAP(userspace_ppis, VGIC_V5_NR_PRIVATE_IRQS);
+
 	/*
 	 * The HMR itself is handled by the hardware, but we still need to have
 	 * a mask that we can use when merging in pending state (only the state
diff --git a/tools/arch/arm64/include/uapi/asm/kvm.h b/tools/arch/arm64/include/uapi/asm/kvm.h
index a792a599b9d6..1c13bfa2d38a 100644
--- a/tools/arch/arm64/include/uapi/asm/kvm.h
+++ b/tools/arch/arm64/include/uapi/asm/kvm.h
@@ -428,6 +428,7 @@ enum {
 #define   KVM_DEV_ARM_ITS_RESTORE_TABLES        2
 #define   KVM_DEV_ARM_VGIC_SAVE_PENDING_TABLES	3
 #define   KVM_DEV_ARM_ITS_CTRL_RESET		4
+#define   KVM_DEV_ARM_VGIC_USERSPACE_PPIS	5
 
 /* Device Control API on vcpu fd */
 #define KVM_ARM_VCPU_PMU_V3_CTRL	0