[PATCH v5 2/2] virt: acrn: Introduce interfaces for virtual device creating/destroying

[Fei Li <fei1.li@intel.com>]

From: Shuo Liu <shuo.a.liu@intel.com>

The ACRN hypervisor can emulate a virtual device within hypervisor for a
Guest VM. The emulated virtual device can work without the ACRN
userspace after creation. The hypervisor do the emulation of that device.

To support the virtual device creating/destroying, HSM provides the
following ioctls:
  - ACRN_IOCTL_CREATE_VDEV
    Pass data struct acrn_vdev from userspace to the hypervisor, and inform
    the hypervisor to create a virtual device for a User VM.
  - ACRN_IOCTL_DESTROY_VDEV
    Pass data struct acrn_vdev from userspace to the hypervisor, and inform
    the hypervisor to destroy a virtual device of a User VM.

These new APIs will be used by user space code vm_add_hv_vdev and
vm_remove_hv_vdev in
https://github.com/projectacrn/acrn-hypervisor/blob/master/devicemodel/core/vmmapi.c

Signed-off-by: Shuo Liu <shuo.a.liu@intel.com>
Signed-off-by: Fei Li <fei1.li@intel.com>
---
 drivers/virt/acrn/hsm.c       | 24 ++++++++++++++++++++
 drivers/virt/acrn/hypercall.h | 26 ++++++++++++++++++++++
 include/uapi/linux/acrn.h     | 42 +++++++++++++++++++++++++++++++++++
 3 files changed, 92 insertions(+)

diff --git a/drivers/virt/acrn/hsm.c b/drivers/virt/acrn/hsm.c
index f567ca59d7c2..5419794fccf1 100644
--- a/drivers/virt/acrn/hsm.c
+++ b/drivers/virt/acrn/hsm.c
@@ -118,6 +118,7 @@ static long acrn_dev_ioctl(struct file *filp, unsigned int cmd,
 	struct acrn_msi_entry *msi;
 	struct acrn_pcidev *pcidev;
 	struct acrn_irqfd irqfd;
+	struct acrn_vdev *vdev;
 	struct page *page;
 	u64 cstate_cmd;
 	int i, ret = 0;
@@ -266,6 +267,29 @@ static long acrn_dev_ioctl(struct file *filp, unsigned int cmd,
 				"Failed to deassign pci device!\n");
 		kfree(pcidev);
 		break;
+	case ACRN_IOCTL_CREATE_VDEV:
+		vdev = memdup_user((void __user *)ioctl_param,
+				   sizeof(struct acrn_vdev));
+		if (IS_ERR(vdev))
+			return PTR_ERR(vdev);
+
+		ret = hcall_create_vdev(vm->vmid, virt_to_phys(vdev));
+		if (ret < 0)
+			dev_dbg(acrn_dev.this_device,
+				"Failed to create virtual device!\n");
+		kfree(vdev);
+		break;
+	case ACRN_IOCTL_DESTROY_VDEV:
+		vdev = memdup_user((void __user *)ioctl_param,
+				   sizeof(struct acrn_vdev));
+		if (IS_ERR(vdev))
+			return PTR_ERR(vdev);
+		ret = hcall_destroy_vdev(vm->vmid, virt_to_phys(vdev));
+		if (ret < 0)
+			dev_dbg(acrn_dev.this_device,
+				"Failed to destroy virtual device!\n");
+		kfree(vdev);
+		break;
 	case ACRN_IOCTL_SET_PTDEV_INTR:
 		irq_info = memdup_user((void __user *)ioctl_param,
 				       sizeof(struct acrn_ptdev_irq));
diff --git a/drivers/virt/acrn/hypercall.h b/drivers/virt/acrn/hypercall.h
index f0c78e52cebb..71d300821a18 100644
--- a/drivers/virt/acrn/hypercall.h
+++ b/drivers/virt/acrn/hypercall.h
@@ -43,6 +43,8 @@
 #define HC_DEASSIGN_PCIDEV		_HC_ID(HC_ID, HC_ID_PCI_BASE + 0x06)
 #define HC_ASSIGN_MMIODEV		_HC_ID(HC_ID, HC_ID_PCI_BASE + 0x07)
 #define HC_DEASSIGN_MMIODEV		_HC_ID(HC_ID, HC_ID_PCI_BASE + 0x08)
+#define HC_CREATE_VDEV			_HC_ID(HC_ID, HC_ID_PCI_BASE + 0x09)
+#define HC_DESTROY_VDEV			_HC_ID(HC_ID, HC_ID_PCI_BASE + 0x0A)
 
 #define HC_ID_PM_BASE			0x80UL
 #define HC_PM_GET_CPU_STATE		_HC_ID(HC_ID, HC_ID_PM_BASE + 0x00)
@@ -196,6 +198,30 @@ static inline long hcall_set_memory_regions(u64 regions_pa)
 	return acrn_hypercall1(HC_VM_SET_MEMORY_REGIONS, regions_pa);
 }
 
+/**
+ * hcall_create_vdev() - Create a virtual device for a User VM
+ * @vmid:	User VM ID
+ * @addr:	Service VM GPA of the &struct acrn_vdev
+ *
+ * Return: 0 on success, <0 on failure
+ */
+static inline long hcall_create_vdev(u64 vmid, u64 addr)
+{
+	return acrn_hypercall2(HC_CREATE_VDEV, vmid, addr);
+}
+
+/**
+ * hcall_destroy_vdev() - Destroy a virtual device of a User VM
+ * @vmid:	User VM ID
+ * @addr:	Service VM GPA of the &struct acrn_vdev
+ *
+ * Return: 0 on success, <0 on failure
+ */
+static inline long hcall_destroy_vdev(u64 vmid, u64 addr)
+{
+	return acrn_hypercall2(HC_DESTROY_VDEV, vmid, addr);
+}
+
 /**
  * hcall_assign_mmiodev() - Assign a MMIO device to a User VM
  * @vmid:	User VM ID
diff --git a/include/uapi/linux/acrn.h b/include/uapi/linux/acrn.h
index 470036d6b1ac..ccf47ed92500 100644
--- a/include/uapi/linux/acrn.h
+++ b/include/uapi/linux/acrn.h
@@ -441,6 +441,44 @@ struct acrn_mmiodev {
 	} res[ACRN_MMIODEV_RES_NUM];
 };
 
+/**
+ * struct acrn_vdev - Info for creating or destroying a virtual device
+ * @id:				Union of identifier of the virtual device
+ * @id.value:			Raw data of the identifier
+ * @id.fields.vendor:		Vendor id of the virtual PCI device
+ * @id.fields.device:		Device id of the virtual PCI device
+ * @id.fields.legacy_id:	ID of the virtual device if not a PCI device
+ * @slot:			Virtual Bus/Device/Function of the virtual
+ *				device
+ * @io_base:			IO resource base address of the virtual device
+ * @io_size:			IO resource size of the virtual device
+ * @args:			Arguments for the virtual device creation
+ *
+ * The created virtual device can be a PCI device or a legacy device (e.g.
+ * a virtual UART controller) and it is emulated by the hypervisor. This
+ * structure will be passed to hypervisor directly.
+ */
+struct acrn_vdev {
+	/*
+	 * the identifier of the device, the low 32 bits represent the vendor
+	 * id and device id of PCI device and the high 32 bits represent the
+	 * device number of the legacy device
+	 */
+	union {
+		__u64 value;
+		struct {
+			__le16 vendor;
+			__le16 device;
+			__le32 legacy_id;
+		} fields;
+	} id;
+
+	__u64	slot;
+	__u32	io_addr[ACRN_PCI_NUM_BARS];
+	__u32	io_size[ACRN_PCI_NUM_BARS];
+	__u8	args[128];
+};
+
 /**
  * struct acrn_msi_entry - Info for injecting a MSI interrupt to a VM
  * @msi_addr:	MSI addr[19:12] with dest vCPU ID
@@ -596,6 +634,10 @@ struct acrn_irqfd {
 	_IOW(ACRN_IOCTL_TYPE, 0x57, struct acrn_mmiodev)
 #define ACRN_IOCTL_DEASSIGN_MMIODEV	\
 	_IOW(ACRN_IOCTL_TYPE, 0x58, struct acrn_mmiodev)
+#define ACRN_IOCTL_CREATE_VDEV	\
+	_IOW(ACRN_IOCTL_TYPE, 0x59, struct acrn_vdev)
+#define ACRN_IOCTL_DESTROY_VDEV	\
+	_IOW(ACRN_IOCTL_TYPE, 0x5A, struct acrn_vdev)
 
 #define ACRN_IOCTL_PM_GET_CPU_STATE	\
 	_IOWR(ACRN_IOCTL_TYPE, 0x60, __u64)
-- 
2.17.1