[RFC PATCH v3 2/2] virt: acrn: Introduce interfaces for virtual device creating/destroying

From: Fei Li
Date: Tue Sep 14 2021 - 02:01:29 EST


From: Shuo Liu <shuo.a.liu@xxxxxxxxx>

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.

Signed-off-by: Shuo Liu <shuo.a.liu@xxxxxxxxx>
Signed-off-by: Fei Li <fei1.li@xxxxxxxxx>
---
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..1408d1063339 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 {
+ __u16 vendor;
+ __u16 device;
+ __u32 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