Commit 29a9f275 authored by Shuo Liu's avatar Shuo Liu Committed by Greg Kroah-Hartman
Browse files

virt: acrn: Introduce interfaces for MMIO device passthrough 

MMIO device passthrough enables an OS in a virtual machine to directly
access a MMIO device in the host. It promises almost the native
performance, which is required in performance-critical scenarios of
ACRN.

HSM provides the following ioctls:
  - Assign - ACRN_IOCTL_ASSIGN_MMIODEV
    Pass data struct acrn_mmiodev from userspace to the hypervisor, and
    inform the hypervisor to assign a MMIO device to a User VM.

  - De-assign - ACRN_IOCTL_DEASSIGN_PCIDEV
    Pass data struct acrn_mmiodev from userspace to the hypervisor, and
    inform the hypervisor to de-assign a MMIO device from a User VM.

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



Signed-off-by: default avatarShuo Liu <shuo.a.liu@intel.com>
Signed-off-by: default avatarFei Li <fei1.li@intel.com>
Link: https://lore.kernel.org/r/20210923084128.18902-2-fei1.li@intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent c31bbc14

drivers/virt/acrn/hsm.c

+25 −0
Original line number Diff line number Diff line
@@ -114,6 +114,7 @@ static long acrn_dev_ioctl(struct file *filp, unsigned int cmd, 
	struct acrn_ptdev_irq *irq_info;

	struct acrn_ioeventfd ioeventfd;

	struct acrn_vm_memmap memmap;

	struct acrn_mmiodev *mmiodev;

	struct acrn_msi_entry *msi;

	struct acrn_pcidev *pcidev;

	struct acrn_irqfd irqfd;
@@ -217,6 +218,30 @@ static long acrn_dev_ioctl(struct file *filp, unsigned int cmd, 


		ret = acrn_vm_memseg_unmap(vm, &memmap);

		break;

	case ACRN_IOCTL_ASSIGN_MMIODEV:

		mmiodev = memdup_user((void __user *)ioctl_param,

				      sizeof(struct acrn_mmiodev));

		if (IS_ERR(mmiodev))

			return PTR_ERR(mmiodev);



		ret = hcall_assign_mmiodev(vm->vmid, virt_to_phys(mmiodev));

		if (ret < 0)

			dev_dbg(acrn_dev.this_device,

				"Failed to assign MMIO device!\n");

		kfree(mmiodev);

		break;

	case ACRN_IOCTL_DEASSIGN_MMIODEV:

		mmiodev = memdup_user((void __user *)ioctl_param,

				      sizeof(struct acrn_mmiodev));

		if (IS_ERR(mmiodev))

			return PTR_ERR(mmiodev);



		ret = hcall_deassign_mmiodev(vm->vmid, virt_to_phys(mmiodev));

		if (ret < 0)

			dev_dbg(acrn_dev.this_device,

				"Failed to deassign MMIO device!\n");

		kfree(mmiodev);

		break;

	case ACRN_IOCTL_ASSIGN_PCIDEV:

		pcidev = memdup_user((void __user *)ioctl_param,

				     sizeof(struct acrn_pcidev));

drivers/virt/acrn/hypercall.h

+26 −0
Original line number Diff line number Diff line
@@ -41,6 +41,8 @@ 
#define HC_RESET_PTDEV_INTR		_HC_ID(HC_ID, HC_ID_PCI_BASE + 0x04)

#define HC_ASSIGN_PCIDEV		_HC_ID(HC_ID, HC_ID_PCI_BASE + 0x05)

#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_ID_PM_BASE			0x80UL

#define HC_PM_GET_CPU_STATE		_HC_ID(HC_ID, HC_ID_PM_BASE + 0x00)
@@ -194,6 +196,30 @@ static inline long hcall_set_memory_regions(u64 regions_pa) 
	return acrn_hypercall1(HC_VM_SET_MEMORY_REGIONS, regions_pa);

}



/**

 * hcall_assign_mmiodev() - Assign a MMIO device to a User VM

 * @vmid:	User VM ID

 * @addr:	Service VM GPA of the &struct acrn_mmiodev

 *

 * Return: 0 on success, <0 on failure

 */

static inline long hcall_assign_mmiodev(u64 vmid, u64 addr)

{

	return acrn_hypercall2(HC_ASSIGN_MMIODEV, vmid, addr);

}



/**

 * hcall_deassign_mmiodev() - De-assign a PCI device from a User VM

 * @vmid:	User VM ID

 * @addr:	Service VM GPA of the &struct acrn_mmiodev

 *

 * Return: 0 on success, <0 on failure

 */

static inline long hcall_deassign_mmiodev(u64 vmid, u64 addr)

{

	return acrn_hypercall2(HC_DEASSIGN_MMIODEV, vmid, addr);

}



/**

 * hcall_assign_pcidev() - Assign a PCI device to a User VM

 * @vmid:	User VM ID

include/uapi/linux/acrn.h

+28 −0
Original line number Diff line number Diff line
@@ -396,6 +396,7 @@ struct acrn_ptdev_irq { 
/* Type of PCI device assignment */

#define ACRN_PTDEV_QUIRK_ASSIGN	(1U << 0)



#define ACRN_MMIODEV_RES_NUM	3

#define ACRN_PCI_NUM_BARS	6

/**

 * struct acrn_pcidev - Info for assigning or de-assigning a PCI device
@@ -417,6 +418,29 @@ struct acrn_pcidev { 
	__u32	bar[ACRN_PCI_NUM_BARS];

};



/**

 * struct acrn_mmiodev - Info for assigning or de-assigning a MMIO device

 * @name:			Name of the MMIO device.

 * @res[].user_vm_pa:		Physical address of User VM of the MMIO region

 *				for the MMIO device.

 * @res[].service_vm_pa:	Physical address of Service VM of the MMIO

 *				region for the MMIO device.

 * @res[].size:			Size of the MMIO region for the MMIO device.

 * @res[].mem_type:		Memory type of the MMIO region for the MMIO

 *				device.

 *

 * This structure will be passed to hypervisor directly.

 */

struct acrn_mmiodev {

	__u8	name[8];

	struct {

		__u64	user_vm_pa;

		__u64	service_vm_pa;

		__u64	size;

		__u64	mem_type;

	} res[ACRN_MMIODEV_RES_NUM];

};



/**

 * struct acrn_msi_entry - Info for injecting a MSI interrupt to a VM

 * @msi_addr:	MSI addr[19:12] with dest vCPU ID
@@ -568,6 +592,10 @@ struct acrn_irqfd { 
	_IOW(ACRN_IOCTL_TYPE, 0x55, struct acrn_pcidev)

#define ACRN_IOCTL_DEASSIGN_PCIDEV	\

	_IOW(ACRN_IOCTL_TYPE, 0x56, struct acrn_pcidev)

#define ACRN_IOCTL_ASSIGN_MMIODEV	\

	_IOW(ACRN_IOCTL_TYPE, 0x57, struct acrn_mmiodev)

#define ACRN_IOCTL_DEASSIGN_MMIODEV	\

	_IOW(ACRN_IOCTL_TYPE, 0x58, struct acrn_mmiodev)



#define ACRN_IOCTL_PM_GET_CPU_STATE	\

	_IOWR(ACRN_IOCTL_TYPE, 0x60, __u64)