arch/um/drivers/vfio_user.c

Source file repositories/reference/linux-study-clean/arch/um/drivers/vfio_user.c

File Facts

System
Linux kernel
Corpus path
arch/um/drivers/vfio_user.c
Extension
.c
Size
7155 bytes
Lines
328
Domain
Architecture Layer
Bucket
arch/um
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

if (ioctl(dev->device, VFIO_DEVICE_GET_REGION_INFO, &region) < 0) {
			err = -errno;
			goto free_region;
		}
		dev->region[i].size = region.size;
		dev->region[i].offset = region.offset;
	}

	/* Only MSI-X is supported currently. */
	irq_info.index = VFIO_PCI_MSIX_IRQ_INDEX;
	if (ioctl(dev->device, VFIO_DEVICE_GET_IRQ_INFO, &irq_info) < 0) {
		err = -errno;
		goto free_region;
	}

	dev->irq_count = irq_info.count;

	dev->irqfd = uml_kmalloc(sizeof(int) * dev->irq_count, UM_GFP_KERNEL);
	if (!dev->irqfd) {
		err = -ENOMEM;
		goto free_region;
	}

	memset(dev->irqfd, -1, sizeof(int) * dev->irq_count);

	err = vfio_set_irqs(dev->device, 0, dev->irq_count, dev->irqfd);
	if (err)
		goto free_irqfd;

	return 0;

free_irqfd:
	kfree(dev->irqfd);
free_region:
	kfree(dev->region);
close_device:
	close(dev->device);
	return err;
}

void uml_vfio_user_teardown_device(struct uml_vfio_user_device *dev)
{
	kfree(dev->irqfd);
	kfree(dev->region);
	close(dev->device);
}

int uml_vfio_user_activate_irq(struct uml_vfio_user_device *dev, int index)
{
	int irqfd;

	irqfd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
	if (irqfd < 0)
		return -errno;

	dev->irqfd[index] = irqfd;
	return irqfd;
}

void uml_vfio_user_deactivate_irq(struct uml_vfio_user_device *dev, int index)
{
	close(dev->irqfd[index]);
	dev->irqfd[index] = -1;
}

int uml_vfio_user_update_irqs(struct uml_vfio_user_device *dev)
{
	return vfio_set_irqs(dev->device, 0, dev->irq_count, dev->irqfd);
}

static int vfio_region_read(struct uml_vfio_user_device *dev, unsigned int index,
			    uint64_t offset, void *buf, uint64_t size)
{
	if (index >= dev->num_regions || offset + size > dev->region[index].size)
		return -EINVAL;

	if (pread(dev->device, buf, size, dev->region[index].offset + offset) < 0)
		return -errno;

	return 0;
}

static int vfio_region_write(struct uml_vfio_user_device *dev, unsigned int index,
			     uint64_t offset, const void *buf, uint64_t size)
{
	if (index >= dev->num_regions || offset + size > dev->region[index].size)
		return -EINVAL;

	if (pwrite(dev->device, buf, size, dev->region[index].offset + offset) < 0)
		return -errno;

Annotation

Implementation Notes