Prev: perf & kvm: Enhance perf to collect KVM guest os statistics from host side
Next: [PATCH] [MTD] Fix JFFS2 sync silent failure
From: Avi Kivity on 17 Apr 2010 14:40
On 04/15/2010 11:55 PM, Tom Lyon wrote:
> This is the second of 2 related, but independent, patches. This is for
> uio.c, the previous is for uio_pci_generic.c.
>
> The 2 patches were previously one large patch. Changes for this version:
> - uio_pci_generic.c just gets extensions so that a single fd can be used
> by non-privileged processes for interrupt control and mmaps
> - All of the DMA and IOMMU related stuff move to uio.c; no longer a need
> to pass ioctls to individual uio drivers. It turns out that the code
> is not PCI specific anyways.
> - A new ioctl to pin DMA buffers to certain IO virtual addresses for KVM.
> - New eventfd based interrupt notifications, including support for PCI
> specific MSI and MSI-X interrupts.
> - PCI specific code to reset PCI functions before and after use
>
>
> @@ -122,4 +126,23 @@
> #define UIO_PORT_GPIO 2
> #define UIO_PORT_OTHER 3
>
> +#endif /* __KERNEL__ */
> +
> +// Kernel& User level defines for ioctls
> +
> +struct uio_dma_map {
> + unsigned long vaddr;
> + unsigned long long dmaaddr;
>

Use __u64 for both, otherwise you need to rewrite the structures in the
kernel in case 32-bit userspace calls a 64-bit kernel.

> + int size;
>

What units? Size is probably too small. Suggest unsigned type to avoid
an extra check in the kernel.

> + int rdwr;
>

What values can this hold?

> +};
> +
> +#define UIO_DMA_MAP_ANYWHERE _IOWR(';', 100, struct uio_dma_map)
>

What does this do? Ignore vaddr?

> +#define UIO_DMA_MAP_IOVA _IOWR(';', 101, struct uio_dma_map)
> +#define UIO_DMA_UNMAP _IOW(';', 102, struct uio_dma_map)
> +#define UIO_DMA_MASK _IOW(';', 103, unsigned long long)
> +#define UIO_EVENTFD_IRQ _IOW(';', 104, int)
> +#define UIO_EVENTFD_MSI _IOW(';', 105, int)
> +#define UIO_EVENTFDS_MSIX _IOW(';', 106, int)
>

These three need some documentation.


--
Do not meddle in the internals of kernels, for they are subtle and quick to panic.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
 | 
Pages: 1
Prev: perf & kvm: Enhance perf to collect KVM guest os statistics from host side
Next: [PATCH] [MTD] Fix JFFS2 sync silent failure