Re: [PATCHv5 3/3] vhost_net: a kernel-level virtio server

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tuesday 15 September 2009, Michael S. Tsirkin wrote:
> Userspace in x86 maps a PCI region, uses it for communication with ppc?

This might have portability issues. On x86 it should work, but if the
host is powerpc or similar, you cannot reliably access PCI I/O memory
through copy_tofrom_user but have to use memcpy_toio/fromio or readl/writel
calls, which don't work on user pointers.

Specifically on powerpc, copy_from_user cannot access unaligned buffers
if they are on an I/O mapping.

	Arnd <><
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux