Re: [PATCH RFC] virtio-pci: add MMIO property

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

 



On 03/19/2012 05:56 PM, Michael S. Tsirkin wrote:
> Currently virtio-pci is specified so that configuration of the device is
> done through a PCI IO space (via BAR 0 of the virtual PCI device).
> However, Linux guests happen to use ioread/iowrite/iomap primitives
> for access, and these work uniformly across memory/io BARs.
>
> While PCI IO accesses are faster than MMIO on x86 kvm,
> MMIO might be helpful on other systems which don't
> implement PIO or where PIO is slower than MMIO.
>
> Add a property to make it possible to tweak the BAR type.
>
> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
>
> This is harmless by default but causes segfaults in memory.c
> when enabled. Thus an RFC until I figure out what's wrong.
>

Should be done via an extra BAR (with the same layout, perhaps extended)
so compatibility is preserved.

-- 
error compiling committee.c: too many arguments to function

_______________________________________________
Virtualization mailing list
Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linuxfoundation.org/mailman/listinfo/virtualization


[Index of Archives]     [KVM Development]     [Libvirt Development]     [Libvirt Users]     [CentOS Virtualization]     [Netdev]     [Ethernet Bridging]     [Linux Wireless]     [Kernel Newbies]     [Security]     [Linux for Hams]     [Netfilter]     [Bugtraq]     [Yosemite Forum]     [MIPS Linux]     [ARM Linux]     [Linux RAID]     [Linux Admin]     [Samba]

  Powered by Linux