On 08/29/2011 02:04 PM, Anthony Liguori wrote: > On 08/29/2011 11:51 AM, Yoder Stuart-B08248 wrote: >> Instead of config space fixed at 0xf, we would propose >> a header and multiple 'device info' records at offset 0x0 that would >> encode everything that user space needs to know about >> the device: > > Why not just use an ioctl with a proper struct? This is more extensible than a struct -- both in features, and in the number of each type of resource that you can have, length of strings you can have, etc. > The config space is weird for PCI access because it's mirroring a well > known binary blob. It's not something to replicate if you're inventing > something new. There's no intent to replicate config space in general -- config space is provided as-is. There's little overlap between config space and the extra information provided. Length can be had from config space, but only by modifying it. Physical address sort-of overlaps, though bus addresess could be different from CPU physical addresses[1]. In both cases, it'd be nice to stay consistent with device-tree regions. "BAR type" is overlap, but doesn't seem too unreasonable to me. -Scott [1] The user is probably less likely to care about the physical address at all in the PCI case, but consistency is nice. -- 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
