* Greg KH (greg@xxxxxxxxx) wrote: > On Fri, Aug 28, 2009 at 12:17:14PM -0700, Chris Wright wrote: > > An SR-IOV capable device includes an SR-IOV PCIe capability which > > describes the Virtual Function (VF) BAR requirements. A typical SR-IOV > > device can support multiple VFs whose BARs must be in a contiguous region, > > effectively an array of VF BARs. The BAR reports the size requirement > > for a single VF. We calculate the full range needed by simply multiplying > > the VF BAR size with the number of possible VFs and create a resource > > spanning the full range. > > > > This all seems sane enough except it artificially inflates the alignment > > requirement for the VF BAR. The VF BAR need only be aligned to the size > > of a single BAR not the contiguous range of VF BARs. This can cause us > > to fail to allocate resources for the BAR despite the fact that we > > actually have enough space. > > > > This patch adds a support for a new resource alignment type, > > IORESOURCE_VSIZEALIGN, and allows struct resource to keep track of the > > size requirements of a VF BAR which are smaller than the full resource > > size. This could also be done all within the PCI layer w/out bloating > > struct resource or using the last available bit for alignment types. > > > > Comments? > > > > Signed-off-by: Chris Wright <chrisw@xxxxxxxxxxxx> > > Cc: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx> > > Cc: Ivan Kokshaysky <ink@xxxxxxxxxxxxxxxxxxxx> > > Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > > Cc: Matthew Wilcox <matthew@xxxxxx> > > Cc: Yu Zhao <yu.zhao@xxxxxxxxx> > > Cc: stable@xxxxxxxxxx > > This is a new feature, which seems to be odd to have it sent to stable > :) Yeah, it's broken now (and shipped in 2.6.30). > Does this fix reported problems in the "wild"? Depending on card firwmware, yeah, I've hit this problem. thanks, -chris -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
