On Sat, Nov 11, 2022 at 07:54:25, "Bjorn Helgaas" <helgaas@xxxxxxxxxx> wrote: > On Tue, Sep 13, 2022 at 09:24:45PM +0800, Xiaochun Lee wrote: > > From: Xiaochun Lee <lixc17@xxxxxxxxxx> > > > > When enable VMDs on Intel CPUs, VMD controllers(8086:28c0) be > > recognized by VMD driver and there are many failed messages of BAR 13 > > when scan the bridges and assign IO resource behind it as listed > > below, the bridge wants to get 0x6000 as its IO resource, but there is > > no IO resources on the host bridge. > > > > VMD host bridge resources: > > vmd 0000:64:00.5: PCI host bridge to bus 10000:80 pci_bus 10000:80: > > root bus resource [bus 80-9f] pci_bus 10000:80: root bus resource [mem > > 0xe0000000-0xe1ffffff] pci_bus 10000:80: root bus resource [mem > > 0x24ffff02010-0x24fffffffff 64bit] > > > > Failed messages of BAR#13: > > pci 10000:80:02.0: BAR 13: no space for [io size 0x1000] pci > > 10000:80:02.0: BAR 13: failed to assign [io size 0x1000] pci > > 10000:80:03.0: BAR 13: no space for [io size 0x1000] pci > > 10000:80:03.0: BAR 13: failed to assign [io size 0x1000] > > > > VMD-enabled root ports use > > Enhanced Configuration Access Mechanism (ECAM) access PCI Express > > configuration space, and offer VMD_CFGBAR as base of PCI Express > > configuration space for the bridges behind it. The configuration space > > includes IO resources, but these IO resources are not actually used on > > X86, especially the NVMes as device connected on this hot plug > > bridges, and it can result in BAR#13 assign IO resource failed. So we > > clear IO resources by setting an IO base value greater than limit to > > these bridges. Hence, we can leverage kernel parameter > > "pci=hpiosize=0KB" to avoid this failed messages show out. > > > > Signed-off-by: Xiaochun Lee <lixc17@xxxxxxxxxx> > > Some of the discussion here got lost because of email issues. Lore has > some: > https://apc01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore. > kernel.org%2Fall%2F1663075485-20591-1-git-send-email- > lixiaochun.2888%40163.com%2FT%2F%23u&data=05%7C01%7Clixc17 > %40lenovo.com%7C9cd095ffdb584e492dec08dac440139b%7C5c7d0b28bdf > 8410caa934df372b16203%7C0%7C0%7C638038076734438158%7CUnknown > %7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1ha > WwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=JzWYkIsaEfINofiqo > XyjEh43VjXO3HZw2JLSsmhpUiQ%3D&reserved=0, > and patchwork has a v2 with a little more discussion: > https://apc01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpatc > hwork.kernel.org%2Fproject%2Flinux-pci%2Fpatch%2F1664288166-7432-1- > git-send-email- > lixiaochun.2888%40163.com%2F&data=05%7C01%7Clixc17%40lenovo. > com%7C9cd095ffdb584e492dec08dac440139b%7C5c7d0b28bdf8410caa934 > df372b16203%7C0%7C0%7C638038076734438158%7CUnknown%7CTWFpb > GZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI > 6Mn0%3D%7C3000%7C%7C%7C&sdata=y%2BtIsepTpyLeoHW6CrgkZz2 > tiMjY0TONfK7zNCKXQ90%3D&reserved=0 > > But the v2 patch doesn't seem to have made it to the mailing lists or to > lore > (https://apc01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flor > e.kernel.org%2Fall%2F%3Fq%3Df%253Alixc17&data=05%7C01%7Clixc1 > 7%40lenovo.com%7C9cd095ffdb584e492dec08dac440139b%7C5c7d0b28bd > f8410caa934df372b16203%7C0%7C0%7C638038076734438158%7CUnknow > n%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1h > aWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=zxGz1hZOD2tvQP > EsbxQTzjHwQvXvqeO%2FUd6I9S%2Fj314%3D&reserved=0) and I don't > apply things until they appear on the mailing list. > > I *would* like to get rid of those "no space" and "failed to assign" > messages. This is an issue for platforms other than VMD, too. Just an FYI > that you need to follow up on this if we want make progress. > > Bjorn Thanks for your comments, so do you mean we'd better come up with a solution to avoid messages like "no space" and "failed to assign" using a common way, for both VMD and other platforms? Xiaochun
