| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20090924220350.GA7321@us.ibm.com> Date: Thu, 24 Sep 2009 15:03:50 -0700 From: Gary Hade <garyhade@...ibm.com> To: Bjorn Helgaas <bjorn.helgaas@...com> Cc: Yinghai Lu <yhlu.kernel@...il.com>, Larry Finger <Larry.Finger@...inger.net>, Gary Hade <garyhade@...ibm.com>, Jesse Barnes <jbarnes@...tuousgeek.org>, Jaswinder Singh Rajput <jaswinder@...nel.org>, Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...e.hu>, Len Brown <lenb@...nel.org>, Linus Torvalds <torvalds@...ux-foundation.org>, x86@...nel.org, linux-kernel@...r.kernel.org Subject: Re: fixing "pci=use_crs" On Thu, Sep 24, 2009 at 07:24:18AM -0600, Bjorn Helgaas wrote: > On Wed, 2009-09-23 at 21:42 -0700, Yinghai Lu wrote: > > On Wed, Sep 23, 2009 at 8:21 PM, Bjorn Helgaas <bjorn.helgaas@...com> wrote: > > > On Wed, 2009-09-23 at 16:28 -0700, Yinghai Lu wrote: > > >> On Wed, Sep 23, 2009 at 4:23 PM, Bjorn Helgaas <bjorn.helgaas@...com> wrote: > > > > > >> > P.S. Yinghai, you posted some patches earlier dealing with "only one > > >> > HT chain." You apparently have some insight into what's going on here, > > >> > but unfortunately, the changelogs mean absolutely nothing to me. Can > > >> > you give me any clues? > > >> > > >> which commit? > > >> > > >> normally we only need to have split root resource into several pieces > > >> when we have two HT chains or other io chains... > > > > > > I meant the patches here: > > > http://lkml.org/lkml/2009/6/24/557 > > > > > > My opinion is that ACPI is there to give us an abstract description of > > > the machine, and we shouldn't have to introduce knowledge like "this > > > machine has two HT chains" or add checks in amd_bus.c about > > > "pci_root_num <= 1". > > > > > > But maybe if I knew what an HT chain was and why you think it affects > > > the description returned by _CRS, it would give me a clue about how to > > > deal with this in a generic way. > > > > we could use _CRS, but lots of BIOS just provide messed up resources > > in _CRS to OS. > > We do have to assume there are BIOS defects here, but in most cases, I > look for Linux deficiencies first. I'm assuming (without real evidence) > that Windows does look at the _CRS, so the worst BIOS defects should be > weeded out by Windows testing. > > > for example, the HW conf register does have mmio high range there, but > > _CRS doesn't report them. > > On Larry's box, _CRS reports *more* ranges than Linux was prepared for. > This would be a bug in the other direction, where _CRS reports *less* > than it should. > > > thought we can use whilelist to use _CRS for them. > > I'm opposed to a whitelist for this issue because it means we have to > continually update the whitelist for new, correctly working machines. > If we can't figure out anything better, we could use a date-based > blacklist (ignore _CRS for all machines older than today). Unless someone has a strong need other than PCI hot-add for root bridge _CRS to be used by default, would it possibly make sense (at least as a first cut) to limit the default use of _CRS to only those root bridges that (1) are located above PCI hotplug capable slots and (2) have _CRS that returns a quantity of ranges that will not overrun the current fixed size resource arrays? Gary -- Gary Hade System x Enablement IBM Linux Technology Center 503-578-4503 IBM T/L: 775-4503 garyhade@...ibm.com http://www.ibm.com/linux/ltc -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists