Bug 202517 - PCI PF memory decode disable when sizing VF BARs
Summary: PCI PF memory decode disable when sizing VF BARs
Status: New
Alias: None
Product: Base System
Classification: Unclassified
Component: kern (show other bugs)
Version: CURRENT
Hardware: amd64 Any
: --- Affects Some People
Assignee: freebsd-bugs (Nobody)
URL:
Keywords: patch
Depends on:
Blocks:
 
Reported: 2015-08-20 13:18 UTC by Eric Badger
Modified: 2016-01-18 14:44 UTC (History)
2 users (show)

See Also:

Attachments
Patch to prevent disabling of PF during VF bar sizing (2.49 KB, patch)
2015-08-20 13:18 UTC, Eric Badger 		no flags Details | Diff
View All Add an attachment (proposed patch, testcase, etc.)

Note You need to log in before you can comment on or make changes to this bug.
Description Eric Badger 2015-08-20 13:18:36 UTC 
Created attachment 160143 [details]
Patch to prevent disabling of PF during VF bar sizing

During IOV config, when setting up VF bars, several calls are made to 'pci_read_bar' (in sys/dev/pci/pci.c) in order to size VF BARs, which causes memory decoding to be turned off temporarily for the PF associated with those VFs. This can interfere with an already running PF.

This was discussed a few months back on -current, but it doesn't look like the fix has hit the source tree:
https://lists.freebsd.org/pipermail/freebsd-current/2015-May/055725.html

I've been using the attached patch (from the above thread) for some time to solve this problem.