On 26/05/2025 7:46 pm, Manuel Bouyer wrote: > On Mon, May 26, 2025 at 07:17:13PM +0100, Andrew Cooper wrote: >> On 26/05/2025 7:06 pm, Andrew Cooper wrote: >>> On 26/05/2025 6:59 pm, Manuel Bouyer wrote: >>>> Hello, >>>> since I updated to Xen 4.18.5 (from 4.18.4), NetBSD's dbregs-related tests >>>> are failing. Only for PV; PVH and HVM guests are fine. They are >>>> failing for both 32bits and 64bits guests. >>>> >>>> I tracked it down to dr6 being 0xffff0ff0 after the trace trap, when at >>>> last one of the lower bits should be 1 (I think it's bit 0, from the code). >>>> >>>> I looked at the commit log between 4.18.4 and 4.18.5 but didn't see >>>> anything obvious. >>>> >>>> Any idea ? >>>> >>> Have you got a link to the test in question? >>> >>> We've had a couple of bugfixes in this area, although debug handling >>> isn't helped by the fact that both the SDM and APM are factually >>> incorrect on how to write a #DB handler (and the vendors are moving at a >>> glacial pace to correct them). >> But yes, having looked between 4.18.4 and 4.18.5, I can't see anything >> relevant to debug handling either. >> >> Judging from your description, it looks like a breakpoint is going missing. >> >> The relevant recent change for that is >> https://xenbits.xen.org/gitweb/?p=xen.git;a=commitdiff;h=54ef601a66e8d812a6a6a308f02524e81201825e >> although it's a bit older than 4.18.4. > Well, my previous xen-debug.gz kernel is from Oct, 3 so it can't be > 4.18.4, it's 4.18.3_20240909 which points to commit > bd51e573a730efc569646379cd59ccba967cde97 > > looks like I forgot to update this server. So I need to looks deeper in > the commit logs
Well, that range does include the aforementioned commit. Can you bisect around d32c77f471fb8400b6512c171a14cdd58f04f0a3 which is the backport of ^ in 4.18 ? ~Andrew
