linux-kernel - Re: CXL memory device not created correctly

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

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <ZHaubgQOFU0+r1MD@bombadil.infradead.org>
Date:   Tue, 30 May 2023 19:18:22 -0700
From:   Luis Chamberlain <mcgrof@...nel.org>
To:     Ira Weiny <ira.weiny@...el.com>
Cc:     Davidlohr Bueso <dave@...olabs.net>, LiuLele <liu.lele@...com>,
        dave.jiang@...el.com, Jonathan.Cameron@...wei.com,
        alison.schofield@...el.com, bhelgaas@...gle.com,
        bwidawsk@...nel.org, dan.j.williams@...el.com, helgaas@...nel.org,
        linux-acpi@...r.kernel.org, linux-cxl@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-pci@...r.kernel.org,
        rostedt@...dmis.org, vishal.l.verma@...el.com
Subject: Re: CXL memory device not created correctly

On Fri, May 19, 2023 at 08:20:44AM -0700, Ira Weiny wrote:
> Davidlohr Bueso wrote:
> > On Fri, 19 May 2023, LiuLele wrote:
> > 
> > >In my testing CXL device /sys/bus/cxl/devices/mem0  not created, and the get error messages :
> > >
> > >```
> > >cxl_pci 0000:0d:00.0: Failed to get interrupt for event Info log
> > >```
> > >
> > >My test environment is a qemu CXL emulator with qemu v8.0.0, Linux kernel v6.3.0.
> > >While with kernel 5.9.13,  /sys/bus/cxl/devices/mem0  can be created.
> > 
> > Yes, this can be annoying and would argue the probe should not error out.
> 
> I had to double check.  Events are mandatory on devices.  On checking
> again interrupt support is mandatory as well.  So that is why I errored
> out here.

The failure essentially creates a user visible regression whereas
booting an older kernel fixes it. It is not a friendly error message
when testing kernels / upgrading / test environments. The only thing
I can think of is if a new kconfig symbol is introduced so to make
such cases a bit more clearer for now as things get settled.

Otherwise for testing this creates a few cycles of just noise. And I'd
imagine even a few developer hours.

  Luis