Re: [RFC PATCH 0/6] QEMU CXL Provide mock CXL events and irq support

[Ira Weiny]

On Tue, Oct 11, 2022 at 10:40:06AM +0100, Jonathan Cameron wrote:
> On Mon, 10 Oct 2022 15:29:38 -0700
> ira.weiny@intel.com wrote:
> 
> > From: Ira Weiny <ira.weiny@intel.com>
> > 
> > CXL Event records inform the OS of various CXL device events.  Thus far CXL
> > memory devices are emulated and therefore don't naturally have events which
> > will occur.
> > 
> > Add mock events and a HMP trigger mechanism to facilitate guest OS testing 
> > of
> > event support.
> > 
> > This support requires a follow on version of the event patch set.  The RFC 
> > was
> > submitted and discussed here:
> > 
> >     
> > https://lore.kernel.org/linux-cxl/20220813053243.757363-1-ira.weiny@intel.com/
> > 
> > I'll post the lore link to the new version shortly.
> > 
> > Instructions for running this test.
> > 
> > Add qmp option to qemu:
> > 
> >     <host> $ qemu-system-x86_64 ... -qmp 
> > unix:/tmp/run_qemu_qmp_0,server,nowait ...
> > 
> >     OR
> > 
> >     <host> $ run_qemu.sh ... --qmp ...
> > 
> > Enable tracing of events within the guest:
> > 
> >     <guest> $ echo "" > /sys/kernel/tracing/trace
> >     <guest> $ echo 1 > /sys/kernel/tracing/events/cxl/enable
> >     <guest> $ echo 1 > /sys/kernel/tracing/tracing_on
> > 
> > Trigger event generation and interrupts in the host:
> > 
> >     <host> $ echo "cxl_event_inject cxl-devX" | qmp-shell -H 
> > /tmp/run_qemu_qmp_0
> > 
> >     Where X == one of the memory devices; cxl-dev0 should work.
> > 
> > View events on the guest:
> > 
> >     <guest> $ cat /sys/kernel/tracing/trace
> 
> Hi Ira,
> 
> Why is this an RFC rather than a patch set to apply?

I really just wanted to see what people think of the over all idea.  The
patches themselves stand on their own if the QEMU community is ok using QEMU as
a test vehicle like this.

> 
> It's useful to have that in the cover letter so we can focus on what
> you want comments on (rather than simply review).

Yes sorry,
Ira

> 
> Thanks,
> 
> Jonathan
> 
> > 
> > 
> > Ira Weiny (6):
> >   qemu/bswap: Add const_le64()
> >   qemu/uuid: Add UUID static initializer
> >   hw/cxl/cxl-events: Add CXL mock events
> >   hw/cxl/mailbox: Wire up get/clear event mailbox commands
> >   hw/cxl/cxl-events: Add event interrupt support
> >   hw/cxl/mailbox: Wire up Get/Set Event Interrupt policy
> > 
> >  hmp-commands.hx             |  14 ++
> >  hw/cxl/cxl-device-utils.c   |   1 +
> >  hw/cxl/cxl-events.c         | 330 ++++++++++++++++++++++++++++++++++++
> >  hw/cxl/cxl-host-stubs.c     |   5 +
> >  hw/cxl/cxl-mailbox-utils.c  | 224 +++++++++++++++++++++---
> >  hw/cxl/meson.build          |   1 +
> >  hw/mem/cxl_type3.c          |   7 +-
> >  include/hw/cxl/cxl_device.h |  22 +++
> >  include/hw/cxl/cxl_events.h | 194 +++++++++++++++++++++
> >  include/qemu/bswap.h        |  10 ++
> >  include/qemu/uuid.h         |  12 ++
> >  include/sysemu/sysemu.h     |   3 +
> >  12 files changed, 802 insertions(+), 21 deletions(-)
> >  create mode 100644 hw/cxl/cxl-events.c
> >  create mode 100644 include/hw/cxl/cxl_events.h
> > 
> > 
> > base-commit: 6f7f81898e4437ea544ee4ca24bef7ec543b1f06
>