Re: [RFC PATCH 7/9] cxl/test: Add generic mock events

From: Ira Weiny <ira.weiny@intel.com>
To: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: "Williams, Dan J" <dan.j.williams@intel.com>,
	"Schofield, Alison" <alison.schofield@intel.com>,
	"Verma, Vishal L" <vishal.l.verma@intel.com>,
	Ben Widawsky <bwidawsk@kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Davidlohr Bueso <dave@stgolabs.net>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-cxl@vger.kernel.org" <linux-cxl@vger.kernel.org>
Subject: Re: [RFC PATCH 7/9] cxl/test: Add generic mock events
Date: Tue, 27 Sep 2022 09:13:58 -0700	[thread overview]
Message-ID: <YzMhRh276QxjdZM4@iweiny-desk3> (raw)
In-Reply-To: <20220927145623.0000040d@huawei.com>

On Tue, Sep 27, 2022 at 02:56:23PM +0100, Jonathan Cameron wrote:
> On Mon, 26 Sep 2022 14:39:52 -0700
> Ira Weiny <ira.weiny@intel.com> wrote:
> 
> > On Tue, Sep 20, 2022 at 09:17:48AM -0700, Jonathan Cameron wrote:
> > > On Thu, 15 Sep 2022 11:53:29 -0700
> > > Ira Weiny <ira.weiny@intel.com> wrote:
> > >   
> > > > On Thu, Aug 25, 2022 at 12:31:19PM +0100, Jonathan Cameron wrote:  
> > > > > On Fri, 12 Aug 2022 22:32:41 -0700
> > > > > ira.weiny@intel.com wrote:
> > > > >     
> > > > > > From: Ira Weiny <ira.weiny@intel.com>
> > > > > > 
> > > > > > Facilitate testing basic Get/Clear Event functionality by creating
> > > > > > multiple logs and generic events with made up UUID's.
> > > > > > 
> > > > > > Data is completely made up with data patterns which should be easy to
> > > > > > spot in trace output.    
> > > > > Hi Ira,
> > > > > 
> > > > > I'm tempted to hack the QEMU emulation for this in with appropriately
> > > > > complex interface to inject all the record types...    
> > > > 
> > > > Every time I look at the QEMU code it makes my head spin.  :-(  
> > > 
> > > You get used to it ;)`  
> > 
> > I'm trying...  :-/
> > 
> > Question though:
> > 
> > Is there a call in qemu which is equivalent to cpu_to_leXX()?  The
> > exec/cpu-all.h is having compilation issues for me because the
> > TARGET_BIG_ENDIAN is not defined (it is defined in a meson generated header).
> > 
> > So I'm afraid that the tswapXX() calls are not what I'm supposed to use.  Is
> > this true?  Are those some sort of internal call?
> I'm confused.  There is cpu_to_le16 in "qemu/bswap.h"

<sigh> I don't know how I missed it.  Sorry.

> 
> I suspect we've played a bit fast and loose with endianness in a few places in
> current qemu code and should probably check all that sometime.

Yea nothing in hw/cxl seems to use any swapping.  I suppose only little endian
hosts have been used thus far?

I greped for 'ENDIAN' and found the tswap* calls.  I guess I should have
grepped for 'cpu_to'!  That found it right away!  :-/  :-D

Sorry for the distraction,
Ira

> Jonathan
> 
> 
> 
> > 
> > Ira
> 