Re: [PULL 00/10] ppc queue

From: Richard Purdie <richard.purdie@linuxfoundation.org>
To: Nicholas Piggin <npiggin@gmail.com>,
	Michael Tokarev <mjt@tls.msk.ru>,
	 Daniel Henrique Barboza <danielhb413@gmail.com>,
	qemu-devel@nongnu.org
Cc: qemu-ppc@nongnu.org, peter.maydell@linaro.org,
	richard.henderson@linaro.org,
	 Bernhard Beschow <shentey@gmail.com>
Subject: Re: [PULL 00/10] ppc queue
Date: Mon, 29 May 2023 08:00:07 +0100	[thread overview]
Message-ID: <f779810abd84d1aae7789f93518f1ac4d1662f4d.camel@linuxfoundation.org> (raw)
In-Reply-To: <CSYJTOIIC83Z.2KLRXWGXHXCW5@wheely>

On Mon, 2023-05-29 at 16:30 +1000, Nicholas Piggin wrote:
> On Mon May 29, 2023 at 4:01 PM AEST, Michael Tokarev wrote:
> > 29.05.2023 05:18, Nicholas Piggin wrote:
> > ..
> > 
> > > > 01/10 target/ppc: Fix fallback to MFSS for MFFS* instructions on pre 3.0 ISAs
> > > > 02/10 target/ppc: Fix width of some 32-bit SPRs
> > > > 03/10 target/ppc: Alignment faults do not set DSISR in ISA v3.0 onward
> > > > 05/10 hw/ppc/prep: Fix wiring of PIC -> CPU interrupt
> > > > 
> > > > Or are these not important for -stable?  Or maybe there are other changes
> > > > which should be picked too?
> > > 
> > > They certainly fix some parts of target emulation, but what is the
> > > guidance for backporting those type of fixes? Most of the patches I sent
> > > including 2,3 were just found from inspection or new test code and not
> > > real software failing.
> > > 
> > > Should just simple ones go in? 32-bit SPRs do not fix entirely the
> > > behaviour of all SPRs, just one aspect. In another fix I had (that
> > > didn't make it in this merge), was a bit more complicated and the
> > > first iteration caused a deadlock that didn't show up in basic test
> > > like booting Linux.
> > > 
> > > My guess is that fixes that correct an issue with real software running
> > > on the target should be ported to stable. Perhaps "obviously correct"
> > > small fixes as well. But not sure about larger changes.
> > 
> > This is exactly why I asked, - because I don't clearly understand how
> > important these to have in -stable. And also to remind that -stable
> > exist, just in case.. ;)
> 
> Ah okay, makes sense. I was just clarifying myself since I wasn't
> too sure.
> 
> > So be it, no actual issue so not applying to -stable.
> 
> I will think about it and try to keep -stable in mind. Of my patches
> there are one or two coming up that could probably go in there, if
> not these ones.

1/10 from me (fallback to MFSS) did fix software failures for Yocto
Project so might be a good candidate for stable. We're carrying that
patch against the last release for now.

Cheers,

Richard