Re: [Qemu-devel] [PATCH] msi: remove return code for msi_init()

[Markus Armbruster <armbru@redhat.com>]

Peter Xu <peterx@redhat.com> writes:

> On Thu, Jun 01, 2017 at 03:06:29PM -0700, Paul Burton wrote:
>> Hi Aurelien/Paolo/Marcel,
>> 
>> On Thursday, 1 June 2017 12:22:06 PDT Aurelien Jarno wrote:
>> > On 2017-06-01 16:23, Paolo Bonzini wrote:
>> > > On 01/06/2017 10:27, Marcel Apfelbaum wrote:
>> > > > On 31/05/2017 11:28, Paolo Bonzini wrote:
>> > > >> No, for now I'd rather just go and remove msi_nonbroken.  When someone
>> > > >> reports a bug, we can add back "msi_broken".
>> > > > 
>> > > > Hi,
>> > > > I agree with the direction, but I am concerned msi_nonbroken is there
>> > > > for a reason.
>> > > > We might break some (obscure/not in use) machine.
>> > > > Maybe we should CC all arch machine maintainers/contributors to give
>> > > > them a chance to object...
>> > > 
>> > > Yeah, Alpha, MIPS and SH are those that support PCI.  Adding Richard and
>> > > Aurelien, do your platforms support MSI on real hardware but not in QEMU?
>> > 
>> > SH clearly doesn't support MSI.
>> > 
>> > The oldest MIPS board also do not support MSI, but I guess the Boston
>> > board might support it. I am adding Paul Burton in Cc: who probably
>> > knows about that.
>> > 
>> > Aurelien
>> 
>> Indeed, real Boston hardware does support MSI (or rather, the Xilinx AXI 
>> Bridge for PCI Express IP used on Boston does) & we make use of it in Linux.
>> 
>> Thanks,
>>     Paul
>
> Does this mean that we'd better still keep the msi_nonbroken bit?

If we still need the "monkey-patch MSI-capable devices to hide board
bugs" logic, it should become opt-in rather than opt-out, i.e. broken
boards set msi_broken (with a suitable comment), non-broken boards don't
touch it.

> Anyway, maybe we can first merge Paolo's fix on edu device:
>
>   [PATCH] edu: fix memory leak on msi_broken platforms
>
> Then we can see whether we still need the rest of the changes.
>
> Thanks,