Re: [Qemu-devel] [PATCH 6/7] ipmi: Fix SSIF ACPI handling to use the right CRS

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, May 12, 2016 at 08:29:53AM -0500, Corey Minyard wrote:
> On 05/12/2016 02:33 AM, Michael S. Tsirkin wrote:
> >On Wed, May 11, 2016 at 02:46:05PM -0500, minyard@acm.org wrote:
> >>From: Corey Minyard <cminyard@mvista.com>
> >>
> >>Signed-off-by: Corey Minyard <cminyard@mvista.com>
> >>---
> >>  hw/acpi/ipmi.c | 4 +++-
> >>  1 file changed, 3 insertions(+), 1 deletion(-)
> >>
> >>diff --git a/hw/acpi/ipmi.c b/hw/acpi/ipmi.c
> >>index 731f4ad..c187fdd 100644
> >>--- a/hw/acpi/ipmi.c
> >>+++ b/hw/acpi/ipmi.c
> >>@@ -49,7 +49,9 @@ static Aml *aml_ipmi_crs(IPMIFwInfo *info)
> >>                              regspacing, info->register_length));
> >>          break;
> >>      case IPMI_MEMSPACE_SMBUS:
> >>-        aml_append(crs, aml_return(aml_int(info->base_address)));
> >>+        aml_append(crs, aml_i2c_serial_bus_device(0, 100000,
> >>+                                                  info->base_address,
> >>+                                                  info->acpi_parent));
> >Isn't this fairly new? If so using these opcodes
> >is likely to break some older guests. Maybe they already don't
> >work, but I'd like to see some explanation about that,
> >and what was tested.
> 
> This is new with the 5.0 specification.
> 
> I haven't done extensive testing on anything but Linux 3.10 and later.
> Well, I might have run 2.6.32, but I can't remember.  I don't have the
> ability to test Windows.
> 
> But isn't the idea of these definitions that they are ignored if the OS
> doesn't understand them?

Not always. It depends, spec does not require it.

You can check which revision does OSPM support but
you have to decide what to do for an old revision then.

>  Otherwise you could never add anything.
> 
> -corey

Question is, what happened before this change?


> >>          break;
> >>      default:
> >>          abort();
> >>-- 
> >>2.7.4