klog.json: add an "Unable ... IOMMU perf counter" message

This message shows performance counters are not supported on AMD IOMMU
hardware.

Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Alex Hung <alex.hung@canonical.com>
---
 data/klog.json | 7 +++++++
 1 file changed, 7 insertions(+)

Dear Alex,


Am 31.03.20 um 03:21 schrieb Alex Hung:
> This message shows performance counters are not supported on AMD IOMMU
> hardware.
> 
> Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
> Signed-off-by: Alex Hung <alex.hung@canonical.com>
> ---
>   data/klog.json | 7 +++++++
>   1 file changed, 7 insertions(+)
> 
> diff --git a/data/klog.json b/data/klog.json
> index 15043658..eb78fe47 100644
> --- a/data/klog.json
> +++ b/data/klog.json
> @@ -2697,6 +2697,13 @@ atform Communications Channel Table (PCCT) and find the PCC subspace communicati
>       "advice": "BIOS setup is configured to enable IOMMU, but BIOS lacks IVRS table that is describing which is the address of IOMMU",
>       "label": "KlogAmdIommuNoIVRS"
>     },
> +  {
> +    "compare_mode": "string",
> +    "log_level": "LOG_LEVEL_MEDIUM",
> +    "pattern": "Unable to read/write to IOMMU perf counter",
> +    "advice": "AMD IOMMU performance counter is not accessible and not supported due to firmware limitations.",

By the way,

https://lore.kernel.org/lkml/20180727102710.GA6738@8bytes.org/

lists the maintainers answer. Maybe the advice can be more direct.

> AMD IOMMU performance counter is not accessible due to a bug in the system firmware.

> +    "label": "KlogAmdIommuPCNotSupported"
> +  },
>     {
>       "compare_mode": "string",
>       "log_level": "LOG_LEVEL_HIGH",

Tested-by: Paul Menzel <pmenzel@molgen.mpg.de>


Kind regards,

Paul

On Fri, Apr 3, 2020 at 3:00 PM Paul Menzel <pmenzel@molgen.mpg.de> wrote:

> Dear Alex,
>
>
> Am 31.03.20 um 03:21 schrieb Alex Hung:
> > This message shows performance counters are not supported on AMD IOMMU
> > hardware.
> >
> > Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
> > Signed-off-by: Alex Hung <alex.hung@canonical.com>
> > ---
> >   data/klog.json | 7 +++++++
> >   1 file changed, 7 insertions(+)
> >
> > diff --git a/data/klog.json b/data/klog.json
> > index 15043658..eb78fe47 100644
> > --- a/data/klog.json
> > +++ b/data/klog.json
> > @@ -2697,6 +2697,13 @@ atform Communications Channel Table (PCCT) and
> find the PCC subspace communicati
> >       "advice": "BIOS setup is configured to enable IOMMU, but BIOS
> lacks IVRS table that is describing which is the address of IOMMU",
> >       "label": "KlogAmdIommuNoIVRS"
> >     },
> > +  {
> > +    "compare_mode": "string",
> > +    "log_level": "LOG_LEVEL_MEDIUM",
> > +    "pattern": "Unable to read/write to IOMMU perf counter",
> > +    "advice": "AMD IOMMU performance counter is not accessible and not
> supported due to firmware limitations.",
>
> By the way,
>
> https://lore.kernel.org/lkml/20180727102710.GA6738@8bytes.org/
>
> lists the maintainers answer. Maybe the advice can be more direct.
>

It says the public version of AMD's BKDG has no references.

Do you prefer the advice to be something like " AMD IOMMU performance
counter is not accessible and not supported due to limitation of AMD's
public document" instead?



>
> > AMD IOMMU performance counter is not accessible due to a bug in the
> system firmware.
>
> > +    "label": "KlogAmdIommuPCNotSupported"
> > +  },
> >     {
> >       "compare_mode": "string",
> >       "log_level": "LOG_LEVEL_HIGH",
>
> Tested-by: Paul Menzel <pmenzel@molgen.mpg.de>
>
>
> Kind regards,
>
> Paul
>