Re: [PATCH v1 0/3] Remove the limitation of Intel PT CPUID info

[Eduardo Habkost]

Hi Luwei Kang,

I was looking for info on intel-pt and just saw this series, and
it was never reviewed or merged (sorry for missing it!).  Is this
still the approach we want to follow for intel-pt?

I'm CCing Jiri Denemark because this might be relevant for a
libvirt issue related to intel-pt we were investigating[1].

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1853972


On Mon, Mar 30, 2020 at 09:56:09AM +0000, Kang, Luwei wrote:
> > -----Original Message-----
> > From: Kang, Luwei <luwei.kang@intel.com>
> > Sent: Tuesday, February 25, 2020 5:38 AM
> > To: pbonzini@redhat.com; rth@twiddle.net; ehabkost@redhat.com
> > Cc: qemu-devel@nongnu.org; Strong, Beeman <beeman.strong@intel.com>;
> > Kang, Luwei <luwei.kang@intel.com>
> > Subject: [PATCH v1 0/3] Remove the limitation of Intel PT CPUID info
> > 
> > The Intel PT feature includes some sub-features(CPUID.(EAX=14H,ECX=0H))
> > and these sub-features are different on different HW platforms. To make the
> > live migration safety(get the same CPUID info with same cpu model on
> > different HW platform), the current Intel PT CPUID information is set to a
> > constant value(from ICELAKE Server).
> > 
> > It will block the new feature in the later HW platform. what's more, the 
> > support
> > of "IP payloads" will disable the Intel PT in KVM guest(patch 1) but it 
> > will come
> > soon.
> > 
> > This patchset remove this limitation and expose all the capabilities to KVM
> > guest. As it will break the live migration safe, Intel PT will be masked as
> > unmigratable.
> 
> Ping.
> 
> Thanks,
> Luwei Kang
> 
> > 
> > Luwei Kang (3):
> >   i386: Remove the limitation of IP payloads for Intel PT
> >   i386: Remove the CPUID limitation of Intel PT
> >   i386: Mark the 'INTEL_PT' CPUID bit as unmigratable
> > 
> >  target/i386/cpu.c | 69 
> > ++++---------------------------------------------------
> >  1 file changed, 5 insertions(+), 64 deletions(-)
> > 
> > --
> > 1.8.3.1
> 

-- 
Eduardo