[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PATCH 4/8] x86/pv: handle reads to the PAT MSR


  • To: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
  • From: Roger Pau Monné <roger.pau@xxxxxxxxxx>
  • Date: Tue, 18 Aug 2020 16:11:50 +0200
  • Authentication-results: esa4.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none
  • Cc: <xen-devel@xxxxxxxxxxxxxxxxxxxx>, Jan Beulich <jbeulich@xxxxxxxx>, Wei Liu <wl@xxxxxxx>
  • Delivery-date: Tue, 18 Aug 2020 14:11:59 +0000
  • Ironport-sdr: QJwo+YKeBCb/M2HsxxLhjLKtT+G249eJwtMwvRUQt8lTdtpAjZ85xf/VkK7+oJPMIR8U3W77/M wIErd+966wLAuCj7CsHct4Nzwuvx6uLpgO00GiqmGTKbpTck3pksQ183zs+re/WIPlGwO5xj71 aMH3Ma359F56lDL1d4vTkdKcLMm3ywhktu7B4g3DcyC/DODw52nGyBlY6Ly/4A5QoAoew+BPVi hnct1Wh5LT0TqPjYBQBDF15gQENTvTYwH4VChlwb0oADTbupr+tFECVkxTB4i8IEpTUw0ZQvBd /QE=
  • List-id: Xen developer discussion <xen-devel.lists.xenproject.org>

On Tue, Aug 18, 2020 at 02:50:24PM +0100, Andrew Cooper wrote:
> On 17/08/2020 16:57, Roger Pau Monne wrote:
> > The value in the PAT MSR is part of the ABI between Xen and PV guests,
> > and there's no reason to not allow a PV guest to read it.
> 
> This is faster than using RDMSR to find the constant.
> 
> > Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
> 
> Acked-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> 
> (Can fix up on commit)

Sure, I didn't write it down because I assumed it would be obvious,
but worth writing down.

Thanks, Roger.



 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.