RE: [PATCH 5/6] KVM: PPC: BOOKE: Allow guest to change MSR_DE

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

 




> -----Original Message-----
> From: Alexander Graf [mailto:agraf@xxxxxxx]
> Sent: Tuesday, July 29, 2014 7:35 PM
> To: Wood Scott-B07421; Bhushan Bharat-R65777
> Cc: kvm-ppc@xxxxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx; Yoder Stuart-B08248
> Subject: Re: [PATCH 5/6] KVM: PPC: BOOKE: Allow guest to change MSR_DE
> 
> 
> On 29.07.14 00:01, Scott Wood wrote:
> > On Fri, 2014-07-11 at 14:09 +0530, Bharat Bhushan wrote:
> >> When userspace is debugging guest then MSR_DE is always set and
> >> MSRP_DEP is set so that guest cannot change MSR_DE.
> >> Guest debug resources are not yet emulated, So there seems no reason
> >> we should stop guest controlling MSR_DE.
> >> Also a followup patch will enable debug emulation and that requires
> >> guest to control MSR_DE.
> > Why does it matter whether we emulate debug resources?  We still don't
> > want the guest to be able to clear MSR[DE] and thus break host debug.
> 
> The patch description is misleading. This patch changes the default of DEP to
> "guest controlled" when it boots up. Once QEMU wants control over the debug
> registers, it gets switched to "QEMU controlled" (that code is already there).

Yes, now default MSR_DE is controlled by guest and when QEMU wants to use debug resources then MSR_DEP is set, so guest cannot change MSR_DE.

Thanks
-Bharat 

> 
> 
> Alex

��.n��������+%������w��{.n�����o�^n�r������&��z�ޗ�zf���h���~����������_��+v���)ߣ�


[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux