> -----Original Message----- > From: Benjamin Herrenschmidt [mailto:benh@xxxxxxxxxxxxxxxxxxx] > Sent: Thursday, July 05, 2012 1:26 AM > To: Alexander Graf > Cc: Caraman Mihai Claudiu-B02008; <kvm-ppc@xxxxxxxxxxxxxxx>; KVM list; > linuxppc-dev; qemu-ppc@xxxxxxxxxx List > Subject: Re: [Qemu-ppc] [RFC PATCH 12/17] PowerPC: booke64: Add DO_KVM > kernel hooks > > On Wed, 2012-07-04 at 16:29 +0200, Alexander Graf wrote: > > > > +#ifdef CONFIG_KVM_BOOKE_HV > > > +#define KVM_BOOKE_HV_MFSPR(reg, spr) \ > > > + BEGIN_FTR_SECTION \ > > > + mfspr reg, spr; \ > > > + END_FTR_SECTION_IFSET(CPU_FTR_EMB_HV) > > > +#else > > > +#define KVM_BOOKE_HV_MFSPR(reg, spr) > > > +#endif > > > > Bleks - this is ugly. Do we really need to open-code the #ifdef here? > > Can't the feature section code determine that the feature is disabled > > and just always not include the code? > > You can't but in any case I don't see the point of the conditional here, > we'll eventually have to load srr1 no ? We can move the load up to here > in all cases or can't we ? I like the idea, but there is a problem with addition macros which may clobber r11 and PROLOG_ADDITION_MASKABLE_GEN is such a case. > If really not, we could have it inside DO_KVM and be done with it no ? 32-bit exception prolog loads srr1 unconditionally, as Alex and Scott mentioned earlier, so we will be suboptimal for this case. -Mike ��.n��������+%������w��{.n�����o�^n�r������&��z�ޗ�zf���h���~����������_��+v���)ߣ�
