Re: [Qemu-ppc] [RFC PATCH 12/17] PowerPC: booke64: Add DO_KVM kernel hooks

On 07.07.2012, at 00:33, Caraman Mihai Claudiu-B02008 wrote:

quoted

-----Original Message-----
From: Benjamin Herrenschmidt [mailto:benh@kernel.crashing.org]
Sent: Thursday, July 05, 2012 1:26 AM
To: Alexander Graf
Cc: Caraman Mihai Claudiu-B02008; <redacted>; KVM =

list;

quoted

linuxppc-dev; qemu-ppc@nongnu.org List
Subject: Re: [Qemu-ppc] [RFC PATCH 12/17] PowerPC: booke64: Add =

DO_KVM

quoted

kernel hooks
=20
On Wed, 2012-07-04 at 16:29 +0200, Alexander Graf wrote:
=20

quoted

quoted

+#ifdef CONFIG_KVM_BOOKE_HV
+#define KVM_BOOKE_HV_MFSPR(reg, spr)				=

\

quoted

quoted

quoted

+	BEGIN_FTR_SECTION					\
+		mfspr	reg, spr;			  	\
+	END_FTR_SECTION_IFSET(CPU_FTR_EMB_HV)
+#else
+#define KVM_BOOKE_HV_MFSPR(reg, spr)
+#endif

=20
Bleks - this is ugly. Do we really need to open-code the #ifdef =

here?

quoted

quoted

Can't the feature section code determine that the feature is =

disabled

quoted

quoted

and just always not include the code?

=20
You can't but in any case I don't see the point of the conditional =

here,

quoted

we'll eventually have to load srr1 no ? We can move the load up to =

here

quoted

in all cases or can't we ?=20

=20
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.

Mike -v please :)


Alex