Re: [PATCH 26/27] KVM: PPC: Add KVM intercept handlers

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Fri, 2010-04-16 at 00:11 +0200, Alexander Graf wrote:
> When an interrupt occurs we don't know yet if we're in guest context or
> in host context. When in guest context, KVM needs to handle it.
> 
> So let's pull the same trick we did on Book3S_64: Just add a macro to
> determine if we're in guest context or not and if so jump on to KVM code.
> 
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

> Signed-off-by: Alexander Graf <agraf@suse.de>
> ---
>  arch/powerpc/kernel/head_32.S |   14 ++++++++++++++
>  1 files changed, 14 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
> index e025e89..98c4b29 100644
> --- a/arch/powerpc/kernel/head_32.S
> +++ b/arch/powerpc/kernel/head_32.S
> @@ -33,6 +33,7 @@
>  #include <asm/asm-offsets.h>
>  #include <asm/ptrace.h>
>  #include <asm/bug.h>
> +#include <asm/kvm_book3s_asm.h>
>  
>  /* 601 only have IBAT; cr0.eq is set on 601 when using this macro */
>  #define LOAD_BAT(n, reg, RA, RB)	\
> @@ -303,6 +304,7 @@ __secondary_hold_acknowledge:
>   */
>  #define EXCEPTION(n, label, hdlr, xfer)		\
>  	. = n;					\
> +	DO_KVM n;				\
>  label:						\
>  	EXCEPTION_PROLOG;			\
>  	addi	r3,r1,STACK_FRAME_OVERHEAD;	\
> @@ -358,6 +360,7 @@ i##n:								\
>   *	-- paulus.
>   */
>  	. = 0x200
> +	DO_KVM  0x200
>  	mtspr	SPRN_SPRG_SCRATCH0,r10
>  	mtspr	SPRN_SPRG_SCRATCH1,r11
>  	mfcr	r10
> @@ -381,6 +384,7 @@ i##n:								\
>  
>  /* Data access exception. */
>  	. = 0x300
> +	DO_KVM  0x300
>  DataAccess:
>  	EXCEPTION_PROLOG
>  	mfspr	r10,SPRN_DSISR
> @@ -397,6 +401,7 @@ DataAccess:
>  
>  /* Instruction access exception. */
>  	. = 0x400
> +	DO_KVM  0x400
>  InstructionAccess:
>  	EXCEPTION_PROLOG
>  	andis.	r0,r9,0x4000		/* no pte found? */
> @@ -413,6 +418,7 @@ InstructionAccess:
>  
>  /* Alignment exception */
>  	. = 0x600
> +	DO_KVM  0x600
>  Alignment:
>  	EXCEPTION_PROLOG
>  	mfspr	r4,SPRN_DAR
> @@ -427,6 +433,7 @@ Alignment:
>  
>  /* Floating-point unavailable */
>  	. = 0x800
> +	DO_KVM  0x800
>  FPUnavailable:
>  BEGIN_FTR_SECTION
>  /*
> @@ -450,6 +457,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_FPU_UNAVAILABLE)
>  
>  /* System call */
>  	. = 0xc00
> +	DO_KVM  0xc00
>  SystemCall:
>  	EXCEPTION_PROLOG
>  	EXC_XFER_EE_LITE(0xc00, DoSyscall)
> @@ -467,9 +475,11 @@ SystemCall:
>   * by executing an altivec instruction.
>   */
>  	. = 0xf00
> +	DO_KVM  0xf00
>  	b	PerformanceMonitor
>  
>  	. = 0xf20
> +	DO_KVM  0xf20
>  	b	AltiVecUnavailable
>  
>  /*
> @@ -882,6 +892,10 @@ __secondary_start:
>  	RFI
>  #endif /* CONFIG_SMP */
>  
> +#ifdef CONFIG_KVM_BOOK3S_HANDLER
> +#include "../kvm/book3s_rmhandlers.S"
> +#endif
> +
>  /*
>   * Those generic dummy functions are kept for CPUs not
>   * included in CONFIG_6xx