Re: [PATCH V4] POWERPC: BOOK3S: KVM: Use the saved dar value and generic make_dsisr

[Alexander Graf <agraf@suse.de>]

On 05/04/2014 07:21 PM, Aneesh Kumar K.V wrote:
> Although it's optional IBM POWER cpus always had DAR value set on
> alignment interrupt. So don't try to compute these values.
>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> ---
> Changes from V3:
> * Use make_dsisr instead of checking feature flag to decide whether to use
>    saved dsisr or not
>
>   arch/powerpc/include/asm/disassemble.h | 34 +++++++++++++++++++++++++++
>   arch/powerpc/kernel/align.c            | 34 +--------------------------
>   arch/powerpc/kvm/book3s_emulate.c      | 43 ++++------------------------------
>   3 files changed, 40 insertions(+), 71 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/disassemble.h b/arch/powerpc/include/asm/disassemble.h
> index 856f8deb557a..6330a61b875a 100644
> --- a/arch/powerpc/include/asm/disassemble.h
> +++ b/arch/powerpc/include/asm/disassemble.h
> @@ -81,4 +81,38 @@ static inline unsigned int get_oc(u32 inst)
>   {
>   	return (inst >> 11) & 0x7fff;
>   }
> +
> +#define IS_XFORM(inst)	(get_op(inst)  == 31)
> +#define IS_DSFORM(inst)	(get_op(inst) >= 56)
> +
> +/*
> + * Create a DSISR value from the instruction
> + */
> +static inline unsigned make_dsisr(unsigned instr)
> +{
> +	unsigned dsisr;
> +
> +
> +	/* bits  6:15 --> 22:31 */
> +	dsisr = (instr & 0x03ff0000) >> 16;
> +
> +	if (IS_XFORM(instr)) {
> +		/* bits 29:30 --> 15:16 */
> +		dsisr |= (instr & 0x00000006) << 14;
> +		/* bit     25 -->    17 */
> +		dsisr |= (instr & 0x00000040) << 8;
> +		/* bits 21:24 --> 18:21 */
> +		dsisr |= (instr & 0x00000780) << 3;
> +	} else {
> +		/* bit      5 -->    17 */
> +		dsisr |= (instr & 0x04000000) >> 12;
> +		/* bits  1: 4 --> 18:21 */
> +		dsisr |= (instr & 0x78000000) >> 17;
> +		/* bits 30:31 --> 12:13 */
> +		if (IS_DSFORM(instr))
> +			dsisr |= (instr & 0x00000003) << 18;
> +	}
> +
> +	return dsisr;
> +}
>   #endif /* __ASM_PPC_DISASSEMBLE_H__ */
> diff --git a/arch/powerpc/kernel/align.c b/arch/powerpc/kernel/align.c
> index 94908af308d8..34f55524d456 100644
> --- a/arch/powerpc/kernel/align.c
> +++ b/arch/powerpc/kernel/align.c
> @@ -25,14 +25,13 @@
>   #include <asm/cputable.h>
>   #include <asm/emulated_ops.h>
>   #include <asm/switch_to.h>
> +#include <asm/disassemble.h>
>   
>   struct aligninfo {
>   	unsigned char len;
>   	unsigned char flags;
>   };
>   
> -#define IS_XFORM(inst)	(((inst) >> 26) == 31)
> -#define IS_DSFORM(inst)	(((inst) >> 26) >= 56)
>   
>   #define INVALID	{ 0, 0 }
>   
> @@ -192,37 +191,6 @@ static struct aligninfo aligninfo[128] = {
>   };
>   
>   /*
> - * Create a DSISR value from the instruction
> - */
> -static inline unsigned make_dsisr(unsigned instr)
> -{
> -	unsigned dsisr;
> -
> -
> -	/* bits  6:15 --> 22:31 */
> -	dsisr = (instr & 0x03ff0000) >> 16;
> -
> -	if (IS_XFORM(instr)) {
> -		/* bits 29:30 --> 15:16 */
> -		dsisr |= (instr & 0x00000006) << 14;
> -		/* bit     25 -->    17 */
> -		dsisr |= (instr & 0x00000040) << 8;
> -		/* bits 21:24 --> 18:21 */
> -		dsisr |= (instr & 0x00000780) << 3;
> -	} else {
> -		/* bit      5 -->    17 */
> -		dsisr |= (instr & 0x04000000) >> 12;
> -		/* bits  1: 4 --> 18:21 */
> -		dsisr |= (instr & 0x78000000) >> 17;
> -		/* bits 30:31 --> 12:13 */
> -		if (IS_DSFORM(instr))
> -			dsisr |= (instr & 0x00000003) << 18;
> -	}
> -
> -	return dsisr;
> -}
> -
> -/*
>    * The dcbz (data cache block zero) instruction
>    * gives an alignment fault if used on non-cacheable
>    * memory.  We handle the fault mainly for the
> diff --git a/arch/powerpc/kvm/book3s_emulate.c b/arch/powerpc/kvm/book3s_emulate.c
> index 99d40f8977e8..04c38f049dfd 100644
> --- a/arch/powerpc/kvm/book3s_emulate.c
> +++ b/arch/powerpc/kvm/book3s_emulate.c
> @@ -569,48 +569,14 @@ unprivileged:
>   
>   u32 kvmppc_alignment_dsisr(struct kvm_vcpu *vcpu, unsigned int inst)
>   {
> -	u32 dsisr = 0;
> -
> -	/*
> -	 * This is what the spec says about DSISR bits (not mentioned = 0):
> -	 *
> -	 * 12:13		[DS]	Set to bits 30:31
> -	 * 15:16		[X]	Set to bits 29:30
> -	 * 17			[X]	Set to bit 25
> -	 *			[D/DS]	Set to bit 5
> -	 * 18:21		[X]	Set to bits 21:24
> -	 *			[D/DS]	Set to bits 1:4
> -	 * 22:26			Set to bits 6:10 (RT/RS/FRT/FRS)
> -	 * 27:31			Set to bits 11:15 (RA)
> -	 */
> -
> -	switch (get_op(inst)) {
> -	/* D-form */
> -	case OP_LFS:
> -	case OP_LFD:
> -	case OP_STFD:
> -	case OP_STFS:
> -		dsisr |= (inst >> 12) & 0x4000;	/* bit 17 */
> -		dsisr |= (inst >> 17) & 0x3c00; /* bits 18:21 */
> -		break;
> -	/* X-form */
> -	case 31:
> -		dsisr |= (inst << 14) & 0x18000; /* bits 15:16 */
> -		dsisr |= (inst << 8)  & 0x04000; /* bit 17 */
> -		dsisr |= (inst << 3)  & 0x03c00; /* bits 18:21 */
> -		break;
> -	default:
> -		printk(KERN_INFO "KVM: Unaligned instruction 0x%x\n", inst);
> -		break;
> -	}
> -
> -	dsisr |= (inst >> 16) & 0x03ff; /* bits 22:31 */
> -
> -	return dsisr;
> +	return make_dsisr(inst);
>   }
>   
>   ulong kvmppc_alignment_dar(struct kvm_vcpu *vcpu, unsigned int inst)
>   {
> +#ifdef CONFIG_PPC_BOOK3S_64
> +	return vcpu->arch.fault_dar;

How about PA6T and G5s?


Alex