Subject: Re: [PATCH v3] powerpc/kvm: support to handle sw breakpoint

From: Segher Boessenkool <[email-masked]>
Date: Sun, 3 Aug 2014 10:51:08 -0500

> +/*
> + * KVMPPC_INST_BOOK3S_DEBUG is debug Instruction for supporting Software Breakpoint.
> + * Based on PowerISA v2.07, Instruction with opcode 0s will be treated as illegal
> + * instruction.
> + */

"primary opcode 0" instead?

> +#define OP_ZERO                 0x0

Using 0x0 where you mean 0, making a #define for 0 in the first place...
This all looks rather silly doesn't it.

> +	case OP_ZERO:
> +		if((inst & 0x00FFFF00) == KVMPPC_INST_BOOK3S_DEBUG) {

You either shouldn't mask at all here, or the mask is wrong (the primary
op is the top six bits, not the top eight).

Segher