Re: [kvm-unit-tests PATCH] powerpc: Fix running the kvm-unit-tests with recent versions of QEMU

On 12/6/22 11:14, Thomas Huth wrote:
> Starting with version 7.0, QEMU starts the pseries guests in 32-bit mode
> instead of 64-bit (see QEMU commit 6e3f09c28a - "spapr: Force 32bit when
> resetting a core"). This causes our test_64bit() in powerpc/emulator.c
> to fail. Let's switch to 64-bit in our startup code instead to fix the
> issue.
> 
> Signed-off-by: Thomas Huth <[email protected]>
> ---
>   powerpc/cstart64.S | 6 ++++++
>   1 file changed, 6 insertions(+)
> 
> diff --git a/powerpc/cstart64.S b/powerpc/cstart64.S
> index 972851f9..206c518f 100644
> --- a/powerpc/cstart64.S
> +++ b/powerpc/cstart64.S
> @@ -23,6 +23,12 @@
>   .globl start
>   start:
>   	FIXUP_ENDIAN
> +	/* Switch to 64-bit mode */
> +	mfmsr	r1
> +	li	r2,1
> +	sldi	r2,r2,63
> +	or	r1,r1,r2
> +	mtmsrd	r1
>   	/*
>   	 * We were loaded at QEMU's kernel load address, but we're not
>   	 * allowed to link there due to how QEMU deals with linker VMAs,

You could add this define in lib/powerpc/asm/ppc_asm.h  :

#define MSR_SF	0x8000000000000000ul

and possibly use the LOAD_REG_IMMEDIATE macro to set the MSR.

Thanks,

C.