Re: [Qemu-devel] [PATCH v2 1/3] spapr: Disable ibm, pa-features HTM bit

[David Gibson]

On Wed, Jul 06, 2016 at 03:35:21PM +1000, Sam Bobroff wrote:
> There are a few issues with our handling of the ibm,pa-features
> HTM bit:
> 
> - We don't support transactional memory in PR KVM, so don't tell
>   the OS that we do.
> 
> - In full emulation we have a minimal implementation of HTM that always
>   fails, so for performance reasons lets not tell the OS that we
>   support it either.
> 
> - In HV KVM mode, we should mirror the host HTM enabled state by
>   checking a KVM capability or looking at the AT_HWCAP2 bit.
> 
> For now unconditionally disable it by removing HTM from the
> pa-features bits.  It will be re-enabled in a subsequent patch
> specifically for HV KVM.
> 
> Signed-off-by: Sam Bobroff <address@hidden>

Reviewed-by: David Gibson <address@hidden>

But I won't merge it until the rest of the series is ready to go.


> ---
>  hw/ppc/spapr.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 78ebd9e..704aae7 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -635,7 +635,7 @@ static void spapr_populate_cpu_dt(CPUState *cs, void 
> *fdt, int offset,
>          0xf6, 0x1f, 0xc7, 0xc0, 0x80, 0xf0,
>          0x80, 0x00, 0x00, 0x00, 0x00, 0x00,
>          0x00, 0x00, 0x00, 0x00, 0x80, 0x00,
> -        0x80, 0x00, 0x80, 0x00, 0x80, 0x00 };
> +        0x80, 0x00, 0x80, 0x00, 0x00, 0x00 };
>      uint8_t *pa_features;
>      size_t pa_size;
>  

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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