Re: [PATCH 2/3] xen/arm: Advertise workaround 1 if we apply 3

[Julien Grall <julien@xxxxxxx>]

Hi Bertrand,

On 03/05/2022 10:38, Bertrand Marquis wrote:
> SMCC_WORKAROUND_3 is handling both Spectre v2 and spectre BHB.
> So when a guest is asking if we support workaround 1, tell yes if we
> apply workaround 3 on exception entry as it handles it.
>
> This will allow guests not supporting Spectre BHB but impacted by
> spectre v2 to still handle it correctly.
> The modified behaviour is coherent with what the Linux kernel does in
> KVM for guests.
>
> While there use ARM_SMCCC_SUCCESS instead of 0 for the return code value
> for workaround detection to be coherent with Workaround 2 handling.
>
> Signed-off-by: Bertrand Marquis <bertrand.marquis@xxxxxxx>
Acked-by: Julien Grall <jgrall@xxxxxxxxxx>

I think we should also consider for backport.

Cheers,

--
Julien Grall