Re: [PATCH 1/2] xen/arm: add a warning if the guest asks for SPI delivery to vcpu != 0.

[Julien Grall <julien.grall@linaro.org>]

Hi Stefano,

On 25/05/14 19:06, Stefano Stabellini wrote:
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>   xen/arch/arm/vgic.c |    5 +++++
>   1 file changed, 5 insertions(+)
>
> diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
> index 4869b87..e4f38a0 100644
> --- a/xen/arch/arm/vgic.c
> +++ b/xen/arch/arm/vgic.c
> @@ -581,6 +581,11 @@ static int vgic_distr_mmio_write(struct vcpu *v, mmio_info_t *info)
>           if ( dabt.size != 0 && dabt.size != 2 ) goto bad_width;
>           rank = vgic_irq_rank(v, 8, gicd_reg - GICD_ITARGETSR);
>           if ( rank == NULL) goto write_ignore;
> +        if ( *r )

This is wrong, ITARGETSR store a  4 bitmask of CPUs, one per interrupt. 
Each bit of the mask correspond to a CPU (see Table 4-17 in the GICv2 
manual).

Furthermore, I think it's safe to just ignore write. The manual says:
"It is IMPLEMENTATION DEFINED which, if any, SPIs are statically 
configured in hardware. The CPU targets field for such an SPI is 
read-only, and returns a value that indicates the CPU targets for the 
interrupt."

With the former comment, your patch #2 is also wrong.

> +        {
> +            gdprintk(XENLOG_DEBUG, "SPI delivery to seconday cpus is unimplemented\n");

s/seconday/secondary/

Regards,

-- 
Julien Grall