On Thu, 8 May 2025, Stewart Hildebrand wrote:
> On Arm, we expect read handlers to have the bits above the access size
> zeroed. vPCI read handlers may return all 1s. Mask off the bits above
> the access size.
>
> Fixes: 9a5e22b64266 ("xen/arm: check read handler behavior")
> Signed-off-by: Stewart Hildebrand <stewart.hildebr...@amd.com>
Reviewed-by: Stefano Stabellini <sstabell...@kernel.org>
> ---
> xen/arch/arm/vpci.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/xen/arch/arm/vpci.c b/xen/arch/arm/vpci.c
> index b63a356bb4a8..3a3ff5d0812c 100644
> --- a/xen/arch/arm/vpci.c
> +++ b/xen/arch/arm/vpci.c
> @@ -37,7 +37,7 @@ static int vpci_mmio_read(struct vcpu *v, mmio_info_t *info,
> if ( vpci_ecam_read(sbdf, ECAM_REG_OFFSET(info->gpa),
> 1U << info->dabt.size, &data) )
> {
> - *r = data;
> + *r = data & invalid;
> return 1;
> }
>
> --
> 2.49.0
>
