Re: [PATCH 1/1] virt: arm-cca-guest: fix error check for RSI_INCOMPLETE

[Suzuki K Poulose <suzuki.poulose@arm.com>]

On 10/04/2026 17:36, Sami Mujawar wrote:
> The RSI interface can return RSI_INCOMPLETE when a report spans
> multiple granules. This is an expected condition and should not be
> treated as a fatal error.
> 
> Currently, arm_cca_report_new() checks for `info.result != RSI_SUCCESS`
> and bails out, which incorrectly flags RSI_INCOMPLETE as a failure.
> Fix the check to only break out on results other than RSI_SUCCESS or
> RSI_INCOMPLETE.
> 
> This ensures partial reports are handled correctly and avoids spurious
> -ENXIO errors when generating attestation reports.
> 
> Fixes: 7999edc484ca ("virt: arm-cca-guest: TSM_REPORT support for realms")
> Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
> Reported-by: Jagdish Gediya <Jagdish.Gediya@arm.com>

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>


> ---
>   drivers/virt/coco/arm-cca-guest/arm-cca-guest.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/virt/coco/arm-cca-guest/arm-cca-guest.c b/drivers/virt/coco/arm-cca-guest/arm-cca-guest.c
> index 0c9ea24a200c..66d00b6ceb78 100644
> --- a/drivers/virt/coco/arm-cca-guest/arm-cca-guest.c
> +++ b/drivers/virt/coco/arm-cca-guest/arm-cca-guest.c
> @@ -157,7 +157,8 @@ static int arm_cca_report_new(struct tsm_report *report, void *data)
>   		} while (info.result == RSI_INCOMPLETE &&
>   			 info.offset < RSI_GRANULE_SIZE);
>   
> -		if (info.result != RSI_SUCCESS) {
> +		/* Break out in case of failure */
> +		if (info.result != RSI_SUCCESS && info.result != RSI_INCOMPLETE) {
>   			ret = -ENXIO;
>   			token_size = 0;
>   			goto exit_free_granule_page;