Re: [PATCH v4] virt: tdx-guest: Handle GetQuote request error code

[Mikko Ylinen <mikko.ylinen@linux.intel.com>]

Hi,

On Thu, Apr 11, 2024 at 02:22:50AM +0000, Kuppuswamy Sathyanarayanan wrote:
> The tdx-guest driver marshals quote requests via hypercall to have a
> quoting enclave sign attestation evidence about the current state of
> the TD. There are 2 possible failures, a transport failure (failure
> to communicate with the quoting agent) and payload failure (a failed
> quote). The driver only checks the former, update it to consider the
> latter payload errors as well.
> 
> Fixes: f4738f56d1dc ("virt: tdx-guest: Add Quote generation support using TSM_REPORTS")
> Reported-by: Xiaoyao Li <xiaoyao.li@intel.com>
> Closes: https://lore.kernel.org/linux-coco/6bdf569c-684a-4459-af7c-4430691804eb@linux.intel.com/T/#u
> Reviewed-by: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
> Acked-by: Kai Huang <kai.huang@intel.com>
> Reviewed-by: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
> ---
> 
> Changes since v3:
>  * Rebased on top of v6.9-rc1
>  * Added Dan's Reviewed-by tag.
> 
> Changes since v2:
>  * Updated the commit log (Dan)
>  * Removed pr_err message.
> 
> Changes since v1:
>  * Updated the commit log (Kirill)
> 
>  drivers/virt/coco/tdx-guest/tdx-guest.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/virt/coco/tdx-guest/tdx-guest.c b/drivers/virt/coco/tdx-guest/tdx-guest.c
> index 1253bf76b570..c39f0007958d 100644
> --- a/drivers/virt/coco/tdx-guest/tdx-guest.c
> +++ b/drivers/virt/coco/tdx-guest/tdx-guest.c
> @@ -228,6 +228,11 @@ static int tdx_report_new(struct tsm_report *report, void *data)
>  		goto done;
>  	}
>  
> +	if (quote_buf->status != GET_QUOTE_SUCCESS) {
> +		ret = -EIO;
> +		goto done;
> +	}
> +
>  	buf = kvmemdup(quote_buf->data, quote_buf->out_len, GFP_KERNEL);
>  	if (!buf) {
>  		ret = -ENOMEM;

Would it be possible to get this queued?

I had the same fix implemented as I ran into the same issue but then
noticed this had already been sent out.

One possible improvement here could be to add a reason for the error
to make it more consistent with the other error paths above:

pr_err("GetQuote failed, status:%llx\n", quote_buf->status);

Anyway, it works as expected as it is so:

Tested-by: Mikko Ylinen <mikko.ylinen@linux.intel.com>

-- Mikko