Re: [PATCH crypto-2.6] crypto: ccp: add timeout support in the SEV command

From: Brijesh Singh
Date: Tue Sep 11 2018 - 20:11:15 EST

On 9/4/18 12:19 AM, Herbert Xu wrote:
> On Wed, Aug 15, 2018 at 04:11:25PM -0500, Brijesh Singh wrote:
>> Currently, the CCP driver assumes that the SEV command issued to the PSP
>> will always return (i.e. it will never hang). But recently, firmware bugs
>> have shown that a command can hang. Since of the SEV commands are used
>> in probe routines, this can cause boot hangs and/or loss of virtualization
>> capabilities.
>> To protect against firmware bugs, add a timeout in the SEV command
>> execution flow. If a command does not complete within the specified
>> timeout then return -ETIMEOUT and stop the driver from executing any
>> further commands since the state of the SEV firmware is unknown.
>> Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
>> Cc: Gary Hook <Gary.Hook@xxxxxxx>
>> Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
>> Cc: linux-kernel@xxxxxxxxxxxxxxx
>> Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx>
>> ---
>> drivers/crypto/ccp/psp-dev.c | 46 +++++++++++++++++++++++++++++++++++++++-----
>> 1 file changed, 41 insertions(+), 5 deletions(-)
> Patch applied. Thanks.
Thanks Herbert.

Can you please include this patch in your next 4.19-rcX pull request?
Multiple folks are encountering this firmware bug on Ryzen systems. I
will submit the modified version of this patch for stable release (s) so
that we fix issues in 4.18,.17 and .16. thank you.