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

On 9/4/18 12:19 AM, Herbert Xu wrote:

On Wed, Aug 15, 2018 at 04:11:25PM -0500, Brijesh Singh wrote:

quoted

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@amd.com>
Cc: Gary Hook <redacted>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Brijesh Singh <redacted>
---
 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.

-Brijesh