On Thu, Aug 04, 2022 at 09:59:44AM -0500, Tom Lendacky wrote:
> On 8/3/22 20:02, Jarkko Sakkinen wrote:
> > From: Jarkko Sakkinen <jarkko@xxxxxxxxxxx>
> >
> > SEV-SNP does not initialize to a legit state, unless the firmware is
> > loaded twice, when SEP API version < 1.43, and the firmware is updated
> > to a later version. Because of this user space needs to work around
> > this with "rmmod && modprobe" combo. Fix this by implementing the
> > workaround to the driver.
> >
> > Reported-by: Harald Hoyer <harald@xxxxxxxxxxx>
> > Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxxx>
> > ---
> > drivers/crypto/ccp/sev-dev.c | 22 +++++++++++++++++++---
> > 1 file changed, 19 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
> > index 799b476fc3e8..f2abb7439dde 100644
> > --- a/drivers/crypto/ccp/sev-dev.c
> > +++ b/drivers/crypto/ccp/sev-dev.c
>
> > @@ -1274,6 +1285,7 @@ void sev_pci_init(void)
> > {
> > struct sev_device *sev = psp_master->sev_data;
> > int error, rc;
> > + int i;
> > if (!sev)
> > return;
> > @@ -1283,9 +1295,13 @@ void sev_pci_init(void)
> > if (sev_get_api_version())
> > goto err;
> > - if (sev_version_greater_or_equal(0, 15) &&
> > - sev_update_firmware(sev->dev) == 0)
> > - sev_get_api_version();
> > + /*
> > + * SEV-SNP does not work properly before loading the FW twice in the API
> > + * versions older than SEV 1.43.
> > + */
> > + for (i = 0; i < sev_version_greater_or_equal(0, 15) + sev_version_less(1, 43); i++)
> > + if (sev_update_firmware(sev->dev) == 0)
> > + sev_get_api_version();
>
> I prefer to have this logic in the sev_update_firmware() function.
>
> And while the loop is correct, it isn't obvious. Something in
> sev_update_firmware() that just does:
>
> ret = sev_do_cmd(SEV_CMD_DOWNLOAD_FIRMWARE, data, &error);
>
> if (!ret && sev_version_greater_or_equal(0, 15) && sev_version_less(1, 43))
> ret = sev_do_cmd(SEV_CMD_DOWNLOAD_FIRMWARE, data, &error);
>
> And place a comment before the second command that references the reason
> for the second download.
OK, I'll do that. Thank you.
BR, Jarkko
