| Message ID | 20220804010223.3619-1-jarkko@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | crypto: ccp: Load the firmware twice when SEV API version < 1.43 | expand |
On Thu, Aug 04, 2022 at 08:13:35AM -0500, Tom Lendacky wrote: > On 8/3/22 20:02, Jarkko Sakkinen wrote: > > From: Jarkko Sakkinen <jarkko@profian.com> > > > > 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. > > The SNP hypervisor patches are placing a minimum supported version > requirement for the SEV firmware that exceeds the specified version > above [1] (for the reason above, as well as some others), so this patch > is not needed, NAK. > > [1] https://lore.kernel.org/lkml/87a0481526e66ddd5f6192cbb43a50708aee2883.1655761627.git.ashish.kalra@amd.com/ > > Thanks, > Tom Hi Tom, Is there any particular reason for this restriction? Does SNP not work with API version <v1.51? Do you have a link to a changelog that describes the changes between different firmware versions? Thanks, Jeremi > > > > > Reported-by: Harald Hoyer <harald@profian.com> > > Signed-off-by: Jarkko Sakkinen <jarkko@profian.com> > > --- > > 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 > > @@ -76,6 +76,9 @@ static void *sev_es_tmr; > > #define NV_LENGTH (32 * 1024) > > static void *sev_init_ex_buffer; > > +/* > > + * SEV API version >= maj.min? > > + */ > > static inline bool sev_version_greater_or_equal(u8 maj, u8 min) > > { > > struct sev_device *sev = psp_master->sev_data; > > @@ -89,6 +92,14 @@ static inline bool sev_version_greater_or_equal(u8 maj, u8 min) > > return false; > > } > > +/* > > + * SEV API version < maj.min? > > + */ > > +static inline bool sev_version_less(u8 maj, u8 min) > > +{ > > + return !sev_version_greater_or_equal(maj, min); > > +} > > + > > static void sev_irq_handler(int irq, void *data, unsigned int status) > > { > > struct sev_device *sev = data; > > @@ -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(); > > /* If an init_ex_path is provided rely on INIT_EX for PSP initialization > > * instead of INIT.
On 8/3/22 20:02, Jarkko Sakkinen wrote: > From: Jarkko Sakkinen <jarkko@profian.com> > > 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@profian.com> > Signed-off-by: Jarkko Sakkinen <jarkko@profian.com> > --- > 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. Thanks, Tom >
On Thu, Aug 04, 2022 at 03:37:20PM +0200, Harald Hoyer wrote: > Am 04.08.22 um 15:13 schrieb Tom Lendacky: > > On 8/3/22 20:02, Jarkko Sakkinen wrote: > > > From: Jarkko Sakkinen <jarkko@profian.com> > > > > > > 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. > > > > The SNP hypervisor patches are placing a minimum supported version > > requirement for the SEV firmware that exceeds the specified version > > above [1] (for the reason above, as well as some others), so this patch > > is not needed, NAK. > > As described in the "Milan Release Notes.txt" of the AMD firmware update package amd_sev_fam19h_model0xh_1.33.03.zip. > > "If upgrading to 1.33.01 or later from something older (picking up > CSF-1201), it is required that two Download Firmware commands be run to fix > the "Committed Version" across the firmware. CSF-1201 fixed a bug where the > committed version in the attestation report was incorrect. Performing a > single Download Firmware will upgrade the firmware, but performing a second > one will correct the committed version. This is a one-time upgrade issue. > " Reference should be part of the commit message. I'll update for the next iteration. Thanks for the remark. BR, Jarkko
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@profian.com> > > > > 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@profian.com> > > Signed-off-by: Jarkko Sakkinen <jarkko@profian.com> > > --- > > 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
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 @@ -76,6 +76,9 @@ static void *sev_es_tmr; #define NV_LENGTH (32 * 1024) static void *sev_init_ex_buffer; +/* + * SEV API version >= maj.min? + */ static inline bool sev_version_greater_or_equal(u8 maj, u8 min) { struct sev_device *sev = psp_master->sev_data; @@ -89,6 +92,14 @@ static inline bool sev_version_greater_or_equal(u8 maj, u8 min) return false; } +/* + * SEV API version < maj.min? + */ +static inline bool sev_version_less(u8 maj, u8 min) +{ + return !sev_version_greater_or_equal(maj, min); +} + static void sev_irq_handler(int irq, void *data, unsigned int status) { struct sev_device *sev = data; @@ -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(); /* If an init_ex_path is provided rely on INIT_EX for PSP initialization * instead of INIT.