[PATCH Part2 RFC v3 13/37] crypto: ccp: Shutdown SNP firmware on kexec

Brijesh Singh
2021-06-02T14:13:25Z

When the kernel is getting ready to kexec, it calls the device_shutdown()
to allow drivers to cleanup before the kexec. If SEV firmware is
initialized then shut it down before kexec'ing the new kernel.

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
drivers/crypto/ccp/sev-dev.c | 53 +++++++++++++++++-------------------
drivers/crypto/ccp/sp-pci.c | 12 ++++++++
2 files changed, 37 insertions(+), 28 deletions(-)

diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index 2203167dbc2e..b225face37b1 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -310,6 +310,9 @@ static int __sev_platform_shutdown_locked(int *error)
struct sev_device *sev = psp_master->sev_data;
int ret;

+ if (sev->state == SEV_STATE_UNINIT)
+ return 0;
+
ret = __sev_do_cmd_locked(SEV_CMD_SHUTDOWN, NULL, error);
if (ret)
return ret;
@@ -1115,6 +1118,22 @@ int sev_dev_init(struct psp_device *psp)
return ret;
}

+static void sev_firmware_shutdown(struct sev_device *sev)
+{
+ sev_platform_shutdown(NULL);
+
+ if (sev_es_tmr) {
+ /* The TMR area was encrypted, flush it from the cache */
+ wbinvd_on_all_cpus();
+
+ free_pages((unsigned long)sev_es_tmr,
+ get_order(SEV_ES_TMR_SIZE));
+ sev_es_tmr = NULL;
+ }
+
+ sev_snp_shutdown(NULL);
+}
+
void sev_dev_destroy(struct psp_device *psp)
{
struct sev_device *sev = psp->sev_data;
@@ -1122,6 +1141,8 @@ void sev_dev_destroy(struct psp_device *psp)
if (!sev)
return;

+ sev_firmware_shutdown(sev);
+
if (sev->misc)
kref_put(&misc_dev->refcount, sev_exit);

@@ -1152,21 +1173,6 @@ void sev_pci_init(void)
if (sev_get_api_version())
goto err;

- /*
- * If platform is not in UNINIT state then firmware upgrade and/or
- * platform INIT command will fail. These command require UNINIT state.
- *
- * In a normal boot we should never run into case where the firmware
- * is not in UNINIT state on boot. But in case of kexec boot, a reboot
- * may not go through a typical shutdown sequence and may leave the
- * firmware in INIT or WORKING state.
- */
-
- if (sev->state != SEV_STATE_UNINIT) {
- sev_platform_shutdown(NULL);
- sev->state = SEV_STATE_UNINIT;
- }
-
if (sev_version_greater_or_equal(0, 15) &&
sev_update_firmware(sev->dev) == 0)
sev_get_api_version();
@@ -1224,19 +1230,10 @@ void sev_pci_init(void)

void sev_pci_exit(void)
{
- if (!psp_master->sev_data)
- return;
-
- sev_platform_shutdown(NULL);
-
- if (sev_es_tmr) {
- /* The TMR area was encrypted, flush it from the cache */
- wbinvd_on_all_cpus();
+ struct sev_device *sev = psp_master->sev_data;

- free_pages((unsigned long)sev_es_tmr,
- get_order(SEV_ES_TMR_SIZE));
- sev_es_tmr = NULL;
- }
+ if (!sev)
+ return;

- sev_snp_shutdown(NULL);
+ sev_firmware_shutdown(sev);
}
diff --git a/drivers/crypto/ccp/sp-pci.c b/drivers/crypto/ccp/sp-pci.c
index f468594ef8af..fb1b499bf04d 100644
--- a/drivers/crypto/ccp/sp-pci.c
+++ b/drivers/crypto/ccp/sp-pci.c
@@ -239,6 +239,17 @@ static int sp_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
return ret;
}

+static void sp_pci_shutdown(struct pci_dev *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct sp_device *sp = dev_get_drvdata(dev);
+
+ if (!sp)
+ return;
+
+ sp_destroy(sp);
+}
+
static void sp_pci_remove(struct pci_dev *pdev)
{
struct device *dev = &pdev->dev;
@@ -369,6 +380,7 @@ static struct pci_driver sp_pci_driver = {
.id_table = sp_pci_table,
.probe = sp_pci_probe,
.remove = sp_pci_remove,
+ .shutdown = sp_pci_shutdown,
.driver.pm = &sp_pci_pm_ops,
};

--
2.17.1