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Subject[Part2 PATCH v9 14/38] crypto: ccp: Implement SEV_FACTORY_RESET ioctl command
Date
The SEV_FACTORY_RESET command can be used by the platform owner to
reset the non-volatile SEV related data. The command is defined in
SEV spec section 5.4

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Gary Hook <gary.hook@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-crypto@vger.kernel.org
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Improvements-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
drivers/crypto/ccp/psp-dev.c | 77 +++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 76 insertions(+), 1 deletion(-)

diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
index 9915a6c604a3..b49583a45a55 100644
--- a/drivers/crypto/ccp/psp-dev.c
+++ b/drivers/crypto/ccp/psp-dev.c
@@ -232,9 +232,84 @@ static int sev_platform_shutdown(int *error)
return rc;
}

+static int sev_get_platform_state(int *state, int *error)
+{
+ int rc;
+
+ rc = __sev_do_cmd_locked(SEV_CMD_PLATFORM_STATUS,
+ &psp_master->status_cmd_buf, error);
+ if (rc)
+ return rc;
+
+ *state = psp_master->status_cmd_buf.state;
+ return rc;
+}
+
+static int sev_ioctl_do_reset(struct sev_issue_cmd *argp)
+{
+ int state, rc;
+
+ /*
+ * The SEV spec requires that FACTORY_RESET must be issued in
+ * UNINIT state. Before we go further lets check if any guest is
+ * active.
+ *
+ * If FW is in WORKING state then deny the request otherwise issue
+ * SHUTDOWN command do INIT -> UNINIT before issuing the FACTORY_RESET.
+ *
+ */
+ rc = sev_get_platform_state(&state, &argp->error);
+ if (rc)
+ return rc;
+
+ if (state == SEV_STATE_WORKING)
+ return -EBUSY;
+
+ if (state == SEV_STATE_INIT) {
+ rc = __sev_platform_shutdown_locked(&argp->error);
+ if (rc)
+ return rc;
+ }
+
+ return __sev_do_cmd_locked(SEV_CMD_FACTORY_RESET, 0, &argp->error);
+}
+
static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
{
- return -ENOTTY;
+ void __user *argp = (void __user *)arg;
+ struct sev_issue_cmd input;
+ int ret = -EFAULT;
+
+ if (!psp_master)
+ return -ENODEV;
+
+ if (ioctl != SEV_ISSUE_CMD)
+ return -EINVAL;
+
+ if (copy_from_user(&input, argp, sizeof(struct sev_issue_cmd)))
+ return -EFAULT;
+
+ if (input.cmd > SEV_MAX)
+ return -EINVAL;
+
+ mutex_lock(&sev_cmd_mutex);
+
+ switch (input.cmd) {
+
+ case SEV_FACTORY_RESET:
+ ret = sev_ioctl_do_reset(&input);
+ break;
+ default:
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (copy_to_user(argp, &input, sizeof(struct sev_issue_cmd)))
+ ret = -EFAULT;
+out:
+ mutex_unlock(&sev_cmd_mutex);
+
+ return ret;
}

static const struct file_operations sev_fops = {
--
2.9.5
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