@@ -32,6 +32,10 @@
 #define SEV_FW_FILE		"amd/sev.fw"
 #define SEV_FW_NAME_SIZE	64
 
+/* Minimum firmware version required for the SEV-SNP support */
+#define SNP_MIN_API_MAJOR	1
+#define SNP_MIN_API_MINOR	30
+
 static DEFINE_MUTEX(sev_cmd_mutex);
 static struct sev_misc_dev *misc_dev;
 

@@ -598,6 +602,95 @@ static int sev_update_firmware(struct device *dev)
 	return ret;
 }
 
+static void snp_set_hsave_pa(void *arg)
+{
+	wrmsrl(MSR_VM_HSAVE_PA, 0);
+}
+
+static int __sev_snp_init_locked(int *error)
+{
+	struct psp_device *psp = psp_master;
+	struct sev_device *sev;
+	int rc = 0;
+
+	if (!psp || !psp->sev_data)
+		return -ENODEV;
+
+	sev = psp->sev_data;
+
+	if (sev->snp_inited)
+		return 0;
+
+	/*
+	 * The SNP_INIT requires the MSR_VM_HSAVE_PA must be set to 0h
+	 * across all cores.
+	 */
+	on_each_cpu(snp_set_hsave_pa, NULL, 1);
+
+	/* Prepare for first SEV guest launch after INIT */
+	wbinvd_on_all_cpus();
+
+	/* Issue the SNP_INIT firmware command. */
+	rc = __sev_do_cmd_locked(SEV_CMD_SNP_INIT, NULL, error);
+	if (rc)
+		return rc;
+
+	sev->snp_inited = true;
+	dev_dbg(sev->dev, "SEV-SNP firmware initialized\n");
+
+	return rc;
+}
+
+int sev_snp_init(int *error)
+{
+	int rc;
+
+	if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP))
+		return -ENODEV;
+
+	mutex_lock(&sev_cmd_mutex);
+	rc = __sev_snp_init_locked(error);
+	mutex_unlock(&sev_cmd_mutex);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(sev_snp_init);
+
+static int __sev_snp_shutdown_locked(int *error)
+{
+	struct sev_device *sev = psp_master->sev_data;
+	int ret;
+
+	if (!sev->snp_inited)
+		return 0;
+
+	/* SHUTDOWN requires the DF_FLUSH */
+	wbinvd_on_all_cpus();
+	__sev_do_cmd_locked(SEV_CMD_SNP_DF_FLUSH, NULL, NULL);
+
+	ret = __sev_do_cmd_locked(SEV_CMD_SNP_SHUTDOWN, NULL, error);
+	if (ret) {
+		dev_err(sev->dev, "SEV-SNP firmware shutdown failed\n");
+		return ret;
+	}
+
+	sev->snp_inited = false;
+	dev_dbg(sev->dev, "SEV-SNP firmware shutdown\n");
+
+	return ret;
+}
+
+static int sev_snp_shutdown(int *error)
+{
+	int rc;
+
+	mutex_lock(&sev_cmd_mutex);
+	rc = __sev_snp_shutdown_locked(NULL);
+	mutex_unlock(&sev_cmd_mutex);
+
+	return rc;
+}
+
 static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
 {
 	struct sev_device *sev = psp_master->sev_data;

@@ -1048,6 +1141,8 @@ static void sev_firmware_shutdown(struct sev_device *sev)
 			   get_order(SEV_ES_TMR_SIZE));
 		sev_es_tmr = NULL;
 	}
+
+	sev_snp_shutdown(NULL);
 }
 
 void sev_dev_destroy(struct psp_device *psp)

@@ -1093,6 +1188,26 @@ void sev_pci_init(void)
 	    sev_update_firmware(sev->dev) == 0)
 		sev_get_api_version();
 
+	/*
+	 * If boot CPU supports the SNP, then first attempt to initialize
+	 * the SNP firmware.
+	 */
+	if (cpu_feature_enabled(X86_FEATURE_SEV_SNP)) {
+		if (!sev_version_greater_or_equal(SNP_MIN_API_MAJOR, SNP_MIN_API_MINOR)) {
+			dev_err(sev->dev, "SEV-SNP support requires firmware version >= %d:%d\n",
+				SNP_MIN_API_MAJOR, SNP_MIN_API_MINOR);
+		} else {
+			rc = sev_snp_init(&error);
+			if (rc) {
+				/*
+				 * If we failed to INIT SNP then don't abort the probe.
+				 * Continue to initialize the legacy SEV firmware.
+				 */
+				dev_err(sev->dev, "SEV-SNP: failed to INIT error %#x\n", error);
+			}
+		}
+	}
+
 	/* Obtain the TMR memory area for SEV-ES use */
 	tmr_page = alloc_pages(GFP_KERNEL, get_order(SEV_ES_TMR_SIZE));
 	if (tmr_page) {

@@ -1117,13 +1232,11 @@ void sev_pci_init(void)
 		rc = sev_platform_init(&error);
 	}
 
-	if (rc) {
+	if (rc)
 		dev_err(sev->dev, "SEV: failed to INIT error %#x\n", error);
-		return;
-	}
 
-	dev_info(sev->dev, "SEV API:%d.%d build:%d\n", sev->api_major,
-		 sev->api_minor, sev->build);
+	dev_info(sev->dev, "SEV%s API:%d.%d build:%d\n", sev->snp_inited ?
+		"-SNP" : "", sev->api_major, sev->api_minor, sev->build);
 
 	return;
 

@@ -52,6 +52,8 @@ struct sev_device {
 	u8 build;
 
 	void *cmd_buf;
+
+	bool snp_inited;
 };
 
 int sev_dev_init(struct psp_device *psp);

@@ -748,6 +748,20 @@ struct sev_data_snp_init_ex {
  */
 int sev_platform_init(int *error);
 
+/**
+ * sev_snp_init - perform SEV SNP_INIT command
+ *
+ * @error: SEV command return code
+ *
+ * Returns:
+ * 0 if the SEV successfully processed the command
+ * -%ENODEV    if the SEV device is not available
+ * -%ENOTSUPP  if the SEV does not support SEV
+ * -%ETIMEDOUT if the SEV command timed out
+ * -%EIO       if the SEV returned a non-zero return code
+ */
+int sev_snp_init(int *error);
+
 /**
  * sev_platform_status - perform SEV PLATFORM_STATUS command
  *

@@ -855,6 +869,8 @@ sev_platform_status(struct sev_user_data_status *status, int *error) { return -E
 
 static inline int sev_platform_init(int *error) { return -ENODEV; }
 
+static inline int sev_snp_init(int *error) { return -ENODEV; }
+
 static inline int
 sev_guest_deactivate(struct sev_data_deactivate *data, int *error) { return -ENODEV; }