[tip:,x86/sev] crypto: ccp: Add support to initialize the AMD-SP for SEV-SNP

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index f760106..564091f 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -246,6 +246,7 @@  static void sev_unbind_asid(struct kvm *kvm, unsigned int handle)
 static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
+	struct sev_platform_init_args init_args = {0};
 	int asid, ret;
 
 	if (kvm->created_vcpus)
@@ -262,7 +263,8 @@  static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
 		goto e_no_asid;
 	sev->asid = asid;
 
-	ret = sev_platform_init(&argp->error);
+	init_args.probe = false;
+	ret = sev_platform_init(&init_args);
 	if (ret)
 		goto e_free;
 
@@ -274,6 +276,7 @@  static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
 	return 0;
 
 e_free:
+	argp->error = init_args.error;
 	sev_asid_free(sev);
 	sev->asid = 0;
 e_no_asid:
diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index e38986d..7129644 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -29,6 +29,7 @@ 
 
 #include <asm/smp.h>
 #include <asm/cacheflush.h>
+#include <asm/e820/types.h>
 
 #include "psp-dev.h"
 #include "sev-dev.h"
@@ -37,6 +38,10 @@ 
 #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	51
+
 static DEFINE_MUTEX(sev_cmd_mutex);
 static struct sev_misc_dev *misc_dev;
 
@@ -80,6 +85,13 @@  static void *sev_es_tmr;
 #define NV_LENGTH (32 * 1024)
 static void *sev_init_ex_buffer;
 
+/*
+ * SEV_DATA_RANGE_LIST:
+ *   Array containing range of pages that firmware transitions to HV-fixed
+ *   page state.
+ */
+struct sev_data_range_list *snp_range_list;
+
 static inline bool sev_version_greater_or_equal(u8 maj, u8 min)
 {
 	struct sev_device *sev = psp_master->sev_data;
@@ -480,20 +492,163 @@  static inline int __sev_do_init_locked(int *psp_ret)
 		return __sev_init_locked(psp_ret);
 }
 
-static int __sev_platform_init_locked(int *error)
+static void snp_set_hsave_pa(void *arg)
+{
+	wrmsrl(MSR_VM_HSAVE_PA, 0);
+}
+
+static int snp_filter_reserved_mem_regions(struct resource *rs, void *arg)
+{
+	struct sev_data_range_list *range_list = arg;
+	struct sev_data_range *range = &range_list->ranges[range_list->num_elements];
+	size_t size;
+
+	/*
+	 * Ensure the list of HV_FIXED pages that will be passed to firmware
+	 * do not exceed the page-sized argument buffer.
+	 */
+	if ((range_list->num_elements * sizeof(struct sev_data_range) +
+	     sizeof(struct sev_data_range_list)) > PAGE_SIZE)
+		return -E2BIG;
+
+	switch (rs->desc) {
+	case E820_TYPE_RESERVED:
+	case E820_TYPE_PMEM:
+	case E820_TYPE_ACPI:
+		range->base = rs->start & PAGE_MASK;
+		size = PAGE_ALIGN((rs->end + 1) - rs->start);
+		range->page_count = size >> PAGE_SHIFT;
+		range_list->num_elements++;
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static int __sev_snp_init_locked(int *error)
 {
-	int rc = 0, psp_ret = SEV_RET_NO_FW_CALL;
 	struct psp_device *psp = psp_master;
+	struct sev_data_snp_init_ex data;
 	struct sev_device *sev;
+	void *arg = &data;
+	int cmd, rc = 0;
 
-	if (!psp || !psp->sev_data)
+	if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP))
 		return -ENODEV;
 
 	sev = psp->sev_data;
 
+	if (sev->snp_initialized)
+		return 0;
+
+	if (!sev_version_greater_or_equal(SNP_MIN_API_MAJOR, SNP_MIN_API_MINOR)) {
+		dev_dbg(sev->dev, "SEV-SNP support requires firmware version >= %d:%d\n",
+			SNP_MIN_API_MAJOR, SNP_MIN_API_MINOR);
+		return 0;
+	}
+
+	/* SNP_INIT requires MSR_VM_HSAVE_PA to be cleared on all CPUs. */
+	on_each_cpu(snp_set_hsave_pa, NULL, 1);
+
+	/*
+	 * Starting in SNP firmware v1.52, the SNP_INIT_EX command takes a list
+	 * of system physical address ranges to convert into HV-fixed page
+	 * states during the RMP initialization.  For instance, the memory that
+	 * UEFI reserves should be included in the that list. This allows system
+	 * components that occasionally write to memory (e.g. logging to UEFI
+	 * reserved regions) to not fail due to RMP initialization and SNP
+	 * enablement.
+	 *
+	 */
+	if (sev_version_greater_or_equal(SNP_MIN_API_MAJOR, 52)) {
+		/*
+		 * Firmware checks that the pages containing the ranges enumerated
+		 * in the RANGES structure are either in the default page state or in the
+		 * firmware page state.
+		 */
+		snp_range_list = kzalloc(PAGE_SIZE, GFP_KERNEL);
+		if (!snp_range_list) {
+			dev_err(sev->dev,
+				"SEV: SNP_INIT_EX range list memory allocation failed\n");
+			return -ENOMEM;
+		}
+
+		/*
+		 * Retrieve all reserved memory regions from the e820 memory map
+		 * to be setup as HV-fixed pages.
+		 */
+		rc = walk_iomem_res_desc(IORES_DESC_NONE, IORESOURCE_MEM, 0, ~0,
+					 snp_range_list, snp_filter_reserved_mem_regions);
+		if (rc) {
+			dev_err(sev->dev,
+				"SEV: SNP_INIT_EX walk_iomem_res_desc failed rc = %d\n", rc);
+			return rc;
+		}
+
+		memset(&data, 0, sizeof(data));
+		data.init_rmp = 1;
+		data.list_paddr_en = 1;
+		data.list_paddr = __psp_pa(snp_range_list);
+		cmd = SEV_CMD_SNP_INIT_EX;
+	} else {
+		cmd = SEV_CMD_SNP_INIT;
+		arg = NULL;
+	}
+
+	/*
+	 * The following sequence must be issued before launching the first SNP
+	 * guest to ensure all dirty cache lines are flushed, including from
+	 * updates to the RMP table itself via the RMPUPDATE instruction:
+	 *
+	 * - WBINVD on all running CPUs
+	 * - SEV_CMD_SNP_INIT[_EX] firmware command
+	 * - WBINVD on all running CPUs
+	 * - SEV_CMD_SNP_DF_FLUSH firmware command
+	 */
+	wbinvd_on_all_cpus();
+
+	rc = __sev_do_cmd_locked(cmd, arg, error);
+	if (rc)
+		return rc;
+
+	/* Prepare for first SNP guest launch after INIT. */
+	wbinvd_on_all_cpus();
+	rc = __sev_do_cmd_locked(SEV_CMD_SNP_DF_FLUSH, NULL, error);
+	if (rc)
+		return rc;
+
+	sev->snp_initialized = true;
+	dev_dbg(sev->dev, "SEV-SNP firmware initialized\n");
+
+	return rc;
+}
+
+static int __sev_platform_init_locked(int *error)
+{
+	int rc, psp_ret = SEV_RET_NO_FW_CALL;
+	struct sev_device *sev;
+
+	if (!psp_master || !psp_master->sev_data)
+		return -ENODEV;
+
+	sev = psp_master->sev_data;
+
 	if (sev->state == SEV_STATE_INIT)
 		return 0;
 
+	if (!sev_es_tmr) {
+		/* Obtain the TMR memory area for SEV-ES use */
+		sev_es_tmr = sev_fw_alloc(SEV_ES_TMR_SIZE);
+		if (sev_es_tmr)
+			/* Must flush the cache before giving it to the firmware */
+			clflush_cache_range(sev_es_tmr, SEV_ES_TMR_SIZE);
+		else
+			dev_warn(sev->dev,
+				 "SEV: TMR allocation failed, SEV-ES support unavailable\n");
+		}
+
 	if (sev_init_ex_buffer) {
 		rc = sev_read_init_ex_file();
 		if (rc)
@@ -536,12 +691,46 @@  static int __sev_platform_init_locked(int *error)
 	return 0;
 }
 
-int sev_platform_init(int *error)
+static int _sev_platform_init_locked(struct sev_platform_init_args *args)
+{
+	struct sev_device *sev;
+	int rc;
+
+	if (!psp_master || !psp_master->sev_data)
+		return -ENODEV;
+
+	sev = psp_master->sev_data;
+
+	if (sev->state == SEV_STATE_INIT)
+		return 0;
+
+	/*
+	 * Legacy guests cannot be running while SNP_INIT(_EX) is executing,
+	 * so perform SEV-SNP initialization at probe time.
+	 */
+	rc = __sev_snp_init_locked(&args->error);
+	if (rc && rc != -ENODEV) {
+		/*
+		 * Don't abort the probe if SNP INIT failed,
+		 * continue to initialize the legacy SEV firmware.
+		 */
+		dev_err(sev->dev, "SEV-SNP: failed to INIT rc %d, error %#x\n",
+			rc, args->error);
+	}
+
+	/* Defer legacy SEV/SEV-ES support if allowed by caller/module. */
+	if (args->probe && !psp_init_on_probe)
+		return 0;
+
+	return __sev_platform_init_locked(&args->error);
+}
+
+int sev_platform_init(struct sev_platform_init_args *args)
 {
 	int rc;
 
 	mutex_lock(&sev_cmd_mutex);
-	rc = __sev_platform_init_locked(error);
+	rc = _sev_platform_init_locked(args);
 	mutex_unlock(&sev_cmd_mutex);
 
 	return rc;
@@ -852,6 +1041,55 @@  fw_err:
 	return ret;
 }
 
+static int __sev_snp_shutdown_locked(int *error)
+{
+	struct sev_device *sev = psp_master->sev_data;
+	struct sev_data_snp_shutdown_ex data;
+	int ret;
+
+	if (!sev->snp_initialized)
+		return 0;
+
+	memset(&data, 0, sizeof(data));
+	data.len = sizeof(data);
+	data.iommu_snp_shutdown = 1;
+
+	wbinvd_on_all_cpus();
+
+	ret = __sev_do_cmd_locked(SEV_CMD_SNP_SHUTDOWN_EX, &data, error);
+	/* SHUTDOWN may require DF_FLUSH */
+	if (*error == SEV_RET_DFFLUSH_REQUIRED) {
+		ret = __sev_do_cmd_locked(SEV_CMD_SNP_DF_FLUSH, NULL, NULL);
+		if (ret) {
+			dev_err(sev->dev, "SEV-SNP DF_FLUSH failed\n");
+			return ret;
+		}
+		/* reissue the shutdown command */
+		ret = __sev_do_cmd_locked(SEV_CMD_SNP_SHUTDOWN_EX, &data,
+					  error);
+	}
+	if (ret) {
+		dev_err(sev->dev, "SEV-SNP firmware shutdown failed\n");
+		return ret;
+	}
+
+	sev->snp_initialized = 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(error);
+	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;
@@ -1299,6 +1537,8 @@  e_err:
 
 static void sev_firmware_shutdown(struct sev_device *sev)
 {
+	int error;
+
 	sev_platform_shutdown(NULL);
 
 	if (sev_es_tmr) {
@@ -1315,6 +1555,13 @@  static void sev_firmware_shutdown(struct sev_device *sev)
 			   get_order(NV_LENGTH));
 		sev_init_ex_buffer = NULL;
 	}
+
+	if (snp_range_list) {
+		kfree(snp_range_list);
+		snp_range_list = NULL;
+	}
+
+	sev_snp_shutdown(&error);
 }
 
 void sev_dev_destroy(struct psp_device *psp)
@@ -1345,7 +1592,8 @@  EXPORT_SYMBOL_GPL(sev_issue_cmd_external_user);
 void sev_pci_init(void)
 {
 	struct sev_device *sev = psp_master->sev_data;
-	int error, rc;
+	struct sev_platform_init_args args = {0};
+	int rc;
 
 	if (!sev)
 		return;
@@ -1370,23 +1618,15 @@  void sev_pci_init(void)
 		}
 	}
 
-	/* Obtain the TMR memory area for SEV-ES use */
-	sev_es_tmr = sev_fw_alloc(SEV_ES_TMR_SIZE);
-	if (sev_es_tmr)
-		/* Must flush the cache before giving it to the firmware */
-		clflush_cache_range(sev_es_tmr, SEV_ES_TMR_SIZE);
-	else
-		dev_warn(sev->dev,
-			 "SEV: TMR allocation failed, SEV-ES support unavailable\n");
-
-	if (!psp_init_on_probe)
-		return;
-
 	/* Initialize the platform */
-	rc = sev_platform_init(&error);
+	args.probe = true;
+	rc = sev_platform_init(&args);
 	if (rc)
 		dev_err(sev->dev, "SEV: failed to INIT error %#x, rc %d\n",
-			error, rc);
+			args.error, rc);
+
+	dev_info(sev->dev, "SEV%s API:%d.%d build:%d\n", sev->snp_initialized ?
+		"-SNP" : "", sev->api_major, sev->api_minor, sev->build);
 
 	return;
 
diff --git a/drivers/crypto/ccp/sev-dev.h b/drivers/crypto/ccp/sev-dev.h
index 778c951..8550632 100644
--- a/drivers/crypto/ccp/sev-dev.h
+++ b/drivers/crypto/ccp/sev-dev.h
@@ -52,6 +52,8 @@  struct sev_device {
 	u8 build;
 
 	void *cmd_buf;
+
+	bool snp_initialized;
 };
 
 int sev_dev_init(struct psp_device *psp);
diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h
index 006e4cd..ef3b917 100644
--- a/include/linux/psp-sev.h
+++ b/include/linux/psp-sev.h
@@ -788,12 +788,25 @@  struct sev_data_snp_shutdown_ex {
 	u32 rsvd1:31;
 } __packed;
 
+/**
+ * struct sev_platform_init_args
+ *
+ * @error: SEV firmware error code
+ * @probe: True if this is being called as part of CCP module probe, which
+ *  will defer SEV_INIT/SEV_INIT_EX firmware initialization until needed
+ *  unless psp_init_on_probe module param is set
+ */
+struct sev_platform_init_args {
+	int error;
+	bool probe;
+};
+
 #ifdef CONFIG_CRYPTO_DEV_SP_PSP
 
 /**
  * sev_platform_init - perform SEV INIT command
  *
- * @error: SEV command return code
+ * @args: struct sev_platform_init_args to pass in arguments
  *
  * Returns:
  * 0 if the SEV successfully processed the command
@@ -802,7 +815,7 @@  struct sev_data_snp_shutdown_ex {
  * -%ETIMEDOUT if the SEV command timed out
  * -%EIO       if the SEV returned a non-zero return code
  */
-int sev_platform_init(int *error);
+int sev_platform_init(struct sev_platform_init_args *args);
 
 /**
  * sev_platform_status - perform SEV PLATFORM_STATUS command
@@ -909,7 +922,7 @@  void *psp_copy_user_blob(u64 uaddr, u32 len);
 static inline int
 sev_platform_status(struct sev_user_data_status *status, int *error) { return -ENODEV; }
 
-static inline int sev_platform_init(int *error) { return -ENODEV; }
+static inline int sev_platform_init(struct sev_platform_init_args *args) { return -ENODEV; }
 
 static inline int
 sev_guest_deactivate(struct sev_data_deactivate *data, int *error) { return -ENODEV; }