1 files changed, 309 insertions, 14 deletions

diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index 9f5ccc1720cb..0d13d47c164b 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -28,6 +28,7 @@
 #include <linux/fs_struct.h>
 #include <linux/psp.h>
 #include <linux/amd-iommu.h>
+#include <linux/crash_dump.h>
 
 #include <asm/smp.h>
 #include <asm/cacheflush.h>
@@ -82,6 +83,21 @@ MODULE_FIRMWARE("amd/amd_sev_fam19h_model1xh.sbin"); /* 4th gen EPYC */
 static bool psp_dead;
 static int psp_timeout;
 
+enum snp_hv_fixed_pages_state {
+	ALLOCATED,
+	HV_FIXED,
+};
+
+struct snp_hv_fixed_pages_entry {
+	struct list_head list;
+	struct page *page;
+	unsigned int order;
+	bool free;
+	enum snp_hv_fixed_pages_state page_state;
+};
+
+static LIST_HEAD(snp_hv_fixed_pages);
+
 /* Trusted Memory Region (TMR):
  *   The TMR is a 1MB area that must be 1MB aligned.  Use the page allocator
  *   to allocate the memory, which will return aligned memory for the specified
@@ -233,6 +249,8 @@ static int sev_cmd_buffer_len(int cmd)
 	case SEV_CMD_SNP_GUEST_REQUEST:		return sizeof(struct sev_data_snp_guest_request);
 	case SEV_CMD_SNP_CONFIG:		return sizeof(struct sev_user_data_snp_config);
 	case SEV_CMD_SNP_COMMIT:		return sizeof(struct sev_data_snp_commit);
+	case SEV_CMD_SNP_FEATURE_INFO:		return sizeof(struct sev_data_snp_feature_info);
+	case SEV_CMD_SNP_VLEK_LOAD:		return sizeof(struct sev_user_data_snp_vlek_load);
 	default:				return 0;
 	}
 
@@ -846,9 +864,10 @@ static int __sev_do_cmd_locked(int cmd, void *data, int *psp_ret)
 	struct sev_device *sev;
 	unsigned int cmdbuff_hi, cmdbuff_lo;
 	unsigned int phys_lsb, phys_msb;
-	unsigned int reg, ret = 0;
+	unsigned int reg;
 	void *cmd_buf;
 	int buf_len;
+	int ret = 0;
 
 	if (!psp || !psp->sev_data)
 		return -ENODEV;
@@ -1073,6 +1092,247 @@ static void snp_set_hsave_pa(void *arg)
 	wrmsrq(MSR_VM_HSAVE_PA, 0);
 }
 
+/* Hypervisor Fixed pages API interface */
+static void snp_hv_fixed_pages_state_update(struct sev_device *sev,
+					    enum snp_hv_fixed_pages_state page_state)
+{
+	struct snp_hv_fixed_pages_entry *entry;
+
+	/* List is protected by sev_cmd_mutex */
+	lockdep_assert_held(&sev_cmd_mutex);
+
+	if (list_empty(&snp_hv_fixed_pages))
+		return;
+
+	list_for_each_entry(entry, &snp_hv_fixed_pages, list)
+		entry->page_state = page_state;
+}
+
+/*
+ * Allocate HV_FIXED pages in 2MB aligned sizes to ensure the whole
+ * 2MB pages are marked as HV_FIXED.
+ */
+struct page *snp_alloc_hv_fixed_pages(unsigned int num_2mb_pages)
+{
+	struct psp_device *psp_master = psp_get_master_device();
+	struct snp_hv_fixed_pages_entry *entry;
+	struct sev_device *sev;
+	unsigned int order;
+	struct page *page;
+
+	if (!psp_master || !psp_master->sev_data)
+		return NULL;
+
+	sev = psp_master->sev_data;
+
+	order = get_order(PMD_SIZE * num_2mb_pages);
+
+	/*
+	 * SNP_INIT_EX is protected by sev_cmd_mutex, therefore this list
+	 * also needs to be protected using the same mutex.
+	 */
+	guard(mutex)(&sev_cmd_mutex);
+
+	/*
+	 * This API uses SNP_INIT_EX to transition allocated pages to HV_Fixed
+	 * page state, fail if SNP is already initialized.
+	 */
+	if (sev->snp_initialized)
+		return NULL;
+
+	/* Re-use freed pages that match the request */
+	list_for_each_entry(entry, &snp_hv_fixed_pages, list) {
+		/* Hypervisor fixed page allocator implements exact fit policy */
+		if (entry->order == order && entry->free) {
+			entry->free = false;
+			memset(page_address(entry->page), 0,
+			       (1 << entry->order) * PAGE_SIZE);
+			return entry->page;
+		}
+	}
+
+	page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
+	if (!page)
+		return NULL;
+
+	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+	if (!entry) {
+		__free_pages(page, order);
+		return NULL;
+	}
+
+	entry->page = page;
+	entry->order = order;
+	list_add_tail(&entry->list, &snp_hv_fixed_pages);
+
+	return page;
+}
+
+void snp_free_hv_fixed_pages(struct page *page)
+{
+	struct psp_device *psp_master = psp_get_master_device();
+	struct snp_hv_fixed_pages_entry *entry, *nentry;
+
+	if (!psp_master || !psp_master->sev_data)
+		return;
+
+	/*
+	 * SNP_INIT_EX is protected by sev_cmd_mutex, therefore this list
+	 * also needs to be protected using the same mutex.
+	 */
+	guard(mutex)(&sev_cmd_mutex);
+
+	list_for_each_entry_safe(entry, nentry, &snp_hv_fixed_pages, list) {
+		if (entry->page != page)
+			continue;
+
+		/*
+		 * HV_FIXED page state cannot be changed until reboot
+		 * and they cannot be used by an SNP guest, so they cannot
+		 * be returned back to the page allocator.
+		 * Mark the pages as free internally to allow possible re-use.
+		 */
+		if (entry->page_state == HV_FIXED) {
+			entry->free = true;
+		} else {
+			__free_pages(page, entry->order);
+			list_del(&entry->list);
+			kfree(entry);
+		}
+		return;
+	}
+}
+
+static void snp_add_hv_fixed_pages(struct sev_device *sev, struct sev_data_range_list *range_list)
+{
+	struct snp_hv_fixed_pages_entry *entry;
+	struct sev_data_range *range;
+	int num_elements;
+
+	lockdep_assert_held(&sev_cmd_mutex);
+
+	if (list_empty(&snp_hv_fixed_pages))
+		return;
+
+	num_elements = list_count_nodes(&snp_hv_fixed_pages) +
+		       range_list->num_elements;
+
+	/*
+	 * Ensure the list of HV_FIXED pages that will be passed to firmware
+	 * do not exceed the page-sized argument buffer.
+	 */
+	if (num_elements * sizeof(*range) + sizeof(*range_list) > PAGE_SIZE) {
+		dev_warn(sev->dev, "Additional HV_Fixed pages cannot be accommodated, omitting\n");
+		return;
+	}
+
+	range = &range_list->ranges[range_list->num_elements];
+	list_for_each_entry(entry, &snp_hv_fixed_pages, list) {
+		range->base = page_to_pfn(entry->page) << PAGE_SHIFT;
+		range->page_count = 1 << entry->order;
+		range++;
+	}
+	range_list->num_elements = num_elements;
+}
+
+static void snp_leak_hv_fixed_pages(void)
+{
+	struct snp_hv_fixed_pages_entry *entry;
+
+	/* List is protected by sev_cmd_mutex */
+	lockdep_assert_held(&sev_cmd_mutex);
+
+	if (list_empty(&snp_hv_fixed_pages))
+		return;
+
+	list_for_each_entry(entry, &snp_hv_fixed_pages, list)
+		if (entry->page_state == HV_FIXED)
+			__snp_leak_pages(page_to_pfn(entry->page),
+					 1 << entry->order, false);
+}
+
+bool sev_is_snp_ciphertext_hiding_supported(void)
+{
+	struct psp_device *psp = psp_master;
+	struct sev_device *sev;
+
+	if (!psp || !psp->sev_data)
+		return false;
+
+	sev = psp->sev_data;
+
+	/*
+	 * Feature information indicates if CipherTextHiding feature is
+	 * supported by the SEV firmware and additionally platform status
+	 * indicates if CipherTextHiding feature is enabled in the
+	 * Platform BIOS.
+	 */
+	return ((sev->snp_feat_info_0.ecx & SNP_CIPHER_TEXT_HIDING_SUPPORTED) &&
+		 sev->snp_plat_status.ciphertext_hiding_cap);
+}
+EXPORT_SYMBOL_GPL(sev_is_snp_ciphertext_hiding_supported);
+
+static int snp_get_platform_data(struct sev_device *sev, int *error)
+{
+	struct sev_data_snp_feature_info snp_feat_info;
+	struct snp_feature_info *feat_info;
+	struct sev_data_snp_addr buf;
+	struct page *page;
+	int rc;
+
+	/*
+	 * This function is expected to be called before SNP is
+	 * initialized.
+	 */
+	if (sev->snp_initialized)
+		return -EINVAL;
+
+	buf.address = __psp_pa(&sev->snp_plat_status);
+	rc = sev_do_cmd(SEV_CMD_SNP_PLATFORM_STATUS, &buf, error);
+	if (rc) {
+		dev_err(sev->dev, "SNP PLATFORM_STATUS command failed, ret = %d, error = %#x\n",
+			rc, *error);
+		return rc;
+	}
+
+	sev->api_major = sev->snp_plat_status.api_major;
+	sev->api_minor = sev->snp_plat_status.api_minor;
+	sev->build = sev->snp_plat_status.build_id;
+
+	/*
+	 * Do feature discovery of the currently loaded firmware,
+	 * and cache feature information from CPUID 0x8000_0024,
+	 * sub-function 0.
+	 */
+	if (!sev->snp_plat_status.feature_info)
+		return 0;
+
+	/*
+	 * Use dynamically allocated structure for the SNP_FEATURE_INFO
+	 * command to ensure structure is 8-byte aligned, and does not
+	 * cross a page boundary.
+	 */
+	page = alloc_page(GFP_KERNEL);
+	if (!page)
+		return -ENOMEM;
+
+	feat_info = page_address(page);
+	snp_feat_info.length = sizeof(snp_feat_info);
+	snp_feat_info.ecx_in = 0;
+	snp_feat_info.feature_info_paddr = __psp_pa(feat_info);
+
+	rc = sev_do_cmd(SEV_CMD_SNP_FEATURE_INFO, &snp_feat_info, error);
+	if (!rc)
+		sev->snp_feat_info_0 = *feat_info;
+	else
+		dev_err(sev->dev, "SNP FEATURE_INFO command failed, ret = %d, error = %#x\n",
+			rc, *error);
+
+	__free_page(page);
+
+	return rc;
+}
+
 static int snp_filter_reserved_mem_regions(struct resource *rs, void *arg)
 {
 	struct sev_data_range_list *range_list = arg;
@@ -1103,7 +1363,7 @@ static int snp_filter_reserved_mem_regions(struct resource *rs, void *arg)
 	return 0;
 }
 
-static int __sev_snp_init_locked(int *error)
+static int __sev_snp_init_locked(int *error, unsigned int max_snp_asid)
 {
 	struct psp_device *psp = psp_master;
 	struct sev_data_snp_init_ex data;
@@ -1163,7 +1423,19 @@ static int __sev_snp_init_locked(int *error)
 			return rc;
 		}
 
+		/*
+		 * Add HV_Fixed pages from other PSP sub-devices, such as SFS to the
+		 * HV_Fixed page list.
+		 */
+		snp_add_hv_fixed_pages(sev, snp_range_list);
+
 		memset(&data, 0, sizeof(data));
+
+		if (max_snp_asid) {
+			data.ciphertext_hiding_en = 1;
+			data.max_snp_asid = max_snp_asid;
+		}
+
 		data.init_rmp = 1;
 		data.list_paddr_en = 1;
 		data.list_paddr = __psp_pa(snp_range_list);
@@ -1202,6 +1474,7 @@ static int __sev_snp_init_locked(int *error)
 		return rc;
 	}
 
+	snp_hv_fixed_pages_state_update(sev, HV_FIXED);
 	sev->snp_initialized = true;
 	dev_dbg(sev->dev, "SEV-SNP firmware initialized\n");
 
@@ -1286,7 +1559,7 @@ static int __sev_platform_init_locked(int *error)
 
 	sev = psp_master->sev_data;
 
-	if (sev->state == SEV_STATE_INIT)
+	if (sev->sev_plat_status.state == SEV_STATE_INIT)
 		return 0;
 
 	__sev_platform_init_handle_tmr(sev);
@@ -1318,7 +1591,7 @@ static int __sev_platform_init_locked(int *error)
 		return rc;
 	}
 
-	sev->state = SEV_STATE_INIT;
+	sev->sev_plat_status.state = SEV_STATE_INIT;
 
 	/* Prepare for first SEV guest launch after INIT */
 	wbinvd_on_all_cpus();
@@ -1345,12 +1618,21 @@ static int _sev_platform_init_locked(struct sev_platform_init_args *args)
 	if (!psp_master || !psp_master->sev_data)
 		return -ENODEV;
 
+	/*
+	 * Skip SNP/SEV initialization under a kdump kernel as SEV/SNP
+	 * may already be initialized in the previous kernel. Since no
+	 * SNP/SEV guests are run under a kdump kernel, there is no
+	 * need to initialize SNP or SEV during kdump boot.
+	 */
+	if (is_kdump_kernel())
+		return 0;
+
 	sev = psp_master->sev_data;
 
-	if (sev->state == SEV_STATE_INIT)
+	if (sev->sev_plat_status.state == SEV_STATE_INIT)
 		return 0;
 
-	rc = __sev_snp_init_locked(&args->error);
+	rc = __sev_snp_init_locked(&args->error, args->max_snp_asid);
 	if (rc && rc != -ENODEV)
 		return rc;
 
@@ -1384,7 +1666,7 @@ static int __sev_platform_shutdown_locked(int *error)
 
 	sev = psp->sev_data;
 
-	if (sev->state == SEV_STATE_UNINIT)
+	if (sev->sev_plat_status.state == SEV_STATE_UNINIT)
 		return 0;
 
 	ret = __sev_do_cmd_locked(SEV_CMD_SHUTDOWN, NULL, error);
@@ -1394,7 +1676,7 @@ static int __sev_platform_shutdown_locked(int *error)
 		return ret;
 	}
 
-	sev->state = SEV_STATE_UNINIT;
+	sev->sev_plat_status.state = SEV_STATE_UNINIT;
 	dev_dbg(sev->dev, "SEV firmware shutdown\n");
 
 	return ret;
@@ -1433,7 +1715,7 @@ static int snp_move_to_init_state(struct sev_issue_cmd *argp, bool *shutdown_req
 {
 	int error, rc;
 
-	rc = __sev_snp_init_locked(&error);
+	rc = __sev_snp_init_locked(&error, 0);
 	if (rc) {
 		argp->error = SEV_RET_INVALID_PLATFORM_STATE;
 		return rc;
@@ -1502,7 +1784,7 @@ static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp, bool wr
 	if (!writable)
 		return -EPERM;
 
-	if (sev->state == SEV_STATE_UNINIT) {
+	if (sev->sev_plat_status.state == SEV_STATE_UNINIT) {
 		rc = sev_move_to_init_state(argp, &shutdown_required);
 		if (rc)
 			return rc;
@@ -1551,7 +1833,7 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
 	data.len = input.length;
 
 cmd:
-	if (sev->state == SEV_STATE_UNINIT) {
+	if (sev->sev_plat_status.state == SEV_STATE_UNINIT) {
 		ret = sev_move_to_init_state(argp, &shutdown_required);
 		if (ret)
 			goto e_free_blob;
@@ -1599,6 +1881,16 @@ static int sev_get_api_version(void)
 	struct sev_user_data_status status;
 	int error = 0, ret;
 
+	/*
+	 * Cache SNP platform status and SNP feature information
+	 * if SNP is available.
+	 */
+	if (cc_platform_has(CC_ATTR_HOST_SEV_SNP)) {
+		ret = snp_get_platform_data(sev, &error);
+		if (ret)
+			return 1;
+	}
+
 	ret = sev_platform_status(&status, &error);
 	if (ret) {
 		dev_err(sev->dev,
@@ -1606,10 +1898,12 @@ static int sev_get_api_version(void)
 		return 1;
 	}
 
+	/* Cache SEV platform status */
+	sev->sev_plat_status = status;
+
 	sev->api_major = status.api_major;
 	sev->api_minor = status.api_minor;
 	sev->build = status.build;
-	sev->state = status.state;
 
 	return 0;
 }
@@ -1784,6 +2078,7 @@ static int __sev_snp_shutdown_locked(int *error, bool panic)
 		return ret;
 	}
 
+	snp_leak_hv_fixed_pages();
 	sev->snp_initialized = false;
 	dev_dbg(sev->dev, "SEV-SNP firmware shutdown\n");
 
@@ -1837,7 +2132,7 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
 	data.oca_cert_len = input.oca_cert_len;
 
 	/* If platform is not in INIT state then transition it to INIT */
-	if (sev->state != SEV_STATE_INIT) {
+	if (sev->sev_plat_status.state != SEV_STATE_INIT) {
 		ret = sev_move_to_init_state(argp, &shutdown_required);
 		if (ret)
 			goto e_free_oca;
@@ -2008,7 +2303,7 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
 
 cmd:
 	/* If platform is not in INIT state then transition it to INIT. */
-	if (sev->state != SEV_STATE_INIT) {
+	if (sev->sev_plat_status.state != SEV_STATE_INIT) {
 		if (!writable) {
 			ret = -EPERM;
 			goto e_free_cert;