[PATCH v4 4/6] crypto: ccp: Add DOWNLOAD_FIRMWARE_EX support

[Dionna Glaze <dionnaglaze@google.com>]

The DOWNLOAD_FIRMWARE_EX command requires cache flushing and introduces
new error codes that could be returned to user space.

The function is in sev-dev.c rather than sev-fw.c to avoid exposing the
__sev_do_cmd_locked function in the sev-dev.h header.

Signed-off-by: Dionna Glaze <dionnaglaze@google.com>
---
 drivers/crypto/ccp/sev-dev.c | 66 +++++++++++++++++++++++++++++++-----
 include/linux/psp-sev.h      | 26 ++++++++++++++
 include/uapi/linux/psp-sev.h |  5 +++
 3 files changed, 89 insertions(+), 8 deletions(-)

diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index 9265b6d534bbe..32f7b6147905e 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -223,6 +223,7 @@ 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_DOWNLOAD_FIRMWARE_EX:	return sizeof(struct sev_data_download_firmware_ex);
 	default:				return 0;
 	}
 
@@ -1597,14 +1598,7 @@ static int sev_update_firmware(struct device *dev)
 		return -1;
 	}
 
-	/*
-	 * SEV FW expects the physical address given to it to be 32
-	 * byte aligned. Memory allocated has structure placed at the
-	 * beginning followed by the firmware being passed to the SEV
-	 * FW. Allocate enough memory for data structure + alignment
-	 * padding + SEV FW.
-	 */
-	data_size = ALIGN(sizeof(struct sev_data_download_firmware), 32);
+	data_size = ALIGN(sizeof(struct sev_data_download_firmware), SEV_FW_ALIGNMENT);
 
 	order = get_order(firmware->size + data_size);
 	p = alloc_pages(GFP_KERNEL, order);
@@ -1645,6 +1639,62 @@ static int sev_update_firmware(struct device *dev)
 	return ret;
 }
 
+int sev_snp_download_firmware_ex(struct sev_device *sev, const u8 *data, u32 size, int *error)
+{
+	struct sev_data_download_firmware_ex *data_ex;
+	int ret, order;
+	struct page *p;
+	u64 data_size;
+	void *fw_dest;
+
+	data_size = ALIGN(sizeof(struct sev_data_download_firmware_ex),
+			  SEV_FW_ALIGNMENT);
+
+	order = get_order(size + data_size);
+	p = alloc_pages(GFP_KERNEL, order);
+	if (!p)
+		return -ENOMEM;
+
+	/*
+	 * Copy firmware data to a kernel allocated contiguous
+	 * memory region.
+	 */
+	data_ex = page_address(p);
+	fw_dest = page_address(p) + data_size;
+	memset(data_ex, 0, data_size);
+	memcpy(fw_dest, data, size);
+
+	data_ex->address = __psp_pa(fw_dest);
+	data_ex->len = size;
+	data_ex->cmdlen = sizeof(struct sev_data_download_firmware_ex);
+
+	/*
+	 * SNP_COMMIT should be issued explicitly to commit the updated
+	 * firmware after guest context pages have been updated.
+	 */
+	ret = sev_do_cmd(SEV_CMD_SNP_DOWNLOAD_FIRMWARE_EX, data_ex, error);
+
+	if (ret)
+		goto free_err;
+
+	__free_pages(p, order);
+
+	/* Need to do a DF_FLUSH after live firmware update */
+	wbinvd_on_all_cpus();
+	ret = __sev_do_cmd_locked(SEV_CMD_SNP_DF_FLUSH, NULL, error);
+	if (ret) {
+		dev_dbg(sev->dev, "DF_FLUSH error %d\n", *error);
+		goto fw_err;
+	}
+
+	return 0;
+
+free_err:
+	__free_pages(p, order);
+fw_err:
+	return ret;
+}
+
 static int __sev_snp_shutdown_locked(int *error, bool panic)
 {
 	struct psp_device *psp = psp_master;
diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h
index 903ddfea85850..6a08c56cd9771 100644
--- a/include/linux/psp-sev.h
+++ b/include/linux/psp-sev.h
@@ -16,6 +16,15 @@
 
 #define SEV_FW_BLOB_MAX_SIZE	0x4000	/* 16KB */
 
+/*
+ * SEV FW expects the physical address given to it to be 32
+ * byte aligned. Memory allocated has structure placed at the
+ * beginning followed by the firmware being passed to the SEV
+ * FW. Allocate enough memory for data structure + alignment
+ * padding + SEV FW.
+ */
+#define SEV_FW_ALIGNMENT       32
+
 /**
  * SEV platform state
  */
@@ -185,6 +194,23 @@ struct sev_data_download_firmware {
 	u32 len;				/* In */
 } __packed;
 
+/**
+ * struct sev_data_download_firmware_ex - DOWNLOAD_FIRMWARE_EX command parameters
+ *
+ * @length: length of this command buffer
+ * @address: physical address of firmware image
+ * @len: len of the firmware image
+ * @commit: automatically commit the newly installed image
+ */
+struct sev_data_download_firmware_ex {
+	u32 cmdlen;				/* In */
+	u32 reserved;				/* In */
+	u64 address;				/* In */
+	u32 len;				/* In */
+	u32 commit:1;				/* In */
+	u32 reserved2:31;			/* In */
+} __packed;
+
 /**
  * struct sev_data_get_id - GET_ID command parameters
  *
diff --git a/include/uapi/linux/psp-sev.h b/include/uapi/linux/psp-sev.h
index 832c15d9155bd..936464d4f282a 100644
--- a/include/uapi/linux/psp-sev.h
+++ b/include/uapi/linux/psp-sev.h
@@ -80,6 +80,11 @@ typedef enum {
 	SEV_RET_INVALID_PAGE_OWNER,
 	SEV_RET_INVALID_PAGE_AEAD_OFLOW,
 	SEV_RET_RMP_INIT_REQUIRED,
+	SEV_RET_BAD_SVN,
+	SEV_RET_BAD_VERSION,
+	SEV_RET_SHUTDOWN_REQUIRED,
+	SEV_RET_UPDATE_FAILED,
+	SEV_RET_RESTORE_REQUIRED,
 	SEV_RET_MAX,
 } sev_ret_code;
 
-- 
2.47.0.199.ga7371fff76-goog