[RFC PATCH 16/21] coco/sev-guest: Make SEV-to-PSP request helpers public

[Alexey Kardashevskiy <aik@amd.com>]

SEV TIO is going to a separate file, these helpers will be reused.

No functional change intended.

Signed-off-by: Alexey Kardashevskiy <aik@amd.com>
---
 drivers/virt/coco/sev-guest/sev-guest.h | 54 ++++++++++++++++++++
 drivers/virt/coco/sev-guest/sev_guest.c | 42 +++------------
 2 files changed, 60 insertions(+), 36 deletions(-)

diff --git a/drivers/virt/coco/sev-guest/sev-guest.h b/drivers/virt/coco/sev-guest/sev-guest.h
new file mode 100644
index 000000000000..765f42ff55aa
--- /dev/null
+++ b/drivers/virt/coco/sev-guest/sev-guest.h
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2024 Advanced Micro Devices, Inc.
+ */
+
+#ifndef __VIRT_SEVGUEST_H__
+#define __VIRT_SEVGUEST_H__
+
+#include <linux/miscdevice.h>
+#include <linux/types.h>
+
+struct snp_guest_crypto {
+	struct crypto_aead *tfm;
+	u8 *iv, *authtag;
+	int iv_len, a_len;
+};
+
+struct snp_guest_dev {
+	struct device *dev;
+	struct miscdevice misc;
+
+	void *certs_data;
+	struct snp_guest_crypto *crypto;
+	/* request and response are in unencrypted memory */
+	struct snp_guest_msg *request, *response;
+
+	/*
+	 * Avoid information leakage by double-buffering shared messages
+	 * in fields that are in regular encrypted memory.
+	 */
+	struct snp_guest_msg secret_request, secret_response;
+
+	struct snp_secrets_page *secrets;
+	struct snp_req_data input;
+	union {
+		struct snp_report_req report;
+		struct snp_derived_key_req derived_key;
+		struct snp_ext_report_req ext_report;
+	} req;
+	u32 *os_area_msg_seqno;
+	u8 *vmpck;
+};
+
+extern struct mutex snp_cmd_mutex;
+
+int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code,
+				struct snp_guest_request_ioctl *rio, u8 type,
+				void *req_buf, size_t req_sz, void *resp_buf,
+				u32 resp_sz);
+
+void *alloc_shared_pages(struct device *dev, size_t sz);
+void free_shared_pages(void *buf, size_t sz);
+
+#endif /* __VIRT_SEVGUEST_H__ */
diff --git a/drivers/virt/coco/sev-guest/sev_guest.c b/drivers/virt/coco/sev-guest/sev_guest.c
index ecc6176633be..d04d270f359e 100644
--- a/drivers/virt/coco/sev-guest/sev_guest.c
+++ b/drivers/virt/coco/sev-guest/sev_guest.c
@@ -30,6 +30,8 @@
 #include <asm/svm.h>
 #include <asm/sev.h>
 
+#include "sev-guest.h"
+
 #define DEVICE_NAME	"sev-guest"
 #define AAD_LEN		48
 #define MSG_HDR_VER	1
@@ -39,38 +41,6 @@
 
 #define SVSM_MAX_RETRIES		3
 
-struct snp_guest_crypto {
-	struct crypto_aead *tfm;
-	u8 *iv, *authtag;
-	int iv_len, a_len;
-};
-
-struct snp_guest_dev {
-	struct device *dev;
-	struct miscdevice misc;
-
-	void *certs_data;
-	struct snp_guest_crypto *crypto;
-	/* request and response are in unencrypted memory */
-	struct snp_guest_msg *request, *response;
-
-	/*
-	 * Avoid information leakage by double-buffering shared messages
-	 * in fields that are in regular encrypted memory.
-	 */
-	struct snp_guest_msg secret_request, secret_response;
-
-	struct snp_secrets_page *secrets;
-	struct snp_req_data input;
-	union {
-		struct snp_report_req report;
-		struct snp_derived_key_req derived_key;
-		struct snp_ext_report_req ext_report;
-	} req;
-	u32 *os_area_msg_seqno;
-	u8 *vmpck;
-};
-
 /*
  * The VMPCK ID represents the key used by the SNP guest to communicate with the
  * SEV firmware in the AMD Secure Processor (ASP, aka PSP). By default, the key
@@ -83,7 +53,7 @@ module_param(vmpck_id, int, 0444);
 MODULE_PARM_DESC(vmpck_id, "The VMPCK ID to use when communicating with the PSP.");
 
 /* Mutex to serialize the shared buffer access and command handling. */
-static DEFINE_MUTEX(snp_cmd_mutex);
+DEFINE_MUTEX(snp_cmd_mutex);
 
 static bool is_vmpck_empty(struct snp_guest_dev *snp_dev)
 {
@@ -435,7 +405,7 @@ static int __handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code,
 	return rc;
 }
 
-static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code,
+int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code,
 				struct snp_guest_request_ioctl *rio, u8 type,
 				void *req_buf, size_t req_sz, void *resp_buf,
 				u32 resp_sz)
@@ -709,7 +679,7 @@ static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long
 	return ret;
 }
 
-static void free_shared_pages(void *buf, size_t sz)
+void free_shared_pages(void *buf, size_t sz)
 {
 	unsigned int npages = PAGE_ALIGN(sz) >> PAGE_SHIFT;
 	int ret;
@@ -726,7 +696,7 @@ static void free_shared_pages(void *buf, size_t sz)
 	__free_pages(virt_to_page(buf), get_order(sz));
 }
 
-static void *alloc_shared_pages(struct device *dev, size_t sz)
+void *alloc_shared_pages(struct device *dev, size_t sz)
 {
 	unsigned int npages = PAGE_ALIGN(sz) >> PAGE_SHIFT;
 	struct page *page;
-- 
2.45.2