diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index 2e49c4a9e7fe..3812692ba3fe 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -14,6 +14,7 @@
 #include <asm/insn.h>
 #include <asm/sev-common.h>
 #include <asm/coco.h>
+#include <asm/set_memory.h>
 
 #define GHCB_PROTOCOL_MIN	1ULL
 #define GHCB_PROTOCOL_MAX	2ULL
@@ -170,10 +171,6 @@ struct snp_guest_msg {
 	u8 payload[PAGE_SIZE - sizeof(struct snp_guest_msg_hdr)];
 } __packed;
 
-struct sev_guest_platform_data {
-	u64 secrets_gpa;
-};
-
 struct snp_guest_req {
 	void *req_buf;
 	size_t req_sz;
@@ -253,6 +250,7 @@ struct snp_msg_desc {
 
 	u32 *os_area_msg_seqno;
 	u8 *vmpck;
+	int vmpck_id;
 };
 
 /*
@@ -438,6 +436,63 @@ u64 sev_get_status(void);
 void sev_show_status(void);
 void snp_update_svsm_ca(void);
 
+static inline void free_shared_pages(void *buf, size_t sz)
+{
+	unsigned int npages = PAGE_ALIGN(sz) >> PAGE_SHIFT;
+	int ret;
+
+	if (!buf)
+		return;
+
+	ret = set_memory_encrypted((unsigned long)buf, npages);
+	if (ret) {
+		WARN_ONCE(ret, "failed to restore encryption mask (leak it)\n");
+		return;
+	}
+
+	__free_pages(virt_to_page(buf), get_order(sz));
+}
+
+static inline void *alloc_shared_pages(size_t sz)
+{
+	unsigned int npages = PAGE_ALIGN(sz) >> PAGE_SHIFT;
+	struct page *page;
+	int ret;
+
+	page = alloc_pages(GFP_KERNEL_ACCOUNT, get_order(sz));
+	if (!page)
+		return NULL;
+
+	ret = set_memory_decrypted((unsigned long)page_address(page), npages);
+	if (ret) {
+		pr_err("failed to mark page shared, ret=%d\n", ret);
+		__free_pages(page, get_order(sz));
+		return NULL;
+	}
+
+	return page_address(page);
+}
+
+static inline bool is_vmpck_empty(struct snp_msg_desc *mdesc)
+{
+	char zero_key[VMPCK_KEY_LEN] = {0};
+
+	if (mdesc->vmpck)
+		return !memcmp(mdesc->vmpck, zero_key, VMPCK_KEY_LEN);
+
+	return true;
+}
+
+int snp_msg_init(struct snp_msg_desc *mdesc, int vmpck_id);
+struct snp_msg_desc *snp_msg_alloc(void);
+
+static inline void snp_msg_cleanup(struct snp_msg_desc *mdesc)
+{
+	mdesc->vmpck = NULL;
+	mdesc->os_area_msg_seqno = NULL;
+	kfree(mdesc->ctx);
+}
+
 #else	/* !CONFIG_AMD_MEM_ENCRYPT */
 
 #define snp_vmpl 0
@@ -474,6 +529,14 @@ static inline u64 snp_get_unsupported_features(u64 status) { return 0; }
 static inline u64 sev_get_status(void) { return 0; }
 static inline void sev_show_status(void) { }
 static inline void snp_update_svsm_ca(void) { }
+static inline void free_shared_pages(void *buf, size_t sz) { }
+static inline void *alloc_shared_pages(size_t sz) { return NULL; }
+static inline bool is_vmpck_empty(struct snp_msg_desc *mdesc) { return false; }
+
+static inline int snp_msg_init(struct snp_msg_desc *mdesc, int vmpck_id) { return -1; }
+static inline struct snp_msg_desc *snp_msg_alloc(void) { return NULL; }
+
+static inline void snp_msg_cleanup(struct snp_msg_desc *mdesc) { }
 
 #endif	/* CONFIG_AMD_MEM_ENCRYPT */
 
diff --git a/arch/x86/coco/sev/core.c b/arch/x86/coco/sev/core.c
index e6a3f3df4637..6787d0972a45 100644
--- a/arch/x86/coco/sev/core.c
+++ b/arch/x86/coco/sev/core.c
@@ -25,6 +25,7 @@
 #include <linux/psp-sev.h>
 #include <linux/dmi.h>
 #include <uapi/linux/sev-guest.h>
+#include <crypto/gcm.h>
 
 #include <asm/init.h>
 #include <asm/cpu_entry_area.h>
@@ -95,6 +96,8 @@ static u64 sev_hv_features __ro_after_init;
 /* Secrets page physical address from the CC blob */
 static u64 secrets_pa __ro_after_init;
 
+static struct snp_msg_desc *snp_mdesc;
+
 /* #VC handler runtime per-CPU data */
 struct sev_es_runtime_data {
 	struct ghcb ghcb_page;
@@ -2489,15 +2492,9 @@ static struct platform_device sev_guest_device = {
 
 static int __init snp_init_platform_device(void)
 {
-	struct sev_guest_platform_data data;
-
 	if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
 		return -ENODEV;
 
-	data.secrets_gpa = secrets_pa;
-	if (platform_device_add_data(&sev_guest_device, &data, sizeof(data)))
-		return -ENODEV;
-
 	if (platform_device_register(&sev_guest_device))
 		return -ENODEV;
 
@@ -2576,3 +2573,127 @@ static int __init sev_sysfs_init(void)
 }
 arch_initcall(sev_sysfs_init);
 #endif // CONFIG_SYSFS
+
+static u8 *get_vmpck(int id, struct snp_secrets_page *secrets, u32 **seqno)
+{
+	u8 *key = NULL;
+
+	switch (id) {
+	case 0:
+		*seqno = &secrets->os_area.msg_seqno_0;
+		key = secrets->vmpck0;
+		break;
+	case 1:
+		*seqno = &secrets->os_area.msg_seqno_1;
+		key = secrets->vmpck1;
+		break;
+	case 2:
+		*seqno = &secrets->os_area.msg_seqno_2;
+		key = secrets->vmpck2;
+		break;
+	case 3:
+		*seqno = &secrets->os_area.msg_seqno_3;
+		key = secrets->vmpck3;
+		break;
+	default:
+		break;
+	}
+
+	return key;
+}
+
+static struct aesgcm_ctx *snp_init_crypto(u8 *key, size_t keylen)
+{
+	struct aesgcm_ctx *ctx;
+
+	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL_ACCOUNT);
+	if (!ctx)
+		return NULL;
+
+	if (aesgcm_expandkey(ctx, key, keylen, AUTHTAG_LEN)) {
+		pr_err("Crypto context initialization failed\n");
+		kfree(ctx);
+		return NULL;
+	}
+
+	return ctx;
+}
+
+int snp_msg_init(struct snp_msg_desc *mdesc, int vmpck_id)
+{
+	/* Adjust the default VMPCK key based on the executing VMPL level */
+	if (vmpck_id == -1)
+		vmpck_id = snp_vmpl;
+
+	mdesc->vmpck = get_vmpck(vmpck_id, mdesc->secrets, &mdesc->os_area_msg_seqno);
+	if (!mdesc->vmpck) {
+		pr_err("Invalid VMPCK%d communication key\n", vmpck_id);
+		return -EINVAL;
+	}
+
+	/* Verify that VMPCK is not zero. */
+	if (is_vmpck_empty(mdesc)) {
+		pr_err("Empty VMPCK%d communication key\n", vmpck_id);
+		return -EINVAL;
+	}
+
+	mdesc->vmpck_id = vmpck_id;
+
+	mdesc->ctx = snp_init_crypto(mdesc->vmpck, VMPCK_KEY_LEN);
+	if (!mdesc->ctx)
+		return -ENOMEM;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snp_msg_init);
+
+struct snp_msg_desc *snp_msg_alloc(void)
+{
+	struct snp_msg_desc *mdesc;
+
+	if (snp_mdesc)
+		return snp_mdesc;
+
+	mdesc = kzalloc(sizeof(struct snp_msg_desc), GFP_KERNEL);
+	if (!mdesc)
+		return ERR_PTR(-ENOMEM);
+
+	mdesc->secrets = ioremap_encrypted(secrets_pa, PAGE_SIZE);
+	if (!mdesc->secrets)
+		return ERR_PTR(-ENODEV);
+
+	/* Ensure SNP guest messages do not span more than a page */
+	BUILD_BUG_ON(sizeof(struct snp_guest_msg) > PAGE_SIZE);
+
+	/* Allocate the shared page used for the request and response message. */
+	mdesc->request = alloc_shared_pages(sizeof(struct snp_guest_msg));
+	if (!mdesc->request)
+		goto e_unmap;
+
+	mdesc->response = alloc_shared_pages(sizeof(struct snp_guest_msg));
+	if (!mdesc->response)
+		goto e_free_request;
+
+	mdesc->certs_data = alloc_shared_pages(SEV_FW_BLOB_MAX_SIZE);
+	if (!mdesc->certs_data)
+		goto e_free_response;
+
+	/* initial the input address for guest request */
+	mdesc->input.req_gpa = __pa(mdesc->request);
+	mdesc->input.resp_gpa = __pa(mdesc->response);
+	mdesc->input.data_gpa = __pa(mdesc->certs_data);
+
+	snp_mdesc = mdesc;
+
+	return mdesc;
+
+e_free_response:
+	free_shared_pages(mdesc->response, sizeof(struct snp_guest_msg));
+e_free_request:
+	free_shared_pages(mdesc->request, sizeof(struct snp_guest_msg));
+e_unmap:
+	iounmap(mdesc->secrets);
+
+	return ERR_PTR(-ENOMEM);
+}
+EXPORT_SYMBOL_GPL(snp_msg_alloc);
diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c
index 38ddabcd7ba3..40509fe18658 100644
--- a/drivers/virt/coco/sev-guest/sev-guest.c
+++ b/drivers/virt/coco/sev-guest/sev-guest.c
@@ -63,16 +63,6 @@ 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);
 
-static bool is_vmpck_empty(struct snp_msg_desc *mdesc)
-{
-	char zero_key[VMPCK_KEY_LEN] = {0};
-
-	if (mdesc->vmpck)
-		return !memcmp(mdesc->vmpck, zero_key, VMPCK_KEY_LEN);
-
-	return true;
-}
-
 /*
  * If an error is received from the host or AMD Secure Processor (ASP) there
  * are two options. Either retry the exact same encrypted request or discontinue
@@ -93,7 +83,7 @@ static bool is_vmpck_empty(struct snp_msg_desc *mdesc)
 static void snp_disable_vmpck(struct snp_msg_desc *mdesc)
 {
 	pr_alert("Disabling VMPCK%d communication key to prevent IV reuse.\n",
-		  vmpck_id);
+		  mdesc->vmpck_id);
 	memzero_explicit(mdesc->vmpck, VMPCK_KEY_LEN);
 	mdesc->vmpck = NULL;
 }
@@ -147,23 +137,6 @@ static inline struct snp_guest_dev *to_snp_dev(struct file *file)
 	return container_of(dev, struct snp_guest_dev, misc);
 }
 
-static struct aesgcm_ctx *snp_init_crypto(u8 *key, size_t keylen)
-{
-	struct aesgcm_ctx *ctx;
-
-	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL_ACCOUNT);
-	if (!ctx)
-		return NULL;
-
-	if (aesgcm_expandkey(ctx, key, keylen, AUTHTAG_LEN)) {
-		pr_err("Crypto context initialization failed\n");
-		kfree(ctx);
-		return NULL;
-	}
-
-	return ctx;
-}
-
 static int verify_and_dec_payload(struct snp_msg_desc *mdesc, struct snp_guest_req *req)
 {
 	struct snp_guest_msg *resp_msg = &mdesc->secret_response;
@@ -385,7 +358,7 @@ static int handle_guest_request(struct snp_msg_desc *mdesc, u64 exit_code,
 	struct snp_guest_req req = {
 		.msg_version	= rio->msg_version,
 		.msg_type	= type,
-		.vmpck_id	= vmpck_id,
+		.vmpck_id	= mdesc->vmpck_id,
 		.req_buf	= req_buf,
 		.req_sz		= req_sz,
 		.resp_buf	= resp_buf,
@@ -609,76 +582,11 @@ 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)
-{
-	unsigned int npages = PAGE_ALIGN(sz) >> PAGE_SHIFT;
-	int ret;
-
-	if (!buf)
-		return;
-
-	ret = set_memory_encrypted((unsigned long)buf, npages);
-	if (ret) {
-		WARN_ONCE(ret, "failed to restore encryption mask (leak it)\n");
-		return;
-	}
-
-	__free_pages(virt_to_page(buf), get_order(sz));
-}
-
-static void *alloc_shared_pages(struct device *dev, size_t sz)
-{
-	unsigned int npages = PAGE_ALIGN(sz) >> PAGE_SHIFT;
-	struct page *page;
-	int ret;
-
-	page = alloc_pages(GFP_KERNEL_ACCOUNT, get_order(sz));
-	if (!page)
-		return NULL;
-
-	ret = set_memory_decrypted((unsigned long)page_address(page), npages);
-	if (ret) {
-		dev_err(dev, "failed to mark page shared, ret=%d\n", ret);
-		__free_pages(page, get_order(sz));
-		return NULL;
-	}
-
-	return page_address(page);
-}
-
 static const struct file_operations snp_guest_fops = {
 	.owner	= THIS_MODULE,
 	.unlocked_ioctl = snp_guest_ioctl,
 };
 
-static u8 *get_vmpck(int id, struct snp_secrets_page *secrets, u32 **seqno)
-{
-	u8 *key = NULL;
-
-	switch (id) {
-	case 0:
-		*seqno = &secrets->os_area.msg_seqno_0;
-		key = secrets->vmpck0;
-		break;
-	case 1:
-		*seqno = &secrets->os_area.msg_seqno_1;
-		key = secrets->vmpck1;
-		break;
-	case 2:
-		*seqno = &secrets->os_area.msg_seqno_2;
-		key = secrets->vmpck2;
-		break;
-	case 3:
-		*seqno = &secrets->os_area.msg_seqno_3;
-		key = secrets->vmpck3;
-		break;
-	default:
-		break;
-	}
-
-	return key;
-}
-
 struct snp_msg_report_resp_hdr {
 	u32 status;
 	u32 report_size;
@@ -978,130 +886,66 @@ static void unregister_sev_tsm(void *data)
 
 static int __init sev_guest_probe(struct platform_device *pdev)
 {
-	struct sev_guest_platform_data *data;
-	struct snp_secrets_page *secrets;
 	struct device *dev = &pdev->dev;
 	struct snp_guest_dev *snp_dev;
 	struct snp_msg_desc *mdesc;
 	struct miscdevice *misc;
-	void __iomem *mapping;
 	int ret;
 
 	if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
 		return -ENODEV;
 
-	if (!dev->platform_data)
-		return -ENODEV;
-
-	data = (struct sev_guest_platform_data *)dev->platform_data;
-	mapping = ioremap_encrypted(data->secrets_gpa, PAGE_SIZE);
-	if (!mapping)
-		return -ENODEV;
-
-	secrets = (__force void *)mapping;
-
-	ret = -ENOMEM;
 	snp_dev = devm_kzalloc(&pdev->dev, sizeof(struct snp_guest_dev), GFP_KERNEL);
 	if (!snp_dev)
-		goto e_unmap;
-
-	mdesc = devm_kzalloc(&pdev->dev, sizeof(struct snp_msg_desc), GFP_KERNEL);
-	if (!mdesc)
-		goto e_unmap;
-
-	/* Adjust the default VMPCK key based on the executing VMPL level */
-	if (vmpck_id == -1)
-		vmpck_id = snp_vmpl;
+		return -ENOMEM;
 
-	ret = -EINVAL;
-	mdesc->vmpck = get_vmpck(vmpck_id, secrets, &mdesc->os_area_msg_seqno);
-	if (!mdesc->vmpck) {
-		dev_err(dev, "Invalid VMPCK%d communication key\n", vmpck_id);
-		goto e_unmap;
-	}
+	mdesc = snp_msg_alloc();
+	if (IS_ERR_OR_NULL(mdesc))
+		return -ENOMEM;
 
-	/* Verify that VMPCK is not zero. */
-	if (is_vmpck_empty(mdesc)) {
-		dev_err(dev, "Empty VMPCK%d communication key\n", vmpck_id);
-		goto e_unmap;
-	}
+	ret = snp_msg_init(mdesc, vmpck_id);
+	if (ret)
+		return -EIO;
 
 	platform_set_drvdata(pdev, snp_dev);
 	snp_dev->dev = dev;
-	mdesc->secrets = secrets;
-
-	/* Ensure SNP guest messages do not span more than a page */
-	BUILD_BUG_ON(sizeof(struct snp_guest_msg) > PAGE_SIZE);
-
-	/* Allocate the shared page used for the request and response message. */
-	mdesc->request = alloc_shared_pages(dev, sizeof(struct snp_guest_msg));
-	if (!mdesc->request)
-		goto e_unmap;
-
-	mdesc->response = alloc_shared_pages(dev, sizeof(struct snp_guest_msg));
-	if (!mdesc->response)
-		goto e_free_request;
-
-	mdesc->certs_data = alloc_shared_pages(dev, SEV_FW_BLOB_MAX_SIZE);
-	if (!mdesc->certs_data)
-		goto e_free_response;
-
-	ret = -EIO;
-	mdesc->ctx = snp_init_crypto(mdesc->vmpck, VMPCK_KEY_LEN);
-	if (!mdesc->ctx)
-		goto e_free_cert_data;
 
 	misc = &snp_dev->misc;
 	misc->minor = MISC_DYNAMIC_MINOR;
 	misc->name = DEVICE_NAME;
 	misc->fops = &snp_guest_fops;
 
-	/* Initialize the input addresses for guest request */
-	mdesc->input.req_gpa = __pa(mdesc->request);
-	mdesc->input.resp_gpa = __pa(mdesc->response);
-	mdesc->input.data_gpa = __pa(mdesc->certs_data);
-
 	/* Set the privlevel_floor attribute based on the vmpck_id */
-	sev_tsm_ops.privlevel_floor = vmpck_id;
+	sev_tsm_ops.privlevel_floor = mdesc->vmpck_id;
 
 	ret = tsm_register(&sev_tsm_ops, snp_dev);
 	if (ret)
-		goto e_free_cert_data;
+		goto e_msg_init;
 
 	ret = devm_add_action_or_reset(&pdev->dev, unregister_sev_tsm, NULL);
 	if (ret)
-		goto e_free_cert_data;
+		goto e_msg_init;
 
 	ret =  misc_register(misc);
 	if (ret)
-		goto e_free_ctx;
+		goto e_msg_init;
 
 	snp_dev->msg_desc = mdesc;
-	dev_info(dev, "Initialized SEV guest driver (using VMPCK%d communication key)\n", vmpck_id);
+	dev_info(dev, "Initialized SEV guest driver (using VMPCK%d communication key)\n",
+		 mdesc->vmpck_id);
 	return 0;
 
-e_free_ctx:
-	kfree(mdesc->ctx);
-e_free_cert_data:
-	free_shared_pages(mdesc->certs_data, SEV_FW_BLOB_MAX_SIZE);
-e_free_response:
-	free_shared_pages(mdesc->response, sizeof(struct snp_guest_msg));
-e_free_request:
-	free_shared_pages(mdesc->request, sizeof(struct snp_guest_msg));
-e_unmap:
-	iounmap(mapping);
+e_msg_init:
+	snp_msg_cleanup(mdesc);
+
 	return ret;
 }
 
 static void __exit sev_guest_remove(struct platform_device *pdev)
 {
 	struct snp_guest_dev *snp_dev = platform_get_drvdata(pdev);
-	struct snp_msg_desc *mdesc = snp_dev->msg_desc;
 
-	free_shared_pages(mdesc->certs_data, SEV_FW_BLOB_MAX_SIZE);
-	free_shared_pages(mdesc->response, sizeof(struct snp_guest_msg));
-	free_shared_pages(mdesc->request, sizeof(struct snp_guest_msg));
-	kfree(mdesc->ctx);
+	snp_msg_cleanup(snp_dev->msg_desc);
 	misc_deregister(&snp_dev->misc);
 }
 
