virt: sevguest: Change driver name to reflect generic SEV support

During patch review, it was decided the SNP guest driver name should not
be SEV-SNP specific, but should be generic for use with anything SEV.
However, this feedback was missed and the driver name, and many of the
driver functions and structures, are SEV-SNP name specific. Rename the
driver to "sev-guest" (to match the misc device that is created) and
update some of the function and structure names, too.

While in the file, adjust the one pr_err() message to be a dev_err()
message so that the message, if issued, uses the driver name.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/307710bb5515c9088a19fd0b930268c7300479b2.1650464054.git.thomas.lendacky@amd.com

arch/x86/include/asm/sev.h

@@ -95,7 +95,7 @@ struct snp_req_data {
 	unsigned int data_npages;
 };
 
-struct snp_guest_platform_data {
+struct sev_guest_platform_data {
 	u64 secrets_gpa;
 };
 

arch/x86/kernel/sev.c

@@ -2166,8 +2166,8 @@ int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, unsigned
 }
 EXPORT_SYMBOL_GPL(snp_issue_guest_request);
 
-static struct platform_device guest_req_device = {
-	.name		= "snp-guest",
+static struct platform_device sev_guest_device = {
+	.name		= "sev-guest",
 	.id		= -1,
 };
 
@@ -2197,7 +2197,7 @@ static u64 get_secrets_page(void)
 
 static int __init snp_init_platform_device(void)
 {
-	struct snp_guest_platform_data data;
+	struct sev_guest_platform_data data;
 	u64 gpa;
 
 	if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
@@ -2208,10 +2208,10 @@ static int __init snp_init_platform_device(void)
 		return -ENODEV;
 
 	data.secrets_gpa = gpa;
-	if (platform_device_add_data(&guest_req_device, &data, sizeof(data)))
+	if (platform_device_add_data(&sev_guest_device, &data, sizeof(data)))
 		return -ENODEV;
 
-	if (platform_device_register(&guest_req_device))
+	if (platform_device_register(&sev_guest_device))
 		return -ENODEV;
 
 	pr_info("SNP guest platform device initialized.\n");

drivers/virt/coco/sevguest/sevguest.c

 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * AMD Secure Encrypted Virtualization Nested Paging (SEV-SNP) guest request interface
+ * AMD Secure Encrypted Virtualization (SEV) guest driver interface
  *
  * Copyright (C) 2021 Advanced Micro Devices, Inc.
  *
  * Author: Brijesh Singh <brijesh.singh@amd.com>
  */
 
-#define pr_fmt(fmt) "SNP: GUEST: " fmt
-
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
@@ -574,7 +572,7 @@ static void free_shared_pages(void *buf, size_t sz)
 	__free_pages(virt_to_page(buf), get_order(sz));
 }
 
-static void *alloc_shared_pages(size_t sz)
+static void *alloc_shared_pages(struct device *dev, size_t sz)
 {
 	unsigned int npages = PAGE_ALIGN(sz) >> PAGE_SHIFT;
 	struct page *page;
@@ -586,7 +584,7 @@ static void *alloc_shared_pages(size_t sz)
 
 	ret = set_memory_decrypted((unsigned long)page_address(page), npages);
 	if (ret) {
-		pr_err("failed to mark page shared, ret=%d\n", ret);
+		dev_err(dev, "failed to mark page shared, ret=%d\n", ret);
 		__free_pages(page, get_order(sz));
 		return NULL;
 	}
@@ -627,10 +625,10 @@ static u8 *get_vmpck(int id, struct snp_secrets_page_layout *layout, u32 **seqno
 	return key;
 }
 
-static int __init snp_guest_probe(struct platform_device *pdev)
+static int __init sev_guest_probe(struct platform_device *pdev)
 {
 	struct snp_secrets_page_layout *layout;
-	struct snp_guest_platform_data *data;
+	struct sev_guest_platform_data *data;
 	struct device *dev = &pdev->dev;
 	struct snp_guest_dev *snp_dev;
 	struct miscdevice *misc;
@@ -639,7 +637,7 @@ static int __init snp_guest_probe(struct platform_device *pdev)
 	if (!dev->platform_data)
 		return -ENODEV;
 
-	data = (struct snp_guest_platform_data *)dev->platform_data;
+	data = (struct sev_guest_platform_data *)dev->platform_data;
 	layout = (__force void *)ioremap_encrypted(data->secrets_gpa, PAGE_SIZE);
 	if (!layout)
 		return -ENODEV;
@@ -667,15 +665,15 @@ static int __init snp_guest_probe(struct platform_device *pdev)
 	snp_dev->layout = layout;
 
 	/* Allocate the shared page used for the request and response message. */
-	snp_dev->request = alloc_shared_pages(sizeof(struct snp_guest_msg));
+	snp_dev->request = alloc_shared_pages(dev, sizeof(struct snp_guest_msg));
 	if (!snp_dev->request)
 		goto e_unmap;
 
-	snp_dev->response = alloc_shared_pages(sizeof(struct snp_guest_msg));
+	snp_dev->response = alloc_shared_pages(dev, sizeof(struct snp_guest_msg));
 	if (!snp_dev->response)
 		goto e_free_request;
 
-	snp_dev->certs_data = alloc_shared_pages(SEV_FW_BLOB_MAX_SIZE);
+	snp_dev->certs_data = alloc_shared_pages(dev, SEV_FW_BLOB_MAX_SIZE);
 	if (!snp_dev->certs_data)
 		goto e_free_response;
 
@@ -698,7 +696,7 @@ static int __init snp_guest_probe(struct platform_device *pdev)
 	if (ret)
 		goto e_free_cert_data;
 
-	dev_info(dev, "Initialized SNP guest driver (using vmpck_id %d)\n", vmpck_id);
+	dev_info(dev, "Initialized SEV guest driver (using vmpck_id %d)\n", vmpck_id);
 	return 0;
 
 e_free_cert_data:
@@ -712,7 +710,7 @@ static int __init snp_guest_probe(struct platform_device *pdev)
 	return ret;
 }
 
-static int __exit snp_guest_remove(struct platform_device *pdev)
+static int __exit sev_guest_remove(struct platform_device *pdev)
 {
 	struct snp_guest_dev *snp_dev = platform_get_drvdata(pdev);
 
@@ -725,16 +723,21 @@ static int __exit snp_guest_remove(struct platform_device *pdev)
 	return 0;
 }
 
-static struct platform_driver snp_guest_driver = {
-	.remove		= __exit_p(snp_guest_remove),
+/*
+ * This driver is a common SEV guest interface driver and meant to support
+ * any SEV guest API. As such, even though it has been introduced along with
+ * the SEV-SNP support, it is named "sev-guest".
+ */
+static struct platform_driver sev_guest_driver = {
+	.remove		= __exit_p(sev_guest_remove),
 	.driver		= {
-		.name = "snp-guest",
+		.name = "sev-guest",
 	},
 };
 
-module_platform_driver_probe(snp_guest_driver, snp_guest_probe);
+module_platform_driver_probe(sev_guest_driver, sev_guest_probe);
 
 MODULE_AUTHOR("Brijesh Singh <brijesh.singh@amd.com>");
 MODULE_LICENSE("GPL");
 MODULE_VERSION("1.0.0");
-MODULE_DESCRIPTION("AMD SNP Guest Driver");
+MODULE_DESCRIPTION("AMD SEV Guest Driver");