@@ -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 */
@@ -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 +2573,126 @@ 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;
+
+ BUILD_BUG_ON(sizeof(struct snp_guest_msg) > PAGE_SIZE);
+
+ 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);
+
+ /* 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);
@@ -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;
@@ -414,7 +387,7 @@ static int get_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_io
req.msg_version = arg->msg_version;
req.msg_type = SNP_MSG_REPORT_REQ;
- req.vmpck_id = vmpck_id;
+ req.vmpck_id = mdesc->vmpck_id;
req.req_buf = report_req;
req.req_sz = sizeof(*report_req);
req.resp_buf = report_resp->data;
@@ -461,7 +434,7 @@ static int get_derived_key(struct snp_guest_dev *snp_dev, struct snp_guest_reque
req.msg_version = arg->msg_version;
req.msg_type = SNP_MSG_KEY_REQ;
- req.vmpck_id = vmpck_id;
+ req.vmpck_id = mdesc->vmpck_id;
req.req_buf = derived_key_req;
req.req_sz = sizeof(*derived_key_req);
req.resp_buf = buf;
@@ -539,7 +512,7 @@ static int get_ext_report(struct snp_guest_dev *snp_dev, struct snp_guest_reques
req.msg_version = arg->msg_version;
req.msg_type = SNP_MSG_REPORT_REQ;
- req.vmpck_id = vmpck_id;
+ req.vmpck_id = mdesc->vmpck_id;
req.req_buf = &report_req->data;
req.req_sz = sizeof(report_req->data);
req.resp_buf = report_resp->data;
@@ -616,76 +589,11 @@ 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;
@@ -979,13 +887,10 @@ 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;
BUILD_BUG_ON(sizeof(struct snp_guest_msg) > PAGE_SIZE);
@@ -993,115 +898,57 @@ static int __init sev_guest_probe(struct platform_device *pdev)
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;
-
- /* 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);
}