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path: root/drivers/virt/coco/sev-guest/sev-guest.c
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Diffstat (limited to 'drivers/virt/coco/sev-guest/sev-guest.c')
-rw-r--r--drivers/virt/coco/sev-guest/sev-guest.c179
1 files changed, 167 insertions, 12 deletions
diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c
index 5bee58ef5f..bc564adcf4 100644
--- a/drivers/virt/coco/sev-guest/sev-guest.c
+++ b/drivers/virt/coco/sev-guest/sev-guest.c
@@ -16,9 +16,13 @@
#include <linux/miscdevice.h>
#include <linux/set_memory.h>
#include <linux/fs.h>
+#include <linux/tsm.h>
#include <crypto/aead.h>
#include <linux/scatterlist.h>
#include <linux/psp-sev.h>
+#include <linux/sockptr.h>
+#include <linux/cleanup.h>
+#include <linux/uuid.h>
#include <uapi/linux/sev-guest.h>
#include <uapi/linux/psp-sev.h>
@@ -475,6 +479,11 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code,
return 0;
}
+struct snp_req_resp {
+ sockptr_t req_data;
+ sockptr_t resp_data;
+};
+
static int get_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_ioctl *arg)
{
struct snp_guest_crypto *crypto = snp_dev->crypto;
@@ -555,22 +564,25 @@ static int get_derived_key(struct snp_guest_dev *snp_dev, struct snp_guest_reque
return rc;
}
-static int get_ext_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_ioctl *arg)
+static int get_ext_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_ioctl *arg,
+ struct snp_req_resp *io)
+
{
struct snp_ext_report_req *req = &snp_dev->req.ext_report;
struct snp_guest_crypto *crypto = snp_dev->crypto;
struct snp_report_resp *resp;
int ret, npages = 0, resp_len;
+ sockptr_t certs_address;
lockdep_assert_held(&snp_cmd_mutex);
- if (!arg->req_data || !arg->resp_data)
+ if (sockptr_is_null(io->req_data) || sockptr_is_null(io->resp_data))
return -EINVAL;
- if (copy_from_user(req, (void __user *)arg->req_data, sizeof(*req)))
+ if (copy_from_sockptr(req, io->req_data, sizeof(*req)))
return -EFAULT;
- /* userspace does not want certificate data */
+ /* caller does not want certificate data */
if (!req->certs_len || !req->certs_address)
goto cmd;
@@ -578,8 +590,13 @@ static int get_ext_report(struct snp_guest_dev *snp_dev, struct snp_guest_reques
!IS_ALIGNED(req->certs_len, PAGE_SIZE))
return -EINVAL;
- if (!access_ok((const void __user *)req->certs_address, req->certs_len))
- return -EFAULT;
+ if (sockptr_is_kernel(io->resp_data)) {
+ certs_address = KERNEL_SOCKPTR((void *)req->certs_address);
+ } else {
+ certs_address = USER_SOCKPTR((void __user *)req->certs_address);
+ if (!access_ok(certs_address.user, req->certs_len))
+ return -EFAULT;
+ }
/*
* Initialize the intermediate buffer with all zeros. This buffer
@@ -609,21 +626,19 @@ cmd:
if (arg->vmm_error == SNP_GUEST_VMM_ERR_INVALID_LEN) {
req->certs_len = snp_dev->input.data_npages << PAGE_SHIFT;
- if (copy_to_user((void __user *)arg->req_data, req, sizeof(*req)))
+ if (copy_to_sockptr(io->req_data, req, sizeof(*req)))
ret = -EFAULT;
}
if (ret)
goto e_free;
- if (npages &&
- copy_to_user((void __user *)req->certs_address, snp_dev->certs_data,
- req->certs_len)) {
+ if (npages && copy_to_sockptr(certs_address, snp_dev->certs_data, req->certs_len)) {
ret = -EFAULT;
goto e_free;
}
- if (copy_to_user((void __user *)arg->resp_data, resp, sizeof(*resp)))
+ if (copy_to_sockptr(io->resp_data, resp, sizeof(*resp)))
ret = -EFAULT;
e_free:
@@ -636,6 +651,7 @@ static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long
struct snp_guest_dev *snp_dev = to_snp_dev(file);
void __user *argp = (void __user *)arg;
struct snp_guest_request_ioctl input;
+ struct snp_req_resp io;
int ret = -ENOTTY;
if (copy_from_user(&input, argp, sizeof(input)))
@@ -664,7 +680,14 @@ static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long
ret = get_derived_key(snp_dev, &input);
break;
case SNP_GET_EXT_REPORT:
- ret = get_ext_report(snp_dev, &input);
+ /*
+ * As get_ext_report() may be called from the ioctl() path and a
+ * kernel internal path (configfs-tsm), decorate the passed
+ * buffers as user pointers.
+ */
+ io.req_data = USER_SOCKPTR((void __user *)input.req_data);
+ io.resp_data = USER_SOCKPTR((void __user *)input.resp_data);
+ ret = get_ext_report(snp_dev, &input, &io);
break;
default:
break;
@@ -748,6 +771,130 @@ static u8 *get_vmpck(int id, struct snp_secrets_page_layout *layout, u32 **seqno
return key;
}
+struct snp_msg_report_resp_hdr {
+ u32 status;
+ u32 report_size;
+ u8 rsvd[24];
+};
+
+struct snp_msg_cert_entry {
+ guid_t guid;
+ u32 offset;
+ u32 length;
+};
+
+static int sev_report_new(struct tsm_report *report, void *data)
+{
+ struct snp_msg_cert_entry *cert_table;
+ struct tsm_desc *desc = &report->desc;
+ struct snp_guest_dev *snp_dev = data;
+ struct snp_msg_report_resp_hdr hdr;
+ const u32 report_size = SZ_4K;
+ const u32 ext_size = SEV_FW_BLOB_MAX_SIZE;
+ u32 certs_size, i, size = report_size + ext_size;
+ int ret;
+
+ if (desc->inblob_len != SNP_REPORT_USER_DATA_SIZE)
+ return -EINVAL;
+
+ void *buf __free(kvfree) = kvzalloc(size, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ guard(mutex)(&snp_cmd_mutex);
+
+ /* Check if the VMPCK is not empty */
+ if (is_vmpck_empty(snp_dev)) {
+ dev_err_ratelimited(snp_dev->dev, "VMPCK is disabled\n");
+ return -ENOTTY;
+ }
+
+ cert_table = buf + report_size;
+ struct snp_ext_report_req ext_req = {
+ .data = { .vmpl = desc->privlevel },
+ .certs_address = (__u64)cert_table,
+ .certs_len = ext_size,
+ };
+ memcpy(&ext_req.data.user_data, desc->inblob, desc->inblob_len);
+
+ struct snp_guest_request_ioctl input = {
+ .msg_version = 1,
+ .req_data = (__u64)&ext_req,
+ .resp_data = (__u64)buf,
+ .exitinfo2 = 0xff,
+ };
+ struct snp_req_resp io = {
+ .req_data = KERNEL_SOCKPTR(&ext_req),
+ .resp_data = KERNEL_SOCKPTR(buf),
+ };
+
+ ret = get_ext_report(snp_dev, &input, &io);
+ if (ret)
+ return ret;
+
+ memcpy(&hdr, buf, sizeof(hdr));
+ if (hdr.status == SEV_RET_INVALID_PARAM)
+ return -EINVAL;
+ if (hdr.status == SEV_RET_INVALID_KEY)
+ return -EINVAL;
+ if (hdr.status)
+ return -ENXIO;
+ if ((hdr.report_size + sizeof(hdr)) > report_size)
+ return -ENOMEM;
+
+ void *rbuf __free(kvfree) = kvzalloc(hdr.report_size, GFP_KERNEL);
+ if (!rbuf)
+ return -ENOMEM;
+
+ memcpy(rbuf, buf + sizeof(hdr), hdr.report_size);
+ report->outblob = no_free_ptr(rbuf);
+ report->outblob_len = hdr.report_size;
+
+ certs_size = 0;
+ for (i = 0; i < ext_size / sizeof(struct snp_msg_cert_entry); i++) {
+ struct snp_msg_cert_entry *ent = &cert_table[i];
+
+ if (guid_is_null(&ent->guid) && !ent->offset && !ent->length)
+ break;
+ certs_size = max(certs_size, ent->offset + ent->length);
+ }
+
+ /* Suspicious that the response populated entries without populating size */
+ if (!certs_size && i)
+ dev_warn_ratelimited(snp_dev->dev, "certificate slots conveyed without size\n");
+
+ /* No certs to report */
+ if (!certs_size)
+ return 0;
+
+ /* Suspicious that the certificate blob size contract was violated
+ */
+ if (certs_size > ext_size) {
+ dev_warn_ratelimited(snp_dev->dev, "certificate data truncated\n");
+ certs_size = ext_size;
+ }
+
+ void *cbuf __free(kvfree) = kvzalloc(certs_size, GFP_KERNEL);
+ if (!cbuf)
+ return -ENOMEM;
+
+ memcpy(cbuf, cert_table, certs_size);
+ report->auxblob = no_free_ptr(cbuf);
+ report->auxblob_len = certs_size;
+
+ return 0;
+}
+
+static const struct tsm_ops sev_tsm_ops = {
+ .name = KBUILD_MODNAME,
+ .report_new = sev_report_new,
+};
+
+static void unregister_sev_tsm(void *data)
+{
+ tsm_unregister(&sev_tsm_ops);
+}
+
static int __init sev_guest_probe(struct platform_device *pdev)
{
struct snp_secrets_page_layout *layout;
@@ -821,6 +968,14 @@ static int __init sev_guest_probe(struct platform_device *pdev)
snp_dev->input.resp_gpa = __pa(snp_dev->response);
snp_dev->input.data_gpa = __pa(snp_dev->certs_data);
+ ret = tsm_register(&sev_tsm_ops, snp_dev, &tsm_report_extra_type);
+ if (ret)
+ goto e_free_cert_data;
+
+ ret = devm_add_action_or_reset(&pdev->dev, unregister_sev_tsm, NULL);
+ if (ret)
+ goto e_free_cert_data;
+
ret = misc_register(misc);
if (ret)
goto e_free_cert_data;