@@ -122,8 +122,6 @@ static u64 snp_get_msg_seqno(struct snp_guest_dev *snp_dev)
{
u64 count;
- lockdep_assert_held(&snp_cmd_mutex);
-
count = snp_dev->secrets->os_area.msg_seqno[snp_dev->vmpck_id] + 1;
/*
@@ -345,6 +343,8 @@ static int snp_send_guest_request(struct snp_guest_dev *snp_dev, struct snp_gues
u64 seqno;
int rc;
+ guard(mutex)(&snp_cmd_mutex);
+
/* Get message sequence and verify that its a non-zero */
seqno = snp_get_msg_seqno(snp_dev);
if (!seqno)
@@ -399,8 +399,6 @@ static int get_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_io
struct snp_report_resp *report_resp;
int rc, resp_len;
- lockdep_assert_held(&snp_cmd_mutex);
-
if (!arg->req_data || !arg->resp_data)
return -EINVAL;
@@ -447,8 +445,6 @@ static int get_derived_key(struct snp_guest_dev *snp_dev, struct snp_guest_reque
/* Response data is 64 bytes and max authsize for GCM is 16 bytes. */
u8 buf[64 + 16];
- lockdep_assert_held(&snp_cmd_mutex);
-
if (!arg->req_data || !arg->resp_data)
return -EINVAL;
@@ -499,8 +495,6 @@ static int get_ext_report(struct snp_guest_dev *snp_dev, struct snp_guest_reques
sockptr_t certs_address;
int ret, resp_len;
- lockdep_assert_held(&snp_cmd_mutex);
-
if (sockptr_is_null(io->req_data) || sockptr_is_null(io->resp_data))
return -EINVAL;
@@ -596,12 +590,9 @@ static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long
if (!input.msg_version)
return -EINVAL;
- mutex_lock(&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");
- mutex_unlock(&snp_cmd_mutex);
return -ENOTTY;
}
@@ -626,8 +617,6 @@ static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long
break;
}
- mutex_unlock(&snp_cmd_mutex);
-
if (input.exitinfo2 && copy_to_user(argp, &input, sizeof(input)))
return -EFAULT;
@@ -724,8 +713,6 @@ static int sev_svsm_report_new(struct tsm_report *report, void *data)
man_len = SZ_4K;
certs_len = SEV_FW_BLOB_MAX_SIZE;
- guard(mutex)(&snp_cmd_mutex);
-
if (guid_is_null(&desc->service_guid)) {
call_id = SVSM_ATTEST_CALL(SVSM_ATTEST_SERVICES);
} else {
@@ -860,8 +847,6 @@ static int sev_report_new(struct tsm_report *report, void *data)
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");
SNP command mutex is used to serialize access to the shared buffer, command handling and message sequence number races. As part of the preparation for moving SEV guest driver common code and making mutex private, take the mutex in snp_send_guest_request() instead of snp_guest_ioctl(). This will result in locking behavior change as detailed below: Current locking behaviour: snp_guest_ioctl() mutex_lock(&snp_cmd_mutex) get_report()/get_derived_key()/get_ext_report() snp_send_guest_request() ... mutex_unlock(&snp_cmd_mutex) New locking behaviour: snp_guest_ioctl() get_report()/get_derived_key()/get_ext_report() snp_send_guest_request() guard(mutex)(&snp_cmd_mutex) ... Remove multiple lockdep check in the sev-guest driver as they are redundant now. Signed-off-by: Nikunj A Dadhania <nikunj@amd.com> --- drivers/virt/coco/sev-guest/sev-guest.c | 19 ++----------------- 1 file changed, 2 insertions(+), 17 deletions(-)