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authorNikunj A Dadhania <nikunj@amd.com>2025-01-06 15:46:21 +0300
committerBorislav Petkov (AMD) <bp@alien8.de>2025-01-07 10:57:19 +0300
commit8234177d2027e52126e40472fe5807f4e94b19a3 (patch)
tree4cfff1630a1fc1e709dd1f293a40826d17d3e008
parent21fc6178e92070523e70fc5db59ac83806d269d6 (diff)
downloadlinux-8234177d2027e52126e40472fe5807f4e94b19a3.tar.xz
virt: sev-guest: Remove is_vmpck_empty() helper
Remove is_vmpck_empty() which uses a local array allocation to check if the VMPCK is empty and replace it with memchr_inv() to directly determine if the VMPCK is empty without additional memory allocation. [ bp: Massage commit message. ] Suggested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Nikunj A Dadhania <nikunj@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20250106124633.1418972-2-nikunj@amd.com
-rw-r--r--drivers/virt/coco/sev-guest/sev-guest.c14
1 files changed, 2 insertions, 12 deletions
diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c
index b699771be029..62328d0b2cb6 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
@@ -335,7 +325,7 @@ static int snp_send_guest_request(struct snp_msg_desc *mdesc, struct snp_guest_r
guard(mutex)(&snp_cmd_mutex);
/* Check if the VMPCK is not empty */
- if (is_vmpck_empty(mdesc)) {
+ if (!mdesc->vmpck || !memchr_inv(mdesc->vmpck, 0, VMPCK_KEY_LEN)) {
pr_err_ratelimited("VMPCK is disabled\n");
return -ENOTTY;
}
@@ -1024,7 +1014,7 @@ static int __init sev_guest_probe(struct platform_device *pdev)
}
/* Verify that VMPCK is not zero. */
- if (is_vmpck_empty(mdesc)) {
+ if (!memchr_inv(mdesc->vmpck, 0, VMPCK_KEY_LEN)) {
dev_err(dev, "Empty VMPCK%d communication key\n", vmpck_id);
goto e_unmap;
}