This is a note to let you know that I've just added the patch titled
crypto: ccp - Flush the SEV-ES TMR memory before giving it to firmware
to the 6.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
crypto-ccp-flush-the-sev-es-tmr-memory-before-giving.patch
and it can be found in the queue-6.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit a7d3173fe0ab77c97b23a8e10e4f222b5d346ead
Author: Tom Lendacky <thomas.lendacky@xxxxxxx>
Date: Mon Jan 23 16:53:08 2023 -0600
crypto: ccp - Flush the SEV-ES TMR memory before giving it to firmware
[ Upstream commit 46a334a98f585ef78d51d8f5736596887bdd7f54 ]
Perform a cache flush on the SEV-ES TMR memory after allocation to prevent
any possibility of the firmware encountering an error should dirty cache
lines be present. Use clflush_cache_range() to flush the SEV-ES TMR memory.
Fixes: 97f9ac3db661 ("crypto: ccp - Add support for SEV-ES to the PSP driver")
Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index 56998bc579d67..3e583f0324874 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -26,6 +26,7 @@
#include <linux/fs_struct.h>
#include <asm/smp.h>
+#include <asm/cacheflush.h>
#include "psp-dev.h"
#include "sev-dev.h"
@@ -1334,7 +1335,10 @@ void sev_pci_init(void)
/* Obtain the TMR memory area for SEV-ES use */
sev_es_tmr = sev_fw_alloc(SEV_ES_TMR_SIZE);
- if (!sev_es_tmr)
+ if (sev_es_tmr)
+ /* Must flush the cache before giving it to the firmware */
+ clflush_cache_range(sev_es_tmr, SEV_ES_TMR_SIZE);
+ else
dev_warn(sev->dev,
"SEV: TMR allocation failed, SEV-ES support unavailable\n");
