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 5.15-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-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit aff4f54cdc09ff2c24aeb921825828d945ba7026 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 7c9149492970d..70174a9118b19 100644 --- a/drivers/crypto/ccp/sev-dev.c +++ b/drivers/crypto/ccp/sev-dev.c @@ -24,6 +24,7 @@ #include <linux/cpufeature.h> #include <asm/smp.h> +#include <asm/cacheflush.h> #include "psp-dev.h" #include "sev-dev.h" @@ -1114,7 +1115,10 @@ 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");