[tip: x86/sev] sev-guest: configfs-tsm: Allow the privlevel_floor attribute to be updated

From: tip-bot2 for Tom Lendacky
Date: Tue Jun 18 2024 - 07:04:08 EST


The following commit has been merged into the x86/sev branch of tip:

Commit-ID: 614dc0fb76327dbd81abd4612fbc2e4ba8f205e6
Gitweb: https://git.kernel.org/tip/614dc0fb76327dbd81abd4612fbc2e4ba8f205e6
Author: Tom Lendacky <thomas.lendacky@xxxxxxx>
AuthorDate: Wed, 05 Jun 2024 10:18:52 -05:00
Committer: Borislav Petkov (AMD) <bp@xxxxxxxxx>
CommitterDate: Mon, 17 Jun 2024 20:42:57 +02:00

sev-guest: configfs-tsm: Allow the privlevel_floor attribute to be updated

With the introduction of an SVSM, Linux will be running at a non-zero
VMPL. Any request for an attestation report at a higher privilege VMPL
than what Linux is currently running will result in an error. Allow for
the privlevel_floor attribute to be updated dynamically.

[ bp: Trim commit message. ]

Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Link: https://lore.kernel.org/r/5a736be9384aebd98a0b7c929660f8a97cbdc366.1717600736.git.thomas.lendacky@xxxxxxx
---
drivers/virt/coco/sev-guest/sev-guest.c | 5 ++++-
include/linux/tsm.h | 2 +-
2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c
index 4597042..3560b3a 100644
--- a/drivers/virt/coco/sev-guest/sev-guest.c
+++ b/drivers/virt/coco/sev-guest/sev-guest.c
@@ -892,7 +892,7 @@ static int sev_report_new(struct tsm_report *report, void *data)
return 0;
}

-static const struct tsm_ops sev_tsm_ops = {
+static struct tsm_ops sev_tsm_ops = {
.name = KBUILD_MODNAME,
.report_new = sev_report_new,
};
@@ -979,6 +979,9 @@ 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);

+ /* Set the privlevel_floor attribute based on the vmpck_id */
+ sev_tsm_ops.privlevel_floor = vmpck_id;
+
ret = tsm_register(&sev_tsm_ops, snp_dev, &tsm_report_extra_type);
if (ret)
goto e_free_cert_data;
diff --git a/include/linux/tsm.h b/include/linux/tsm.h
index de8324a..50c5769 100644
--- a/include/linux/tsm.h
+++ b/include/linux/tsm.h
@@ -54,7 +54,7 @@ struct tsm_report {
*/
struct tsm_ops {
const char *name;
- const unsigned int privlevel_floor;
+ unsigned int privlevel_floor;
int (*report_new)(struct tsm_report *report, void *data);
};