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From: Tom Lendacky <thomas.lendacky@amd.com>
To: <linux-kernel@vger.kernel.org>, <x86@kernel.org>
CC: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
	Borislav Petkov <bp@alien8.de>, Dave Hansen <dave.hansen@linux.intel.com>,
	"H. Peter Anvin" <hpa@zytor.com>, Andy Lutomirski <luto@kernel.org>, "Peter
 Zijlstra" <peterz@infradead.org>, Dan Williams <dan.j.williams@intel.com>,
	Michael Roth <michael.roth@amd.com>, Ashish Kalra <ashish.kalra@amd.com>
Subject: [PATCH v2 10/14] configfs-tsm: Allow the privlevel_floor attribute to be updated
Date: Fri, 8 Mar 2024 12:35:25 -0600
Message-ID: <45573c903efedc3d4bd00e902ba6a4b1f0cbbbc6.1709922929.git.thomas.lendacky@amd.com>
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With the introduction of an SVSM, Linux will be running at a non-zero
VMPL. Any request for an attestation report at a higher priviledge VMPL
than what Linux is currently running will result in an error. Allow for
the privlevel_floor attribute to be updated dynamically so that the
attribute may be set dynamically.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
 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 1ff897913bf4..bba6531cb606 100644
--- a/drivers/virt/coco/sev-guest/sev-guest.c
+++ b/drivers/virt/coco/sev-guest/sev-guest.c
@@ -885,7 +885,7 @@ 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,
 };
@@ -972,6 +972,9 @@ 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 current VMPL */
+	sev_tsm_ops.privlevel_floor = snp_get_vmpl();
+
 	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 de8324a2223c..50c5769657d8 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);
 };
 
-- 
2.43.2