linux-kernel - [PATCH v4 7/7] crypto: ccp: Move SEV/SNP Platform initialization to KVM

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <8ddb15b23f5c7c9a250109a402b6541e5bc72d0f.1739997129.git.ashish.kalra@amd.com>
Date: Wed, 19 Feb 2025 20:55:18 +0000
From: Ashish Kalra <Ashish.Kalra@....com>
To: <seanjc@...gle.com>, <pbonzini@...hat.com>, <tglx@...utronix.de>,
	<mingo@...hat.com>, <bp@...en8.de>, <dave.hansen@...ux.intel.com>,
	<x86@...nel.org>, <hpa@...or.com>, <thomas.lendacky@....com>,
	<john.allen@....com>, <herbert@...dor.apana.org.au>
CC: <michael.roth@....com>, <dionnaglaze@...gle.com>, <nikunj@....com>,
	<ardb@...nel.org>, <kevinloughlin@...gle.com>, <Neeraj.Upadhyay@....com>,
	<aik@....com>, <kvm@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	<linux-crypto@...r.kernel.org>, <linux-coco@...ts.linux.dev>
Subject: [PATCH v4 7/7] crypto: ccp: Move SEV/SNP Platform initialization to KVM

From: Ashish Kalra <ashish.kalra@....com>

SNP initialization is forced during PSP driver probe purely because SNP
can't be initialized if VMs are running.  But the only in-tree user of
SEV/SNP functionality is KVM, and KVM depends on PSP driver for the same.
Forcing SEV/SNP initialization because a hypervisor could be running
legacy non-confidential VMs make no sense.

This patch removes SEV/SNP initialization from the PSP driver probe
time and moves the requirement to initialize SEV/SNP functionality
to KVM if it wants to use SEV/SNP.

Suggested-by: Sean Christopherson <seanjc@...gle.com>
Reviewed-by: Alexey Kardashevskiy <aik@....com>
Signed-off-by: Ashish Kalra <ashish.kalra@....com>
---
 drivers/crypto/ccp/sev-dev.c | 25 +------------------------
 1 file changed, 1 insertion(+), 24 deletions(-)

diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index f0f3e6d29200..99a663dbc2b6 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -1346,18 +1346,13 @@ static int _sev_platform_init_locked(struct sev_platform_init_args *args)
 	if (sev->state == SEV_STATE_INIT)
 		return 0;
 
-	/*
-	 * Legacy guests cannot be running while SNP_INIT(_EX) is executing,
-	 * so perform SEV-SNP initialization at probe time.
-	 */
 	rc = __sev_snp_init_locked(&args->error);
 	if (rc && rc != -ENODEV) {
 		/*
 		 * Don't abort the probe if SNP INIT failed,
 		 * continue to initialize the legacy SEV firmware.
 		 */
-		dev_err(sev->dev, "SEV-SNP: failed to INIT rc %d, error %#x\n",
-			rc, args->error);
+		dev_err(sev->dev, "SEV-SNP: failed to INIT, continue SEV INIT\n");
 	}
 
 	/* Defer legacy SEV/SEV-ES support if allowed by caller/module. */
@@ -2505,9 +2500,7 @@ EXPORT_SYMBOL_GPL(sev_issue_cmd_external_user);
 void sev_pci_init(void)
 {
 	struct sev_device *sev = psp_master->sev_data;
-	struct sev_platform_init_args args = {0};
 	u8 api_major, api_minor, build;
-	int rc;
 
 	if (!sev)
 		return;
@@ -2530,16 +2523,6 @@ void sev_pci_init(void)
 			 api_major, api_minor, build,
 			 sev->api_major, sev->api_minor, sev->build);
 
-	/* Initialize the platform */
-	args.probe = true;
-	rc = sev_platform_init(&args);
-	if (rc)
-		dev_err(sev->dev, "SEV: failed to INIT error %#x, rc %d\n",
-			args.error, rc);
-
-	dev_info(sev->dev, "SEV%s API:%d.%d build:%d\n", sev->snp_initialized ?
-		"-SNP" : "", sev->api_major, sev->api_minor, sev->build);
-
 	return;
 
 err:
@@ -2550,10 +2533,4 @@ void sev_pci_init(void)
 
 void sev_pci_exit(void)
 {
-	struct sev_device *sev = psp_master->sev_data;
-
-	if (!sev)
-		return;
-
-	sev_firmware_shutdown(sev);
 }
-- 
2.34.1