linux-kernel - [PATCH Part2 RFC v3 13/37] crypto: ccp: Shutdown SNP firmware on kexec

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Message-Id: <20210602141057.27107-14-brijesh.singh@amd.com>
Date:   Wed,  2 Jun 2021 09:10:33 -0500
From:   Brijesh Singh <brijesh.singh@....com>
To:     x86@...nel.org, linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
        linux-coco@...ts.linux.dev, linux-mm@...ck.org,
        linux-crypto@...r.kernel.org
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Joerg Roedel <jroedel@...e.de>,
        Tom Lendacky <thomas.lendacky@....com>,
        "H. Peter Anvin" <hpa@...or.com>, Ard Biesheuvel <ardb@...nel.org>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Andy Lutomirski <luto@...nel.org>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Sergio Lopez <slp@...hat.com>, Peter Gonda <pgonda@...gle.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
        David Rientjes <rientjes@...gle.com>, tony.luck@...el.com,
        npmccallum@...hat.com, Borislav Petkov <bp@...e.de>,
        Brijesh Singh <brijesh.singh@....com>
Subject: [PATCH Part2 RFC v3 13/37] crypto: ccp: Shutdown SNP firmware on kexec

When the kernel is getting ready to kexec, it calls the device_shutdown()
to allow drivers to cleanup before the kexec. If SEV firmware is
initialized then shut it down before kexec'ing the new kernel.

Signed-off-by: Brijesh Singh <brijesh.singh@....com>
---
 drivers/crypto/ccp/sev-dev.c | 53 +++++++++++++++++-------------------
 drivers/crypto/ccp/sp-pci.c  | 12 ++++++++
 2 files changed, 37 insertions(+), 28 deletions(-)

diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index 2203167dbc2e..b225face37b1 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -310,6 +310,9 @@ static int __sev_platform_shutdown_locked(int *error)
 	struct sev_device *sev = psp_master->sev_data;
 	int ret;
 
+	if (sev->state == SEV_STATE_UNINIT)
+		return 0;
+
 	ret = __sev_do_cmd_locked(SEV_CMD_SHUTDOWN, NULL, error);
 	if (ret)
 		return ret;
@@ -1115,6 +1118,22 @@ int sev_dev_init(struct psp_device *psp)
 	return ret;
 }
 
+static void sev_firmware_shutdown(struct sev_device *sev)
+{
+	sev_platform_shutdown(NULL);
+
+	if (sev_es_tmr) {
+		/* The TMR area was encrypted, flush it from the cache */
+		wbinvd_on_all_cpus();
+
+		free_pages((unsigned long)sev_es_tmr,
+			   get_order(SEV_ES_TMR_SIZE));
+		sev_es_tmr = NULL;
+	}
+
+	sev_snp_shutdown(NULL);
+}
+
 void sev_dev_destroy(struct psp_device *psp)
 {
 	struct sev_device *sev = psp->sev_data;
@@ -1122,6 +1141,8 @@ void sev_dev_destroy(struct psp_device *psp)
 	if (!sev)
 		return;
 
+	sev_firmware_shutdown(sev);
+
 	if (sev->misc)
 		kref_put(&misc_dev->refcount, sev_exit);
 
@@ -1152,21 +1173,6 @@ void sev_pci_init(void)
 	if (sev_get_api_version())
 		goto err;
 
-	/*
-	 * If platform is not in UNINIT state then firmware upgrade and/or
-	 * platform INIT command will fail. These command require UNINIT state.
-	 *
-	 * In a normal boot we should never run into case where the firmware
-	 * is not in UNINIT state on boot. But in case of kexec boot, a reboot
-	 * may not go through a typical shutdown sequence and may leave the
-	 * firmware in INIT or WORKING state.
-	 */
-
-	if (sev->state != SEV_STATE_UNINIT) {
-		sev_platform_shutdown(NULL);
-		sev->state = SEV_STATE_UNINIT;
-	}
-
 	if (sev_version_greater_or_equal(0, 15) &&
 	    sev_update_firmware(sev->dev) == 0)
 		sev_get_api_version();
@@ -1224,19 +1230,10 @@ void sev_pci_init(void)
 
 void sev_pci_exit(void)
 {
-	if (!psp_master->sev_data)
-		return;
-
-	sev_platform_shutdown(NULL);
-
-	if (sev_es_tmr) {
-		/* The TMR area was encrypted, flush it from the cache */
-		wbinvd_on_all_cpus();
+	struct sev_device *sev = psp_master->sev_data;
 
-		free_pages((unsigned long)sev_es_tmr,
-			   get_order(SEV_ES_TMR_SIZE));
-		sev_es_tmr = NULL;
-	}
+	if (!sev)
+		return;
 
-	sev_snp_shutdown(NULL);
+	sev_firmware_shutdown(sev);
 }
diff --git a/drivers/crypto/ccp/sp-pci.c b/drivers/crypto/ccp/sp-pci.c
index f468594ef8af..fb1b499bf04d 100644
--- a/drivers/crypto/ccp/sp-pci.c
+++ b/drivers/crypto/ccp/sp-pci.c
@@ -239,6 +239,17 @@ static int sp_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	return ret;
 }
 
+static void sp_pci_shutdown(struct pci_dev *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct sp_device *sp = dev_get_drvdata(dev);
+
+	if (!sp)
+		return;
+
+	sp_destroy(sp);
+}
+
 static void sp_pci_remove(struct pci_dev *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -369,6 +380,7 @@ static struct pci_driver sp_pci_driver = {
 	.id_table = sp_pci_table,
 	.probe = sp_pci_probe,
 	.remove = sp_pci_remove,
+	.shutdown = sp_pci_shutdown,
 	.driver.pm = &sp_pci_pm_ops,
 };
 
-- 
2.17.1