linux-kernel - [RFC PATCH 01/35] KVM: SVM: Remove the call to sev_platform

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Date:   Mon, 14 Sep 2020 15:15:15 -0500
From:   Tom Lendacky <thomas.lendacky@....com>
To:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org, x86@...nel.org
Cc:     Paolo Bonzini <pbonzini@...hat.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>,
        Sean Christopherson <sean.j.christopherson@...el.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Borislav Petkov <bp@...en8.de>, Ingo Molnar <mingo@...hat.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Brijesh Singh <brijesh.singh@....com>
Subject: [RFC PATCH 01/35] KVM: SVM: Remove the call to sev_platform_status() during setup

From: Tom Lendacky <thomas.lendacky@....com>

When both KVM support and the CCP driver are built into the kernel instead
of as modules, KVM initialization happens before CCP initialization. As a
result, sev_platform_status() will return a failure when it is called from
sev_hardware_setup(), when this isn't really an error condition.

Since sev_platform_status() doesn't need to be called at this time anyway,
remove the invocation from sev_hardware_setup().

Signed-off-by: Tom Lendacky <thomas.lendacky@....com>
---
 arch/x86/kvm/svm/sev.c | 22 +---------------------
 1 file changed, 1 insertion(+), 21 deletions(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 402dc4234e39..fab382e2dad2 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -1117,9 +1117,6 @@ void sev_vm_destroy(struct kvm *kvm)
 
 int __init sev_hardware_setup(void)
 {
-	struct sev_user_data_status *status;
-	int rc;
-
 	/* Maximum number of encrypted guests supported simultaneously */
 	max_sev_asid = cpuid_ecx(0x8000001F);
 
@@ -1138,26 +1135,9 @@ int __init sev_hardware_setup(void)
 	if (!sev_reclaim_asid_bitmap)
 		return 1;
 
-	status = kmalloc(sizeof(*status), GFP_KERNEL);
-	if (!status)
-		return 1;
-
-	/*
-	 * Check SEV platform status.
-	 *
-	 * PLATFORM_STATUS can be called in any state, if we failed to query
-	 * the PLATFORM status then either PSP firmware does not support SEV
-	 * feature or SEV firmware is dead.
-	 */
-	rc = sev_platform_status(status, NULL);
-	if (rc)
-		goto err;
-
 	pr_info("SEV supported\n");
 
-err:
-	kfree(status);
-	return rc;
+	return 0;
 }
 
 void sev_hardware_teardown(void)
-- 
2.28.0