releases/5.11.21/kvm-svm-free-sev_asid_bitmap-during-init-if-sev-setu.patch

From 0b8ee6dbd987984f51ccaaeb0a3caf66f91a110e Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Wed, 21 Apr 2021 19:11:12 -0700
Subject: KVM: SVM: Free sev_asid_bitmap during init if SEV setup fails

From: Sean Christopherson <seanjc@google.com>

[ Upstream commit f31b88b35f90f6b7ae4abc1015494a285f459221 ]

Free sev_asid_bitmap if the reclaim bitmap allocation fails, othwerise
KVM will unnecessarily keep the bitmap when SEV is not fully enabled.

Freeing the page is also necessary to avoid introducing a bug when a
future patch eliminates svm_sev_enabled() in favor of using the global
'sev' flag directly.  While sev_hardware_enabled() checks max_sev_asid,
which is true even if KVM setup fails, 'sev' will be true if and only
if KVM setup fully succeeds.

Fixes: 33af3a7ef9e6 ("KVM: SVM: Reduce WBINVD/DF_FLUSH invocations")
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210422021125.3417167-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/x86/kvm/svm/sev.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 80c49a5e593a..7c233c79c124 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -1276,8 +1276,11 @@ void __init sev_hardware_setup(void)
 		goto out;
 
 	sev_reclaim_asid_bitmap = bitmap_zalloc(max_sev_asid, GFP_KERNEL);
-	if (!sev_reclaim_asid_bitmap)
+	if (!sev_reclaim_asid_bitmap) {
+		bitmap_free(sev_asid_bitmap);
+		sev_asid_bitmap = NULL;
 		goto out;
+	}
 
 	pr_info("SEV supported: %u ASIDs\n", max_sev_asid - min_sev_asid + 1);
 	sev_supported = true;
-- 
2.30.2