From a3f11f72f2c74e22a2f073f818e6f1a78a2add35 Mon Sep 17 00:00:00 2001
From: Wanpeng Li <wanpengli@tencent.com>
Date: Tue, 4 Jan 2022 22:41:03 -0800
Subject: [PATCH 6/6] KVM: SEV: Mark nested locking of kvm->lock
Git-commit: 597cb7968cb6243e915ba9599195656be14773e5
Patch-mainline: v5.16
References: bsc#1194526
Both source and dest vms' kvm->locks are held in sev_lock_two_vms.
Mark one with a different subtype to avoid false positives from lockdep.
Fixes: c9d61dcb0bc26 (KVM: SEV: accept signals in sev_lock_two_vms)
Reported-by: Yiru Xu <xyru1999@gmail.com>
Tested-by: Jinrong Liang <cloudliang@tencent.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1641364863-26331-1-git-send-email-wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Li Zhang <lizhang@suse.de>
---
arch/x86/kvm/svm/sev.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 973f77982532..b4948760180d 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -1566,7 +1566,7 @@ static int sev_lock_two_vms(struct kvm *dst_kvm, struct kvm *src_kvm)
r = -EINTR;
if (mutex_lock_killable(&dst_kvm->lock))
goto release_src;
- if (mutex_lock_killable(&src_kvm->lock))
+ if (mutex_lock_killable_nested(&src_kvm->lock, SINGLE_DEPTH_NESTING))
goto unlock_dst;
return 0;
--
2.31.1