From: Claudio Imbrenda <imbrenda@linux.ibm.com>
Date: Tue, 23 Jun 2026 15:33:27 +0000 (+0200)
Subject: KVM: s390: Fix locking in kvm_s390_set_mem_control()
X-Git-Tag: v7.2-rc1~30^2~2^2~3
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=9b0bf9b93cbff50764713b62d0f38d5238eea8c8;p=thirdparty%2Flinux.git

KVM: s390: Fix locking in kvm_s390_set_mem_control()

Add the missing locking around dat_reset_cmma().

Fixes: e38c884df921 ("KVM: s390: Switch to new gmap")
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-ID: <20260623153331.233784-7-imbrenda@linux.ibm.com>
---

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 8a3d55410f06e..221b2fb199d4e 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -990,9 +990,11 @@ static int kvm_s390_set_mem_control(struct kvm *kvm, struct kvm_device_attr *att
 		if (!kvm->arch.use_cmma)
 			break;
 
+		guard(mutex)(&kvm->lock);
 		VM_EVENT(kvm, 3, "%s", "RESET: CMMA states");
 		do {
-			start_gfn = dat_reset_cmma(kvm->arch.gmap->asce, start_gfn);
+			scoped_guard(read_lock, &kvm->mmu_lock)
+				start_gfn = dat_reset_cmma(kvm->arch.gmap->asce, start_gfn);
 			cond_resched();
 		} while (start_gfn);
 		ret = 0;