[PATCH v4 3/5] RISC-V: KVM: switch to kvm_trylock/unlock_all_vcpus

Maxim Levitsky mlevitsk at redhat.com
Wed Apr 30 13:30:11 PDT 2025


Use the kvm_trylock_all_vcpus()/unlock_all_vcpus() instead of riscv's own
implementation, to avoid triggering a lockdep warning,
if the VM is configured to have more than MAX_LOCK_DEPTH vCPUs.

Compile tested only.

Suggested-by: Paolo Bonzini <pbonzini at redhat.com>
Signed-off-by: Maxim Levitsky <mlevitsk at redhat.com>
---
 arch/riscv/kvm/aia_device.c | 34 ++--------------------------------
 1 file changed, 2 insertions(+), 32 deletions(-)

diff --git a/arch/riscv/kvm/aia_device.c b/arch/riscv/kvm/aia_device.c
index 39cd26af5a69..6315821f0d69 100644
--- a/arch/riscv/kvm/aia_device.c
+++ b/arch/riscv/kvm/aia_device.c
@@ -12,36 +12,6 @@
 #include <linux/kvm_host.h>
 #include <linux/uaccess.h>
 
-static void unlock_vcpus(struct kvm *kvm, int vcpu_lock_idx)
-{
-	struct kvm_vcpu *tmp_vcpu;
-
-	for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
-		tmp_vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx);
-		mutex_unlock(&tmp_vcpu->mutex);
-	}
-}
-
-static void unlock_all_vcpus(struct kvm *kvm)
-{
-	unlock_vcpus(kvm, atomic_read(&kvm->online_vcpus) - 1);
-}
-
-static bool lock_all_vcpus(struct kvm *kvm)
-{
-	struct kvm_vcpu *tmp_vcpu;
-	unsigned long c;
-
-	kvm_for_each_vcpu(c, tmp_vcpu, kvm) {
-		if (!mutex_trylock(&tmp_vcpu->mutex)) {
-			unlock_vcpus(kvm, c - 1);
-			return false;
-		}
-	}
-
-	return true;
-}
-
 static int aia_create(struct kvm_device *dev, u32 type)
 {
 	int ret;
@@ -53,7 +23,7 @@ static int aia_create(struct kvm_device *dev, u32 type)
 		return -EEXIST;
 
 	ret = -EBUSY;
-	if (!lock_all_vcpus(kvm))
+	if (kvm_trylock_all_vcpus(kvm))
 		return ret;
 
 	kvm_for_each_vcpu(i, vcpu, kvm) {
@@ -65,7 +35,7 @@ static int aia_create(struct kvm_device *dev, u32 type)
 	kvm->arch.aia.in_kernel = true;
 
 out_unlock:
-	unlock_all_vcpus(kvm);
+	kvm_unlock_all_vcpus(kvm);
 	return ret;
 }
 
-- 
2.46.0




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