Commit 32bd348b authored by Wanpeng Li's avatar Wanpeng Li Committed by Paolo Bonzini
Browse files

KVM: Fix last_boosted_vcpu index assignment bug 



In kvm_vcpu_on_spin(), the loop counter 'i' is incorrectly written to
last_boosted_vcpu instead of the actual vCPU index 'idx'. This causes
last_boosted_vcpu to store the loop iteration count rather than the
vCPU index, leading to incorrect round-robin behavior in subsequent
directed yield operations.

Fix this by using 'idx' instead of 'i' in the assignment.

Signed-off-by: default avatarWanpeng Li <wanpengli@tencent.com>
Reviewed-by: default avatarSean Christopherson <seanjc@google.com>
Message-ID: <20251110033232.12538-7-kernellwp@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent ac3fd01e

virt/kvm/kvm_main.c

+1 −1
Original line number Diff line number Diff line
@@ -4026,7 +4026,7 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode) 


		yielded = kvm_vcpu_yield_to(vcpu);

		if (yielded > 0) {

			WRITE_ONCE(kvm->last_boosted_vcpu, i);

			WRITE_ONCE(kvm->last_boosted_vcpu, idx);

			break;

		} else if (yielded < 0 && !--try) {

			break;