superrob1500
/
mirror-linux
mirror of https://github.com/torvalds/linux
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

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: Wanpeng Li <wanpengli@tencent.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20251110033232.12538-7-kernellwp@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
pull/1354/merge
Wanpeng Li 2025-11-10 11:32:27 +08:00 committed by Paolo Bonzini
parent ac3fd01e4c
commit 32bd348be3
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
virt/kvm/kvm_main.c
View File

@ -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;