From 2e4682ba2ed79d8082b78d292b3b80f54d970b7a Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Thu, 10 Mar 2016 16:30:22 +0100 Subject: KVM: add missing memory barrier in kvm_{make,check}_request kvm_make_request and kvm_check_request imply a producer-consumer relationship; add implicit memory barriers to them. There was indeed already a place that was adding an explicit smp_mb() to order between kvm_check_request and the processing of the request. That memory barrier can be removed (as an added benefit, kvm_check_request can use smp_mb__after_atomic which is free on x86). Signed-off-by: Paolo Bonzini --- arch/x86/kvm/irq_comm.c | 3 --- 1 file changed, 3 deletions(-) (limited to 'arch/x86/kvm') diff --git a/arch/x86/kvm/irq_comm.c b/arch/x86/kvm/irq_comm.c index 54ead79e444b..dfb4c6476877 100644 --- a/arch/x86/kvm/irq_comm.c +++ b/arch/x86/kvm/irq_comm.c @@ -382,9 +382,6 @@ void kvm_scan_ioapic_routes(struct kvm_vcpu *vcpu, u32 i, nr_ioapic_pins; int idx; - /* kvm->irq_routing must be read after clearing - * KVM_SCAN_IOAPIC. */ - smp_mb(); idx = srcu_read_lock(&kvm->irq_srcu); table = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu); nr_ioapic_pins = min_t(u32, table->nr_rt_entries, -- cgit v1.2.3