linux-kernel - [PATCH 2/6] KVM: lapic: do not set KVM_REQ

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 19 Dec 2016 10:47:14 +0100
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     rkrcmar@...hat.com, rkagan@...tuozzo.com, dplotnikov@...tuozzo.com
Subject: [PATCH 2/6] KVM: lapic: do not set KVM_REQ_EVENT unnecessarily on EOI

On EOI, there is no need to set KVM_REQ_EVENT unconditionally.  The PPR
update is already setting it if resetting the ISR bit causes PPR to
decrease.  Even a level-triggered IOAPIC interrupt will set KVM_REQ_EVENT
on a reinjection (ioapic_service -> kvm_irq_delivery_to_apic and from
there to __apic_accept_irq).

Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
---
 arch/x86/kvm/lapic.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index e35cbd44c505..70c7428b7a57 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1066,7 +1066,6 @@ static int apic_set_eoi(struct kvm_lapic *apic)
 		kvm_hv_synic_send_eoi(apic->vcpu, vector);
 
 	kvm_ioapic_send_eoi(apic, vector);
-	kvm_make_request(KVM_REQ_EVENT, apic->vcpu);
 	return vector;
 }
 
@@ -1081,7 +1080,6 @@ void kvm_apic_set_eoi_accelerated(struct kvm_vcpu *vcpu, int vector)
 	trace_kvm_eoi(apic, vector);
 
 	kvm_ioapic_send_eoi(apic, vector);
-	kvm_make_request(KVM_REQ_EVENT, apic->vcpu);
 }
 EXPORT_SYMBOL_GPL(kvm_apic_set_eoi_accelerated);
 
-- 
1.8.3.1