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Commit d1ebdbf9 authored by James Sullivan's avatar James Sullivan Committed by Paolo Bonzini
Browse files

kvm: x86: Deliver MSI IRQ to only lowest prio cpu if msi_redir_hint is true 



An MSI interrupt should only be delivered to the lowest priority CPU
when it has RH=1, regardless of the delivery mode. Modified
kvm_is_dm_lowest_prio() to check for either irq->delivery_mode == APIC_DM_LOWPRI
or irq->msi_redir_hint.

Moved kvm_is_dm_lowest_prio() into lapic.h and renamed to
kvm_lowest_prio_delivery().

Changed a check in kvm_irq_delivery_to_apic_fast() from
irq->delivery_mode == APIC_DM_LOWPRI to kvm_is_dm_lowest_prio().

Signed-off-by: default avatarJames Sullivan <sullivan.james.f@gmail.com>
Reviewed-by: default avatarRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 93bbf0b8

arch/x86/kvm/irq_comm.c

+4 −7
Original line number Diff line number Diff line
@@ -31,6 +31,8 @@ 


#include "ioapic.h"



#include "lapic.h"



static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,

			   struct kvm *kvm, int irq_source_id, int level,

			   bool line_status)
@@ -48,11 +50,6 @@ static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e, 
				line_status);

}



inline static bool kvm_is_dm_lowest_prio(struct kvm_lapic_irq *irq)

{

	return irq->delivery_mode == APIC_DM_LOWEST;

}



int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,

		struct kvm_lapic_irq *irq, unsigned long *dest_map)

{
@@ -60,7 +57,7 @@ int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src, 
	struct kvm_vcpu *vcpu, *lowest = NULL;



	if (irq->dest_mode == 0 && irq->dest_id == 0xff &&

			kvm_is_dm_lowest_prio(irq)) {

			kvm_lowest_prio_delivery(irq)) {

		printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");

		irq->delivery_mode = APIC_DM_FIXED;

	}
@@ -76,7 +73,7 @@ int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src, 
					irq->dest_id, irq->dest_mode))

			continue;



		if (!kvm_is_dm_lowest_prio(irq)) {

		if (!kvm_lowest_prio_delivery(irq)) {

			if (r < 0)

				r = 0;

			r += kvm_apic_set_irq(vcpu, irq, dest_map);

arch/x86/kvm/lapic.c

+1 −1
Original line number Diff line number Diff line
@@ -728,7 +728,7 @@ bool kvm_irq_delivery_to_apic_fast(struct kvm *kvm, struct kvm_lapic *src, 


		dst = map->logical_map[cid];



		if (irq->delivery_mode == APIC_DM_LOWEST) {

		if (kvm_lowest_prio_delivery(irq)) {

			int l = -1;

			for_each_set_bit(i, &bitmap, 16) {

				if (!dst[i])

arch/x86/kvm/lapic.h

+6 −0
Original line number Diff line number Diff line
@@ -153,6 +153,12 @@ static inline bool kvm_apic_has_events(struct kvm_vcpu *vcpu) 
	return vcpu->arch.apic->pending_events;

}



static inline bool kvm_lowest_prio_delivery(struct kvm_lapic_irq *irq)

{

	return (irq->delivery_mode == APIC_DM_LOWEST ||

			irq->msi_redir_hint);

}



bool kvm_apic_pending_eoi(struct kvm_vcpu *vcpu, int vector);



void wait_lapic_expire(struct kvm_vcpu *vcpu);