iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

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

Browse Source 
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: James Sullivan <sullivan.james.f@gmail.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
James Sullivan 2015-03-18 19:26:04 -06:00 committed by Paolo Bonzini
parent 93bbf0b8bc
commit d1ebdbf99a
3 changed files with 11 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
arch/x86/kvm/irq_comm.c
View File

@ -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);

2
arch/x86/kvm/lapic.c
View File

@ -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])

6
arch/x86/kvm/lapic.h
View File

@ -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);