We have kvm_arch_vcpu_should_kick() to decide whether the target cpu
needs to be kicked. The previous condition was wrong, because
architectures that don't use vcpu->mode would not get interrupts and
also suboptimal, because it sent IPI in cases where none was necessary.
The situation is even more convoluted. MIPS and POWERPC return 1 from
kvm_arch_vcpu_should_kick(), but implement vcpu->mode for some reason,
so now they might kick uselessly. This is not a huge problem.
s390, on the other hand, never changed vcpu->mode, so it would always be
OUTSIDE_GUEST_MODE before and therefore didn't send IPIs.
I don't see a reason why s390 had kvm_make_all_cpus_request() that did
nothing but set the bit in vcpu->request, so the new behavior seems
better.
Signed-off-by: Radim Krčmář <rkrcmar@xxxxxxxxxx>
---
arch/s390/kvm/kvm-s390.c | 4 +---
virt/kvm/kvm_main.c | 2 +-
2 files changed, 2 insertions(+), 4 deletions(-)
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index fd6cd05bb6a7..45b6d9ca5d24 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -2130,9 +2130,7 @@ static void kvm_gmap_notifier(struct gmap *gmap, unsigned long start,
int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
{
- /* kvm common code refers to this, but never calls it */
- BUG();
- return 0;
+ return 1;
}
static int kvm_arch_vcpu_ioctl_get_one_reg(struct kvm_vcpu *vcpu,
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index f489167839c4..2389e9c41cd2 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -187,7 +187,7 @@ bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req)
smp_mb__after_atomic();
if (cpus != NULL && cpu != -1 && cpu != me &&
- kvm_vcpu_exiting_guest_mode(vcpu) != OUTSIDE_GUEST_MODE)
+ kvm_arch_vcpu_should_kick(vcpu))
cpumask_set_cpu(cpu, cpus);
}
if (unlikely(cpus == NULL))
--
2.12.0
