On 10/27/2009 06:41 PM, Chris Lalancette wrote:
This patch series aims to get kdump working inside a KVM guest.
The current problem with using kdump is that KVM always delivers
PIT interrupts to the BSP, and the BSP only. While this is
technically allowed by the MPS spec, most motherboards actually
deliver timer interrupts to *any* LAPIC in virtual wire mode.
Since a crash can occur on any CPU, timer interrupts must
be able to reach any CPU in order for kdump to work properly.
Therefore, this patch series kicks all of the relevant vCPUs
when delivering a timer interrupt. With these patches in
place, kdump in a RHEL-5 guest works properly.
This is pretty expensive on large guests. However I suppose under
normal conditions we won't be in virtual wire mode?
The kick from i8254 code is pretty bad, as you mention. I forget why it
is needed at all - shouldn't kvm_set_irq() end up kicking the correct
vcpu (and note the pic still insists on the bsp:)
/*
* callback when PIC0 irq status changed
*/
static void pic_irq_request(void *opaque, int level)
{
struct kvm *kvm = opaque;
struct kvm_vcpu *vcpu = kvm->bsp_vcpu;
struct kvm_pic *s = pic_irqchip(kvm);
int irq = pic_get_irq(&s->pics[0]);
s->output = level;
if (vcpu && level && (s->pics[0].isr_ack & (1 << irq))) {
s->pics[0].isr_ack &= ~(1 << irq);
kvm_vcpu_kick(vcpu);
}
}
--
error compiling committee.c: too many arguments to function
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