linux/arch/x86/kvm/irq.c
Andrey Smetanin d62caabb41 kvm/x86: per-vcpu apicv deactivation support
The decision on whether to use hardware APIC virtualization used to be
taken globally, based on the availability of the feature in the CPU
and the value of a module parameter.

However, under certain circumstances we want to control it on per-vcpu
basis.  In particular, when the userspace activates HyperV synthetic
interrupt controller (SynIC), APICv has to be disabled as it's
incompatible with SynIC auto-EOI behavior.

To achieve that, introduce 'apicv_active' flag on struct
kvm_vcpu_arch, and kvm_vcpu_deactivate_apicv() function to turn APICv
off.  The flag is initialized based on the module parameter and CPU
capability, and consulted whenever an APICv-specific action is
performed.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-25 17:24:21 +01:00

150 lines
3.4 KiB
C

/*
* irq.c: API for in kernel interrupt controller
* Copyright (c) 2007, Intel Corporation.
* Copyright 2009 Red Hat, Inc. and/or its affiliates.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
* Place - Suite 330, Boston, MA 02111-1307 USA.
* Authors:
* Yaozu (Eddie) Dong <Eddie.dong@intel.com>
*
*/
#include <linux/module.h>
#include <linux/kvm_host.h>
#include "irq.h"
#include "i8254.h"
#include "x86.h"
/*
* check if there are pending timer events
* to be processed.
*/
int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
{
return apic_has_pending_timer(vcpu);
}
EXPORT_SYMBOL(kvm_cpu_has_pending_timer);
/*
* check if there is a pending userspace external interrupt
*/
static int pending_userspace_extint(struct kvm_vcpu *v)
{
return v->arch.pending_external_vector != -1;
}
/*
* check if there is pending interrupt from
* non-APIC source without intack.
*/
static int kvm_cpu_has_extint(struct kvm_vcpu *v)
{
u8 accept = kvm_apic_accept_pic_intr(v);
if (accept) {
if (irqchip_split(v->kvm))
return pending_userspace_extint(v);
else
return pic_irqchip(v->kvm)->output;
} else
return 0;
}
/*
* check if there is injectable interrupt:
* when virtual interrupt delivery enabled,
* interrupt from apic will handled by hardware,
* we don't need to check it here.
*/
int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v)
{
if (!lapic_in_kernel(v))
return v->arch.interrupt.pending;
if (kvm_cpu_has_extint(v))
return 1;
if (kvm_vcpu_apicv_active(v))
return 0;
return kvm_apic_has_interrupt(v) != -1; /* LAPIC */
}
/*
* check if there is pending interrupt without
* intack.
*/
int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
{
if (!lapic_in_kernel(v))
return v->arch.interrupt.pending;
if (kvm_cpu_has_extint(v))
return 1;
return kvm_apic_has_interrupt(v) != -1; /* LAPIC */
}
EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt);
/*
* Read pending interrupt(from non-APIC source)
* vector and intack.
*/
static int kvm_cpu_get_extint(struct kvm_vcpu *v)
{
if (kvm_cpu_has_extint(v)) {
if (irqchip_split(v->kvm)) {
int vector = v->arch.pending_external_vector;
v->arch.pending_external_vector = -1;
return vector;
} else
return kvm_pic_read_irq(v->kvm); /* PIC */
} else
return -1;
}
/*
* Read pending interrupt vector and intack.
*/
int kvm_cpu_get_interrupt(struct kvm_vcpu *v)
{
int vector;
if (!lapic_in_kernel(v))
return v->arch.interrupt.nr;
vector = kvm_cpu_get_extint(v);
if (vector != -1)
return vector; /* PIC */
return kvm_get_apic_interrupt(v); /* APIC */
}
EXPORT_SYMBOL_GPL(kvm_cpu_get_interrupt);
void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu)
{
kvm_inject_apic_timer_irqs(vcpu);
/* TODO: PIT, RTC etc. */
}
EXPORT_SYMBOL_GPL(kvm_inject_pending_timer_irqs);
void __kvm_migrate_timers(struct kvm_vcpu *vcpu)
{
__kvm_migrate_apic_timer(vcpu);
__kvm_migrate_pit_timer(vcpu);
}