linux_dsm_epyc7002/virt/kvm/arm/vgic/vgic-irqfd.c
Shanker Donthineni 0bdbf3b071 KVM: arm/arm64: vgic: Stop injecting the MSI occurrence twice
The IRQFD framework calls the architecture dependent function
twice if the corresponding GSI type is edge triggered. For ARM,
the function kvm_set_msi() is getting called twice whenever the
IRQFD receives the event signal. The rest of the code path is
trying to inject the MSI without any validation checks. No need
to call the function vgic_its_inject_msi() second time to avoid
an unnecessary overhead in IRQ queue logic. It also avoids the
possibility of VM seeing the MSI twice.

Simple fix, return -1 if the argument 'level' value is zero.

Cc: stable@vger.kernel.org
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-02-08 15:13:14 +00:00

130 lines
3.3 KiB
C

/*
* Copyright (C) 2015, 2016 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that 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, see <http://www.gnu.org/licenses/>.
*/
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <trace/events/kvm.h>
#include <kvm/arm_vgic.h>
#include "vgic.h"
/**
* vgic_irqfd_set_irq: inject the IRQ corresponding to the
* irqchip routing entry
*
* This is the entry point for irqfd IRQ injection
*/
static int vgic_irqfd_set_irq(struct kvm_kernel_irq_routing_entry *e,
struct kvm *kvm, int irq_source_id,
int level, bool line_status)
{
unsigned int spi_id = e->irqchip.pin + VGIC_NR_PRIVATE_IRQS;
if (!vgic_valid_spi(kvm, spi_id))
return -EINVAL;
return kvm_vgic_inject_irq(kvm, 0, spi_id, level);
}
/**
* kvm_set_routing_entry: populate a kvm routing entry
* from a user routing entry
*
* @kvm: the VM this entry is applied to
* @e: kvm kernel routing entry handle
* @ue: user api routing entry handle
* return 0 on success, -EINVAL on errors.
*/
int kvm_set_routing_entry(struct kvm *kvm,
struct kvm_kernel_irq_routing_entry *e,
const struct kvm_irq_routing_entry *ue)
{
int r = -EINVAL;
switch (ue->type) {
case KVM_IRQ_ROUTING_IRQCHIP:
e->set = vgic_irqfd_set_irq;
e->irqchip.irqchip = ue->u.irqchip.irqchip;
e->irqchip.pin = ue->u.irqchip.pin;
if ((e->irqchip.pin >= KVM_IRQCHIP_NUM_PINS) ||
(e->irqchip.irqchip >= KVM_NR_IRQCHIPS))
goto out;
break;
case KVM_IRQ_ROUTING_MSI:
e->set = kvm_set_msi;
e->msi.address_lo = ue->u.msi.address_lo;
e->msi.address_hi = ue->u.msi.address_hi;
e->msi.data = ue->u.msi.data;
e->msi.flags = ue->flags;
e->msi.devid = ue->u.msi.devid;
break;
default:
goto out;
}
r = 0;
out:
return r;
}
/**
* kvm_set_msi: inject the MSI corresponding to the
* MSI routing entry
*
* This is the entry point for irqfd MSI injection
* and userspace MSI injection.
*/
int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
struct kvm *kvm, int irq_source_id,
int level, bool line_status)
{
struct kvm_msi msi;
msi.address_lo = e->msi.address_lo;
msi.address_hi = e->msi.address_hi;
msi.data = e->msi.data;
msi.flags = e->msi.flags;
msi.devid = e->msi.devid;
if (!vgic_has_its(kvm))
return -ENODEV;
if (!level)
return -1;
return vgic_its_inject_msi(kvm, &msi);
}
int kvm_vgic_setup_default_irq_routing(struct kvm *kvm)
{
struct kvm_irq_routing_entry *entries;
struct vgic_dist *dist = &kvm->arch.vgic;
u32 nr = dist->nr_spis;
int i, ret;
entries = kcalloc(nr, sizeof(struct kvm_kernel_irq_routing_entry),
GFP_KERNEL);
if (!entries)
return -ENOMEM;
for (i = 0; i < nr; i++) {
entries[i].gsi = i;
entries[i].type = KVM_IRQ_ROUTING_IRQCHIP;
entries[i].u.irqchip.irqchip = 0;
entries[i].u.irqchip.pin = i;
}
ret = kvm_set_irq_routing(kvm, entries, nr, 0);
kfree(entries);
return ret;
}