Actually I don't, but however the idea of the patch was exactly what
you pointed out.
Thanks,
Vincenzo
2013/7/22 Paolo Bonzini <pbonz...@redhat.com>:
> Il 22/07/2013 16:18, Vincenzo Maffione ha scritto:
>> Actually our research group (at University of Pisa) is working on some
>> paravirtualization extensions of the e1000 NIC emulation that needs
>> KVM_IRQFD_FLAG_RESAMPLE support. This is one of the reasons why I'm
>> proposing this patch.
>>
>> Do you suggest modifying vfio_enable_intx_kvm() to take advantage of
>> the patch? I haven't addressed vfio only because I wasn't sure I am
>> "permitted" to do that.
>
> If you have a patch to do that, I guess it's welcome. :)
>
> Otherwise, this patch makes sense from the point of view of supporting
> the KVM API in a more complete manner.
>
> Paolo
>
>>
>>
>> Thanks,
>> Vincenzo
>>
>> 2013/7/22 Alex Williamson <alex.william...@redhat.com>:
>>>
>>> On Mon, 2013-07-22 at 12:43 +0200, Vincenzo Maffione wrote:
>>>> From e59e35380380c2986cd0164f11dcd8a07a8e4e59 Mon Sep 17 00:00:00 2001
>>>> From: Vincenzo Maffione <v.maffi...@gmail.com>
>>>> Date: Mon, 22 Jul 2013 11:51:33 +0200
>>>> Subject: [PATCH] kvm: add KVM_IRQFD_FLAG_RESAMPLE support
>>>>
>>>> Added an EventNotifier* parameter to
>>>> kvm-all.c:kvm_irqchip_add_irqfd_notifier(), in order to give KVM
>>>> another eventfd to be used as "resamplefd". See the documentation
>>>> in the linux kernel sources in Documentation/virtual/kvm/api.txt
>>>> (section 4.75) for more details.
>>>> When the added parameter is passed NULL, the behaviour of the
>>>> function is unchanged with respect to the previous versions.
>>>>
>>>> Signed-off-by: Vincenzo Maffione <v.maffi...@gmail.com>
>>>> ---
>>>> hw/misc/vfio.c | 4 ++--
>>>> hw/virtio/virtio-pci.c | 2 +-
>>>> include/sysemu/kvm.h | 3 ++-
>>>> kvm-all.c | 17 +++++++++++++----
>>>> 4 files changed, 18 insertions(+), 8 deletions(-)
>>>>
>>>> diff --git a/hw/misc/vfio.c b/hw/misc/vfio.c
>>>> index ad8ce77..54af34a 100644
>>>> --- a/hw/misc/vfio.c
>>>> +++ b/hw/misc/vfio.c
>>>> @@ -646,7 +646,7 @@ static int vfio_msix_vector_do_use(PCIDevice
>>>> *pdev, unsigned int nr,
>>>> vector->virq = msg ? kvm_irqchip_add_msi_route(kvm_state, *msg) : -1;
>>>> if (vector->virq < 0 ||
>>>> kvm_irqchip_add_irqfd_notifier(kvm_state, &vector->interrupt,
>>>> - vector->virq) < 0) {
>>>> + NULL, vector->virq) < 0) {
>>>> if (vector->virq >= 0) {
>>>> kvm_irqchip_release_virq(kvm_state, vector->virq);
>>>> vector->virq = -1;
>>>> @@ -814,7 +814,7 @@ retry:
>>>> vector->virq = kvm_irqchip_add_msi_route(kvm_state, msg);
>>>> if (vector->virq < 0 ||
>>>> kvm_irqchip_add_irqfd_notifier(kvm_state, &vector->interrupt,
>>>> - vector->virq) < 0) {
>>>> + NULL, vector->virq) < 0) {
>>>> qemu_set_fd_handler(event_notifier_get_fd(&vector->interrupt),
>>>> vfio_msi_interrupt, NULL, vector);
>>>> }
>>>
>>>
>>> Why doesn't this address the only current user of
>>> KVM_IRQFD_FLAG_RESAMPLE, vfio_enable_intx_kvm()? Thanks,
>>>
>>> Alex
>>>
>>>
>>>> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
>>>> index c38cfd1..c4db407 100644
>>>> --- a/hw/virtio/virtio-pci.c
>>>> +++ b/hw/virtio/virtio-pci.c
>>>> @@ -508,7 +508,7 @@ static int kvm_virtio_pci_irqfd_use(VirtIOPCIProxy
>>>> *proxy,
>>>> VirtQueue *vq = virtio_get_queue(proxy->vdev, queue_no);
>>>> EventNotifier *n = virtio_queue_get_guest_notifier(vq);
>>>> int ret;
>>>> - ret = kvm_irqchip_add_irqfd_notifier(kvm_state, n, irqfd->virq);
>>>> + ret = kvm_irqchip_add_irqfd_notifier(kvm_state, n, NULL, irqfd->virq);
>>>> return ret;
>>>> }
>>>>
>>>> diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
>>>> index 1e08a85..9e5d78e 100644
>>>> --- a/include/sysemu/kvm.h
>>>> +++ b/include/sysemu/kvm.h
>>>> @@ -309,7 +309,8 @@ int kvm_irqchip_add_msi_route(KVMState *s, MSIMessage
>>>> msg);
>>>> int kvm_irqchip_update_msi_route(KVMState *s, int virq, MSIMessage msg);
>>>> void kvm_irqchip_release_virq(KVMState *s, int virq);
>>>>
>>>> -int kvm_irqchip_add_irqfd_notifier(KVMState *s, EventNotifier *n, int
>>>> virq);
>>>> +int kvm_irqchip_add_irqfd_notifier(KVMState *s, EventNotifier *n,
>>>> + EventNotifier *rn, int virq);
>>>> int kvm_irqchip_remove_irqfd_notifier(KVMState *s, EventNotifier *n, int
>>>> virq);
>>>> void kvm_pc_gsi_handler(void *opaque, int n, int level);
>>>> void kvm_pc_setup_irq_routing(bool pci_enabled);
>>>> diff --git a/kvm-all.c b/kvm-all.c
>>>> index 232c39a..3f69b41 100644
>>>> --- a/kvm-all.c
>>>> +++ b/kvm-all.c
>>>> @@ -1230,7 +1230,8 @@ int kvm_irqchip_update_msi_route(KVMState *s,
>>>> int virq, MSIMessage msg)
>>>> return kvm_update_routing_entry(s, &kroute);
>>>> }
>>>>
>>>> -static int kvm_irqchip_assign_irqfd(KVMState *s, int fd, int virq, bool
>>>> assign)
>>>> +static int kvm_irqchip_assign_irqfd(KVMState *s, int fd, int rfd, int
>>>> virq,
>>>> + bool assign)
>>>> {
>>>> struct kvm_irqfd irqfd = {
>>>> .fd = fd,
>>>> @@ -1238,6 +1239,11 @@ static int kvm_irqchip_assign_irqfd(KVMState
>>>> *s, int fd, int virq, bool assign)
>>>> .flags = assign ? 0 : KVM_IRQFD_FLAG_DEASSIGN,
>>>> };
>>>>
>>>> + if (rfd != -1) {
>>>> + irqfd.flags |= KVM_IRQFD_FLAG_RESAMPLE;
>>>> + irqfd.resamplefd = rfd;
>>>> + }
>>>> +
>>>> if (!kvm_irqfds_enabled()) {
>>>> return -ENOSYS;
>>>> }
>>>> @@ -1276,14 +1282,17 @@ int kvm_irqchip_update_msi_route(KVMState *s,
>>>> int virq, MSIMessage msg)
>>>> }
>>>> #endif /* !KVM_CAP_IRQ_ROUTING */
>>>>
>>>> -int kvm_irqchip_add_irqfd_notifier(KVMState *s, EventNotifier *n, int
>>>> virq)
>>>> +int kvm_irqchip_add_irqfd_notifier(KVMState *s, EventNotifier *n,
>>>> + EventNotifier *rn, int virq)
>>>> {
>>>> - return kvm_irqchip_assign_irqfd(s, event_notifier_get_fd(n), virq,
>>>> true);
>>>> + return kvm_irqchip_assign_irqfd(s, event_notifier_get_fd(n),
>>>> + rn ? event_notifier_get_fd(rn) : -1, virq, true);
>>>> }
>>>>
>>>> int kvm_irqchip_remove_irqfd_notifier(KVMState *s, EventNotifier *n, int
>>>> virq)
>>>> {
>>>> - return kvm_irqchip_assign_irqfd(s, event_notifier_get_fd(n), virq,
>>>> false);
>>>> + return kvm_irqchip_assign_irqfd(s, event_notifier_get_fd(n), -1, virq,
>>>> + false);
>>>> }
>>>>
>>>> static int kvm_irqchip_create(KVMState *s)
>>>> --
>>>> 1.8.3.3
>>>
>>>
>>>
>>>
>>
>>
>>
>
--
Vincenzo Maffione
