From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [RFC PATCH v2 3/4] KVM: ioeventfd for s390 css devices. Date: Sun, 24 Feb 2013 11:47:50 +0200 Message-ID: <20130224094750.GD25269@redhat.com> References: <1361534989-38884-1-git-send-email-cornelia.huck@de.ibm.com> <1361534989-38884-4-git-send-email-cornelia.huck@de.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: KVM , linux-s390 , qemu-devel To: Cornelia Huck Return-path: Received: from mx1.redhat.com ([209.132.183.28]:4046 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751172Ab3BXJrt (ORCPT ); Sun, 24 Feb 2013 04:47:49 -0500 Content-Disposition: inline In-Reply-To: <1361534989-38884-4-git-send-email-cornelia.huck@de.ibm.com> Sender: kvm-owner@vger.kernel.org List-ID: On Fri, Feb 22, 2013 at 01:09:48PM +0100, Cornelia Huck wrote: > Enhance KVM_IOEVENTFD with a new flag that allows to attach to s390 css > devices. > > Signed-off-by: Cornelia Huck > --- > Documentation/virtual/kvm/api.txt | 7 +++++++ > include/uapi/linux/kvm.h | 2 ++ > virt/kvm/eventfd.c | 8 ++++++-- > 3 files changed, 15 insertions(+), 2 deletions(-) > > diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt > index c2534c3..40e799c 100644 > --- a/Documentation/virtual/kvm/api.txt > +++ b/Documentation/virtual/kvm/api.txt > @@ -1468,15 +1468,22 @@ struct kvm_ioeventfd { > __u8 pad[36]; > }; > > +For the special case of s390 css devices, the ioevent is matched to a > +subchannel/virtqueue tuple instead. > + > The following flags are defined: > > #define KVM_IOEVENTFD_FLAG_DATAMATCH (1 << kvm_ioeventfd_flag_nr_datamatch) > #define KVM_IOEVENTFD_FLAG_PIO (1 << kvm_ioeventfd_flag_nr_pio) > #define KVM_IOEVENTFD_FLAG_DEASSIGN (1 << kvm_ioeventfd_flag_nr_deassign) > +#define KVM_IOEVENTFD_FLAG_CSS (1 << kvm_ioeventfd_flag_nr_css) > > If datamatch flag is set, the event will be signaled only if the written value > to the registered address is equal to datamatch in struct kvm_ioeventfd. > > +For css devices, addr contains the subchannel id and datamatch the virtqueue > +index. > + > > 4.60 KVM_DIRTY_TLB > > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > index 9a2db57..1df0766 100644 > --- a/include/uapi/linux/kvm.h > +++ b/include/uapi/linux/kvm.h > @@ -448,12 +448,14 @@ enum { > kvm_ioeventfd_flag_nr_datamatch, > kvm_ioeventfd_flag_nr_pio, > kvm_ioeventfd_flag_nr_deassign, > + kvm_ioeventfd_flag_nr_css, > kvm_ioeventfd_flag_nr_max, > }; > > #define KVM_IOEVENTFD_FLAG_DATAMATCH (1 << kvm_ioeventfd_flag_nr_datamatch) > #define KVM_IOEVENTFD_FLAG_PIO (1 << kvm_ioeventfd_flag_nr_pio) > #define KVM_IOEVENTFD_FLAG_DEASSIGN (1 << kvm_ioeventfd_flag_nr_deassign) > +#define KVM_IOEVENTFD_FLAG_CSS (1 << kvm_ioeventfd_flag_nr_css) So let's explicitly name is KVM_IOEVENTFD_S390_VIRTIO_CCW or even KVM_IOEVENTFD_S390_VIRTIO_CCW_NOTIFY? Also, maybe we want to add KVM_IOEVENTFD_S390_VIRTIO_NOTIFY as well? > > #define KVM_IOEVENTFD_VALID_FLAG_MASK ((1 << kvm_ioeventfd_flag_nr_max) - 1) > > diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c > index f0ced1a..7347652 100644 > --- a/virt/kvm/eventfd.c > +++ b/virt/kvm/eventfd.c > @@ -679,11 +679,13 @@ static int > kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args) > { > int pio = args->flags & KVM_IOEVENTFD_FLAG_PIO; > - enum kvm_bus bus_idx = pio ? KVM_PIO_BUS : KVM_MMIO_BUS; > + int css = args->flags & KVM_IOEVENTFD_FLAG_CSS; > + enum kvm_bus bus_idx; > struct _ioeventfd *p; > struct eventfd_ctx *eventfd; > int ret; > > + bus_idx = pio ? KVM_PIO_BUS : css ? KVM_CSS_BUS: KVM_MMIO_BUS; > /* must be natural-word sized */ > switch (args->len) { > case 1: > @@ -759,11 +761,13 @@ static int > kvm_deassign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args) > { > int pio = args->flags & KVM_IOEVENTFD_FLAG_PIO; > - enum kvm_bus bus_idx = pio ? KVM_PIO_BUS : KVM_MMIO_BUS; > + int css = args->flags & KVM_IOEVENTFD_FLAG_CSS; > + enum kvm_bus bus_idx; > struct _ioeventfd *p, *tmp; > struct eventfd_ctx *eventfd; > int ret = -ENOENT; > > + bus_idx = pio ? KVM_PIO_BUS : css ? KVM_CSS_BUS: KVM_MMIO_BUS; > eventfd = eventfd_ctx_fdget(args->fd); > if (IS_ERR(eventfd)) > return PTR_ERR(eventfd); > -- > 1.7.12.4