From 2b83451b45d720ca38c03878ce42ff9139cad9e3 Mon Sep 17 00:00:00 2001 From: Cornelia Huck Date: Thu, 28 Feb 2013 12:33:20 +0100 Subject: KVM: ioeventfd for virtio-ccw devices. Enhance KVM_IOEVENTFD with a new flag that allows to attach to virtio-ccw devices on s390 via the KVM_VIRTIO_CCW_NOTIFY_BUS. Signed-off-by: Cornelia Huck Signed-off-by: Marcelo Tosatti --- Documentation/virtual/kvm/api.txt | 8 ++++++++ include/uapi/linux/kvm.h | 3 +++ virt/kvm/eventfd.c | 17 +++++++++++++---- 3 files changed, 24 insertions(+), 4 deletions(-) diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 119358dfb74..c16b442556e 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -1486,15 +1486,23 @@ struct kvm_ioeventfd { __u8 pad[36]; }; +For the special case of virtio-ccw devices on s390, 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_VIRTIO_CCW_NOTIFY \ + (1 << kvm_ioeventfd_flag_nr_virtio_ccw_notify) 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 virtio-ccw 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 3c56ba3d80c..74d0ff3dfd6 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -449,12 +449,15 @@ enum { kvm_ioeventfd_flag_nr_datamatch, kvm_ioeventfd_flag_nr_pio, kvm_ioeventfd_flag_nr_deassign, + kvm_ioeventfd_flag_nr_virtio_ccw_notify, 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_VIRTIO_CCW_NOTIFY \ + (1 << kvm_ioeventfd_flag_nr_virtio_ccw_notify) #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 0b6fe69bb03..020522ed909 100644 --- a/virt/kvm/eventfd.c +++ b/virt/kvm/eventfd.c @@ -674,15 +674,24 @@ ioeventfd_check_collision(struct kvm *kvm, struct _ioeventfd *p) return false; } +static enum kvm_bus ioeventfd_bus_from_flags(__u32 flags) +{ + if (flags & KVM_IOEVENTFD_FLAG_PIO) + return KVM_PIO_BUS; + if (flags & KVM_IOEVENTFD_FLAG_VIRTIO_CCW_NOTIFY) + return KVM_VIRTIO_CCW_NOTIFY_BUS; + return KVM_MMIO_BUS; +} + 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; + enum kvm_bus bus_idx; struct _ioeventfd *p; struct eventfd_ctx *eventfd; int ret; + bus_idx = ioeventfd_bus_from_flags(args->flags); /* must be natural-word sized */ switch (args->len) { case 1: @@ -757,12 +766,12 @@ fail: 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; + enum kvm_bus bus_idx; struct _ioeventfd *p, *tmp; struct eventfd_ctx *eventfd; int ret = -ENOENT; + bus_idx = ioeventfd_bus_from_flags(args->flags); eventfd = eventfd_ctx_fdget(args->fd); if (IS_ERR(eventfd)) return PTR_ERR(eventfd); -- cgit v1.2.3