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authorCornelia Huck <cornelia.huck@de.ibm.com>2013-02-28 12:33:20 +0100
committerMarcelo Tosatti <mtosatti@redhat.com>2013-03-05 19:12:17 -0300
commit2b83451b45d720ca38c03878ce42ff9139cad9e3 (patch)
tree374b4ab82ffc115dc8cb76f783f7735521b6c7bf
parent060f0ce6ff975decd1e0ee318c08e228bccbee1e (diff)
downloadlinux-2b83451b45d720ca38c03878ce42ff9139cad9e3.tar.gz
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 <cornelia.huck@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
-rw-r--r--Documentation/virtual/kvm/api.txt8
-rw-r--r--include/uapi/linux/kvm.h3
-rw-r--r--virt/kvm/eventfd.c17
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);