@@ -35,6 +35,7 @@
#include <errno.h>
#include <sys/ioctl.h>
#include <inttypes.h>
+#include <sys/eventfd.h>
#include "libkvm.h"
#if defined(__x86_64__) || defined(__i386__)
@@ -1440,3 +1441,31 @@ int kvm_assign_set_msix_entry(kvm_context_t kvm,
return ret;
}
#endif
+
+static int assign_irqfd(kvm_context_t kvm, int fd, int gsi)
+{
+ int r;
+ struct kvm_irqfd data = {
+ .fd = fd,
+ .gsi = gsi,
+ };
+
+ r = ioctl(kvm->vm_fd, KVM_ASSIGN_IRQFD, &data);
+ if (r == -1)
+ r = -errno;
+ return r;
+}
+
+int kvm_irqfd(kvm_context_t kvm, int gsi)
+{
+ int fd;
+
+ if (!kvm_check_extension(kvm, KVM_CAP_IRQFD))
+ return -ENOENT;
+
+ fd = eventfd(0, 0);
+ if (fd < 0)
+ return fd;
+
+ return assign_irqfd(kvm, fd, gsi);
+}
@@ -856,6 +856,19 @@ int kvm_commit_irq_routes(kvm_context_t kvm);
*/
int kvm_get_irq_route_gsi(kvm_context_t kvm);
+/*!
+ * \brief Create a file descriptor for injecting interrupts
+ *
+ * Creates an eventfd based file-descriptor that maps to a specific GSI
+ * in the guest. eventfd compliant signaling (write() from userspace, or
+ * eventfd_signal() from kernelspace) will cause the GSI to inject
+ * itself into the guest at the next available window.
+ *
+ * \param kvm Pointer to the current kvm_context
+ * \param gsi GSI to assign to this fd
+ */
+int kvm_irqfd(kvm_context_t kvm, int gsi);
+
#ifdef KVM_CAP_DEVICE_MSIX
int kvm_assign_set_msix_nr(kvm_context_t kvm,
struct kvm_assigned_msix_nr *msix_nr);
(applies to kvm-userspace.git 84474e4f39) This adds userspace support for the irqfd mechanism in the kernel, published here: http://lkml.org/lkml/2009/4/23/328 There are no current users, though the future virtual-bus v4 has plans to adopt it. Signed-off-by: Gregory Haskins <ghaskins@novell.com> --- libkvm/libkvm.c | 29 +++++++++++++++++++++++++++++ libkvm/libkvm.h | 13 +++++++++++++ 2 files changed, 42 insertions(+), 0 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html