| Message ID | 20090424042756.1896.90317.stgit@dev.haskins.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Apr 24, 2009 at 12:30:17AM -0400, Gregory Haskins wrote: > +int kvm_irqfd(kvm_context_t kvm, int gsi) > +{ > + int fd, r; > + > + if (!kvm_check_extension(kvm, KVM_CAP_IRQFD)) > + return -ENOENT; > + > + fd = eventfd(0, 0); > + if (fd < 0) > + return fd; > + > + r = assign_irqfd(kvm, fd, gsi); > + if (r < 0) > + return r; Do we need to close fd on error? > + > + return fd; > +} -- 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
Michael S. Tsirkin wrote: > On Fri, Apr 24, 2009 at 12:30:17AM -0400, Gregory Haskins wrote: > >> +int kvm_irqfd(kvm_context_t kvm, int gsi) >> +{ >> + int fd, r; >> + >> + if (!kvm_check_extension(kvm, KVM_CAP_IRQFD)) >> + return -ENOENT; >> + >> + fd = eventfd(0, 0); >> + if (fd < 0) >> + return fd; >> + >> + r = assign_irqfd(kvm, fd, gsi); >> + if (r < 0) >> + return r; >> > > Do we need to close fd on error? > Good catch. This will be changing in v3 to do the allocation in kernel, but I will be sure to properly cleanup this type of leak, however that ends up looking. Thanks Michael. -Greg > >> + >> + return fd; >> +} >>
diff --git a/libkvm/libkvm.c b/libkvm/libkvm.c index 0610e3f..8c994a3 100644 --- a/libkvm/libkvm.c +++ b/libkvm/libkvm.c @@ -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 +1441,35 @@ 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, r; + + if (!kvm_check_extension(kvm, KVM_CAP_IRQFD)) + return -ENOENT; + + fd = eventfd(0, 0); + if (fd < 0) + return fd; + + r = assign_irqfd(kvm, fd, gsi); + if (r < 0) + return r; + + return fd; +} diff --git a/libkvm/libkvm.h b/libkvm/libkvm.h index ce6f054..404c028 100644 --- a/libkvm/libkvm.h +++ b/libkvm/libkvm.h @@ -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/2009/4/24/6 This is v2. Changes since v1: *) bug-fix to prevent returning "0" for success on allocation --------------------- 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 | 33 +++++++++++++++++++++++++++++++++ libkvm/libkvm.h | 13 +++++++++++++ 2 files changed, 46 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