| Message ID | 20090602154233.30489.81627.stgit@dev.haskins.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Gregory Haskins wrote: > irqfd lets you create an eventfd based file-desriptor to inject interrupts > to a kvm guest. We associate one gsi per fd for fine-grained routing. > > [note: this is meant to work in conjunction with the POLLHUP version of > irqfd, which has not yet been accepted into kvm.git] > > [ Changelog: > > v8: > *) removed deassign() verb in favor of POLLHUP support on close() > *) only include sys/eventfd.h if CAP_IRQFD is defined to properly > support older kernels > *) s/ENOENT/ENOSYS > ] > Hmm..it would appear I already released a 'v8' in the past. :( In any case, this is the latest version to consider -Greg > Signed-off-by: Gregory Haskins <ghaskins@novell.com> > --- > > kvm/libkvm/libkvm.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ > kvm/libkvm/libkvm.h | 14 ++++++++++++++ > 2 files changed, 63 insertions(+), 0 deletions(-) > > diff --git a/kvm/libkvm/libkvm.c b/kvm/libkvm/libkvm.c > index ba0a5d1..10cb2ac 100644 > --- a/kvm/libkvm/libkvm.c > +++ b/kvm/libkvm/libkvm.c > @@ -1444,3 +1444,52 @@ int kvm_assign_set_msix_entry(kvm_context_t kvm, > return ret; > } > #endif > + > +#ifdef KVM_CAP_IRQFD > + > +#include <sys/eventfd.h> > + > +static int _kvm_irqfd(kvm_context_t kvm, int fd, int gsi, int flags) > +{ > + int r; > + struct kvm_irqfd data = { > + .fd = fd, > + .gsi = gsi, > + .flags = flags, > + }; > + > + r = ioctl(kvm->vm_fd, KVM_IRQFD, &data); > + if (r == -1) > + r = -errno; > + return r; > +} > + > +int kvm_irqfd(kvm_context_t kvm, int gsi, int flags) > +{ > + int r; > + int fd; > + > + if (!kvm_check_extension(kvm, KVM_CAP_IRQFD)) > + return -ENOENT; > + > + fd = eventfd(0, 0); > + if (fd < 0) > + return -errno; > + > + r = _kvm_irqfd(kvm, fd, gsi, 0); > + if (r < 0) { > + close(fd); > + return -errno; > + } > + > + return fd; > +} > + > +#else /* KVM_CAP_IRQFD */ > + > +int kvm_irqfd(kvm_context_t kvm, int gsi, int flags) > +{ > + return -ENOSYS; > +} > + > +#endif /* KVM_CAP_IRQFD */ > diff --git a/kvm/libkvm/libkvm.h b/kvm/libkvm/libkvm.h > index 4821a1e..aca8ed6 100644 > --- a/kvm/libkvm/libkvm.h > +++ b/kvm/libkvm/libkvm.h > @@ -856,6 +856,20 @@ 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 > + * \param flags reserved, must be zero > + */ > +int kvm_irqfd(kvm_context_t kvm, int gsi, int flags); > + > #ifdef KVM_CAP_DEVICE_MSIX > int kvm_assign_set_msix_nr(kvm_context_t kvm, > struct kvm_assigned_msix_nr *msix_nr); > > -- > 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 >
Gregory Haskins wrote: > irqfd lets you create an eventfd based file-desriptor to inject interrupts > to a kvm guest. We associate one gsi per fd for fine-grained routing. > > [note: this is meant to work in conjunction with the POLLHUP version of > irqfd, which has not yet been accepted into kvm.git] > Applied with two changes: added a dependency on CONFIG_eventfd (with the kvm external module, you can have irqfd support without eventfd support), and adjusted for the new libkvm location (libkvm-all.[ch]).
diff --git a/kvm/libkvm/libkvm.c b/kvm/libkvm/libkvm.c index ba0a5d1..10cb2ac 100644 --- a/kvm/libkvm/libkvm.c +++ b/kvm/libkvm/libkvm.c @@ -1444,3 +1444,52 @@ int kvm_assign_set_msix_entry(kvm_context_t kvm, return ret; } #endif + +#ifdef KVM_CAP_IRQFD + +#include <sys/eventfd.h> + +static int _kvm_irqfd(kvm_context_t kvm, int fd, int gsi, int flags) +{ + int r; + struct kvm_irqfd data = { + .fd = fd, + .gsi = gsi, + .flags = flags, + }; + + r = ioctl(kvm->vm_fd, KVM_IRQFD, &data); + if (r == -1) + r = -errno; + return r; +} + +int kvm_irqfd(kvm_context_t kvm, int gsi, int flags) +{ + int r; + int fd; + + if (!kvm_check_extension(kvm, KVM_CAP_IRQFD)) + return -ENOENT; + + fd = eventfd(0, 0); + if (fd < 0) + return -errno; + + r = _kvm_irqfd(kvm, fd, gsi, 0); + if (r < 0) { + close(fd); + return -errno; + } + + return fd; +} + +#else /* KVM_CAP_IRQFD */ + +int kvm_irqfd(kvm_context_t kvm, int gsi, int flags) +{ + return -ENOSYS; +} + +#endif /* KVM_CAP_IRQFD */ diff --git a/kvm/libkvm/libkvm.h b/kvm/libkvm/libkvm.h index 4821a1e..aca8ed6 100644 --- a/kvm/libkvm/libkvm.h +++ b/kvm/libkvm/libkvm.h @@ -856,6 +856,20 @@ 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 + * \param flags reserved, must be zero + */ +int kvm_irqfd(kvm_context_t kvm, int gsi, int flags); + #ifdef KVM_CAP_DEVICE_MSIX int kvm_assign_set_msix_nr(kvm_context_t kvm, struct kvm_assigned_msix_nr *msix_nr);
irqfd lets you create an eventfd based file-desriptor to inject interrupts to a kvm guest. We associate one gsi per fd for fine-grained routing. [note: this is meant to work in conjunction with the POLLHUP version of irqfd, which has not yet been accepted into kvm.git] [ Changelog: v8: *) removed deassign() verb in favor of POLLHUP support on close() *) only include sys/eventfd.h if CAP_IRQFD is defined to properly support older kernels *) s/ENOENT/ENOSYS ] Signed-off-by: Gregory Haskins <ghaskins@novell.com> --- kvm/libkvm/libkvm.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ kvm/libkvm/libkvm.h | 14 ++++++++++++++ 2 files changed, 63 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