An iosignalfd allows an eventfd to attach to a specific PIO/MMIO region in the guest. Any guest-writes to that region will trigger an eventfd signal.
For more details, see the kernel side patches submitted here: http://lkml.org/lkml/2009/5/15/303 Signed-off-by: Gregory Haskins <ghask...@novell.com> --- kvm/libkvm/libkvm.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++ kvm/libkvm/libkvm.h | 39 +++++++++++++++++++++++++++++ 2 files changed, 107 insertions(+), 0 deletions(-) diff --git a/kvm/libkvm/libkvm.c b/kvm/libkvm/libkvm.c index ccab985..dc3414f 100644 --- a/kvm/libkvm/libkvm.c +++ b/kvm/libkvm/libkvm.c @@ -1501,3 +1501,71 @@ int kvm_destroy_irqfd(kvm_context_t kvm, int fd, int gsi, int flags) } #endif /* KVM_CAP_IRQFD */ + +#ifdef KVM_CAP_IOSIGNALFD + +int kvm_assign_iosignalfd(kvm_context_t kvm, unsigned long cookie, + unsigned long addr, size_t len, + int fd, int flags) +{ + int r; + int type = flags & IOSIGNALFD_FLAG_PIO; + struct kvm_iosignalfd data = { + .cookie = cookie, + .addr = addr, + .len = len, + .fd = fd, + .flags = type ? KVM_IOSIGNALFD_FLAG_PIO : 0, + }; + + if (!kvm_check_extension(kvm, KVM_CAP_IOSIGNALFD)) + return -ENOENT; + + r = ioctl(kvm->vm_fd, KVM_IOSIGNALFD, &data); + if (r == -1) + r = -errno; + return r; +} + +int kvm_deassign_iosignalfd(kvm_context_t kvm, unsigned long cookie, + unsigned long addr, int flags) +{ + int r; + int type = flags & IOSIGNALFD_FLAG_PIO; + int cvalid = flags & IOSIGNALFD_FLAG_COOKIE; + struct kvm_iosignalfd data = { + .cookie = cookie, + .addr = addr, + .flags = KVM_IOSIGNALFD_FLAG_DEASSIGN | + (type ? KVM_IOSIGNALFD_FLAG_PIO : 0) | + (cvalid ? KVM_IOSIGNALFD_FLAG_COOKIE : 0), + }; + + if (!kvm_check_extension(kvm, KVM_CAP_IOSIGNALFD)) + return -ENOENT; + + r = ioctl(kvm->vm_fd, KVM_IOSIGNALFD, &data); + if (r == -1) + r = -errno; + return r; +} + +#else /* KVM_CAP_IOSIGNALFD */ + +int kvm_assign_iosignalfd(kvm_context_t kvm, unsigned long cookie, + unsigned long addr, size_t len, + int fd, int flags) +{ + return -ENOENT; +} + +int kvm_deassign_iosignalfd(kvm_context_t kvm, unsigned long cookie, + unsigned long addr, int flags) +{ + return -ENOENT; +} + +#endif /* KVM_CAP_IOSIGNALFD */ + + + diff --git a/kvm/libkvm/libkvm.h b/kvm/libkvm/libkvm.h index 3ccbe3d..ea81e55 100644 --- a/kvm/libkvm/libkvm.h +++ b/kvm/libkvm/libkvm.h @@ -882,6 +882,45 @@ int kvm_create_irqfd(kvm_context_t kvm, int gsi, int flags); */ int kvm_destroy_irqfd(kvm_context_t kvm, int fd, int gsi, int flags); +enum { + iosignalfd_option_pio, + iosignalfd_option_cookie, +}; + +#define IOSIGNALFD_FLAG_PIO (1 << iosignalfd_option_pio) +#define IOSIGNALFD_FLAG_COOKIE (1 << iosignalfd_option_cookie) + +/*! + * \brief Assign an eventfd to an IO port (PIO or MMIO) + * + * Assigns an eventfd based file-descriptor to a specific PIO or MMIO + * address range. Any guest writes to the specified range will generate + * an eventfd signal. + * + * \param kvm Pointer to the current kvm_context + * \param cookie A user-assigned cookie for optional use in deassign + * \param addr The IO address + * \param len The length of the IO region at the address + * \param fd The eventfd file-descriptor + * \param flags FLAG_PIO: PIO, else MMIO + */ +int kvm_assign_iosignalfd(kvm_context_t kvm, unsigned long cookie, + unsigned long addr, size_t len, + int fd, int flags); + +/*! + * \brief Deassign an iosignalfd from a previously registered IO port + * + * Deassigns an iosignalfd previously registered with kvm_assign_iosignalfd() + * + * \param kvm Pointer to the current kvm_context + * \param cookie The cookie to (optionally) match (must specifcy FLAG_COOKIE) + * \param addr The IO address to deassign + * \param flags FLAG_PIO: PIO, else MMIO, FLAG_COOKIE: cookie is valid + */ +int kvm_deassign_iosignalfd(kvm_context_t kvm, unsigned long cookie, + unsigned long addr, 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 majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
