Document KVM_IOEVENTFD that can be used to receive notifications of PIO/MMIO events without triggering an exit.
Cc: Avi Kivity <[email protected]> Cc: Marcelo Tosatti <[email protected]> Signed-off-by: Sasha Levin <[email protected]> --- Documentation/virtual/kvm/api.txt | 30 ++++++++++++++++++++++++++++++ 1 files changed, 30 insertions(+), 0 deletions(-) diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 42542eb..80c5fcd 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -1291,6 +1291,36 @@ Returns the tsc frequency of the guest. The unit of the return value is KHz. If the host has unstable tsc this ioctl returns -EIO instead as an error. +4.56 KVM_IOEVENTFD + +Capability: KVM_CAP_IOEVENTFD +Architectures: all +Type: vm ioctl +Parameters: struct kvm_ioeventfd (in) +Returns: 0 on success, !0 on error + +This ioctl attaches or deattaches an ioeventfd to a legal pio/mmio address +within the guest. A guest write in the registered address will signal the +provided event instead of triggering an exit. + +struct kvm_ioeventfd { + __u64 datamatch; + __u64 addr; /* legal pio/mmio address */ + __u32 len; /* 1, 2, 4, or 8 bytes */ + __s32 fd; + __u32 flags; + __u8 pad[36]; +}; + +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) + +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. + 5. The kvm_run structure Application code obtains a pointer to the kvm_run structure by -- 1.7.5.rc3 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
