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| author | Sasha Levin <levinsasha928@gmail.com> | 2011-05-28 14:12:30 +0300 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2011-07-12 13:15:56 +0300 |
| commit | 55399a02e90fdc6cd45165b2df5dd97b7c3f018f (patch) | |
| tree | 6922e5531791206ac55996cdd4ce49417b0bc6bc /Documentation/virtual | |
| parent | 823e396558e509b7c3225cd76806f3d6643ff5f8 (diff) | |
| download | lwn-55399a02e90fdc6cd45165b2df5dd97b7c3f018f.tar.gz lwn-55399a02e90fdc6cd45165b2df5dd97b7c3f018f.zip | |
KVM: Document KVM_IOEVENTFD
Document KVM_IOEVENTFD that can be used to receive
notifications of PIO/MMIO events without triggering
an exit.
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'Documentation/virtual')
| -rw-r--r-- | 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 67cc0f5b9974..3755a390f886 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -1323,6 +1323,36 @@ struct kvm_lapic_state { Copies the input argument into the the Local APIC registers. The data format and layout are the same as documented in the architecture manual. +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 detaches 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 |