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| author | Otavio Salvador <otavio@ossystems.com.br> | 2020-05-20 08:43:03 -0300 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2020-05-20 08:43:03 -0300 |
| commit | 1279cd128bba968ebe0a2df7f7ae38bae90250ef (patch) | |
| tree | df6b1a190760f51465122ca4c13492d5ac5984c6 /Documentation/virtual/kvm/api.txt | |
| parent | 0a8ab17689e628c84a666195bfc6ab85d11cf057 (diff) | |
| parent | 2ae782ca839e0ee07de37122ddea362adff2e975 (diff) | |
Merge pull request #76 from toradex/4.9-2.3.x-imx
4.9 2.3.x imx
Diffstat (limited to 'Documentation/virtual/kvm/api.txt')
| -rw-r--r-- | Documentation/virtual/kvm/api.txt | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 3ff58a8ffabb..d1908e50b506 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -13,7 +13,7 @@ of a virtual machine. The ioctls belong to three classes - VM ioctls: These query and set attributes that affect an entire virtual machine, for example memory layout. In addition a VM ioctl is used to - create virtual cpus (vcpus). + create virtual cpus (vcpus) and devices. Only run VM ioctls from the same process (address space) that was used to create the VM. @@ -24,6 +24,11 @@ of a virtual machine. The ioctls belong to three classes Only run vcpu ioctls from the same thread that was used to create the vcpu. + - device ioctls: These query and set attributes that control the operation + of a single device. + + device ioctls must be issued from the same process (address space) that + was used to create the VM. 2. File descriptors ------------------- @@ -32,10 +37,11 @@ The kvm API is centered around file descriptors. An initial open("/dev/kvm") obtains a handle to the kvm subsystem; this handle can be used to issue system ioctls. A KVM_CREATE_VM ioctl on this handle will create a VM file descriptor which can be used to issue VM -ioctls. A KVM_CREATE_VCPU ioctl on a VM fd will create a virtual cpu -and return a file descriptor pointing to it. Finally, ioctls on a vcpu -fd can be used to control the vcpu, including the important task of -actually running guest code. +ioctls. A KVM_CREATE_VCPU or KVM_CREATE_DEVICE ioctl on a VM fd will +create a virtual cpu or device and return a file descriptor pointing to +the new resource. Finally, ioctls on a vcpu or device fd can be used +to control the vcpu or device. For vcpus, this includes the important +task of actually running guest code. In general file descriptors can be migrated among processes by means of fork() and the SCM_RIGHTS facility of unix domain socket. These |