docs/devel/multi-process.rst

103 once the QEMU vhost user code has configured the vhost user application,
104 mission-mode IO is performed by the application. The vhost user
105 application is a daemon process that can be contacted via a known UNIX
112 QEMU is to contact the vhost application and send it configuration
114 process, the application can also be sent other file descriptors over
115 the socket, which then can be used by the vhost user application in
132 socket to the vhost application. This path is accelerated by the QEMU
134 application can directly receive MMIO store notifications from the KVM
140 Another optimization used by the vhost application is the ability to
146 application program.
151 The vhost application is also allowed to directly access guest memory,
153 done with file descriptors sent to the vhost user application by QEMU.
154 These descriptors can be passed to ``mmap()`` by the vhost application
155 to map the guest address space into the vhost application.
160 as a listener for IOMMU mapping changes. The vhost application maintains
170 emulation application, using a file descriptor to inject interrupts into
171 the VM via KVM, and allowing the application to ``mmap()`` the guest
175 application works and the needs of separated device emulation. The most
182 has been sent to the vhost application.
186 desired, in which the emulation application should only be allowed to
192 emulation). ``qemu-io`` is not a device emulation application per se, but it
835 application does, where the QEMU process sets up *eventfds* that cause