[QNX hypervisor 2.2 user manual]6.3 communication between guest and external

Hypervisor In the system Guest You can share memory areas to share information with others Guset or Hypervisor Host To transmit data .

stay QNX Hypervisor In the system , Running on the Guest The client program in can create and manage shared memory , Then use the shared memory area to exchange data . It should be noted that , This shared memory area is not created and managed by , It is Hypervisor.Host Applications can also create a shared memory area or attach a shared memory area created by others if permission allows .

QNX Hypervisor Provided hypervisor-shmem-examples-*.tgz Contains QNX Guest Related shared memory case program code ：ghstest.c and Hypervisor Host Relevant case program code ：hhstest.c.

In order to Hypervisor Host And Guest Modules that share data perform write operations , You need to use virtualization API（libhyp.a）. This part is not included in QNX hypervisor file , But in  Virtualization API Reference Described in . To include this additional documentation , And support for host Module write operation , You can contact QNX interface （QNX representative）.

One 、 Working mechanism of shared memory

In order to use shared memory , One Guest Client program or Hypervisor Host The program in needs to do something ：

• Map shared memory area ;
• When the shared memory area is updated , Hardware interrupts can be used to notify other users of shared memory ;

Hypervisor Provides shmem Virtual device , The device realizes the mapping of setting the shared memory area and the interrupts required for using the shared memory . This virtual device provides additional functionality for using shared memory , Include