Ported user space support for host devices, user space host device example, and vnc...

[palacios.git] / linux_usr / v3_user_host_dev_example.c

diff --git a/linux_usr/v3_user_host_dev_example.c b/linux_usr/v3_user_host_dev_example.c
new file mode 100644 (file)
index 0000000..833f3c5
--- /dev/null
+++ b/linux_usr/v3_user_host_dev_example.c
@@ -0,0 +1,124 @@
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <sys/select.h>
+#include <malloc.h>
+
+#include "v3_user_host_dev.h"
+
+void usage()
+{
+    fprintf(stderr,"v3_host_dev_example /dev/v3-vm0 user:mydev busywait|select\n");
+}
+
+
+int do_work(struct palacios_host_dev_host_request_response *req, 
+           struct palacios_host_dev_host_request_response **resp)
+{
+    uint64_t datasize;
+    
+    //
+    //
+    // Process request here, perhaps calling these functions:
+    //
+    // uint64_t v3_user_host_dev_read_guest_mem(int devfd, void *gpa, void *dest, uint64_t len);
+    // uint64_t v3_user_host_dev_write_guest_mem(int devfd, void *gpa, void *src, uint64_t len);
+    // int      v3_user_host_dev_inject_guest_irq(int devfd, uint8_t irq);
+    //
+    // determine datasize - # bytes to include in response
+    //
+    // now built a response
+    *resp = malloc(sizeof(struct palacios_host_dev_host_request_response) + datasize);
+    (*resp)->data_len = sizeof(struct palacios_host_dev_host_request_response) + datasize;
+
+    //
+    // Fill out the fields of the response - notice that there are six kinds of things to response to:
+    //   - read/write device port
+    //   - read/write device mem
+    //   - read/write device configuration space
+
+    return 0;
+}
+
+int main(int argc, char *argv[])
+{
+    int devfd;
+    int mode=0;
+    char *vm, *url;
+
+    if (argc!=4) { 
+       usage();
+       exit(-1);
+    }
+    
+    vm=argv[1];
+    url=argv[2];
+    mode = argv[3][0]=='s';
+
+    fprintf(stderr,"Attempting to rendezvous with host device %s on vm %s\n", url, vm);
+    
+    if ((devfd = v3_user_host_dev_rendezvous(vm,url))<0) { 
+       perror("failed to rendezvous");
+       exit(-1);
+    }
+    
+    fprintf(stderr,"Rendezvous succeeded, I will now operate in %s mode\n", mode==0 ? "busywait" : "select");
+    
+    if (mode==0) { 
+       //busywait
+
+       struct palacios_host_dev_host_request_response *req;
+       struct palacios_host_dev_host_request_response *resp;
+       uint64_t datasize;
+
+       while (1) { 
+           while (!(v3_user_host_dev_have_request(devfd))) { 
+           }
+           v3_user_host_dev_pull_request(devfd, &req);
+
+           do_work(req, &resp);
+           
+           v3_user_host_dev_push_response(devfd, resp);
+
+           free(resp);
+           free(req);
+       }
+    } else {
+
+       struct palacios_host_dev_host_request_response *req;
+       struct palacios_host_dev_host_request_response *resp;
+       uint64_t datasize;
+       fd_set   readset;
+       int rc;
+
+       // select-based operation so that you can wait for multiple things
+       
+       while (1) { 
+           FD_ZERO(&readset);
+           FD_SET(devfd,&readset);
+
+           rc = select(devfd+1, &readset, 0, 0, 0);  // pick whatever you want to select on, just include devfd
+
+           if (rc>0) { 
+               if (FD_ISSET(devfd,&readset)) { 
+                   // a request is read for us!
+                   v3_user_host_dev_pull_request(devfd, &req);
+
+                   do_work(req, &resp);
+                   
+                   v3_user_host_dev_push_response(devfd, resp);
+                   
+                   free(resp);
+                   free(req);
+               }
+           }
+       }
+    }
+
+    v3_user_host_dev_depart(devfd);
+
+    return 0;
+                   
+}