xen-access: minor fixes

Only copy the VCPU_PAUSED flag to the response. Copy the entire mem_access
struct which is useful and easily forgotten when also testing the emulate
response flags. Turn off singlestepping on the vCPUs once we are done
processing all events, as we might have turned on singlestep there and leave
the VM in an undesirable state.

Signed-off-by: Tamas K Lengyel <tlengyel@novetta.com>
Cc: Razvan Cojocaru <rcojocaru@bitdefender.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Acked-by: Razvan Cojocaru <rcojocaru@bitdefender.com>

diff --git a/tools/tests/xen-access/xen-access.c b/tools/tests/xen-access/xen-access.c
index 7993947419d71fea155d9c3f62375a4ab9deea00..ef892460f2f997b248a9de63b0a3159b88eaf91f 100644 (file)
--- a/tools/tests/xen-access/xen-access.c
+++ b/tools/tests/xen-access/xen-access.c
@@ -537,16 +537,10 @@ int main(int argc, char *argv[])
 
             if ( altp2m )
             {
-                uint32_t vcpu_id;
-
                 rc = xc_altp2m_switch_to_view( xch, domain_id, 0 );
                 rc = xc_altp2m_destroy_view(xch, domain_id, altp2m_view_id);
                 rc = xc_altp2m_set_domain_state(xch, domain_id, 0);
                 rc = xc_monitor_singlestep(xch, domain_id, 0);
-
-                for ( vcpu_id = 0; vcpu_id<XEN_LEGACY_MAX_VCPUS; vcpu_id++)
-                    rc = control_singlestep(xch, domain_id, vcpu_id, 0);
-
             } else {
                 rc = xc_set_mem_access(xch, domain_id, XENMEM_access_rwx, ~0ull, 0);
                 rc = xc_set_mem_access(xch, domain_id, XENMEM_access_rwx, START_PFN,
@@ -570,8 +564,6 @@ int main(int argc, char *argv[])
 
         while ( RING_HAS_UNCONSUMED_REQUESTS(&xenaccess->vm_event.back_ring) )
         {
-            xenmem_access_t access;
-
             get_request(&xenaccess->vm_event, &req);
 
             if ( req.version != VM_EVENT_INTERFACE_VERSION )
@@ -584,16 +576,25 @@ int main(int argc, char *argv[])
             memset( &rsp, 0, sizeof (rsp) );
             rsp.version = VM_EVENT_INTERFACE_VERSION;
             rsp.vcpu_id = req.vcpu_id;
-            rsp.flags = req.flags;
+            rsp.flags = (req.flags & VM_EVENT_FLAG_VCPU_PAUSED);
+            rsp.reason = req.reason;
 
             switch (req.reason) {
             case VM_EVENT_REASON_MEM_ACCESS:
-                rc = xc_get_mem_access(xch, domain_id, req.u.mem_access.gfn, &access);
-                if (rc < 0)
+                if ( !shutting_down )
                 {
-                    ERROR("Error %d getting mem_access event\n", rc);
-                    interrupted = -1;
-                    continue;
+                    /*
+                     * This serves no other purpose here then demonstrating the use of the API.
+                     * At shutdown we have already reset all the permissions so really no use getting it again.
+                     */
+                    xenmem_access_t access;
+                    rc = xc_get_mem_access(xch, domain_id, req.u.mem_access.gfn, &access);
+                    if (rc < 0)
+                    {
+                        ERROR("Error %d getting mem_access event\n", rc);
+                        interrupted = -1;
+                        continue;
+                    }
                 }
 
                 printf("PAGE ACCESS: %c%c%c for GFN %"PRIx64" (offset %06"
@@ -614,11 +615,8 @@ int main(int argc, char *argv[])
                 {
                     DPRINTF("\tSwitching back to default view!\n");
 
-                    rsp.reason = req.reason;
-                    rsp.flags = req.flags;
+                    rsp.flags |= VM_EVENT_FLAG_TOGGLE_SINGLESTEP;
                     rsp.altp2m_idx = 0;
-
-                    control_singlestep(xch, domain_id, rsp.vcpu_id, 1);
                 }
                 else if ( default_access != after_first_access )
                 {
@@ -633,7 +631,7 @@ int main(int argc, char *argv[])
                     }
                 }
 
-                rsp.u.mem_access.gfn = req.u.mem_access.gfn;
+                rsp.u.mem_access = req.u.mem_access;
                 break;
             case VM_EVENT_REASON_SOFTWARE_BREAKPOINT:
                 printf("Breakpoint: rip=%016"PRIx64", gfn=%"PRIx64" (vcpu %d)\n",
@@ -662,12 +660,11 @@ int main(int argc, char *argv[])
                 {
                     printf("\tSwitching altp2m to view %u!\n", altp2m_view_id);
 
-                    rsp.reason = req.reason;
                     rsp.flags |= VM_EVENT_FLAG_ALTERNATE_P2M;
                     rsp.altp2m_idx = altp2m_view_id;
                 }
 
-                control_singlestep(xch, domain_id, req.vcpu_id, 0);
+                rsp.flags |= VM_EVENT_FLAG_TOGGLE_SINGLESTEP;
 
                 break;
             default:
@@ -694,6 +691,13 @@ int main(int argc, char *argv[])
     DPRINTF("xenaccess shut down on signal %d\n", interrupted);
 
 exit:
+    if ( altp2m )
+    {
+        uint32_t vcpu_id;
+        for ( vcpu_id = 0; vcpu_id<XEN_LEGACY_MAX_VCPUS; vcpu_id++)
+            rc = control_singlestep(xch, domain_id, vcpu_id, 0);
+    }
+
     /* Tear down domain xenaccess */
     rc1 = xenaccess_teardown(xch, xenaccess);
     if ( rc1 != 0 )