[Qemu-devel] [QEMU][RFC V2 02/10] xen: modify QEMU status path in XenStore

[Julien Grall]

QEMU will now write its status in another XenStore path because multiple
QEMU can run for a same domain. If xen_dmid machine option is not specified,
it means that an old version of Xen is used, so status is written in the old
path.

Signed-off-by: Julien Grall <address@hidden>
---
 xen-all.c |   16 +++++++++++++++-
 1 files changed, 15 insertions(+), 1 deletions(-)

diff --git a/xen-all.c b/xen-all.c
index 61def2e..df6927d 100644
--- a/xen-all.c
+++ b/xen-all.c
@@ -36,6 +36,7 @@
 
 static MemoryRegion ram_memory, ram_640k, ram_lo, ram_hi;
 static MemoryRegion *framebuffer;
+static uint32_t xen_dmid = ~0;
 
 /* Compatibility with older version */
 #if __XEN_LATEST_INTERFACE_VERSION__ < 0x0003020a
@@ -958,7 +959,14 @@ static void xenstore_record_dm_state(struct xs_handle *xs, 
const char *state)
         exit(1);
     }
 
-    snprintf(path, sizeof (path), "/local/domain/0/device-model/%u/state", 
xen_domid);
+    if (xen_dmid == ~0) {
+        snprintf(path, sizeof(path), "/local/domain/0/device-model/%u/state",
+                 xen_domid);
+    } else {
+        snprintf(path, sizeof(path), "/local/domain/0/dms/%u/%u/state",
+                 xen_domid, xen_dmid);
+    }
+
     if (!xs_write(xs, XBT_NULL, path, state, strlen(state))) {
         fprintf(stderr, "error recording dm state\n");
         exit(1);
@@ -1077,6 +1085,12 @@ int xen_hvm_init(void)
     unsigned long ioreq_pfn;
     unsigned long bufioreq_evtchn;
     XenIOState *state;
+    QemuOptsList *list = qemu_find_opts("machine");
+
+    if (!QTAILQ_EMPTY(&list->head)) {
+        xen_dmid = qemu_opt_get_number(QTAILQ_FIRST(&list->head),
+                                       "xen_dmid", ~0);
+    }
 
     state = g_malloc0(sizeof (XenIOState));
 
-- 
Julien Grall