diff mbox

[v2,2/2] libxl: do not start dom0 qemu for stubdomain when not needed

Message ID 1501260134-11837-2-git-send-email-marmarek@invisiblethingslab.com (mailing list archive)
State New, archived
Headers show

Commit Message

Marek Marczykowski-Górecki July 28, 2017, 4:42 p.m. UTC
Do not setup vfb+vkb when no access method was configured. Then check if
qemu is really needed.

The only not configurable thing forcing qemu running in dom0 after this
change are consoles used to save/restore. But even in that case, there
is much smaller part of qemu exposed.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
---
 tools/libxl/libxl_dm.c | 54 ++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 39 insertions(+), 15 deletions(-)

Comments

Wei Liu July 31, 2017, 4:23 p.m. UTC | #1
On Fri, Jul 28, 2017 at 06:42:14PM +0200, Marek Marczykowski-Górecki wrote:
> Do not setup vfb+vkb when no access method was configured. Then check if
> qemu is really needed.
> 
> The only not configurable thing forcing qemu running in dom0 after this
> change are consoles used to save/restore. But even in that case, there
> is much smaller part of qemu exposed.
> 
> Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>

Acked-by: Wei Liu <wei.liu2@citrix.com>

> +                /* will be changed back to LIBXL__CONSOLE_BACKEND_IOEMU if qemu
> +                 * will be in use */

Hmm... I don't think there is requirement in CODING_STYLE for
multiple-line comment, so there are quite a few styles in use. But
looking at libxl code the prevailing style seems to be:

   /*
    *  xxxx
    *  xxxx
    */

I will make the adjustment while committing.
Ian Jackson July 31, 2017, 4:36 p.m. UTC | #2
Wei Liu writes ("Re: [PATCH v2 2/2] libxl: do not start dom0 qemu for stubdomain when not needed"):
> Hmm... I don't think there is requirement in CODING_STYLE for
> multiple-line comment, so there are quite a few styles in use. But
> looking at libxl code the prevailing style seems to be:
> 
>    /*
>     *  xxxx
>     *  xxxx
>     */
> 
> I will make the adjustment while committing.

Personally I think this is well into the kind of territory that is not
worth arguing over.  Even a mix of styles here is fine.  (I think we
should mandate the initial `*' on continuation lines.)

Ian.
diff mbox

Patch

diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c
index 44ebd70..e0e6a99 100644
--- a/tools/libxl/libxl_dm.c
+++ b/tools/libxl/libxl_dm.c
@@ -1868,13 +1868,17 @@  void libxl__spawn_stub_dm(libxl__egc *egc, libxl__stub_dm_spawn_state *sdss)
     ret = libxl__domain_build_info_setdefault(gc, &dm_config->b_info);
     if (ret) goto out;
 
-    GCNEW(vfb);
-    GCNEW(vkb);
-    libxl__vfb_and_vkb_from_hvm_guest_config(gc, guest_config, vfb, vkb);
-    dm_config->vfbs = vfb;
-    dm_config->num_vfbs = 1;
-    dm_config->vkbs = vkb;
-    dm_config->num_vkbs = 1;
+    if (libxl_defbool_val(guest_config->b_info.u.hvm.vnc.enable)
+        || libxl_defbool_val(guest_config->b_info.u.hvm.spice.enable)
+        || libxl_defbool_val(guest_config->b_info.u.hvm.sdl.enable)) {
+        GCNEW(vfb);
+        GCNEW(vkb);
+        libxl__vfb_and_vkb_from_hvm_guest_config(gc, guest_config, vfb, vkb);
+        dm_config->vfbs = vfb;
+        dm_config->num_vfbs = 1;
+        dm_config->vkbs = vkb;
+        dm_config->num_vkbs = 1;
+    }
 
     stubdom_state->pv_kernel.path
         = libxl__abs_path(gc, "ioemu-stubdom.gz", libxl__xenfirmwaredir_path());
@@ -1959,6 +1963,7 @@  static void spawn_stub_launch_dm(libxl__egc *egc,
     libxl__domain_build_state *const d_state = sdss->dm.build_state;
     libxl__domain_build_state *const stubdom_state = &sdss->dm_state;
     uint32_t dm_domid = sdss->pvqemu.guest_domid;
+    int need_qemu;
 
     if (ret) {
         LOGD(ERROR, guest_domid, "error connecting disk devices");
@@ -1975,12 +1980,16 @@  static void spawn_stub_launch_dm(libxl__egc *egc,
         if (ret)
             goto out;
     }
-    ret = libxl__device_vfb_add(gc, dm_domid, &dm_config->vfbs[0]);
-    if (ret)
-        goto out;
-    ret = libxl__device_vkb_add(gc, dm_domid, &dm_config->vkbs[0]);
-    if (ret)
-        goto out;
+    if (dm_config->num_vfbs) {
+        ret = libxl__device_vfb_add(gc, dm_domid, &dm_config->vfbs[0]);
+        if (ret)
+            goto out;
+    }
+    if (dm_config->num_vkbs) {
+        ret = libxl__device_vkb_add(gc, dm_domid, &dm_config->vkbs[0]);
+        if (ret)
+            goto out;
+    }
 
     if (guest_config->b_info.u.hvm.serial)
         num_console++;
@@ -1988,7 +1997,6 @@  static void spawn_stub_launch_dm(libxl__egc *egc,
     console = libxl__calloc(gc, num_console, sizeof(libxl__device_console));
 
     for (i = 0; i < num_console; i++) {
-        libxl__device device;
         console[i].devid = i;
         console[i].consback = LIBXL__CONSOLE_BACKEND_IOEMU;
         /* STUBDOM_CONSOLE_LOGGING (console 0) is for minios logging
@@ -2005,6 +2013,9 @@  static void spawn_stub_launch_dm(libxl__egc *egc,
                 if (ret) goto out;
                 console[i].output = GCSPRINTF("file:%s", filename);
                 free(filename);
+                /* will be changed back to LIBXL__CONSOLE_BACKEND_IOEMU if qemu
+                 * will be in use */
+                console[i].consback = LIBXL__CONSOLE_BACKEND_XENCONSOLED;
                 break;
             case STUBDOM_CONSOLE_SAVE:
                 console[i].output = GCSPRINTF("file:%s",
@@ -2019,6 +2030,14 @@  static void spawn_stub_launch_dm(libxl__egc *egc,
                 console[i].output = "pty";
                 break;
         }
+    }
+
+    need_qemu = libxl__need_xenpv_qemu(gc, dm_config);
+
+    for (i = 0; i < num_console; i++) {
+        libxl__device device;
+        if (need_qemu)
+            console[i].consback = LIBXL__CONSOLE_BACKEND_IOEMU;
         ret = libxl__device_console_add(gc, dm_domid, &console[i],
                         i == STUBDOM_CONSOLE_LOGGING ? stubdom_state : NULL,
                         &device);
@@ -2032,7 +2051,12 @@  static void spawn_stub_launch_dm(libxl__egc *egc,
     sdss->pvqemu.build_state = &sdss->dm_state;
     sdss->pvqemu.callback = spawn_stubdom_pvqemu_cb;
 
-    libxl__spawn_local_dm(egc, &sdss->pvqemu);
+    if (!need_qemu) {
+        /* If dom0 qemu not needed, do not launch it */
+        spawn_stubdom_pvqemu_cb(egc, &sdss->pvqemu, 0);
+    } else {
+        libxl__spawn_local_dm(egc, &sdss->pvqemu);
+    }
 
     return;