Marek Marczykowski-Górecki wrote:
On Sat, Feb 07, 2015 at 12:22:51PM +0100, Marek Marczykowski-Górecki wrote:
On Thu, Feb 05, 2015 at 02:53:44PM -0700, Jim Fehlig wrote:
Marek Marczykowski-Górecki wrote:
Vfb entries in domain config are used only by PV drivers. Qemu parameters are build based on b_info struct. So fill it with the same data as vfb entries (actually the first one). This will additionally allow graphic-less domain, when no <graphics/> entries are present in domain XML (previously VNC was always enabled).
This should already be handled in libxlMakeVfbList().
Indeed, I've blindly rebased that patch from older version, but...
Is there something missing in that function?
... yes, if there is no graphics defined, the driver will set b_info->u.hvm.nographic to 1. Which isn't enough to disable graphic, because actual condition in libxl is: if (info->nographic && (!info->sdl && !info->vnc)) { flexarray_append(dm_args, "-nographic"); }
I'll think about some better solution (perhaps only part about initially setting vnc and sdl to false?).
The problem is when domain XML contains no <video/> nor <graphics/> elements - libxl defaults then to setting up VNC (on 127.0.0.1). The solution here is to disable VNC/SDL and enable only when domain config says so. This still make VNC set when only <video/> is present (without <graphics type='vnc'/>), but at least there is a way make domain really headless.
Below is patch which implement that approach. Note that it makes a big change in behaviour - it can make user's configuration broken (if he/she relied on this bug).
The current behavior is a regression wrt the legacy Xen driver. In that driver, the absence of <video> and <graphics> results in invoking qemu with -nographic. Since we aim for compatibility with the old Xen driver, I'd argue you are fixing the bug :-).
Disclaimer: I've tested it only with qemu in stubdomain.
I've tested it with a regular HVM domain.
-----8<----- From 37126eea6927f38fcb7f7f1190143fd7de54e9e6 Mon Sep 17 00:00:00 2001 From: Marek Marczykowski <marmarek@invisiblethingslab.com> Date: Sun, 7 Apr 2013 19:48:03 +0200 Subject: [PATCH] libxl: disable VNC and SDL until explicitly enabled Cc: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Otherwise when VM have no graphics defined, it is still enabled (with some libxl defaults).
The commit message should indicate this fixes a regression wrt the legacy Xen driver.
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> --- src/libxl/libxl_conf.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c index 1811a83..7ee4e54 100644 --- a/src/libxl/libxl_conf.c +++ b/src/libxl/libxl_conf.c @@ -745,6 +745,10 @@ libxlMakeDomBuildInfo(virDomainDefPtr def, return -1; }
+ /* Disable VNC and SDL until explicitly enabled */ + libxl_defbool_set(&b_info->u.hvm.vnc.enable, 0); + libxl_defbool_set(&b_info->u.hvm.sdl.enable, 0);
ACK. I'll adjust the commit message and push shortly. Regards, Jim