On 10/3/18 3:25 PM, Marek Marczykowski-Górecki wrote:
On Wed, Oct 03, 2018 at 03:13:30PM -0600, Jim Fehlig wrote:
On 10/2/18 4:50 PM, Jim Fehlig wrote:
On 9/30/18 8:15 PM, Marek Marczykowski-Górecki wrote:
Since this is something between PV and HVM, it makes sense to put the setting in place where domain type is specified. To enable it, use <os><type machine="xenpvh">...</type></os>. It is also included in capabilities.xml, for every supported HVM guest type - it doesn't seems to be any other requirement (besides new enough Xen).
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> --- Changes in v2 proposed by Jim: - use new_arch_added var instead of i == nr_guest_archs for clarity - improve comment - adjust for now required Xen >= 4.6 (remove part for Xen < 4.5)
Changes in v3: - limit VIR_DOMAIN_OSTYPE_XEN -> VIR_DOMAIN_OSTYPE_LINUX conversion to Xen PV only - do not accept VIR_DOMAIN_OSTYPE_LINUX for PVH - fix reported capabilities for PVH - remove hostdev passthrough and video/graphics
No video, graphics or hostdev passthrough - bummer. Begs the question: what to do with PVH XML config containing these devices? Reject it? Silently ignore? I'll also need to remember to enable these as PVH gains support for the devices.
- use #ifdef LIBXL_DOMAIN_TYPE_PVH instead of hypervisor version to check for PVH support
This is a much better approach than the version check. I should have thought of that earlier, sorry.
Actually it is not. LIBXL_DOMAIN_TYPE_PVH is a value in the enum libxl_domain_type. Too bad PVH support isn't advertised in libxl.h with something like LIBXL_HAVE_PVH. Looks like we are stuck with the version check :-(.
Hmm, but that version check is a runtime check. How to fix compile error regarding missing LIBXL_DOMAIN_TYPE_PVH then? Let configure check that and define some HAVE_xxx?
AFAICT, PVH support actually came in Xen 4.10 commit 27f826844d3666f151e86d66198583757cccbbed Author: Roger Pau Monne <roger.pau@citrix.com> Date: Fri Sep 22 16:25:07 2017 +0100 libxl: introduce a PVH guest type git describe --contains 27f826844d3 4.10.0-rc1~219 And the only thing in that commit to check is the addition of LIBXL_DOMAIN_TYPE_PVH to the libxl_domain_type enum. I think we'll have to check it with AC_COMPILE_IFELSE. I've been fiddling with the below patch, which at least works on a Xen >= 4.10. Can you check it on Xen < 4.10 too, and squash it into your series? Regards, Jim diff --git a/m4/virt-driver-libxl.m4 b/m4/virt-driver-libxl.m4 index 479d9116a4..ae309abb80 100644 --- a/m4/virt-driver-libxl.m4 +++ b/m4/virt-driver-libxl.m4 @@ -73,6 +73,22 @@ AC_DEFUN([LIBVIRT_DRIVER_CHECK_LIBXL], [ ],[ LIBXL_LIBS="$LIBXL_LIBS -lxenstore -lxenctrl" ]) + + dnl Check if Xen has support for PVH + AC_MSG_CHECKING([for Xen PVH support]) + AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <libxl.h>]], + [[int dummy = LIBXL_DOMAIN_TYPE_PVH;]]) + ], + [ + AC_MSG_RESULT([yes]) + AC_DEFINE_UNQUOTED([HAVE_XEN_PVH], [1], [Define to 1 if Xen has PVH support.]) + ], + [ + AC_MSG_RESULT([no]) + AC_DEFINE_UNQUOTED([HAVE_XEN_PVH], [0], [Define to 1 if Xen has PVH support.]) + ] + ) + fi AC_SUBST([LIBXL_CFLAGS])