[libvirt] [PATCH v4 2/5] libxl: add support for PVH
Jim Fehlig
jfehlig at suse.com
Sat Oct 13 14:46:19 UTC 2018
On 10/7/18 9:39 AM, 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 at 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
> - use #ifdef LIBXL_DOMAIN_TYPE_PVH instead of hypervisor version to
> check for PVH support
> - compile fix for Xen < 4.9
>
> Changes in v4:
> - revert to "i == nr_guest_archs-1" check
> - let configure check for LIBXL_DOMAIN_TYPE_PVH and use #ifdef
> HAVE_XEN_PVH then
> - fix comment about Xen version
> ---
> docs/formatcaps.html.in | 4 +--
> docs/schemas/domaincommon.rng | 1 +-
> m4/virt-driver-libxl.m4 | 3 ++-
> src/conf/domain_conf.c | 6 ++--
> src/libxl/libxl_capabilities.c | 38 ++++++++++++++++++++++-----
> src/libxl/libxl_conf.c | 50 ++++++++++++++++++++++++++++++-----
> src/libxl/libxl_driver.c | 6 ++--
> 7 files changed, 90 insertions(+), 18 deletions(-)
>
> diff --git a/docs/formatcaps.html.in b/docs/formatcaps.html.in
> index 0d9c53d..fe113bc 100644
> --- a/docs/formatcaps.html.in
> +++ b/docs/formatcaps.html.in
> @@ -104,8 +104,8 @@
> <dt><code>machine</code></dt><dd>Machine type, for use in
> <a href="formatdomain.html#attributeOSTypeMachine">machine</a>
> attribute of os/type element in domain XML. For example Xen
> - supports <code>xenfv</code> for HVM or <code>xenpv</code> for
> - PV.</dd>
> + supports <code>xenfv</code> for HVM, <code>xenpv</code> for
> + PV, or <code>xenpvh</code> for PVH.</dd>
> <dt><code>domain</code></dt><dd>The <code>type</code> attribute of
> this element specifies the type of hypervisor required to run the
> domain. Use in <a href="formatdomain.html#attributeDomainType">type</a>
> diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
> index 099a949..820a7c6 100644
> --- a/docs/schemas/domaincommon.rng
> +++ b/docs/schemas/domaincommon.rng
> @@ -341,6 +341,7 @@
> <choice>
> <value>xenpv</value>
> <value>xenfv</value>
> + <value>xenpvh</value>
> </choice>
> </attribute>
> </optional>
> diff --git a/m4/virt-driver-libxl.m4 b/m4/virt-driver-libxl.m4
> index 479d911..2cd97cc 100644
> --- a/m4/virt-driver-libxl.m4
> +++ b/m4/virt-driver-libxl.m4
> @@ -75,6 +75,9 @@ AC_DEFUN([LIBVIRT_DRIVER_CHECK_LIBXL], [
> ])
> fi
>
> + dnl Check if Xen has support for PVH
> + AC_CHECK_DECL(LIBXL_DOMAIN_TYPE_PVH, [AC_DEFINE([HAVE_XEN_PVH], [1], [Define to 1 if Xen has PVH support.])], [], [#include <libxl.h>])
Nice! I was unable to get this to work, probably due to some botched quoting.
> +
> AC_SUBST([LIBXL_CFLAGS])
> AC_SUBST([LIBXL_LIBS])
> ])
> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
> index 9911d56..a945ad4 100644
> --- a/src/conf/domain_conf.c
> +++ b/src/conf/domain_conf.c
> @@ -19094,7 +19094,8 @@ virDomainDefParseCaps(virDomainDefPtr def,
> * be 'xen'. So we accept the former and convert
> */
> if (def->os.type == VIR_DOMAIN_OSTYPE_LINUX &&
> - def->virtType == VIR_DOMAIN_VIRT_XEN) {
> + def->virtType == VIR_DOMAIN_VIRT_XEN &&
> + (!def->os.machine || STREQ(def->os.machine, "xenpv"))) {
> def->os.type = VIR_DOMAIN_OSTYPE_XEN;
> }
>
> @@ -27705,7 +27706,8 @@ virDomainDefFormatInternal(virDomainDefPtr def,
> * be 'xen'. So we convert to the former for backcompat
> */
> if (def->virtType == VIR_DOMAIN_VIRT_XEN &&
> - def->os.type == VIR_DOMAIN_OSTYPE_XEN)
> + def->os.type == VIR_DOMAIN_OSTYPE_XEN &&
> + (!def->os.machine || STREQ(def->os.machine, "xenpv")))
> virBufferAsprintf(buf, ">%s</type>\n",
> virDomainOSTypeToString(VIR_DOMAIN_OSTYPE_LINUX));
> else
> diff --git a/src/libxl/libxl_capabilities.c b/src/libxl/libxl_capabilities.c
> index 18596c7..eecd5e9 100644
> --- a/src/libxl/libxl_capabilities.c
> +++ b/src/libxl/libxl_capabilities.c
> @@ -57,6 +57,7 @@ struct guest_arch {
> virArch arch;
> int bits;
> int hvm;
> + int pvh;
> int pae;
> int nonpae;
> int ia64_be;
> @@ -491,13 +492,33 @@ libxlCapsInitGuests(libxl_ctx *ctx, virCapsPtr caps)
> guest_archs[i].nonpae = nonpae;
> if (ia64_be)
> guest_archs[i].ia64_be = ia64_be;
> +
> + /*
> + * Xen 4.10 introduced support for the PVH guest type, which
> + * requires hardware virtualization support similar to the
> + * HVM guest type. Add a PVH guest type for each new HVM
> + * guest type.
> + */
> +#ifdef HAVE_XEN_PVH
> + if (hvm && i == nr_guest_archs-1) {
> + i = nr_guest_archs;
> + /* Ensure we have not exhausted the guest_archs array */
> + if (nr_guest_archs >= ARRAY_CARDINALITY(guest_archs))
> + continue;
> + guest_archs[nr_guest_archs].arch = arch;
> + guest_archs[nr_guest_archs].pvh = 1;
> + nr_guest_archs++;
> + }
> +#endif
> }
> }
> regfree(®ex);
>
> for (i = 0; i < nr_guest_archs; ++i) {
> virCapsGuestPtr guest;
> - char const *const xen_machines[] = {guest_archs[i].hvm ? "xenfv" : "xenpv"};
> + char const *const xen_machines[] = {
> + guest_archs[i].hvm ? "xenfv" :
> + (guest_archs[i].pvh ? "xenpvh" : "xenpv")};
I had some couch time at the start of the weekend and was finally able to try
using this series with virt-install. As it turns out, reporting duplicate
<guest> blocks for <os_type> 'xen' is not quite right. Instead we will want to
report the additional <machine> under the existing 'xen' <guest> blocks. E.g.
instead of adding a duplicate
<guest>
<os_type>xen</os_type>
<arch name='x86_64'>
<wordsize>64</wordsize>
<emulator>/usr/lib/xen/bin/qemu-system-i386</emulator>
<machine>xenpvh</machine>
<domain type='xen'/>
</arch>
...
</guest>
we'll want to include the xenpvh machine in the existing <guest> config for xen
<guest>
<os_type>xen</os_type>
<arch name='x86_64'>
<wordsize>64</wordsize>
<emulator>/usr/lib/xen/bin/qemu-system-i386</emulator>
<machine>xenpvh</machine>
<machine>xenpv</machine>
<domain type='xen'/>
</arch>
</guest>
With this change to the capabilities reporting, virt-install works without
modification using
virt-install --paravirt --machine xenpv ...
I didn't think too hard about the best way to handle this, but the attached diff
is a POC hack that works with unmodified virt-install.
Regards,
Jim
-------------- next part --------------
A non-text attachment was scrubbed...
Name: dom-caps.diff
Type: text/x-patch
Size: 2400 bytes
Desc: not available
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20181013/102e6301/attachment-0001.bin>
More information about the libvir-list
mailing list