relax qemu64 VCPU feature checking in the libvirt output

resolves: rhbz#2107503

Signed-off-by: Laszlo Ersek <lersek@redhat.com>

0030-output-create_libvirt_xml-relax-VCPU-feature-checkin.patch

@@ -0,0 +1,69 @@
+From 29c6ee9322da082e3be9faa94cf4a6840b49cd97 Mon Sep 17 00:00:00 2001
+From: Laszlo Ersek <lersek@redhat.com>
+Date: Fri, 22 Jul 2022 09:36:27 +0200
+Subject: [PATCH] output/create_libvirt_xml: relax VCPU feature checking for
+ "qemu64"
+
+When the source domain doesn't specify a VCPU model ("s_cpu_model" is
+None), and the guest OS is assumed to work with the default VCPU model
+("gcaps_default_cpu" is true), we don't output any <cpu> element. In that
+case, libvirtd augments the domain config with:
+
+  [1] <cpu mode='custom' match='exact' check='none'>
+        <model fallback='forbid'>qemu64</model>
+      </cpu>
+
+where the @check='none' attribute ensures that the converted domain will
+be launched, for example, on an Intel host, despite the "qemu64" VCPU
+model containing AMD-only feature flags such as "svm".
+
+However, if the source domain explicitly specifies the "qemu64" model
+(mostly seen with "-i libvirt -ic qemu://..."), we presently output
+
+  [2] <cpu match='minimum'>
+        <model fallback='allow'>qemu64</model>
+      </cpu>
+
+which libvirtd completes as
+
+  [3] <cpu mode='custom' match='minimum' check='partial'>
+        <model fallback='allow'>qemu64</model>
+      </cpu>
+
+In [3], cpu/@match='minimum' and cpu/model/@fallback='allow' are both
+laxer than @match='exact' and @fallback='forbid', respectively, in [1].
+
+However, cpu/@check='partial' in [3] is stricter than @check='none' in
+[1]; it causes libvirtd to catch the "svm" feature flag on an Intel host,
+and prevents the converted domain from starting.
+
+The "qemu64" VCPU model is supposed to run on every possible host
+<https://gitlab.com/qemu-project/qemu/-/blob/master/docs/system/cpu-models-x86.rst.inc>,
+therefore make an exception for the explicitly specified "qemu64" VCPU
+model, and generate the @check='none' attribute.
+
+Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2107503
+Signed-off-by: Laszlo Ersek <lersek@redhat.com>
+Message-Id: <20220722073627.6511-1-lersek@redhat.com>
+Acked-by: Richard W.M. Jones <rjones@redhat.com>
+(cherry picked from commit e5297c3180fd3ebea41a40f4c5a66969a24b9ff3)
+---
+ output/create_libvirt_xml.ml | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/output/create_libvirt_xml.ml b/output/create_libvirt_xml.ml
+index 531a4f75..bd01304d 100644
+--- a/output/create_libvirt_xml.ml
++++ b/output/create_libvirt_xml.ml
+@@ -192,6 +192,8 @@ let create_libvirt_xml ?pool source inspect
+            List.push_back cpu_attrs ("mode", "host-passthrough");
+      | Some model ->
+          List.push_back cpu_attrs ("match", "minimum");
++         if model = "qemu64" then
++           List.push_back cpu_attrs ("check", "none");
+          (match source.s_cpu_vendor with
+           | None -> ()
+           | Some vendor ->
+-- 
+2.31.1
+

virt-v2v.spec

@@ -16,7 +16,7 @@
 Name:          virt-v2v
 Epoch:         1
 Version:       2.0.7
-Release:       2%{?dist}
+Release:       3%{?dist}
 Summary:       Convert a virtual machine to run on KVM
 
 License:       GPLv2+
@@ -62,6 +62,7 @@ Patch0026:     0026-common-Adapt-to-renamed-function-On_exit.rmdir-On_ex.patch
 Patch0027:     0027-o-rhv-Unmount-the-temporary-NFS-mountpoint-as-late-a.patch
 Patch0028:     0028-output-Permit-output-modes-to-wait-on-the-local-NBD-.patch
 Patch0029:     0029-o-rhv-Wait-for-the-NBD-server-to-exit-to-avoid-a-rac.patch
+Patch0030:     0030-output-create_libvirt_xml-relax-VCPU-feature-checkin.patch
 
 %if !0%{?rhel}
 # libguestfs hasn't been built on i686 for a while since there is no
@@ -340,6 +341,9 @@ rm $RPM_BUILD_ROOT%{_mandir}/man1/virt-v2v-in-place.1*
 
 
 %changelog
+* Mon Jul 25 Laszlo Ersek <lersek@redhat.com> - 1:2.0.7-3
+- relax qemu64 VCPU feature checking in the libvirt output
+  resolves rhbz#2107503
 * Fri Jul 15 2022 Richard W.M. Jones <rjones@redhat.com> - 1:2.0.7-2
 - Rebase to stable branch version 2.0.7
   resolves: rhbz#2059287, rhbz#1658126, rhbz#1788823, rhbz#1854275