File libvirt-qemu-Don-t-compare-host-passthrough-CPU-to-host-CPU.patch of Package libvirt
From c840ab85aed49f5841ea50ffa8500bf16e0dec91 Mon Sep 17 00:00:00 2001
Message-Id: <c840ab85aed49f5841ea50ffa8500bf16e0dec91@dist-git>
From: Jiri Denemark <jdenemar@redhat.com>
Date: Fri, 4 Mar 2016 15:52:09 +0100
Subject: [PATCH] qemu: Don't compare host-passthrough CPU to host CPU
This is a RHEL-6 only version of how upstream handles host-passthrough
CPUs thanks to the following commits:
adf0d770 qemu: Remove CPU features functions calling for non-x86 platform
445a09bdc qemu: Don't compare CPU against host for TCG
adff345e1 qemu: Allow enabling/disabling features with host-passthrough
In other words, upstream no longer tries to compare a host-passthrough
guest CPU with a host CPU.
Backporting all of them (or even more if we wanted cleaner backports) is
too risky and unnecessary since RHEL-6 does not support TCG or non-x86
architectures.
This patch fixes a crash of libvirtd which may happen when restoring a
domain with host-passthrough CPU once we started to use correct flags
thanks to "qemu: Fix formatting flags in qemuDomainSaveImageOpen" patch.
https://bugzilla.redhat.com/show_bug.cgi?id=1307094
https://bugzilla.redhat.com/show_bug.cgi?id=1310747
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
---
src/qemu/qemu_command.c | 48 +++++++++++++++++++++++++-----------------------
1 file changed, 25 insertions(+), 23 deletions(-)
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 3ad5c26..55196ba 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -4515,33 +4515,35 @@ qemuBuildCpuArgStr(const struct qemud_driver *driver,
cpuUpdate(cpu, host) < 0)
goto cleanup;
- cmp = cpuGuestData(host, cpu, &data, &compare_msg);
- switch (cmp) {
- case VIR_CPU_COMPARE_INCOMPATIBLE:
- if (compare_msg) {
- virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
- _("guest and host CPU are not compatible: %s"),
- compare_msg);
- } else {
- virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
- _("guest CPU is not compatible with host CPU"));
+ if (cpu->mode != VIR_CPU_MODE_HOST_PASSTHROUGH) {
+ cmp = cpuGuestData(host, cpu, &data, &compare_msg);
+ switch (cmp) {
+ case VIR_CPU_COMPARE_INCOMPATIBLE:
+ if (compare_msg) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+ _("guest and host CPU are not compatible: %s"),
+ compare_msg);
+ } else {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+ _("guest CPU is not compatible with host CPU"));
+ }
+ /* fall through */
+ case VIR_CPU_COMPARE_ERROR:
+ goto cleanup;
+
+ default:
+ break;
}
- /* fall through */
- case VIR_CPU_COMPARE_ERROR:
- goto cleanup;
- default:
- break;
+ /* Only 'svm' requires --enable-nesting. The nested
+ * 'vmx' patches now simply hook off the CPU features
+ */
+ hasSVM = cpuHasFeature(host->arch, data, "svm");
+ if (hasSVM < 0)
+ goto cleanup;
+ *hasHwVirt = hasSVM > 0 ? true : false;
}
- /* Only 'svm' requires --enable-nesting. The nested
- * 'vmx' patches now simply hook off the CPU features
- */
- hasSVM = cpuHasFeature(host->arch, data, "svm");
- if (hasSVM < 0)
- goto cleanup;
- *hasHwVirt = hasSVM > 0 ? true : false;
-
if (cpu->mode == VIR_CPU_MODE_HOST_PASSTHROUGH) {
const char *mode = virCPUModeTypeToString(cpu->mode);
if (!qemuCapsGet(caps, QEMU_CAPS_CPU_HOST)) {
--
2.7.2
