[libvirt] [v5][PATCH 2/4] PowerPC : Add support for launching VMs in 'compat' mode.
From: Prerna Saxena <prerna(a)linux.vnet.ibm.com>
Date: Tue, 28 Oct 2014 15:05:59 +0530
PowerISA allows processors to run VMs in binary compatibility ("compat")
mode supporting an older version of ISA. QEMU has recently added support to
explicitly denote a VM running in compatibility mode through commit 6d9412ea
& 8dfa3a5e85.
Now, a "compat" mode VM can be run by invoking this qemu commandline on a
POWER8 host: -cpu host,compat=power7.
This patch allows libvirt to exploit cpu mode 'host-model' to describe this
new mode for PowerKVM guests. As an example:
When a user wants to request a power7 vm to run in compatibility mode on
a Power8 host, this can be described in XML as follows :
<cpu mode='host-model'>
<model>power7</model>
</cpu>
Signed-off-by: Prerna Saxena <prerna(a)linux.vnet.ibm.com>
Signed-off-by: Li Zhang <zhlcindy(a)linux.vnet.ibm.com>
Signed-off-by: Pradipta Kr. Banerjee <bpradip(a)in.ibm.com>
---
src/conf/cpu_conf.c | 1 +
src/cpu/cpu_powerpc.c | 11 ++---------
src/qemu/qemu_command.c | 10 +++++++++-
3 files changed, 12 insertions(+), 10 deletions(-)
diff --git a/src/conf/cpu_conf.c b/src/conf/cpu_conf.c
index 9b7fbb0..0e7a979 100644
--- a/src/conf/cpu_conf.c
+++ b/src/conf/cpu_conf.c
@@ -619,6 +619,7 @@ virCPUDefFormatBuf(virBufferPtr buf,
return 0;
formatModel = (def->mode == VIR_CPU_MODE_CUSTOM ||
+ def->mode == VIR_CPU_MODE_HOST_MODEL ||
(flags & VIR_DOMAIN_XML_UPDATE_CPU));
formatFallback = (def->type == VIR_CPU_TYPE_GUEST &&
(def->mode == VIR_CPU_MODE_HOST_MODEL ||
diff --git a/src/cpu/cpu_powerpc.c b/src/cpu/cpu_powerpc.c
index d591c18..4ea1835 100644
--- a/src/cpu/cpu_powerpc.c
+++ b/src/cpu/cpu_powerpc.c
@@ -562,8 +562,8 @@ ppcUpdate(virCPUDefPtr guest,
static virCPUDefPtr
ppcBaseline(virCPUDefPtr *cpus,
unsigned int ncpus,
- const char **models,
- unsigned int nmodels,
+ const char **models ATTRIBUTE_UNUSED,
+ unsigned int nmodels ATTRIBUTE_UNUSED,
unsigned int flags)
{
struct ppc_map *map = NULL;
@@ -583,13 +583,6 @@ ppcBaseline(virCPUDefPtr *cpus,
goto error;
}
- if (!cpuModelIsAllowed(model->name, models, nmodels)) {
- virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
- _("CPU model %s is not supported by hypervisor"),
- model->name);
- goto error;
- }
-
for (i = 0; i < ncpus; i++) {
const struct ppc_vendor *vnd;
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index d60f274..34f6535 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -6221,7 +6221,9 @@ qemuBuildCpuModelArgStr(virQEMUDriverPtr driver,
*hasHwVirt = hasSVM > 0 ? true : false;
}
- if (cpu->mode == VIR_CPU_MODE_HOST_PASSTHROUGH) {
+ if ((cpu->mode == VIR_CPU_MODE_HOST_PASSTHROUGH) ||
+ ((cpu->mode == VIR_CPU_MODE_HOST_MODEL) &&
+ ARCH_IS_PPC64(def->os.arch))) {
const char *mode = virCPUModeTypeToString(cpu->mode);
if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_CPU_HOST)) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
@@ -6236,6 +6238,12 @@ qemuBuildCpuModelArgStr(virQEMUDriverPtr driver,
goto cleanup;
}
virBufferAddLit(buf, "host");
+
+ if (ARCH_IS_PPC64(def->os.arch) &&
+ cpu->mode == VIR_CPU_MODE_HOST_MODEL) {
+ virBufferAsprintf(buf, ",compat=%s", def->cpu->model);
+ }
+
} else {
if (VIR_ALLOC(guest) < 0)
goto cleanup;
--
1.9.3
--
Prerna Saxena
Linux Technology Centre,
IBM Systems and Technology Lab,
Bangalore, India