Introduce global libxl option for enabling nested HVM feature, similar
to kvm module parameter. This will prevent enabling experimental feature
by mere presence of <cpu mode='host-passthrough'> element in domain
config, unless explicitly enabled. <cpu mode='host-passthrough'> element
may be used to configure other features, like NUMA, or CPUID.
Also, adjust xenconfig driver to appropriately translate to/from
nestedhvm=1.
While at it, adjust xenconfig driver to not override def->cpu if already
set elsewhere. This will help with adding cpuid support.
---
As for xenconfig part, I'm not sure if missing "nestedhvm" option in xl
config shouldn't produce <cpu> element too, to disable nested HVM (as it
would be on plain xl). Any preference?
Changes since v3:
- use config option nested_hvm, instead of requiring explicit <feature
...> entries
- title changed from "libxl: do not enable nested HVM by mere presence
of <cpu> element"
- xenconfig: don't add <feature policy='force' name='vmx'/> since it is
implied by presence of <cpu> element
- xenconfig: produce <cpu> element even when converting on host not
supporting vmx/svm, to not lose setting value
Changes since v2:
- new patch
---
src/libxl/libxl.conf | 6 ++++++-
src/libxl/libxl_conf.c | 7 ++++++-
src/libxl/libxl_conf.h | 2 ++-
src/xenconfig/xen_xl.c | 37 +++++++++++------------------------
tests/libxlxml2domconfigtest.c | 3 +++-
5 files changed, 29 insertions(+), 26 deletions(-)
diff --git a/src/libxl/libxl.conf b/src/libxl/libxl.conf
index 264af7c..0e842c9 100644
--- a/src/libxl/libxl.conf
+++ b/src/libxl/libxl.conf
@@ -41,3 +41,9 @@
#
#keepalive_interval = 5
#keepalive_count = 5
+
+# Nested HVM global control. In order to use nested HVM feature, this option
+# needs to be enabled, in addition to specifying <cpu mode='host-passthrough'>
+# in domain configuration.
+# By default it is disabled.
+#nested_hvm = 0
diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c
index 66956a7..417ce7c 100644
--- a/src/libxl/libxl_conf.c
+++ b/src/libxl/libxl_conf.c
@@ -366,7 +366,9 @@ libxlMakeDomBuildInfo(virDomainDefPtr def,
return -1;
}
- if (ARCH_IS_X86(def->os.arch)) {
+ /* consider host support for nested HVM only if global nested_hvm
+ * option enable it */
+ if (cfg->nested_hvm && ARCH_IS_X86(def->os.arch)) {
vmx = virCPUCheckFeature(caps->host.arch, caps->host.cpu, "vmx");
svm = virCPUCheckFeature(caps->host.arch, caps->host.cpu, "svm");
hasHwVirt = vmx | svm;
@@ -1699,6 +1701,9 @@ int libxlDriverConfigLoadFile(libxlDriverConfigPtr cfg,
if (virConfGetValueUInt(conf, "keepalive_count", &cfg->keepAliveCount) < 0)
goto cleanup;
+ if (virConfGetValueBool(conf, "nested_hvm", &cfg->nested_hvm) < 0)
+ goto cleanup;
+
ret = 0;
cleanup:
diff --git a/src/libxl/libxl_conf.h b/src/libxl/libxl_conf.h
index 8eefe06..e32a5e7 100644
--- a/src/libxl/libxl_conf.h
+++ b/src/libxl/libxl_conf.h
@@ -88,6 +88,8 @@ struct _libxlDriverConfig {
int keepAliveInterval;
unsigned int keepAliveCount;
+ bool nested_hvm;
+
/* Once created, caps are immutable */
virCapsPtr caps;
diff --git a/src/xenconfig/xen_xl.c b/src/xenconfig/xen_xl.c
index 6cda305..394cc0d 100644
--- a/src/xenconfig/xen_xl.c
+++ b/src/xenconfig/xen_xl.c
@@ -170,17 +170,8 @@ xenParseXLOS(virConfPtr conf, virDomainDefPtr def, virCapsPtr caps)
if (xenConfigGetBool(conf, "nestedhvm", &val, -1) < 0)
return -1;
- if (val == 1) {
- virCPUDefPtr cpu;
-
- if (VIR_ALLOC(cpu) < 0)
- return -1;
-
- cpu->mode = VIR_CPU_MODE_HOST_PASSTHROUGH;
- cpu->type = VIR_CPU_TYPE_GUEST;
- def->cpu = cpu;
- } else if (val == 0) {
- const char *vtfeature = NULL;
+ if (val != -1) {
+ const char *vtfeature = "vmx";
if (caps && caps->host.cpu && ARCH_IS_X86(def->os.arch)) {
if (virCPUCheckFeature(caps->host.arch, caps->host.cpu, "vmx"))
@@ -189,28 +180,24 @@ xenParseXLOS(virConfPtr conf, virDomainDefPtr def, virCapsPtr caps)
vtfeature = "svm";
}
- if (vtfeature) {
+ if (!def->cpu) {
virCPUDefPtr cpu;
-
if (VIR_ALLOC(cpu) < 0)
return -1;
- if (VIR_ALLOC(cpu->features) < 0) {
- VIR_FREE(cpu);
- return -1;
- }
-
- if (VIR_STRDUP(cpu->features->name, vtfeature) < 0) {
- VIR_FREE(cpu->features);
- VIR_FREE(cpu);
- return -1;
- }
- cpu->features->policy = VIR_CPU_FEATURE_DISABLE;
- cpu->nfeatures = cpu->nfeatures_max = 1;
cpu->mode = VIR_CPU_MODE_HOST_PASSTHROUGH;
cpu->type = VIR_CPU_TYPE_GUEST;
+ cpu->nfeatures = 0;
+ cpu->nfeatures_max = 0;
def->cpu = cpu;
}
+
+ if (val == 0) {
+ if (virCPUDefAddFeature(def->cpu,
+ vtfeature,
+ VIR_CPU_FEATURE_DISABLE) < 0)
+ return -1;
+ }
}
} else {
if (xenConfigCopyStringOpt(conf, "bootloader", &def->os.bootloader) < 0)
diff --git a/tests/libxlxml2domconfigtest.c b/tests/libxlxml2domconfigtest.c
index 0105550..f2af286 100644
--- a/tests/libxlxml2domconfigtest.c
+++ b/tests/libxlxml2domconfigtest.c
@@ -74,6 +74,9 @@ testCompareXMLToDomConfig(const char *xmlfile,
if (!(log = (xentoollog_logger *)xtl_createlogger_stdiostream(stderr, XTL_DEBUG, 0)))
goto cleanup;
+ /* for testing nested HVM */
+ cfg->nested_hvm = true;
+
/* replace logger with stderr one */
libxl_ctx_free(cfg->ctx);
--
git-series 0.9.1
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