On 03/21/2018 10:32 AM, Marek Marczykowski-Górecki wrote:
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.
Signed-off-by: Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>
Reviewed-by: Daniel P. Berrangé <berrange@xxxxxxxxxx>
---
Changes since v4:
- add nested_hvm option to test_libvirtd_libxl.aug.in and libvirtd_libxl.aug
- make it possible to override nested_hvm=0 with explicit <feature
policy='require' name='vmx'/>
- split xenconfig changes into separate commits
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/libvirtd_libxl.aug | 2 ++
src/libxl/libxl.conf | 8 ++++++++
src/libxl/libxl_conf.c | 12 +++++++++++-
src/libxl/libxl_conf.h | 2 ++
src/libxl/test_libvirtd_libxl.aug.in | 1 +
tests/libxlxml2domconfigtest.c | 3 +++
6 files changed, 27 insertions(+), 1 deletion(-)
diff --git a/src/libxl/libvirtd_libxl.aug b/src/libxl/libvirtd_libxl.aug
index b31cc07..58b9af3 100644
--- a/src/libxl/libvirtd_libxl.aug
+++ b/src/libxl/libvirtd_libxl.aug
@@ -28,12 +28,14 @@ module Libvirtd_libxl =
let lock_entry = str_entry "lock_manager"
let keepalive_interval_entry = int_entry "keepalive_interval"
let keepalive_count_entry = int_entry "keepalive_count"
+ let nested_hvm_entry = bool_entry "nested_hvm"
(* Each entry in the config is one of the following ... *)
let entry = autoballoon_entry
| lock_entry
| keepalive_interval_entry
| keepalive_count_entry
+ | nested_hvm_entry
let comment = [ label "#comment" . del /#[ \t]*/ "# " . store /([^ \t\n][^\n]*)?/ . del /\n/ "\n" ]
let empty = [ label "#empty" . eol ]
diff --git a/src/libxl/libxl.conf b/src/libxl/libxl.conf
index 264af7c..72825a7 100644
--- a/src/libxl/libxl.conf
+++ b/src/libxl/libxl.conf
@@ -41,3 +41,11 @@
#
#keepalive_interval = 5
#keepalive_count = 5
+
+# Nested HVM default 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. This can be overridden in domain configuration by
+# explicitly setting <feature policy='require' name='vmx'/> inside <cpu/>
+# element.
Cool, the setting can be overridden by per-domain config.
+# By default it is disabled.
+#nested_hvm = 0
diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c
index dcfdd67..3b9e828 100644
--- a/src/libxl/libxl_conf.c
+++ b/src/libxl/libxl_conf.c
@@ -360,7 +360,9 @@ libxlMakeDomBuildInfo(virDomainDefPtr def,
bool hasHwVirt = false;
bool svm = false, vmx = false;
- if (ARCH_IS_X86(def->os.arch)) {
+ /* enable nested HVM only if global nested_hvm option enable it and
+ * host support 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;
But IIUC this change will not allow per-domain config to override the global
setting. If cfg->nested_hvm is false, svm and vmx are both false and
FEATURE_REQUIRE is not honored.
Regards,
Jim
@@ -380,6 +382,11 @@ libxlMakeDomBuildInfo(virDomainDefPtr def,
case VIR_CPU_FEATURE_FORCE:
case VIR_CPU_FEATURE_REQUIRE:
+ if ((vmx && STREQ(def->cpu->features[i].name, "vmx")) ||
+ (svm && STREQ(def->cpu->features[i].name, "svm")))
+ hasHwVirt = true;
+ break;
+
case VIR_CPU_FEATURE_OPTIONAL:
case VIR_CPU_FEATURE_LAST:
break;
@@ -1699,6 +1706,9 @@ 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 ce9db26..27cfc1a 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/libxl/test_libvirtd_libxl.aug.in b/src/libxl/test_libvirtd_libxl.aug.in
index 63558e5..9106abe 100644
--- a/src/libxl/test_libvirtd_libxl.aug.in
+++ b/src/libxl/test_libvirtd_libxl.aug.in
@@ -6,3 +6,4 @@ module Test_libvirtd_libxl =
{ "lock_manager" = "lockd" }
{ "keepalive_interval" = "5" }
{ "keepalive_count" = "5" }
+{ "nested_hvm" = "1" }
diff --git a/tests/libxlxml2domconfigtest.c b/tests/libxlxml2domconfigtest.c
index cfbc37c..8819032 100644
--- a/tests/libxlxml2domconfigtest.c
+++ b/tests/libxlxml2domconfigtest.c
@@ -76,6 +76,9 @@ 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);
--
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