8:06 a.m.
From: Wim ten Have <wim.ten.have(a)oracle.com>
Xen feature nestedhvm is the option on Xen 4.4+ which enables
nested virtualization when mode host-passthrough is applied.
nested HVM is enabled by adding below on the target domain;
<cpu mode='host-passthrough'/>
Virtualization on target domain can be disabled by specifying
such under feature policy rule on target name;
[On Intel (VT-x) architecture]
<feature policy='disable' name='vmx'/>
or:
[On AMD (AMD-V) architecture]
<feature policy='disable' name='svm'/>
Signed-off-by: Joao Martins <joao.m.martins(a)oracle.com>
Signed-off-by: Wim ten Have <wim.ten.have(a)oracle.com>
---
src/libxl/libxl_conf.c | 39 ++++++++++++++++++++++++++++++++++++++-
src/libxl/libxl_conf.h | 1 +
src/libxl/libxl_domain.c | 2 +-
3 files changed, 40 insertions(+), 2 deletions(-)
diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c
index 4bab651..56bc097 100644
--- a/src/libxl/libxl_conf.c
+++ b/src/libxl/libxl_conf.c
@@ -47,6 +47,7 @@
#include "libxl_utils.h"
#include "virstoragefile.h"
#include "secret_util.h"
+#include "cpu/cpu.h"
#define VIR_FROM_THIS VIR_FROM_LIBXL
@@ -293,6 +294,7 @@ libxlMakeChrdevStr(virDomainChrDefPtr def, char **buf)
static int
libxlMakeDomBuildInfo(virDomainDefPtr def,
libxl_ctx *ctx,
+ virCapsPtr caps,
libxl_domain_config *d_config)
{
libxl_domain_build_info *b_info = &d_config->b_info;
@@ -374,6 +376,40 @@ libxlMakeDomBuildInfo(virDomainDefPtr def,
def->features[VIR_DOMAIN_FEATURE_ACPI] ==
VIR_TRISTATE_SWITCH_ON);
+ if (caps &&
+ def->cpu && def->cpu->mode ==
(VIR_CPU_MODE_HOST_PASSTHROUGH)) {
+ bool hasHwVirt = false;
+ bool svm = false, vmx = false;
+
+ if (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;
+ }
+
+ if (def->cpu->nfeatures) {
+ for (i = 0; i < def->cpu->nfeatures; i++) {
+
+ switch (def->cpu->features[i].policy) {
+
+ case VIR_CPU_FEATURE_DISABLE:
+ case VIR_CPU_FEATURE_FORBID:
+ if ((vmx && STREQ(def->cpu->features[i].name,
"vmx")) ||
+ (svm && STREQ(def->cpu->features[i].name,
"svm")))
+ hasHwVirt = false;
+ break;
+
+ case VIR_CPU_FEATURE_FORCE:
+ case VIR_CPU_FEATURE_REQUIRE:
+ case VIR_CPU_FEATURE_OPTIONAL:
+ case VIR_CPU_FEATURE_LAST:
+ break;
+ }
+ }
+ }
+ libxl_defbool_set(&b_info->u.hvm.nested_hvm, hasHwVirt);
+ }
+
if (def->nsounds > 0) {
/*
* Use first sound device. man xl.cfg(5) describes soundhw as
@@ -2089,6 +2125,7 @@ libxlBuildDomainConfig(virPortAllocatorPtr graphicsports,
virDomainDefPtr def,
const char *channelDir LIBXL_ATTR_UNUSED,
libxl_ctx *ctx,
+ virCapsPtr caps,
libxl_domain_config *d_config)
{
libxl_domain_config_init(d_config);
@@ -2096,7 +2133,7 @@ libxlBuildDomainConfig(virPortAllocatorPtr graphicsports,
if (libxlMakeDomCreateInfo(ctx, def, &d_config->c_info) < 0)
return -1;
- if (libxlMakeDomBuildInfo(def, ctx, d_config) < 0)
+ if (libxlMakeDomBuildInfo(def, ctx, caps, d_config) < 0)
return -1;
if (libxlMakeDiskList(def, d_config) < 0)
diff --git a/src/libxl/libxl_conf.h b/src/libxl/libxl_conf.h
index c653c9f..264df11 100644
--- a/src/libxl/libxl_conf.h
+++ b/src/libxl/libxl_conf.h
@@ -217,6 +217,7 @@ libxlBuildDomainConfig(virPortAllocatorPtr graphicsports,
virDomainDefPtr def,
const char *channelDir LIBXL_ATTR_UNUSED,
libxl_ctx *ctx,
+ virCapsPtr caps,
libxl_domain_config *d_config);
static inline void
diff --git a/src/libxl/libxl_domain.c b/src/libxl/libxl_domain.c
index ea28c93..256cf1d 100644
--- a/src/libxl/libxl_domain.c
+++ b/src/libxl/libxl_domain.c
@@ -1256,7 +1256,7 @@ libxlDomainStart(libxlDriverPrivatePtr driver,
goto cleanup_dom;
if (libxlBuildDomainConfig(driver->reservedGraphicsPorts, vm->def,
- cfg->channelDir, cfg->ctx, &d_config) < 0)
+ cfg->channelDir, cfg->ctx, cfg->caps,
&d_config) < 0)
goto cleanup_dom;
if (cfg->autoballoon && libxlDomainFreeMem(cfg->ctx, &d_config)
< 0)
--
2.9.3