[PATCH v3 12/13] x86/altp2m: Add altp2mhvm HVM domain parameter.

[Ed White <edmund.h.white@intel.com>]

The altp2mhvm and nestedhvm parameters are mutually
exclusive and cannot be set together.

Signed-off-by: Ed White <edmund.h.white@intel.com>
---
 docs/man/xl.cfg.pod.5           | 12 ++++++++++++
 tools/libxl/libxl_create.c      |  1 +
 tools/libxl/libxl_dom.c         |  2 ++
 tools/libxl/libxl_types.idl     |  1 +
 tools/libxl/xl_cmdimpl.c        |  8 ++++++++
 xen/arch/x86/hvm/hvm.c          | 16 +++++++++++++++-
 xen/include/public/hvm/params.h |  5 ++++-
 7 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/docs/man/xl.cfg.pod.5 b/docs/man/xl.cfg.pod.5
index a3e0e2e..18afd46 100644
--- a/docs/man/xl.cfg.pod.5
+++ b/docs/man/xl.cfg.pod.5
@@ -1035,6 +1035,18 @@ enabled by default and you should usually omit it. It may be necessary
 to disable the HPET in order to improve compatibility with guest
 Operating Systems (X86 only)
 
+=item B<altp2mhvm=BOOLEAN>
+
+Enables or disables hvm guest access to alternate-p2m capability.
+Alternate-p2m allows a guest to manage multiple p2m guest physical
+"memory views" (as opposed to a single p2m). This option is
+disabled by default and is available only to hvm domains.
+You may want this option if you want to access-control/isolate
+access to specific guest physical memory pages accessed by
+the guest, e.g. for HVM domain memory introspection or
+for isolation/access-control of memory between components within
+a single guest hvm domain.
+
 =item B<nestedhvm=BOOLEAN>
 
 Enable or disables guest access to hardware virtualisation features,
diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
index 86384d2..35e322e 100644
--- a/tools/libxl/libxl_create.c
+++ b/tools/libxl/libxl_create.c
@@ -329,6 +329,7 @@ int libxl__domain_build_info_setdefault(libxl__gc *gc,
         libxl_defbool_setdefault(&b_info->u.hvm.hpet,               true);
         libxl_defbool_setdefault(&b_info->u.hvm.vpt_align,          true);
         libxl_defbool_setdefault(&b_info->u.hvm.nested_hvm,         false);
+        libxl_defbool_setdefault(&b_info->u.hvm.altp2mhvm,          false);
         libxl_defbool_setdefault(&b_info->u.hvm.usb,                false);
         libxl_defbool_setdefault(&b_info->u.hvm.xen_platform_pci,   true);
 
diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index 600393d..b75f49b 100644
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -300,6 +300,8 @@ static void hvm_set_conf_params(xc_interface *handle, uint32_t domid,
                     libxl_defbool_val(info->u.hvm.vpt_align));
     xc_hvm_param_set(handle, domid, HVM_PARAM_NESTEDHVM,
                     libxl_defbool_val(info->u.hvm.nested_hvm));
+    xc_hvm_param_set(handle, domid, HVM_PARAM_ALTP2MHVM,
+                    libxl_defbool_val(info->u.hvm.altp2mhvm));
 }
 
 int libxl__build_pre(libxl__gc *gc, uint32_t domid,
diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
index 23f27d4..66a89cf 100644
--- a/tools/libxl/libxl_types.idl
+++ b/tools/libxl/libxl_types.idl
@@ -437,6 +437,7 @@ libxl_domain_build_info = Struct("domain_build_info",[
                                        ("mmio_hole_memkb",  MemKB),
                                        ("timer_mode",       libxl_timer_mode),
                                        ("nested_hvm",       libxl_defbool),
+                                       ("altp2mhvm",        libxl_defbool),
                                        ("smbios_firmware",  string),
                                        ("acpi_firmware",    string),
                                        ("nographic",        libxl_defbool),
diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
index c858068..ccb0de9 100644
--- a/tools/libxl/xl_cmdimpl.c
+++ b/tools/libxl/xl_cmdimpl.c
@@ -1500,6 +1500,14 @@ static void parse_config_data(const char *config_source,
 
         xlu_cfg_get_defbool(config, "nestedhvm", &b_info->u.hvm.nested_hvm, 0);
 
+        xlu_cfg_get_defbool(config, "altp2mhvm", &b_info->u.hvm.altp2mhvm, 0);
+
+        if (strcmp(libxl_defbool_to_string(b_info->u.hvm.nested_hvm), "True") == 0 &&
+            strcmp(libxl_defbool_to_string(b_info->u.hvm.altp2mhvm), "True") == 0) {
+            fprintf(stderr, "ERROR: nestedhvm and altp2mhvm cannot be used together\n");
+            exit (1);
+        }
+
         xlu_cfg_replace_string(config, "smbios_firmware",
                                &b_info->u.hvm.smbios_firmware, 0);
         xlu_cfg_replace_string(config, "acpi_firmware",
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 0d81050..92c123c 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -5754,6 +5754,7 @@ static int hvm_allow_set_param(struct domain *d,
     case HVM_PARAM_VIRIDIAN:
     case HVM_PARAM_IOREQ_SERVER_PFN:
     case HVM_PARAM_NR_IOREQ_SERVER_PAGES:
+    case HVM_PARAM_ALTP2MHVM:
         if ( value != 0 && a->value != value )
             rc = -EEXIST;
         break;
@@ -5876,6 +5877,9 @@ static int hvmop_set_param(
          */
         if ( cpu_has_svm && !paging_mode_hap(d) && a.value )
             rc = -EINVAL;
+        if ( a.value &&
+             d->arch.hvm_domain.params[HVM_PARAM_ALTP2MHVM] )
+            rc = -EINVAL;
         /* Set up NHVM state for any vcpus that are already up. */
         if ( a.value &&
              !d->arch.hvm_domain.params[HVM_PARAM_NESTEDHVM] )
@@ -5886,6 +5890,13 @@ static int hvmop_set_param(
             for_each_vcpu(d, v)
                 nestedhvm_vcpu_destroy(v);
         break;
+    case HVM_PARAM_ALTP2MHVM:
+        if ( a.value > 1 )
+            rc = -EINVAL;
+        if ( a.value &&
+             d->arch.hvm_domain.params[HVM_PARAM_NESTEDHVM] )
+            rc = -EINVAL;
+        break;
     case HVM_PARAM_BUFIOREQ_EVTCHN:
         rc = -EINVAL;
         break;
@@ -5946,6 +5957,7 @@ static int hvm_allow_get_param(struct domain *d,
     case HVM_PARAM_STORE_EVTCHN:
     case HVM_PARAM_CONSOLE_PFN:
     case HVM_PARAM_CONSOLE_EVTCHN:
+    case HVM_PARAM_ALTP2MHVM:
         break;
     /*
      * The following parameters must not be read by the guest
@@ -6460,7 +6472,8 @@ long do_hvm_op(unsigned long op, XEN_GUEST_HANDLE_PARAM(void) arg)
             return -ESRCH;
 
         rc = -EINVAL;
-        if ( is_hvm_domain(d) && hvm_altp2m_supported() )
+        if ( is_hvm_domain(d) && hvm_altp2m_supported() &&
+             d->arch.hvm_domain.params[HVM_PARAM_ALTP2MHVM] )
         {
             a.state = altp2m_active(d);
             rc = __copy_to_guest(arg, &a, 1) ? -EFAULT : 0;
@@ -6486,6 +6499,7 @@ long do_hvm_op(unsigned long op, XEN_GUEST_HANDLE_PARAM(void) arg)
 
         rc = -EINVAL;
         if ( is_hvm_domain(d) && hvm_altp2m_supported() &&
+             d->arch.hvm_domain.params[HVM_PARAM_ALTP2MHVM] &&
              !nestedhvm_enabled(d) )
         {
             ostate = d->arch.altp2m_active;
diff --git a/xen/include/public/hvm/params.h b/xen/include/public/hvm/params.h
index 7c73089..1b5f840 100644
--- a/xen/include/public/hvm/params.h
+++ b/xen/include/public/hvm/params.h
@@ -187,6 +187,9 @@
 /* Location of the VM Generation ID in guest physical address space. */
 #define HVM_PARAM_VM_GENERATION_ID_ADDR 34
 
-#define HVM_NR_PARAMS          35
+/* Boolean: Enable altp2m (hvm only) */
+#define HVM_PARAM_ALTP2MHVM    35
+
+#define HVM_NR_PARAMS          36
 
 #endif /* __XEN_PUBLIC_HVM_PARAMS_H__ */
-- 
1.9.1