tools: Pass max_vcpus to XEN_DOMCTL_createdomain

XEN_DOMCTL_max_vcpus is a mandatory hypercall, but nothing actually prevents a
toolstack from unpausing a domain with no vcpus.

Originally, d->vcpus[] was an embedded array in struct domain, but c/s
fb442e217 "x86_64: allow more vCPU-s per guest" in Xen 4.0 altered it to being
dynamically allocated.  A side effect of this is that d->vcpu[] is NULL until
XEN_DOMCTL_max_vcpus has completed, but a lot of hypercalls blindly
dereference it.

Even today, the behaviour of XEN_DOMCTL_max_vcpus is a mandatory singleton
call which can't change the number of vcpus once a value has been chosen.

In preparation to remote the hypercall, extend xen_domctl_createdomain with
the a max_vcpus field and arrange for all callers to pass the appropriate
value.  There is no change in construction behaviour yet, but later patches
will rearrange the hypervisor internals.

For the python stubs, extend the domain_create keyword list to take a
max_vcpus parameter, in lieu of deleting the pyxc_domain_max_vcpus function.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>

diff --git a/tools/helpers/init-xenstore-domain.c b/tools/helpers/init-xenstore-domain.c
index 47717508a228df07b4d7d8ced3fbc54fe6f5623c..3236d144166ea36318aa453e9d3291af5e7fceee 100644 (file)
--- a/tools/helpers/init-xenstore-domain.c
+++ b/tools/helpers/init-xenstore-domain.c
@@ -66,6 +66,7 @@ static int build(xc_interface *xch)
     struct xen_domctl_createdomain config = {
         .ssidref = SECINITSID_DOMU,
         .flags = XEN_DOMCTL_CDF_xs_domain,
+        .max_vcpus = 1,
         .max_evtchn_port = -1, /* No limit. */
 
         /*
@@ -100,7 +101,7 @@ static int build(xc_interface *xch)
         fprintf(stderr, "xc_domain_create failed\n");
         goto err;
     }
-    rv = xc_domain_max_vcpus(xch, domid, 1);
+    rv = xc_domain_max_vcpus(xch, domid, config.max_vcpus);
     if ( rv )
     {
         fprintf(stderr, "xc_domain_max_vcpus failed\n");

diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
index 8b755e412d1423cb65e6f627589239d6d67d5eba..60676304e9b524e0bd498a55757f710b1e6f6b1e 100644 (file)
--- a/tools/libxl/libxl_create.c
+++ b/tools/libxl/libxl_create.c
@@ -566,6 +566,7 @@ int libxl__domain_make(libxl__gc *gc, libxl_domain_config *d_config,
     if (!libxl_domid_valid_guest(*domid)) {
         struct xen_domctl_createdomain create = {
             .ssidref = info->ssidref,
+            .max_vcpus = b_info->max_vcpus,
             .max_evtchn_port = b_info->event_channels,
             .max_grant_frames = b_info->max_grant_frames,
             .max_maptrack_frames = b_info->max_maptrack_frames,

diff --git a/tools/ocaml/libs/xc/xenctrl.ml b/tools/ocaml/libs/xc/xenctrl.ml
index 42f45c4b67e0dd48ce4a55d0eb620b0e2b9edfc1..40fbd3790ff042e6bbb702c0d0ef92fa755fb069 100644 (file)
--- a/tools/ocaml/libs/xc/xenctrl.ml
+++ b/tools/ocaml/libs/xc/xenctrl.ml
@@ -63,6 +63,7 @@ type domctl_create_config =
        ssidref: int32;
        handle: string;
        flags: domain_create_flag list;
+       max_vcpus: int;
        max_evtchn_port: int;
        max_grant_frames: int;
        max_maptrack_frames: int;

diff --git a/tools/ocaml/libs/xc/xenctrl.mli b/tools/ocaml/libs/xc/xenctrl.mli
index 0db58162d0179d9c9e7d3b5f10948718c9d17783..906ce9486b769aef057561d9f4b24bea5d3c6732 100644 (file)
--- a/tools/ocaml/libs/xc/xenctrl.mli
+++ b/tools/ocaml/libs/xc/xenctrl.mli
@@ -55,6 +55,7 @@ type domctl_create_config = {
   ssidref: int32;
   handle: string;
   flags: domain_create_flag list;
+  max_vcpus: int;
   max_evtchn_port: int;
   max_grant_frames: int;
   max_maptrack_frames: int;

diff --git a/tools/ocaml/libs/xc/xenctrl_stubs.c b/tools/ocaml/libs/xc/xenctrl_stubs.c
index 1b5abd9f3a8af58faaf47d80f556fb5d07d2a516..578a014eac3468fbe919f1e28e94e6f0e265dd04 100644 (file)
--- a/tools/ocaml/libs/xc/xenctrl_stubs.c
+++ b/tools/ocaml/libs/xc/xenctrl_stubs.c
@@ -128,15 +128,17 @@ CAMLprim value stub_xc_domain_create(value xch, value config)
 #define VAL_SSIDREF             Field(config, 0)
 #define VAL_HANDLE              Field(config, 1)
 #define VAL_FLAGS               Field(config, 2)
-#define VAL_MAX_EVTCHN_PORT     Field(config, 3)
-#define VAL_MAX_GRANT_FRAMES    Field(config, 4)
-#define VAL_MAX_MAPTRACK_FRAMES Field(config, 5)
-#define VAL_ARCH                Field(config, 6)
+#define VAL_MAX_VCPUS           Field(config, 3)
+#define VAL_MAX_EVTCHN_PORT     Field(config, 4)
+#define VAL_MAX_GRANT_FRAMES    Field(config, 5)
+#define VAL_MAX_MAPTRACK_FRAMES Field(config, 6)
+#define VAL_ARCH                Field(config, 7)
 
        uint32_t domid = 0;
        int result;
        struct xen_domctl_createdomain cfg = {
                .ssidref = Int32_val(VAL_SSIDREF),
+               .max_vcpus = Int_val(VAL_MAX_VCPUS),
                .max_evtchn_port = Int_val(VAL_MAX_EVTCHN_PORT),
                .max_grant_frames = Int_val(VAL_MAX_GRANT_FRAMES),
                .max_maptrack_frames = Int_val(VAL_MAX_MAPTRACK_FRAMES),
@@ -178,6 +180,7 @@ CAMLprim value stub_xc_domain_create(value xch, value config)
 #undef VAL_MAX_MAPTRACK_FRAMES
 #undef VAL_MAX_GRANT_FRAMES
 #undef VAL_MAX_EVTCHN_PORT
+#undef VAL_MAX_VCPUS
 #undef VAL_FLAGS
 #undef VAL_HANDLE
 #undef VAL_SSIDREF

diff --git a/tools/python/xen/lowlevel/xc/xc.c b/tools/python/xen/lowlevel/xc/xc.c
index 6bd58ecbcdc3c42a97ea9cb68fa1232eb0d74dd6..b137d5a839b50a77316377f41ae9ca3b0c279996 100644 (file)
--- a/tools/python/xen/lowlevel/xc/xc.c
+++ b/tools/python/xen/lowlevel/xc/xc.c
@@ -125,16 +125,19 @@ static PyObject *pyxc_domain_create(XcObject *self,
             0xde, 0xad, 0xbe, 0xef, 0xde, 0xad, 0xbe, 0xef,
             0xde, 0xad, 0xbe, 0xef, 0xde, 0xad, 0xbe, 0xef,
         },
+        .max_vcpus = 1,
         .max_evtchn_port = -1, /* No limit. */
         .max_grant_frames = 32,
         .max_maptrack_frames = 1024,
     };
 
-    static char *kwd_list[] = { "domid", "ssidref", "handle", "flags", "target", NULL };
+    static char *kwd_list[] = { "domid", "ssidref", "handle", "flags",
+                                "target", "max_vcpus", NULL };
 
-    if ( !PyArg_ParseTupleAndKeywords(args, kwds, "|iiOii", kwd_list,
+    if ( !PyArg_ParseTupleAndKeywords(args, kwds, "|iiOiii", kwd_list,
                                       &dom, &config.ssidref, &pyhandle,
-                                      &config.flags, &target))
+                                      &config.flags, &target,
+                                      &config.max_vcpus) )
         return NULL;
     if ( pyhandle != NULL )
     {

diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
index 2b496d4e3141f17b235780d77b05837d1be62de1..512e21d1b83e73f0fcc3f4ee48e26ff960610f33 100644 (file)
--- a/xen/include/public/domctl.h
+++ b/xen/include/public/domctl.h
@@ -70,6 +70,7 @@ struct xen_domctl_createdomain {
      * Various domain limits, which impact the quantity of resources (global
      * mapping space, xenheap, etc) a guest may consume.
      */
+    uint32_t max_vcpus;
     uint32_t max_evtchn_port;
     uint32_t max_grant_frames;
     uint32_t max_maptrack_frames;