tools: Delete XEN_DOMCTL_disable_migrate

It is conceptually wrong for this information to exist in the hypervisor in
the first place.  Only the toolstack is capable of correctly reasoning about
the non-migrateability of guests.

This hypercall has only ever existed to control the visibility of the
Invariant TSC flag to the guest.  Now that we have properly disentanged that
and moved ITSC into the guests CPUID policy, delete this hypercall.

Furthermore, this fixes a corner case where Xen would override the toolstacks
choice of ITSC for a xenstore stubdomain.  That said, init-xenstore-domain
doesn't currently ask for ITSC, and MiniOS doesn't know what ITSC is either,
so nothing actually changes in practice.

Bump the DOMCTL_INTERFACE_VERSION for 4.15

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>

tools/libs/ctrl/include/xenctrl.h

@@ -1351,8 +1351,6 @@ int xc_domain_get_tsc_info(xc_interface *xch,
                            uint32_t *gtsc_khz,
                            uint32_t *incarnation);
 
-int xc_domain_disable_migrate(xc_interface *xch, uint32_t domid);
-
 int xc_domain_maximum_gpfn(xc_interface *xch, uint32_t domid, xen_pfn_t *gpfns);
 
 int xc_domain_nr_gpfns(xc_interface *xch, uint32_t domid, xen_pfn_t *gpfns);

tools/libs/ctrl/xc_domain.c

@@ -815,15 +815,6 @@ int xc_domain_set_time_offset(xc_interface *xch,
     return do_domctl(xch, &domctl);
 }
 
-int xc_domain_disable_migrate(xc_interface *xch, uint32_t domid)
-{
-    DECLARE_DOMCTL;
-    domctl.cmd = XEN_DOMCTL_disable_migrate;
-    domctl.domain = domid;
-    domctl.u.disable_migrate.disable = 1;
-    return do_domctl(xch, &domctl);
-}
-
 int xc_domain_set_tsc_info(xc_interface *xch,
                            uint32_t domid,
                            uint32_t tsc_mode,

tools/libxl/libxl_dom.c

@@ -257,12 +257,6 @@ int libxl__build_pre(libxl__gc *gc, uint32_t domid,
         return ERROR_FAIL;
     }
 
-    if (libxl_defbool_val(d_config->b_info.disable_migrate) &&
-        xc_domain_disable_migrate(ctx->xch, domid) != 0) {
-        LOG(ERROR, "Couldn't set nomigrate");
-        return ERROR_FAIL;
-    }
-
     /*
      * Check if the domain has any CPU or node affinity already. If not, try
      * to build up the latter via automatic NUMA placement. In fact, in case

tools/python/xen/lowlevel/xc/xc.c

@@ -1469,20 +1469,6 @@ static PyObject *pyxc_domain_set_tsc_info(XcObject *self, PyObject *args)
     return zero;
 }
 
-static PyObject *pyxc_domain_disable_migrate(XcObject *self, PyObject *args)
-{
-    uint32_t dom;
-
-    if (!PyArg_ParseTuple(args, "i", &dom))
-        return NULL;
-
-    if (xc_domain_disable_migrate(self->xc_handle, dom) != 0)
-        return pyxc_error_to_exception(self->xc_handle);
-
-    Py_INCREF(zero);
-    return zero;
-}
-
 static PyObject *pyxc_domain_send_trigger(XcObject *self,
                                           PyObject *args,
                                           PyObject *kwds)
@@ -2306,13 +2292,6 @@ static PyMethodDef pyxc_methods[] = {
       "                   1=always emulate 2=never emulate\n"
       "Returns: [int] 0 on success; -1 on error.\n" },
 
-    { "domain_disable_migrate",
-      (PyCFunction)pyxc_domain_disable_migrate,
-      METH_VARARGS, "\n"
-      "Marks domain as non-migratable AND non-restoreable\n"
-      " dom        [int]: Domain whose TSC mode is being set.\n"
-      "Returns: [int] 0 on success; -1 on error.\n" },
-
     { "domain_send_trigger",
       (PyCFunction)pyxc_domain_send_trigger,
       METH_VARARGS | METH_KEYWORDS, "\n"

xen/arch/arm/domctl.c

@@ -146,10 +146,6 @@ long arch_do_domctl(struct xen_domctl *domctl, struct domain *d,
         return 0;
     }
 
-    case XEN_DOMCTL_disable_migrate:
-        d->disable_migrate = domctl->u.disable_migrate.disable;
-        return 0;
-
     case XEN_DOMCTL_vuart_op:
     {
         int rc;

xen/arch/x86/cpuid.c

@@ -708,7 +708,8 @@ int init_domain_cpuid_policy(struct domain *d)
     if ( !p )
         return -ENOMEM;
 
-    if ( d->disable_migrate )
+    /* The hardware domain can't migrate.  Give it ITSC if available. */
+    if ( is_hardware_domain(d) )
         p->extd.itsc = cpu_has_itsc;
 
     /*

xen/arch/x86/domctl.c

@@ -1277,11 +1277,6 @@ long arch_do_domctl(
 
         break;
 
-    case XEN_DOMCTL_disable_migrate:
-        d->disable_migrate = domctl->u.disable_migrate.disable;
-        recalculate_cpuid_policy(d);
-        break;
-
     case XEN_DOMCTL_get_cpu_policy:
         /* Process the CPUID leaves. */
         if ( guest_handle_is_null(domctl->u.cpu_policy.cpuid_policy) )

xen/common/domain.c

@@ -371,7 +371,6 @@ struct domain *domain_create(domid_t domid,
         if ( hardware_domid < 0 || hardware_domid >= DOMID_FIRST_RESERVED )
             panic("The value of hardware_dom must be a valid domain ID\n");
 
-        d->disable_migrate = true;
         old_hwdom = hardware_domain;
         hardware_domain = d;
     }
@@ -452,9 +451,6 @@ struct domain *domain_create(domid_t domid,
         watchdog_domain_init(d);
         init_status |= INIT_watchdog;
 
-        if ( is_xenstore_domain(d) )
-            d->disable_migrate = true;
-
         d->iomem_caps = rangeset_new(d, "I/O Memory", RANGESETF_prettyprint_hex);
         d->irq_caps   = rangeset_new(d, "Interrupts", 0);
         if ( !d->iomem_caps || !d->irq_caps )

xen/include/public/domctl.h

@@ -38,7 +38,7 @@
 #include "hvm/save.h"
 #include "memory.h"
 
-#define XEN_DOMCTL_INTERFACE_VERSION 0x00000012
+#define XEN_DOMCTL_INTERFACE_VERSION 0x00000013
 
 /*
  * NB. xen_domctl.domain is an IN/OUT parameter for this operation.
@@ -730,11 +730,6 @@ struct xen_domctl_hvmcontext_partial {
     XEN_GUEST_HANDLE_64(uint8) buffer;  /* OUT: buffer to write record into */
 };
 
-/* XEN_DOMCTL_disable_migrate */
-struct xen_domctl_disable_migrate {
-    uint32_t disable; /* IN: 1: disable migration and restore */
-};
-
 
 /* XEN_DOMCTL_gettscinfo */
 /* XEN_DOMCTL_settscinfo */
@@ -1191,7 +1186,7 @@ struct xen_domctl {
 #define XEN_DOMCTL_gethvmcontext_partial         55
 #define XEN_DOMCTL_vm_event_op                   56
 #define XEN_DOMCTL_mem_sharing_op                57
-#define XEN_DOMCTL_disable_migrate               58
+/* #define XEN_DOMCTL_disable_migrate            58 - Obsolete */
 #define XEN_DOMCTL_gettscinfo                    59
 #define XEN_DOMCTL_settscinfo                    60
 #define XEN_DOMCTL_getpageframeinfo3             61
@@ -1242,7 +1237,6 @@ struct xen_domctl {
         struct xen_domctl_ioport_permission ioport_permission;
         struct xen_domctl_hypercall_init    hypercall_init;
         struct xen_domctl_settimeoffset     settimeoffset;
-        struct xen_domctl_disable_migrate   disable_migrate;
         struct xen_domctl_tsc_info          tsc_info;
         struct xen_domctl_hvmcontext        hvmcontext;
         struct xen_domctl_hvmcontext_partial hvmcontext_partial;

xen/include/xen/sched.h

@@ -401,8 +401,6 @@ struct domain
     bool             is_privileged;
     /* Can this guest access the Xen console? */
     bool             is_console;
-    /* Non-migratable and non-restoreable? */
-    bool             disable_migrate;
     /* Is this guest being debugged by dom0? */
     bool             debugger_attached;
     /*

xen/xsm/flask/hooks.c

@@ -710,7 +710,6 @@ static int flask_domctl(struct domain *d, int cmd)
         return current_has_perm(d, SECCLASS_DOMAIN, DOMAIN__SETDEBUGGING);
 
     case XEN_DOMCTL_subscribe:
-    case XEN_DOMCTL_disable_migrate:
         return current_has_perm(d, SECCLASS_DOMAIN, DOMAIN__SET_MISC_INFO);
 
     case XEN_DOMCTL_set_virq_handler:

xen/xsm/flask/policy/access_vectors

@@ -176,7 +176,7 @@ class domain
     getpodtarget
 # XENMEM_set_pod_target
     setpodtarget
-# XEN_DOMCTL_subscribe, XEN_DOMCTL_disable_migrate
+# XEN_DOMCTL_subscribe
     set_misc_info
 # XEN_DOMCTL_set_virq_handler
     set_virq_handler