x86_64: allow more vCPU-s per guest

Since the shared info layout is fixed, guests are required to use
VCPUOP_register_vcpu_info prior to booting any vCPU beyond the
traditional limit of 32.

MAX_VIRT_CPUS, being an implemetation detail of the hypervisor, is no
longer being exposed in the public headers.

The tools changes are clearly incomplete (and done only so things
would
build again), and the current state of the tools (using scalar
variables all over the place to represent vCPU bitmaps) very likely
doesn't permit booting DomU-s with more than the traditional number of
vCPU-s. Testing of the extended functionality was done with Dom0 (96
vCPU-s, as well as 128 vCPU-s out of which the kernel elected - by way
of a simple kernel side patch - to use only some, resulting in a
sparse
bitmap).

ia64 changes only to make things build, and build-tested only (and the
tools part only as far as the build would go without encountering
unrelated problems in the blktap code).

Signed-off-by: Jan Beulich <jbeulich@novell.com>

1 files changed, 15 insertions, 3 deletions

diff --git a/tools/debugger/xenitp/xenitp.c b/tools/debugger/xenitp/xenitp.c
index 95d3820f94..847d7bd7a6 100644
--- a/tools/debugger/xenitp/xenitp.c
+++ b/tools/debugger/xenitp/xenitp.c
@@ -955,7 +955,7 @@ char *parse_arg (char **buf)
     return res;
 }
 
-vcpu_guest_context_any_t vcpu_ctx_any[MAX_VIRT_CPUS];
+vcpu_guest_context_any_t *vcpu_ctx_any;
 
 int vcpu_setcontext (int vcpu)
 {
@@ -1584,11 +1584,23 @@ void xenitp (int vcpu)
 {
     int ret;
     struct sigaction sa;
-
-    cur_ctx = &vcpu_ctx_any[vcpu].c;
+    xc_dominfo_t dominfo;
 
     xc_handle = xc_interface_open (); /* for accessing control interface */
 
+    ret = xc_domain_getinfo (xc_handle, domid, 1, &dominfo);
+    if (ret < 0) {
+        perror ("xc_domain_getinfo");
+        exit (-1);
+    }
+
+    vcpu_ctx_any = calloc (sizeof(vcpu_ctx_any), dominfo.max_vcpu_id + 1);
+    if (!vcpu_ctx_any) {
+        perror ("vcpu context array alloc");
+        exit (-1);
+    }
+    cur_ctx = &vcpu_ctx_any[vcpu].c;
+
     if (xc_domain_setdebugging (xc_handle, domid, 1) != 0)
         perror ("setdebugging");