[PATCH v2 1/7] tools: Make some callers of xc_domain_getinfo() use xc_domain_getinfolist()

[Alejandro Vallejo <alejandro.vallejo@xxxxxxxxx>]

xc_domain_getinfo() is slow and prone to races because N hypercalls are
needed to find information about N domains. xc_domain_getinfolist() finds
the same information in a single hypercall as long as a big enough buffer
is provided. Plus, xc_domain_getinfo() is disappearing on a future patch
so migrate the callers interested in more than 1 domain to the the *list()
version.

Signed-off-by: Alejandro Vallejo <alejandro.vallejo@xxxxxxxxx>
---
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Cc: Wei Liu <wl@xxxxxxx>
Cc: Anthony PERARD <anthony.perard@xxxxxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
---
 tools/include/xenctrl.h           | 12 ++++++++++++
 tools/python/xen/lowlevel/xc/xc.c | 28 ++++++++++++++--------------
 tools/xenmon/xenbaked.c           |  6 +++---
 3 files changed, 29 insertions(+), 17 deletions(-)

diff --git a/tools/include/xenctrl.h b/tools/include/xenctrl.h
index 05967ecc92..f5bc7f58b6 100644
--- a/tools/include/xenctrl.h
+++ b/tools/include/xenctrl.h
@@ -468,6 +468,18 @@ typedef struct xc_dominfo {
 
 typedef xen_domctl_getdomaininfo_t xc_domaininfo_t;
 
+static inline unsigned int dominfo_shutdown_reason(const xc_domaininfo_t *info)
+{
+    return (info->flags >> XEN_DOMINF_shutdownshift) & XEN_DOMINF_shutdownmask;
+}
+
+static inline bool dominfo_shutdown_with(xc_domaininfo_t *info, unsigned int 
expected_reason)
+{
+    /* The reason doesn't make sense unless the domain is actually shutdown */
+    return (info->flags & XEN_DOMINF_shutdown) &&
+           (dominfo_shutdown_reason(info) == expected_reason);
+}
+
 typedef union 
 {
 #if defined(__i386__) || defined(__x86_64__)
diff --git a/tools/python/xen/lowlevel/xc/xc.c 
b/tools/python/xen/lowlevel/xc/xc.c
index 35901c2d63..d7ce299650 100644
--- a/tools/python/xen/lowlevel/xc/xc.c
+++ b/tools/python/xen/lowlevel/xc/xc.c
@@ -342,7 +342,7 @@ static PyObject *pyxc_domain_getinfo(XcObject *self,
     uint32_t first_dom = 0;
     int max_doms = 1024, nr_doms, i;
     size_t j;
-    xc_dominfo_t *info;
+    xc_domaininfo_t *info;
 
     static char *kwd_list[] = { "first_dom", "max_doms", NULL };
 
@@ -350,11 +350,11 @@ static PyObject *pyxc_domain_getinfo(XcObject *self,
                                       &first_dom, &max_doms) )
         return NULL;
 
-    info = calloc(max_doms, sizeof(xc_dominfo_t));
+    info = calloc(max_doms, sizeof(*info));
     if (info == NULL)
         return PyErr_NoMemory();
 
-    nr_doms = xc_domain_getinfo(self->xc_handle, first_dom, max_doms, info);
+    nr_doms = xc_domain_getinfolist(self->xc_handle, first_dom, max_doms, 
info);
 
     if (nr_doms < 0)
     {
@@ -368,21 +368,21 @@ static PyObject *pyxc_domain_getinfo(XcObject *self,
         info_dict = Py_BuildValue(
             "{s:i,s:i,s:i,s:i,s:i,s:i,s:i,s:i,s:i,s:i"
             ",s:L,s:L,s:L,s:i,s:i,s:i}",
-            "domid",           (int)info[i].domid,
+            "domid",           (int)info[i].domain,
             "online_vcpus",    info[i].nr_online_vcpus,
             "max_vcpu_id",     info[i].max_vcpu_id,
-            "hvm",             info[i].hvm,
-            "dying",           info[i].dying,
-            "crashed",         info[i].crashed,
-            "shutdown",        info[i].shutdown,
-            "paused",          info[i].paused,
-            "blocked",         info[i].blocked,
-            "running",         info[i].running,
-            "mem_kb",          (long long)info[i].nr_pages*(XC_PAGE_SIZE/1024),
+            "hvm",             !!(info[i].flags & XEN_DOMINF_hvm_guest),
+            "dying",           !!(info[i].flags & XEN_DOMINF_dying),
+            "crashed",         dominfo_shutdown_with(&info[i], SHUTDOWN_crash),
+            "shutdown",        !!(info[i].flags & XEN_DOMINF_shutdown),
+            "paused",          !!(info[i].flags & XEN_DOMINF_paused),
+            "blocked",         !!(info[i].flags & XEN_DOMINF_blocked),
+            "running",         !!(info[i].flags & XEN_DOMINF_running),
+            "mem_kb",          (long 
long)info[i].tot_pages*(XC_PAGE_SIZE/1024),
             "cpu_time",        (long long)info[i].cpu_time,
-            "maxmem_kb",       (long long)info[i].max_memkb,
+            "maxmem_kb",       (long long)(info[i].max_pages << (XC_PAGE_SHIFT 
- 10)),
             "ssidref",         (int)info[i].ssidref,
-            "shutdown_reason", info[i].shutdown_reason,
+            "shutdown_reason", dominfo_shutdown_reason(&info[i]),
             "cpupool",         (int)info[i].cpupool);
         pyhandle = PyList_New(sizeof(xen_domain_handle_t));
         if ( (pyhandle == NULL) || (info_dict == NULL) )
diff --git a/tools/xenmon/xenbaked.c b/tools/xenmon/xenbaked.c
index 4dddbd20e2..8632b10ea4 100644
--- a/tools/xenmon/xenbaked.c
+++ b/tools/xenmon/xenbaked.c
@@ -775,7 +775,7 @@ static void global_init_domain(int domid, int idx)
 static int indexof(int domid)
 {
     int idx;
-    xc_dominfo_t dominfo[NDOMAINS];
+    xc_domaininfo_t dominfo[NDOMAINS];
     xc_interface *xc_handle;
     int ndomains;
   
@@ -797,7 +797,7 @@ static int indexof(int domid)
 
     // call domaininfo hypercall to try and garbage collect unused entries
     xc_handle = xc_interface_open(0,0,0);
-    ndomains = xc_domain_getinfo(xc_handle, 0, NDOMAINS, dominfo);
+    ndomains = xc_domain_getinfolist(xc_handle, 0, NDOMAINS, dominfo);
     xc_interface_close(xc_handle);
 
     // for each domain in our data, look for it in the system dominfo structure
@@ -808,7 +808,7 @@ static int indexof(int domid)
         int jdx;
     
         for (jdx=0; jdx<ndomains; jdx++) {
-            if (dominfo[jdx].domid == domid)
+            if (dominfo[jdx].domain == domid)
                 break;
         }
         if (jdx == ndomains)        // we didn't find domid in the dominfo 
struct
-- 
2.34.1