[PATCH 1/3] KVM-userspace: introduce -nodes command line option

[PATCH 1/3] KVM-userspace: introduce -nodes command line option

[Andre Przywara]

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The attached patch parses a list of host nodes given on the command line 
and passes it on to lower levels (namely qemu-kvm.c)

Signed-off-by: Andre Przywara <andre.przywara@amd.com>

-- 
Andre Przywara
AMD-Operating System Research Center (OSRC), Dresden, Germany
Tel: +49 351 277-84917
----to satisfy European Law for business letters:
AMD Saxony Limited Liability Company & Co. KG,
Wilschdorfer Landstr. 101, 01109 Dresden, Germany
Register Court Dresden: HRA 4896, General Partner authorized
to represent: AMD Saxony LLC (Wilmington, Delaware, US)
General Manager of AMD Saxony LLC: Dr. Hans-R. Deppe, Thomas McCoy

[-- Attachment #2: kvmnuma_cmdline.patch --]
[-- Type: text/plain, Size: 2700 bytes --]

commit d34354eb622f667169edebd830364f646cd8f93e
Author: Andre Przywara <andre.przywara@amd.com>
Date:   Tue Nov 25 23:01:24 2008 +0100

    introduce -nodes comand line option

diff --git a/qemu/sysemu.h b/qemu/sysemu.h
index 5abda5c..07acaf4 100644
--- a/qemu/sysemu.h
+++ b/qemu/sysemu.h
@@ -99,6 +99,11 @@ extern int win2k_install_hack;
 extern int alt_grab;
 extern int usb_enabled;
 extern int smp_cpus;
+
+#define MAX_NODES 64
+extern int numnumanodes;
+extern int hostnodes[MAX_NODES];
+
 extern int cursor_hide;
 extern int graphic_rotate;
 extern int no_quit;
diff --git a/qemu/vl.c b/qemu/vl.c
index 92325e6..681b3de 100644
--- a/qemu/vl.c
+++ b/qemu/vl.c
@@ -228,6 +228,8 @@ int usb_enabled = 0;
 const char *assigned_devices[MAX_DEV_ASSIGN_CMDLINE];
 int assigned_devices_index;
 int smp_cpus = 1;
+int numnumanodes = 0;
+int hostnodes[MAX_NODES];
 const char *vnc_display;
 int acpi_enabled = 1;
 int fd_bootchk = 1;
@@ -4193,6 +4195,7 @@ enum {
     QEMU_OPTION_usb,
     QEMU_OPTION_usbdevice,
     QEMU_OPTION_smp,
+    QEMU_OPTION_nodes,
     QEMU_OPTION_vnc,
     QEMU_OPTION_no_acpi,
     QEMU_OPTION_curses,
@@ -4320,6 +4323,7 @@ static const QEMUOption qemu_options[] = {
     { "win2k-hack", 0, QEMU_OPTION_win2k_hack },
     { "usbdevice", HAS_ARG, QEMU_OPTION_usbdevice },
     { "smp", HAS_ARG, QEMU_OPTION_smp },
+    { "nodes", HAS_ARG, QEMU_OPTION_nodes },
     { "vnc", HAS_ARG, QEMU_OPTION_vnc },
 #ifdef CONFIG_CURSES
     { "curses", 0, QEMU_OPTION_curses },
@@ -4711,6 +4715,25 @@ static void termsig_setup(void)
 
 #endif
 
+static int parse_to_array (const char *arg, int *array, int maxentries)
+{
+const char *s;
+char *end;
+int num;
+int value;
+
+    num=0;
+    for (s=arg; s!=NULL; s = strchr (end, ','))
+	{
+		while (*s == ',') s++;
+	    value = strtol (s, &end, 10);
+	    if (end == s) break;
+	    if (num >= maxentries) break;
+	    array[num++] = value;
+	}
+	return num;
+}
+
 int main(int argc, char **argv)
 {
 #ifdef CONFIG_GDBSTUB
@@ -5290,6 +5313,13 @@ int main(int argc, char **argv)
                     exit(1);
                 }
                 break;
+            case QEMU_OPTION_nodes:
+                numnumanodes = parse_to_array (optarg, hostnodes,MAX_NODES);
+                if (numnumanodes < 0) {
+                    fprintf(stderr, "Invalid number of NUMA nodes\n");
+                    exit(1);
+                }
+                break;
 	    case QEMU_OPTION_vnc:
 		vnc_display = optarg;
 		break;
@@ -5442,6 +5472,9 @@ int main(int argc, char **argv)
            monitor_device = "stdio";
     }
 
+    if (numnumanodes > smp_cpus)
+        numnumanodes = smp_cpus;
+
 #ifndef _WIN32
     if (daemonize) {
 	pid_t pid;

Re: [PATCH 1/3] KVM-userspace: introduce -nodes command line option

[Daniel P. Berrange]

On Thu, Nov 27, 2008 at 11:25:12PM +0100, Andre Przywara wrote:
> The attached patch parses a list of host nodes given on the command line 
> and passes it on to lower levels (namely qemu-kvm.c)


> diff --git a/qemu/sysemu.h b/qemu/sysemu.h
> index 5abda5c..07acaf4 100644
> --- a/qemu/sysemu.h
> +++ b/qemu/sysemu.h
> @@ -99,6 +99,11 @@ extern int win2k_install_hack;
>  extern int alt_grab;
>  extern int usb_enabled;
>  extern int smp_cpus;
> +
> +#define MAX_NODES 64
> +extern int numnumanodes;
> +extern int hostnodes[MAX_NODES];

This is rather less than Linux / libnuma seems to allow for max
nodes. In numa.h there is

#if defined(__x86_64__) || defined(__i386__) 
#define NUMA_NUM_NODES  128
#else
#define NUMA_NUM_NODES  2048
#endif

Should we just use that NUMA_NUM_NODES constant directly from numa.h
when numa is compiled in, so we're guarenteed to match.

Daniel
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