Commit ee785fed authored by Chegu Vinod's avatar Chegu Vinod Committed by Blue Swirl
Browse files

Fixes related to processing of qemu's -numa option



The -numa option to qemu is used to create [fake] numa nodes
and expose them to the guest OS instance.

There are a couple of issues with the -numa option:

a) Max VCPU's that can be specified for a guest while using
   the qemu's -numa option is 64. Due to a typecasting issue
   when the number of VCPUs is > 32 the VCPUs don't show up
   under the specified [fake] numa nodes.

b) KVM currently has support for 160VCPUs per guest. The
   qemu's -numa option has only support for upto 64VCPUs
   per guest.
This patch addresses these two issues.

Below are examples of (a) and (b)

a) >32 VCPUs are specified with the -numa option:

/usr/local/bin/qemu-system-x86_64 \
-enable-kvm \
71:01:01 \
-net tap,ifname=tap0,script=no,downscript=no \
-vnc :4

...
Upstream qemu :
--------------

QEMU 1.1.50 monitor - type 'help' for more information
(qemu) info numa
6 nodes
node 0 cpus: 0 1 2 3 4 5 6 7 8 9 32 33 34 35 36 37 38 39 40 41
node 0 size: 131072 MB
node 1 cpus: 10 11 12 13 14 15 16 17 18 19 42 43 44 45 46 47 48 49 50 51
node 1 size: 131072 MB
node 2 cpus: 20 21 22 23 24 25 26 27 28 29 52 53 54 55 56 57 58 59
node 2 size: 131072 MB
node 3 cpus: 30
node 3 size: 131072 MB
node 4 cpus:
node 4 size: 131072 MB
node 5 cpus: 31
node 5 size: 131072 MB

With the patch applied :
-----------------------

QEMU 1.1.50 monitor - type 'help' for more information
(qemu) info numa
6 nodes
node 0 cpus: 0 1 2 3 4 5 6 7 8 9
node 0 size: 131072 MB
node 1 cpus: 10 11 12 13 14 15 16 17 18 19
node 1 size: 131072 MB
node 2 cpus: 20 21 22 23 24 25 26 27 28 29
node 2 size: 131072 MB
node 3 cpus: 30 31 32 33 34 35 36 37 38 39
node 3 size: 131072 MB
node 4 cpus: 40 41 42 43 44 45 46 47 48 49
node 4 size: 131072 MB
node 5 cpus: 50 51 52 53 54 55 56 57 58 59
node 5 size: 131072 MB

b) >64 VCPUs specified with -numa option:

/usr/local/bin/qemu-system-x86_64 \
-enable-kvm \
-cpu Westmere,+rdtscp,+pdpe1gb,+dca,+pdcm,+xtpr,+tm2,+est,+smx,+vmx,+ds_cpl,+monitor,+dtes64,+pclmuldq,+pbe,+tm,+ht,+ss,+acpi,+d-vnc :4

...

Upstream qemu :
--------------

only 63 CPUs in NUMA mode supported.
only 64 CPUs in NUMA mode supported.
QEMU 1.1.50 monitor - type 'help' for more information
(qemu) info numa
8 nodes
node 0 cpus: 6 7 8 9 38 39 40 41 70 71 72 73
node 0 size: 65536 MB
node 1 cpus: 10 11 12 13 14 15 16 17 18 19 42 43 44 45 46 47 48 49 50 51 74 75 76 77 78 79
node 1 size: 65536 MB
node 2 cpus: 20 21 22 23 24 25 26 27 28 29 52 53 54 55 56 57 58 59 60 61
node 2 size: 65536 MB
node 3 cpus: 30 62
node 3 size: 65536 MB
node 4 cpus:
node 4 size: 65536 MB
node 5 cpus:
node 5 size: 65536 MB
node 6 cpus: 31 63
node 6 size: 65536 MB
node 7 cpus: 0 1 2 3 4 5 32 33 34 35 36 37 64 65 66 67 68 69
node 7 size: 65536 MB

With the patch applied :
-----------------------

QEMU 1.1.50 monitor - type 'help' for more information
(qemu) info numa
8 nodes
node 0 cpus: 0 1 2 3 4 5 6 7 8 9
node 0 size: 65536 MB
node 1 cpus: 10 11 12 13 14 15 16 17 18 19
node 1 size: 65536 MB
node 2 cpus: 20 21 22 23 24 25 26 27 28 29
node 2 size: 65536 MB
node 3 cpus: 30 31 32 33 34 35 36 37 38 39
node 3 size: 65536 MB
node 4 cpus: 40 41 42 43 44 45 46 47 48 49
node 4 size: 65536 MB
node 5 cpus: 50 51 52 53 54 55 56 57 58 59
node 5 size: 65536 MB
node 6 cpus: 60 61 62 63 64 65 66 67 68 69
node 6 size: 65536 MB
node 7 cpus: 70 71 72 73 74 75 76 77 78 79
Signed-off-by: default avatarChegu Vinod &lt;chegu_vinod@hp.com&gt;, Jim Hull &lt;jim.hull@hp.com&gt;, Craig Hada <craig.hada@hp.com>
Tested-by: default avatarEduardo Habkost <ehabkost@redhat.com>
Reviewed-by: default avatarEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: default avatarBlue Swirl <blauwirbel@gmail.com>
parent 161abfb5
......@@ -36,6 +36,7 @@
#include "cpus.h"
#include "qtest.h"
#include "main-loop.h"
#include "bitmap.h"
#ifndef _WIN32
#include "compatfd.h"
......@@ -1159,7 +1160,7 @@ void set_numa_modes(void)
for (env = first_cpu; env != NULL; env = env->next_cpu) {
for (i = 0; i < nb_numa_nodes; i++) {
if (node_cpumask[i] & (1 << env->cpu_index)) {
if (test_bit(env->cpu_index, node_cpumask[i])) {
env->numa_node = i;
}
}
......
......@@ -49,6 +49,7 @@
#include "memory.h"
#include "exec-memory.h"
#include "arch_init.h"
#include "bitmap.h"
/* output Bochs bios info messages */
//#define DEBUG_BIOS
......@@ -625,7 +626,7 @@ static void *bochs_bios_init(void)
numa_fw_cfg[0] = cpu_to_le64(nb_numa_nodes);
for (i = 0; i < max_cpus; i++) {
for (j = 0; j < nb_numa_nodes; j++) {
if (node_cpumask[j] & (1 << i)) {
if (test_bit(i, node_cpumask[j])) {
numa_fw_cfg[i + 1] = cpu_to_le64(j);
break;
}
......
......@@ -134,9 +134,10 @@ extern uint8_t qemu_extra_params_fw[2];
extern QEMUClock *rtc_clock;
#define MAX_NODES 64
#define MAX_CPUMASK_BITS 255
extern int nb_numa_nodes;
extern uint64_t node_mem[MAX_NODES];
extern uint64_t node_cpumask[MAX_NODES];
extern unsigned long *node_cpumask[MAX_NODES];
#define MAX_OPTION_ROMS 16
typedef struct QEMUOptionRom {
......
......@@ -28,6 +28,7 @@
#include <errno.h>
#include <sys/time.h>
#include <zlib.h>
#include "bitmap.h"
/* Needed early for CONFIG_BSD etc. */
#include "config-host.h"
......@@ -241,7 +242,7 @@ QTAILQ_HEAD(, FWBootEntry) fw_boot_order = QTAILQ_HEAD_INITIALIZER(fw_boot_order
int nb_numa_nodes;
uint64_t node_mem[MAX_NODES];
uint64_t node_cpumask[MAX_NODES];
unsigned long *node_cpumask[MAX_NODES];
uint8_t qemu_uuid[16];
......@@ -952,6 +953,8 @@ static void numa_add(const char *optarg)
unsigned long long value, endvalue;
int nodenr;
value = endvalue = 0ULL;
optarg = get_opt_name(option, 128, optarg, ',') + 1;
if (!strcmp(option, "node")) {
if (get_param_value(option, 128, "nodeid", optarg) == 0) {
......@@ -971,27 +974,22 @@ static void numa_add(const char *optarg)
}
node_mem[nodenr] = sval;
}
if (get_param_value(option, 128, "cpus", optarg) == 0) {
node_cpumask[nodenr] = 0;
} else {
if (get_param_value(option, 128, "cpus", optarg) != 0) {
value = strtoull(option, &endptr, 10);
if (value >= 64) {
value = 63;
fprintf(stderr, "only 64 CPUs in NUMA mode supported.\n");
if (*endptr == '-') {
endvalue = strtoull(endptr+1, &endptr, 10);
} else {
if (*endptr == '-') {
endvalue = strtoull(endptr+1, &endptr, 10);
if (endvalue >= 63) {
endvalue = 62;
fprintf(stderr,
"only 63 CPUs in NUMA mode supported.\n");
}
value = (2ULL << endvalue) - (1ULL << value);
} else {
value = 1ULL << value;
}
endvalue = value;
}
if (!(endvalue < MAX_CPUMASK_BITS)) {
endvalue = MAX_CPUMASK_BITS - 1;
fprintf(stderr,
"A max of %d CPUs are supported in a guest\n",
MAX_CPUMASK_BITS);
}
node_cpumask[nodenr] = value;
bitmap_set(node_cpumask[nodenr], value, endvalue-value+1);
}
nb_numa_nodes++;
}
......@@ -2331,7 +2329,7 @@ int main(int argc, char **argv, char **envp)
for (i = 0; i < MAX_NODES; i++) {
node_mem[i] = 0;
node_cpumask[i] = 0;
node_cpumask[i] = bitmap_new(MAX_CPUMASK_BITS);
}
nb_numa_nodes = 0;
......@@ -3468,8 +3466,9 @@ int main(int argc, char **argv, char **envp)
}
for (i = 0; i < nb_numa_nodes; i++) {
if (node_cpumask[i] != 0)
if (!bitmap_empty(node_cpumask[i], MAX_CPUMASK_BITS)) {
break;
}
}
/* assigning the VCPUs round-robin is easier to implement, guest OSes
* must cope with this anyway, because there are BIOSes out there in
......@@ -3477,7 +3476,7 @@ int main(int argc, char **argv, char **envp)
*/
if (i == nb_numa_nodes) {
for (i = 0; i < max_cpus; i++) {
node_cpumask[i % nb_numa_nodes] |= 1 << i;
set_bit(i, node_cpumask[i % nb_numa_nodes]);
}
}
}
......
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