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From 420f81563a6ff3e695f7643a1bcbbc332b9f7132 Mon Sep 17 00:00:00 2001
From: Saverio Miroddi <saverio.pub2@gmail.com>
Date: Tue, 31 Oct 2017 20:59:05 +0100
Subject: [PATCH] Current pinning patch
Changes 2017/10/31:
- Fix: the MAX_VCPUS was arbitrary; it's now set to CPU_SETSIZE
- Fix: the allowed vcpus were equated to the cores number, without accounting sockets and threads
- Change: removed all the debug information, and a now unneded warning
- Change: cleaned spacing
---
cpus.c | 12 +++++++++++
qemu-options.hx | 10 ++++++++++
vl.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 84 insertions(+)
diff --git a/cpus.c b/cpus.c
index 38eba8bff33..1ff63e0d847 100644
--- a/cpus.c
+++ b/cpus.c
@@ -57,6 +57,9 @@
#ifdef CONFIG_LINUX
#include <sys/prctl.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <inttypes.h>
#ifndef PR_MCE_KILL
#define PR_MCE_KILL 33
@@ -1919,9 +1922,11 @@ static void qemu_hax_start_vcpu(CPUState *cpu)
#endif
}
+extern int vcpu_affinity[];
static void qemu_kvm_start_vcpu(CPUState *cpu)
{
char thread_name[VCPU_THREAD_NAME_SIZE];
+ cpu_set_t cpuset;
cpu->thread = g_malloc0(sizeof(QemuThread));
cpu->halt_cond = g_malloc0(sizeof(QemuCond));
@@ -1930,6 +1935,13 @@ static void qemu_kvm_start_vcpu(CPUState *cpu)
cpu->cpu_index);
qemu_thread_create(cpu->thread, thread_name, qemu_kvm_cpu_thread_fn,
cpu, QEMU_THREAD_JOINABLE);
+
+ if (vcpu_affinity[cpu->cpu_index] != -1) {
+ CPU_ZERO(&cpuset);
+ CPU_SET(vcpu_affinity[cpu->cpu_index], &cpuset);
+ pthread_setaffinity_np((cpu->thread)->thread, sizeof(cpu_set_t), &cpuset);
+ }
+
}
static void qemu_hvf_start_vcpu(CPUState *cpu)
diff --git a/qemu-options.hx b/qemu-options.hx
index ca4e412f2f8..9dd6dcd93cf 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -169,6 +169,16 @@ given, the total number of CPUs @var{n} can be omitted. @var{maxcpus}
specifies the maximum number of hotpluggable CPUs.
ETEXI
+DEF("vcpu", HAS_ARG, QEMU_OPTION_vcpu,
+ "-vcpu [vcpunum=]n[,affinity=affinity]\n"
+ "-vcpu [vcpunum=]n[,affinity=affinity]\n", QEMU_ARCH_ALL)
+STEXI
+@item -vcpu [vcpunum=]@var{n}[,affinity=@var{affinity}]
+@itemx -vcpu [vcpunum=]@var{n}[,affinity=@var{affinity}]
+@findex -vcpu
+VCPU Affinity. If specified, specify for all the CPUs.
+ETEXI
+
DEF("numa", HAS_ARG, QEMU_OPTION_numa,
"-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
"-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
diff --git a/vl.c b/vl.c
index fce1fd12d8b..4e6110c5a71 100644
--- a/vl.c
+++ b/vl.c
@@ -135,6 +135,7 @@ int main(int argc, char **argv)
#define MAX_VIRTIO_CONSOLES 1
#define MAX_SCLP_CONSOLES 1
+#define MAX_VCPUS CPU_SETSIZE
static const char *data_dir[16];
static int data_dir_idx;
const char *bios_name = NULL;
@@ -164,6 +165,8 @@ int smp_cpus;
unsigned int max_cpus;
int smp_cores = 1;
int smp_threads = 1;
+int vcpu_affinity[MAX_VCPUS];
+int num_affinity = 0;
int acpi_enabled = 1;
int no_hpet = 0;
int fd_bootchk = 1;
@@ -1290,6 +1293,57 @@ static QemuOptsList qemu_smp_opts = {
},
};
+static QemuOptsList qemu_vcpu_opts = {
+ .name = "vcpu-opts",
+ .implied_opt_name = "vcpunum",
+ .head = QTAILQ_HEAD_INITIALIZER(qemu_vcpu_opts.head),
+ .desc = {
+ {
+ .name = "vcpunum",
+ .type = QEMU_OPT_NUMBER,
+ }, {
+ .name = "affinity",
+ .type = QEMU_OPT_NUMBER,
+ },
+ { /*End of list */ }
+ },
+};
+
+static int parse_vcpu(void *opaque, QemuOpts *opts, Error **errp)
+{
+ if (opts) {
+ unsigned vcpu = qemu_opt_get_number(opts, "vcpunum", 0);
+ unsigned affinity = qemu_opt_get_number(opts,"affinity", 0);
+
+ if (vcpu < smp_cpus * smp_cores * smp_threads) {
+ if (vcpu_affinity[vcpu] == -1) {
+ vcpu_affinity[vcpu] = affinity;
+ }
+ else {
+ error_report("Duplicate affinity statement for vcpu %d\n", vcpu);
+ return -1;
+ }
+ num_affinity += 1;
+ }
+ else {
+ error_report("VCPU %d is more than allowed %d VCPUs in the system\n", vcpu, smp_cores);
+ return -1;
+ }
+ }
+ return 0;
+}
+
+static void parse_vcpu_opts(MachineClass *mc)
+{
+ int i;
+ for (i = 0; i < MAX_VCPUS; i++)
+ vcpu_affinity[i] = -1;
+
+ if (qemu_opts_foreach(qemu_find_opts("vcpu-opts"), parse_vcpu, NULL, NULL)) {
+ exit(1);
+ }
+}
+
static void smp_parse(QemuOpts *opts)
{
if (opts) {
@@ -3092,6 +3146,7 @@ int main(int argc, char **argv, char **envp)
qemu_add_opts(&qemu_accel_opts);
qemu_add_opts(&qemu_mem_opts);
qemu_add_opts(&qemu_smp_opts);
+ qemu_add_opts(&qemu_vcpu_opts);
qemu_add_opts(&qemu_boot_opts);
qemu_add_opts(&qemu_sandbox_opts);
qemu_add_opts(&qemu_add_fd_opts);
@@ -3771,6 +3826,12 @@ int main(int argc, char **argv, char **envp)
exit(1);
}
break;
+ case QEMU_OPTION_vcpu:
+ if (!qemu_opts_parse_noisily(qemu_find_opts("vcpu-opts"),
+ optarg, true)) {
+ exit(1);
+ }
+ break;
case QEMU_OPTION_vnc:
vnc_parse(optarg, &error_fatal);
break;
@@ -4211,6 +4272,7 @@ int main(int argc, char **argv, char **envp)
exit(1);
}
+ parse_vcpu_opts(machine_class);
/*
* Get the default machine options from the machine if it is not already
* specified either by the configuration file or by the command line.
|