Update: Native qemu cpu thread pinning

Updated cpus.c file with new qemu_thread_set_affinity (1)
Removed redundant definition from already exisitng patch No. 14 (2)

Signed-off-by: Roja Eswaran <roja@zededa.com>

pkg/xen-tools/patches-4.19.0/14-qemu-Init-CPU-mask-per-VCPU.patch

@@ -3,14 +3,6 @@ From: Nikolay Martyanov <ohmspectator@gmail.com>
 Date: Wed, 28 Sep 2022 15:52:24 +0200
 Subject: [PATCH 14/15] qemu: Init CPU mask per VCPU.
 
-Signed-off-by: Nikolay Martyanov <ohmspectator@gmail.com>
----
- tools/qemu-xen/include/hw/boards.h   |  1 +
- tools/qemu-xen/include/hw/core/cpu.h |  2 +
- tools/qemu-xen/softmmu/cpus.c        | 31 ++++++++++++
- tools/qemu-xen/softmmu/vl.c          | 75 ++++++++++++++++++++++++++++
- 4 files changed, 109 insertions(+)
-
 diff --git a/tools/qemu-xen/include/hw/boards.h b/tools/qemu-xen/include/hw/boards.h
 index b06f13e..a4b4f11 100644
 --- a/tools/qemu-xen/include/hw/boards.h
@@ -38,59 +30,6 @@ index 397fd3a..1bf357b 100644
      /* Should CPU start in powered-off state? */
      bool start_powered_off;
 
-diff --git a/tools/qemu-xen/softmmu/cpus.c b/tools/qemu-xen/softmmu/cpus.c
-index 9cbc817..2867325 100644
---- a/tools/qemu-xen/softmmu/cpus.c
-+++ b/tools/qemu-xen/softmmu/cpus.c
-@@ -72,6 +72,25 @@ static QemuMutex qemu_global_mutex;
-  */
- static const AccelOpsClass *cpus_accel;
-
-+
-+static inline void cpumask_clear_bit(uint64_t *mask, uint8_t bit)
-+{
-+    *mask &= ~(1ul << bit);
-+}
-+
-+static inline long cpumask_get_min_bit(uint64_t mask)
-+{
-+  return __builtin_ffsll(mask) - 1;
-+  }
-+
-+static long pick_pcpu(uint64_t *cpumask)
-+{
-+    long ret = cpumask_get_min_bit(*cpumask);
-+    cpumask_clear_bit(cpumask, ret);
-+    return ret;
-+}
-+
-+
- bool cpu_is_stopped(CPUState *cpu)
- {
-     return cpu->stopped || !runstate_is_running();
-@@ -635,6 +654,21 @@ void qemu_init_vcpu(CPUState *cpu)
-     cpu->stopped = true;
-     cpu->random_seed = qemu_guest_random_seed_thread_part1();
-
-+    cpu->pinned = ms->cpu_pin;
-+    static uint64_t vm_cpumask;
-+    uint64_t vcpu_cpumask;
-+    if (!vm_cpumask)
-+        vm_cpumask = ms->cpumask;
-+    if (!cpu->pinned) {
-+        /* If the CPUs are not pinned, assign the whole CPU mask to the VCPU */
-+        vcpu_cpumask = vm_cpumask;
-+    } else {
-+        /* If the CPUs are pinned, pick only one CPU for this VCPU */
-+        vcpu_cpumask = 1ull << pick_pcpu(&vm_cpumask);
-+    }
-+
-+    cpu->cpumask = vcpu_cpumask;
-+
-     if (!cpu->as) {
-         /* If the target cpu hasn't set up any address spaces itself,
-          * give it the default one.
-
 
 diff --git a/tools/qemu-xen/softmmu/vl.c b/tools/qemu-xen/softmmu/vl.c
 index ea20b23..98287f4 100644

pkg/xen-tools/patches-4.19.0/23-qemu-native-thread-affinity.patch

@@ -0,0 +1,58 @@
+--- a/tools/qemu-xen/softmmu/cpus.c	2023-08-16 02:43:53
++++ b/tools/qemu-xen/softmmu/cpus.c	2024-10-22 11:51:09
+@@ -619,6 +619,23 @@ const AccelOpsClass *cpus_get_accel(void)
+     cpus_accel = ops;
+ }
+
++static inline void cpumask_clear_bit(uint64_t *mask, uint8_t bit)
++{
++    *mask &= ~(1ul << bit);
++}
++
++static inline long cpumask_get_min_bit(uint64_t mask)
++{
++  return __builtin_ffsll(mask) - 1;
++}
++
++static long pick_pcpu(uint64_t *cpumask)
++{
++    long ret = cpumask_get_min_bit(*cpumask);
++    cpumask_clear_bit(cpumask, ret);
++    return ret;
++}
++
+ const AccelOpsClass *cpus_get_accel(void)
+ {
+     /* broken if we call this early */
+@@ -629,12 +646,30 @@ void qemu_init_vcpu(CPUState *cpu)
+ void qemu_init_vcpu(CPUState *cpu)
+ {
+     MachineState *ms = MACHINE(qdev_get_machine());
+-
++    unsigned long *bitmap = NULL;
+     cpu->nr_cores = ms->smp.cores;
+     cpu->nr_threads =  ms->smp.threads;
+     cpu->stopped = true;
+     cpu->random_seed = qemu_guest_random_seed_thread_part1();
++    cpu->pinned = ms->cpu_pin;
++    static uint64_t vm_cpumask;
++    uint64_t vcpu_cpumask;
++    if (!vm_cpumask)
++	    vm_cpumask = ms->cpumask;
++    if (!cpu->pinned) {
++	    vcpu_cpumask = vm_cpumask;
++    } else {
++	     vcpu_cpumask = 1ull << pick_pcpu(&vm_cpumask);
++    }
++    cpu->cpumask = vcpu_cpumask;
+
++    if(cpu_can_run(cpu))
++	    warn_report("Change a CPU affinity after the CPU may have been running for a while\n");
++    if (cpu->cpumask){
++	    bitmap = bitmap_new(cpu->cpumask);
++	    qemu_thread_set_affinity(cpu->thread, bitmap, cpu->cpumask);
++    }
++
+     if (!cpu->as) {
+         /* If the target cpu hasn't set up any address spaces itself,
+          * give it the default one.