[PATCH RFC 5/7] util: Make qemu_prealloc_mem() optionally consume a ThreadContext

[David Hildenbrand]

... and implement it under POSIX. When a ThreadContext is provided,
create new threads via the context such that these new threads obtain a
porperly configured CPU affinity.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 backends/hostmem.c     |  5 +++--
 hw/virtio/virtio-mem.c |  2 +-
 include/qemu/osdep.h   |  4 +++-
 util/oslib-posix.c     | 20 ++++++++++++++------
 util/oslib-win32.c     |  2 +-
 5 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/backends/hostmem.c b/backends/hostmem.c
index caff42d3a5..46bd4cc494 100644
--- a/backends/hostmem.c
+++ b/backends/hostmem.c
@@ -232,7 +232,8 @@ static void host_memory_backend_set_prealloc(Object *obj, 
bool value,
         void *ptr = memory_region_get_ram_ptr(&backend->mr);
         uint64_t sz = memory_region_size(&backend->mr);
 
-        qemu_prealloc_mem(fd, ptr, sz, backend->prealloc_threads, &local_err);
+        qemu_prealloc_mem(fd, ptr, sz, backend->prealloc_threads, NULL,
+                          &local_err);
         if (local_err) {
             error_propagate(errp, local_err);
             return;
@@ -394,7 +395,7 @@ host_memory_backend_memory_complete(UserCreatable *uc, 
Error **errp)
          */
         if (backend->prealloc) {
             qemu_prealloc_mem(memory_region_get_fd(&backend->mr), ptr, sz,
-                              backend->prealloc_threads, &local_err);
+                              backend->prealloc_threads, NULL, &local_err);
             if (local_err) {
                 goto out;
             }
diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c
index 0e9ef4ff19..ed170def48 100644
--- a/hw/virtio/virtio-mem.c
+++ b/hw/virtio/virtio-mem.c
@@ -467,7 +467,7 @@ static int virtio_mem_set_block_state(VirtIOMEM *vmem, 
uint64_t start_gpa,
             int fd = memory_region_get_fd(&vmem->memdev->mr);
             Error *local_err = NULL;
 
-            qemu_prealloc_mem(fd, area, size, 1, &local_err);
+            qemu_prealloc_mem(fd, area, size, 1, NULL, &local_err);
             if (local_err) {
                 static bool warned;
 
diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
index e556e45143..625298c8bc 100644
--- a/include/qemu/osdep.h
+++ b/include/qemu/osdep.h
@@ -568,6 +568,8 @@ unsigned long qemu_getauxval(unsigned long type);
 
 void qemu_set_tty_echo(int fd, bool echo);
 
+typedef struct ThreadContext ThreadContext;
+
 /**
  * qemu_prealloc_mem:
  * @fd: the fd mapped into the area, -1 for anonymous memory
@@ -582,7 +584,7 @@ void qemu_set_tty_echo(int fd, bool echo);
  * after allocating file blocks for mapped files.
  */
 void qemu_prealloc_mem(int fd, char *area, size_t sz, int max_threads,
-                       Error **errp);
+                       ThreadContext *tc, Error **errp);
 
 /**
  * qemu_get_pid_name:
diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index fa66f73bf8..ce5fea3126 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -404,7 +404,8 @@ static inline int get_memset_num_threads(size_t hpagesize, 
size_t numpages,
 }
 
 static int touch_all_pages(char *area, size_t hpagesize, size_t numpages,
-                           int max_threads, bool use_madv_populate_write)
+                           int max_threads, ThreadContext *tc,
+                           bool use_madv_populate_write)
 {
     static gsize initialized = 0;
     MemsetContext context = {
@@ -443,9 +444,16 @@ static int touch_all_pages(char *area, size_t hpagesize, 
size_t numpages,
         context.threads[i].numpages = numpages_per_thread + (i < leftover);
         context.threads[i].hpagesize = hpagesize;
         context.threads[i].context = &context;
-        qemu_thread_create(&context.threads[i].pgthread, "touch_pages",
-                           touch_fn, &context.threads[i],
-                           QEMU_THREAD_JOINABLE);
+        if (tc) {
+            thread_context_create_thread(tc, &context.threads[i].pgthread,
+                                         "touch_pages",
+                                         touch_fn, &context.threads[i],
+                                         QEMU_THREAD_JOINABLE);
+        } else {
+            qemu_thread_create(&context.threads[i].pgthread, "touch_pages",
+                               touch_fn, &context.threads[i],
+                               QEMU_THREAD_JOINABLE);
+        }
         addr += context.threads[i].numpages * hpagesize;
     }
 
@@ -481,7 +489,7 @@ static bool madv_populate_write_possible(char *area, size_t 
pagesize)
 }
 
 void qemu_prealloc_mem(int fd, char *area, size_t sz, int max_threads,
-                       Error **errp)
+                       ThreadContext *tc, Error **errp)
 {
     static gsize initialized;
     int ret;
@@ -522,7 +530,7 @@ void qemu_prealloc_mem(int fd, char *area, size_t sz, int 
max_threads,
     }
 
     /* touch pages simultaneously */
-    ret = touch_all_pages(area, hpagesize, numpages, max_threads,
+    ret = touch_all_pages(area, hpagesize, numpages, max_threads, tc,
                           use_madv_populate_write);
     if (ret) {
         error_setg_errno(errp, -ret,
diff --git a/util/oslib-win32.c b/util/oslib-win32.c
index e1cb725ecc..a67cb3822e 100644
--- a/util/oslib-win32.c
+++ b/util/oslib-win32.c
@@ -269,7 +269,7 @@ int getpagesize(void)
 }
 
 void qemu_prealloc_mem(int fd, char *area, size_t sz, int max_threads,
-                       Error **errp)
+                       ThreadContext *tc, Error **errp)
 {
     int i;
     size_t pagesize = qemu_real_host_page_size();
-- 
2.35.3