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From: Steve Sistare <steven.sistare@oracle.com>
To: qemu-devel@nongnu.org
Cc: Peter Xu <peterx@redhat.com>, Fabiano Rosas <farosas@suse.de>,
	David Hildenbrand <david@redhat.com>,
	Igor Mammedov <imammedo@redhat.com>,
	Eduardo Habkost <eduardo@habkost.net>,
	Marcel Apfelbaum <marcel.apfelbaum@gmail.com>,
	Philippe Mathieu-Daude <philmd@linaro.org>,
	Paolo Bonzini <pbonzini@redhat.com>,
	"Daniel P. Berrange" <berrange@redhat.com>,
	Markus Armbruster <armbru@redhat.com>,
	Steve Sistare <steven.sistare@oracle.com>
Subject: [PATCH V1 17/26] machine: memfd-alloc option
Date: Mon, 29 Apr 2024 08:55:26 -0700	[thread overview]
Message-ID: <1714406135-451286-18-git-send-email-steven.sistare@oracle.com> (raw)
In-Reply-To: <1714406135-451286-1-git-send-email-steven.sistare@oracle.com>

Allocate anonymous memory using memfd_create if the memfd-alloc machine
option is set.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
---
 hw/core/machine.c   | 22 ++++++++++++++++++++++
 include/hw/boards.h |  1 +
 qemu-options.hx     |  6 ++++++
 system/memory.c     |  9 ++++++---
 system/physmem.c    | 18 +++++++++++++++++-
 system/trace-events |  1 +
 6 files changed, 53 insertions(+), 4 deletions(-)

diff --git a/hw/core/machine.c b/hw/core/machine.c
index 582c2df..9567b97 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -443,6 +443,20 @@ static void machine_set_mem_merge(Object *obj, bool value, Error **errp)
     ms->mem_merge = value;
 }
 
+static bool machine_get_memfd_alloc(Object *obj, Error **errp)
+{
+    MachineState *ms = MACHINE(obj);
+
+    return ms->memfd_alloc;
+}
+
+static void machine_set_memfd_alloc(Object *obj, bool value, Error **errp)
+{
+    MachineState *ms = MACHINE(obj);
+
+    ms->memfd_alloc = value;
+}
+
 static bool machine_get_usb(Object *obj, Error **errp)
 {
     MachineState *ms = MACHINE(obj);
@@ -1044,6 +1058,11 @@ static void machine_class_init(ObjectClass *oc, void *data)
     object_class_property_set_description(oc, "mem-merge",
         "Enable/disable memory merge support");
 
+    object_class_property_add_bool(oc, "memfd-alloc",
+        machine_get_memfd_alloc, machine_set_memfd_alloc);
+    object_class_property_set_description(oc, "memfd-alloc",
+        "Enable/disable allocating anonymous memory using memfd_create");
+
     object_class_property_add_bool(oc, "usb",
         machine_get_usb, machine_set_usb);
     object_class_property_set_description(oc, "usb",
@@ -1387,6 +1406,9 @@ static bool create_default_memdev(MachineState *ms, const char *path, Error **er
     if (!object_property_set_int(obj, "size", ms->ram_size, errp)) {
         goto out;
     }
+    if (!object_property_set_bool(obj, "share", ms->memfd_alloc, errp)) {
+        goto out;
+    }
     object_property_add_child(object_get_objects_root(), mc->default_ram_id,
                               obj);
     /* Ensure backend's memory region name is equal to mc->default_ram_id */
diff --git a/include/hw/boards.h b/include/hw/boards.h
index 69c1ba4..96259c3 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -372,6 +372,7 @@ struct MachineState {
     bool dump_guest_core;
     bool mem_merge;
     bool require_guest_memfd;
+    bool memfd_alloc;
     bool usb;
     bool usb_disabled;
     char *firmware;
diff --git a/qemu-options.hx b/qemu-options.hx
index cf61f6b..f0dfda5 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -32,6 +32,7 @@ DEF("machine", HAS_ARG, QEMU_OPTION_machine, \
     "                vmport=on|off|auto controls emulation of vmport (default: auto)\n"
     "                dump-guest-core=on|off include guest memory in a core dump (default=on)\n"
     "                mem-merge=on|off controls memory merge support (default: on)\n"
+    "                memfd-alloc=on|off controls allocating anonymous guest RAM using memfd_create (default: off)\n"
     "                aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n"
     "                dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n"
     "                suppress-vmdesc=on|off disables self-describing migration (default=off)\n"
@@ -79,6 +80,11 @@ SRST
         supported by the host, de-duplicates identical memory pages
         among VMs instances (enabled by default).
 
+    ``memfd-alloc=on|off``
+        Enables or disables allocation of anonymous guest RAM using
+        memfd_create.  Any associated memory-backend objects are created with
+        share=on.  The memfd-alloc default is off.
+
     ``aes-key-wrap=on|off``
         Enables or disables AES key wrapping support on s390-ccw hosts.
         This feature controls whether AES wrapping keys will be created
diff --git a/system/memory.c b/system/memory.c
index 49f1cb2..ca04a0e 100644
--- a/system/memory.c
+++ b/system/memory.c
@@ -1552,8 +1552,9 @@ bool memory_region_init_ram_nomigrate(MemoryRegion *mr,
                                       uint64_t size,
                                       Error **errp)
 {
+    uint32_t flags = current_machine->memfd_alloc ? RAM_SHARED : 0;
     return memory_region_init_ram_flags_nomigrate(mr, owner, name,
-                                                  size, 0, errp);
+                                                  size, flags, errp);
 }
 
 bool memory_region_init_ram_flags_nomigrate(MemoryRegion *mr,
@@ -1713,8 +1714,9 @@ bool memory_region_init_rom_nomigrate(MemoryRegion *mr,
                                       uint64_t size,
                                       Error **errp)
 {
+    uint32_t flags = current_machine->memfd_alloc ? RAM_SHARED : 0;
     if (!memory_region_init_ram_flags_nomigrate(mr, owner, name,
-                                                size, 0, errp)) {
+                                                size, flags, errp)) {
          return false;
     }
     mr->readonly = true;
@@ -1731,6 +1733,7 @@ bool memory_region_init_rom_device_nomigrate(MemoryRegion *mr,
                                              Error **errp)
 {
     Error *err = NULL;
+    uint32_t flags = current_machine->memfd_alloc ? RAM_SHARED : 0;
     assert(ops);
     memory_region_init(mr, owner, name, size);
     mr->ops = ops;
@@ -1738,7 +1741,7 @@ bool memory_region_init_rom_device_nomigrate(MemoryRegion *mr,
     mr->terminates = true;
     mr->rom_device = true;
     mr->destructor = memory_region_destructor_ram;
-    mr->ram_block = qemu_ram_alloc(size, 0, mr, &err);
+    mr->ram_block = qemu_ram_alloc(size, flags, mr, &err);
     if (err) {
         mr->size = int128_zero();
         object_unparent(OBJECT(mr));
diff --git a/system/physmem.c b/system/physmem.c
index c736af5..36d97ec 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -45,6 +45,7 @@
 #include "qemu/qemu-print.h"
 #include "qemu/log.h"
 #include "qemu/memalign.h"
+#include "qemu/memfd.h"
 #include "exec/memory.h"
 #include "exec/ioport.h"
 #include "sysemu/dma.h"
@@ -1825,6 +1826,19 @@ static void *ram_block_alloc_host(RAMBlock *rb, Error **errp)
     if (xen_enabled()) {
         xen_ram_alloc(rb->offset, rb->max_length, mr, errp);
 
+    } else if (rb->flags & RAM_SHARED) {
+        if (rb->fd == -1) {
+            mr->align = QEMU_VMALLOC_ALIGN;
+            rb->fd = qemu_memfd_create(rb->idstr, rb->max_length + mr->align,
+                                       0, 0, 0, errp);
+        }
+        if (rb->fd >= 0) {
+            int mfd = rb->fd;
+            qemu_set_cloexec(mfd);
+            host = file_ram_alloc(rb, rb->max_length, mfd, false, 0, errp);
+            trace_qemu_anon_memfd_alloc(rb->idstr, rb->max_length, mfd, host);
+        }
+
     } else {
         host = qemu_anon_ram_alloc(rb->max_length, &mr->align,
                                    qemu_ram_is_shared(rb),
@@ -2106,8 +2120,10 @@ RAMBlock *qemu_ram_alloc_resizeable(ram_addr_t size, ram_addr_t maxsz,
                                                      void *host),
                                      MemoryRegion *mr, Error **errp)
 {
+    uint32_t flags = current_machine->memfd_alloc ? RAM_SHARED : 0;
+    flags |= RAM_RESIZEABLE;
     return qemu_ram_alloc_internal(size, maxsz, resized, NULL,
-                                   RAM_RESIZEABLE, mr, errp);
+                                   flags, mr, errp);
 }
 
 static void reclaim_ramblock(RAMBlock *block)
diff --git a/system/trace-events b/system/trace-events
index f0a80ba..0092734 100644
--- a/system/trace-events
+++ b/system/trace-events
@@ -41,3 +41,4 @@ dirtylimit_vcpu_execute(int cpu_index, int64_t sleep_time_us) "CPU[%d] sleep %"P
 
 # physmem.c
 ram_block_create(const char *name, uint32_t flags, int fd, size_t used_length, size_t max_length, size_t align) "%s, flags %u, fd %d, len %lu, maxlen %lu, align %lu"
+qemu_anon_memfd_alloc(const char *name, size_t size, int fd, void *ptr) "%s size %zu fd %d -> %p"
-- 
1.8.3.1



  parent reply	other threads:[~2024-04-29 15:56 UTC|newest]

Thread overview: 113+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-29 15:55 [PATCH V1 00/26] Live update: cpr-exec Steve Sistare
2024-04-29 15:55 ` [PATCH V1 01/26] oslib: qemu_clear_cloexec Steve Sistare
2024-05-06 23:27   ` Fabiano Rosas
2024-05-07  8:56     ` Daniel P. Berrangé
2024-05-07 13:54       ` Fabiano Rosas
2024-04-29 15:55 ` [PATCH V1 02/26] vl: helper to request re-exec Steve Sistare
2024-04-29 15:55 ` [PATCH V1 03/26] migration: SAVEVM_FOREACH Steve Sistare
2024-05-06 23:17   ` Fabiano Rosas
2024-05-13 19:27     ` Steven Sistare
2024-05-27 18:14       ` Peter Xu
2024-04-29 15:55 ` [PATCH V1 04/26] migration: delete unused parameter mis Steve Sistare
2024-05-06 21:50   ` Fabiano Rosas
2024-05-27 18:02   ` Peter Xu
2024-04-29 15:55 ` [PATCH V1 05/26] migration: precreate vmstate Steve Sistare
2024-05-07 21:02   ` Fabiano Rosas
2024-05-13 19:28     ` Steven Sistare
2024-05-24 13:56   ` Fabiano Rosas
2024-05-27 18:16   ` Peter Xu
2024-05-28 15:09     ` Steven Sistare via
2024-05-29 18:39       ` Peter Xu
2024-05-30 17:04         ` Steven Sistare via
2024-04-29 15:55 ` [PATCH V1 06/26] migration: precreate vmstate for exec Steve Sistare
2024-05-06 23:34   ` Fabiano Rosas
2024-05-13 19:28     ` Steven Sistare
2024-05-13 21:21       ` Fabiano Rosas
2024-04-29 15:55 ` [PATCH V1 07/26] migration: VMStateId Steve Sistare
2024-05-07 21:03   ` Fabiano Rosas
2024-05-27 18:20   ` Peter Xu
2024-05-28 15:10     ` Steven Sistare via
2024-05-28 17:44       ` Peter Xu
2024-05-29 17:30         ` Steven Sistare via
2024-05-29 18:53           ` Peter Xu
2024-05-30 17:11             ` Steven Sistare via
2024-05-30 18:03               ` Peter Xu
2024-04-29 15:55 ` [PATCH V1 08/26] migration: vmstate_info_void_ptr Steve Sistare
2024-05-07 21:33   ` Fabiano Rosas
2024-05-27 18:31   ` Peter Xu
2024-05-28 15:10     ` Steven Sistare via
2024-05-28 18:21       ` Peter Xu
2024-05-29 17:30         ` Steven Sistare via
2024-04-29 15:55 ` [PATCH V1 09/26] migration: vmstate_register_named Steve Sistare
2024-05-09 14:19   ` Fabiano Rosas
2024-05-09 14:32     ` Fabiano Rosas
2024-05-13 19:29       ` Steven Sistare
2024-04-29 15:55 ` [PATCH V1 10/26] migration: vmstate_unregister_named Steve Sistare
2024-04-29 15:55 ` [PATCH V1 11/26] migration: vmstate_register at init time Steve Sistare
2024-04-29 15:55 ` [PATCH V1 12/26] migration: vmstate factory object Steve Sistare
2024-04-29 15:55 ` [PATCH V1 13/26] physmem: ram_block_create Steve Sistare
2024-05-13 18:37   ` Fabiano Rosas
2024-05-13 19:30     ` Steven Sistare
2024-04-29 15:55 ` [PATCH V1 14/26] physmem: hoist guest_memfd creation Steve Sistare
2024-04-29 15:55 ` [PATCH V1 15/26] physmem: hoist host memory allocation Steve Sistare
2024-04-29 15:55 ` [PATCH V1 16/26] physmem: set ram block idstr earlier Steve Sistare
2024-04-29 15:55 ` Steve Sistare [this message]
2024-05-28 21:12   ` [PATCH V1 17/26] machine: memfd-alloc option Peter Xu
2024-05-29 17:31     ` Steven Sistare via
2024-05-29 19:14       ` Peter Xu
2024-05-30 17:11         ` Steven Sistare via
2024-05-30 18:14           ` Peter Xu
2024-05-31 19:32             ` Steven Sistare via
2024-04-29 15:55 ` [PATCH V1 18/26] migration: cpr-exec-args parameter Steve Sistare
2024-05-02 12:23   ` Markus Armbruster
2024-05-02 16:00     ` Steven Sistare
2024-05-21  8:13   ` Daniel P. Berrangé
2024-04-29 15:55 ` [PATCH V1 19/26] physmem: preserve ram blocks for cpr Steve Sistare
2024-05-28 21:44   ` Peter Xu
2024-05-29 17:31     ` Steven Sistare via
2024-05-29 19:25       ` Peter Xu
2024-05-30 17:12         ` Steven Sistare via
2024-05-30 18:39           ` Peter Xu
2024-05-31 19:32             ` Steven Sistare via
2024-04-29 15:55 ` [PATCH V1 20/26] migration: cpr-exec mode Steve Sistare
2024-05-02 12:23   ` Markus Armbruster
2024-05-02 16:00     ` Steven Sistare
2024-05-03  6:26       ` Markus Armbruster
2024-05-21  8:20   ` Daniel P. Berrangé
2024-05-24 14:58   ` Fabiano Rosas
2024-05-27 18:54     ` Steven Sistare via
2024-04-29 15:55 ` [PATCH V1 21/26] migration: migrate_add_blocker_mode Steve Sistare
2024-05-09 17:47   ` Fabiano Rosas
2024-04-29 15:55 ` [PATCH V1 22/26] migration: ram block cpr-exec blockers Steve Sistare
2024-05-09 18:01   ` Fabiano Rosas
2024-05-13 19:29     ` Steven Sistare
2024-04-29 15:55 ` [PATCH V1 23/26] migration: misc " Steve Sistare
2024-05-09 18:05   ` Fabiano Rosas
2024-05-24 12:40   ` Fabiano Rosas
2024-05-27 19:02     ` Steven Sistare via
2024-04-29 15:55 ` [PATCH V1 24/26] seccomp: cpr-exec blocker Steve Sistare
2024-05-09 18:16   ` Fabiano Rosas
2024-05-10  7:54   ` Daniel P. Berrangé
2024-05-13 19:29     ` Steven Sistare
2024-05-21  7:14       ` Daniel P. Berrangé
2024-04-29 15:55 ` [PATCH V1 25/26] migration: fix mismatched GPAs during cpr-exec Steve Sistare
2024-05-09 18:39   ` Fabiano Rosas
2024-04-29 15:55 ` [PATCH V1 26/26] migration: only-migratable-modes Steve Sistare
2024-05-09 19:14   ` Fabiano Rosas
2024-05-13 19:48     ` Steven Sistare
2024-05-13 21:57       ` Fabiano Rosas
2024-05-21  8:05   ` Daniel P. Berrangé
2024-05-02 16:13 ` cpr-exec doc (was Re: [PATCH V1 00/26] Live update: cpr-exec) Steven Sistare
2024-05-02 18:15   ` Peter Xu
2024-05-20 18:30 ` [PATCH V1 00/26] Live update: cpr-exec Steven Sistare
2024-05-20 22:28   ` Fabiano Rosas
2024-05-21  2:31     ` Peter Xu
2024-05-21 11:46       ` Steven Sistare
2024-05-27 17:45         ` Peter Xu
2024-05-28 15:10           ` Steven Sistare via
2024-05-28 16:42             ` Peter Xu
2024-05-30 17:17               ` Steven Sistare via
2024-05-30 19:23                 ` Peter Xu
2024-05-24 13:02 ` Fabiano Rosas
2024-05-24 14:07   ` Steven Sistare
2024-05-27 18:07 ` Peter Xu

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