0001-ivshmem-flat-memory-support.patch

From e830291535405f73b9b8d32e97b273b806ed3097 Mon Sep 17 00:00:00 2001
From: Jaroslaw Kurowski <jaroslaw.kurowski@tii.ae>
Date: Thu, 21 Nov 2024 14:19:07 +0400
Subject: ivshmem flat memory support

---
 contrib/ivshmem-server/ivshmem-server.c |  7 ++-
 hw/i386/pc_q35.c                        |  2 +
 hw/misc/ivshmem.c                       | 74 ++++++++++++++++++++++---
 include/hw/misc/ivshmem.h               |  1 +
 4 files changed, 72 insertions(+), 12 deletions(-)

diff --git a/contrib/ivshmem-server/ivshmem-server.c b/contrib/ivshmem-server/ivshmem-server.c
index 2f3c732..e7c7774 100644
--- a/contrib/ivshmem-server/ivshmem-server.c
+++ b/contrib/ivshmem-server/ivshmem-server.c
@@ -11,6 +11,7 @@
 
 #include <sys/socket.h>
 #include <sys/un.h>
+#include <sys/mman.h>
 
 #include "ivshmem-server.h"
 
@@ -297,11 +298,10 @@ ivshmem_server_start(IvshmemServer *server)
                              server->shm_path);
         shm_fd = shm_open(server->shm_path, O_CREAT | O_RDWR, S_IRWXU);
     } else {
-        gchar *filename = g_strdup_printf("%s/ivshmem.XXXXXX", server->shm_path);
+        gchar *filename = g_strdup_printf("%s/ivshmem", server->shm_path);
         IVSHMEM_SERVER_DEBUG(server, "Using file-backed shared memory: %s\n",
                              server->shm_path);
-        shm_fd = mkstemp(filename);
-        unlink(filename);
+        shm_fd = open(filename, O_RDWR | O_CREAT, 0666);
         g_free(filename);
     }
 
@@ -347,6 +347,7 @@ ivshmem_server_start(IvshmemServer *server)
 
     server->sock_fd = sock_fd;
     server->shm_fd = shm_fd;
+    server->cur_id = 1;
 
     return 0;
 
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index c7bc8a2..d76939e 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -28,6 +28,7 @@
  * THE SOFTWARE.
  */
 
+#include "hw/misc/ivshmem.h"
 #include "qemu/osdep.h"
 #include "qemu/units.h"
 #include "hw/acpi/acpi.h"
@@ -361,6 +362,7 @@ static void pc_q35_machine_options(MachineClass *m)
     machine_class_allow_dynamic_sysbus_dev(m, TYPE_INTEL_IOMMU_DEVICE);
     machine_class_allow_dynamic_sysbus_dev(m, TYPE_RAMFB_DEVICE);
     machine_class_allow_dynamic_sysbus_dev(m, TYPE_VMBUS_BRIDGE);
+    machine_class_allow_dynamic_sysbus_dev(m, TYPE_IVSHMEM_FLAT);
     compat_props_add(m->compat_props,
                      pc_q35_compat_defaults, pc_q35_compat_defaults_len);
 }
diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
index de49d1b..b1761b3 100644
--- a/hw/misc/ivshmem.c
+++ b/hw/misc/ivshmem.c
@@ -36,6 +36,7 @@
 #include "chardev/char-fe.h"
 #include "sysemu/hostmem.h"
 #include "qapi/visitor.h"
+#include "hw/sysbus.h"
 
 #include "hw/misc/ivshmem.h"
 #include "qom/object.h"
@@ -59,6 +60,7 @@
 
 #define TYPE_IVSHMEM_COMMON "ivshmem-common"
 typedef struct IVShmemState IVShmemState;
+typedef struct IvshmemFTState IvshmemFTState;
 DECLARE_INSTANCE_CHECKER(IVShmemState, IVSHMEM_COMMON,
                          TYPE_IVSHMEM_COMMON)
 
@@ -74,6 +76,9 @@ DECLARE_INSTANCE_CHECKER(IVShmemState, IVSHMEM_DOORBELL,
 DECLARE_INSTANCE_CHECKER(IVShmemState, IVSHMEM,
                          TYPE_IVSHMEM)
 
+#define TYPE_IVSHMEM_FLAT "ivshmem-flat"
+DECLARE_INSTANCE_CHECKER(IvshmemFTState, IVSHMEM_FLAT, TYPE_IVSHMEM_FLAT)
+
 typedef struct Peer {
     int nb_eventfds;
     EventNotifier *eventfds;
@@ -117,6 +122,15 @@ struct IVShmemState {
     /* migration stuff */
     OnOffAuto master;
     Error *migration_blocker;
+
+    /* flat memory stuff */
+    uint64_t flataddr;
+    DeviceState *flat_dev;
+    MemoryRegion flat_mem;
+};
+
+struct IvshmemFTState {
+    SysBusDevice parent_obj;
 };
 
 /* registers for the Inter-VM shared memory device */
@@ -476,8 +490,11 @@ static void setup_interrupt(IVShmemState *s, int vector, Error **errp)
 
 static void process_msg_shmem(IVShmemState *s, int fd, Error **errp)
 {
+    Error *local_err = NULL;
     struct stat buf;
     size_t size;
+    void *ptr;
+    SysBusDevice *sbd;
 
     if (s->ivshmem_bar2) {
         error_setg(errp, "server sent unexpected shared memory message");
@@ -494,13 +511,26 @@ static void process_msg_shmem(IVShmemState *s, int fd, Error **errp)
 
     size = buf.st_size;
 
+    if (s->flataddr) {
+
+        ptr = mmap(0, size, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_HUGETLB|MAP_LOCKED,
+                fd, 0);
+        s->flat_dev = sysbus_create_simple(TYPE_IVSHMEM_FLAT, -1, 0);
+
+        memory_region_init_ram_ptr(&s->flat_mem, OBJECT(IVSHMEM_FLAT(s->flat_dev)),
+                                   "ivshmem.flat", size, ptr);
+        sbd = SYS_BUS_DEVICE(s->flat_dev);
+        sysbus_init_mmio(sbd, &s->flat_mem);
+        sysbus_mmio_map(sbd, 0, s->flataddr);
+    }
+
     /* mmap the region and map into the BAR2 */
-    if (!memory_region_init_ram_from_fd(&s->server_bar2, OBJECT(s),
-                                        "ivshmem.bar2", size, RAM_SHARED,
-                                        fd, 0, errp)) {
+    memory_region_init_ram_from_fd(&s->server_bar2, OBJECT(s), "ivshmem.bar2",
+                                   size, RAM_SHARED, fd, 0, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
         return;
     }
-
     s->ivshmem_bar2 = &s->server_bar2;
 }
 
@@ -832,7 +862,6 @@ static void ivshmem_write_config(PCIDevice *pdev, uint32_t address,
 
 static void ivshmem_common_realize(PCIDevice *dev, Error **errp)
 {
-    ERRP_GUARD();
     IVShmemState *s = IVSHMEM_COMMON(dev);
     Error *err = NULL;
     uint8_t *pci_conf;
@@ -902,7 +931,8 @@ static void ivshmem_common_realize(PCIDevice *dev, Error **errp)
     if (!ivshmem_is_master(s)) {
         error_setg(&s->migration_blocker,
                    "Migration is disabled when using feature 'peer mode' in device 'ivshmem'");
-        if (migrate_add_blocker(&s->migration_blocker, errp) < 0) {
+        if (migrate_add_blocker(s->migration_blocker, errp) < 0) {
+            error_free(s->migration_blocker);
             return;
         }
     }
@@ -920,7 +950,10 @@ static void ivshmem_exit(PCIDevice *dev)
     IVShmemState *s = IVSHMEM_COMMON(dev);
     int i;
 
-    migrate_del_blocker(&s->migration_blocker);
+    if (s->migration_blocker) {
+        migrate_del_blocker(s->migration_blocker);
+        error_free(s->migration_blocker);
+    }
 
     if (memory_region_is_mapped(s->ivshmem_bar2)) {
         if (!s->hostmem) {
@@ -1014,7 +1047,7 @@ static const VMStateDescription ivshmem_plain_vmsd = {
     .minimum_version_id = 0,
     .pre_load = ivshmem_pre_load,
     .post_load = ivshmem_post_load,
-    .fields = (const VMStateField[]) {
+    .fields = (VMStateField[]) {
         VMSTATE_PCI_DEVICE(parent_obj, IVShmemState),
         VMSTATE_UINT32(intrstatus, IVShmemState),
         VMSTATE_UINT32(intrmask, IVShmemState),
@@ -1068,7 +1101,7 @@ static const VMStateDescription ivshmem_doorbell_vmsd = {
     .minimum_version_id = 0,
     .pre_load = ivshmem_pre_load,
     .post_load = ivshmem_post_load,
-    .fields = (const VMStateField[]) {
+    .fields = (VMStateField[]) {
         VMSTATE_PCI_DEVICE(parent_obj, IVShmemState),
         VMSTATE_MSIX(parent_obj, IVShmemState),
         VMSTATE_UINT32(intrstatus, IVShmemState),
@@ -1083,6 +1116,7 @@ static Property ivshmem_doorbell_properties[] = {
     DEFINE_PROP_BIT("ioeventfd", IVShmemState, features, IVSHMEM_IOEVENTFD,
                     true),
     DEFINE_PROP_ON_OFF_AUTO("master", IVShmemState, master, ON_OFF_AUTO_OFF),
+    DEFINE_PROP_UINT64("flataddr", IVShmemState, flataddr, 0),
     DEFINE_PROP_END_OF_LIST(),
 };
 
@@ -1115,6 +1149,20 @@ static void ivshmem_doorbell_class_init(ObjectClass *klass, void *data)
     dc->vmsd = &ivshmem_doorbell_vmsd;
 }
 
+static Property ivshmem_flat_props[] = {
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void ivshmem_flat_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->hotpluggable = true;
+    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+    device_class_set_props(dc, ivshmem_flat_props);
+    dc->user_creatable = false;
+}
+
 static const TypeInfo ivshmem_doorbell_info = {
     .name          = TYPE_IVSHMEM_DOORBELL,
     .parent        = TYPE_IVSHMEM_COMMON,
@@ -1123,11 +1171,19 @@ static const TypeInfo ivshmem_doorbell_info = {
     .class_init    = ivshmem_doorbell_class_init,
 };
 
+static const TypeInfo ivshmem_flat_info = {
+    .name = TYPE_IVSHMEM_FLAT,
+    .parent = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(IvshmemFTState),
+    .class_init = ivshmem_flat_class_init,
+};
+
 static void ivshmem_register_types(void)
 {
     type_register_static(&ivshmem_common_info);
     type_register_static(&ivshmem_plain_info);
     type_register_static(&ivshmem_doorbell_info);
+    type_register_static(&ivshmem_flat_info);
 }
 
 type_init(ivshmem_register_types)
diff --git a/include/hw/misc/ivshmem.h b/include/hw/misc/ivshmem.h
index 433ef53..43aeab7 100644
--- a/include/hw/misc/ivshmem.h
+++ b/include/hw/misc/ivshmem.h
@@ -21,5 +21,6 @@
 #define IVSHMEM_H
 
 #define IVSHMEM_PROTOCOL_VERSION 0
+#define TYPE_IVSHMEM_FLAT "ivshmem-flat"
 
 #endif /* IVSHMEM_H */
-- 
2.47.0