ivshmem has its very own code to create and map shared memory.
Replace that with an implicitly created memory backend. Reduces the
number of ways we create BAR 2 from three to two.
Signed-off-by: Markus Armbruster <arm...@redhat.com>
---
hw/misc/ivshmem.c | 89 +++++++++++++++++++++----------------------------------
1 file changed, 33 insertions(+), 56 deletions(-)
diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
index 8d54fa9..9931d5e 100644
--- a/hw/misc/ivshmem.c
+++ b/hw/misc/ivshmem.c
@@ -26,6 +26,7 @@
#include "migration/migration.h"
#include "qemu/error-report.h"
#include "qemu/event_notifier.h"
+#include "qom/object_interfaces.h"
#include "sysemu/char.h"
#include "sysemu/hostmem.h"
#include "qapi/visitor.h"
@@ -369,31 +370,6 @@ static int check_shm_size(IVShmemState *s, int fd, Error
**errp)
}
}
-/* create the shared memory BAR when we are not using the server, so we can
- * create the BAR and map the memory immediately */
-static int create_shared_memory_BAR(IVShmemState *s, int fd, uint8_t attr,
- Error **errp)
-{
- void * ptr;
-
- ptr = mmap(0, s->ivshmem_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
- if (ptr == MAP_FAILED) {
- error_setg_errno(errp, errno, "Failed to mmap shared memory");
- return -1;
- }
-
- memory_region_init_ram_ptr(&s->ivshmem, OBJECT(s), "ivshmem.bar2",
- s->ivshmem_size, ptr);
- qemu_set_ram_fd(s->ivshmem.ram_addr, fd);
- vmstate_register_ram(&s->ivshmem, DEVICE(s));
- memory_region_add_subregion(&s->bar, 0, &s->ivshmem);
-
- /* region for shared memory */
- pci_register_bar(PCI_DEVICE(s), 2, attr, &s->bar);
-
- return 0;
-}
-
static void ivshmem_add_eventfd(IVShmemState *s, int posn, int i)
{
memory_region_add_eventfd(&s->ivshmem_mmio,
@@ -833,6 +809,33 @@ static void ivshmem_write_config(PCIDevice *pdev, uint32_t
address,
}
}
+static HostMemoryBackend *desugar_shm(const char *shm, size_t size)
+{
+ /* TODO avoid the detour through QemuOpts */
+ static int counter;
+ QemuOpts *opts = qemu_opts_create(qemu_find_opts("object"),
+ NULL, 0, &error_abort);
+ char *path;
+ Object *obj;
+
+ qemu_opt_set(opts, "qom-type", "memory-backend-file",
+ &error_abort);
+ /* FIXME need a better way to make up an ID */
+ qemu_opts_set_id(opts, g_strdup_printf("ivshmem-backend-%d", counter++));
+ path = g_strdup_printf("/dev/shm/%s", shm);
+ qemu_opt_set(opts, "mem-path", path, &error_abort);
+ qemu_opt_set_number(opts, "size", size, &error_abort);
+ qemu_opt_set_bool(opts, "share", true, &error_abort);
+ g_free(path);
+
+ obj = user_creatable_add_opts(opts, &error_abort);
+ qemu_opts_del(opts);
+
+ user_creatable_complete(obj, &error_abort);
+
+ return MEMORY_BACKEND(obj);
+}
+
static void pci_ivshmem_realize(PCIDevice *dev, Error **errp)
{
IVShmemState *s = IVSHMEM(dev);
@@ -911,6 +914,10 @@ static void pci_ivshmem_realize(PCIDevice *dev, Error
**errp)
attr |= PCI_BASE_ADDRESS_MEM_TYPE_64;
}
+ if (s->shmobj) {
+ s->hostmem = desugar_shm(s->shmobj, s->ivshmem_size);
+ }
+
if (s->hostmem != NULL) {
MemoryRegion *mr;
@@ -921,7 +928,7 @@ static void pci_ivshmem_realize(PCIDevice *dev, Error
**errp)
vmstate_register_ram(mr, DEVICE(s));
memory_region_add_subregion(&s->bar, 0, mr);
pci_register_bar(PCI_DEVICE(s), 2, attr, &s->bar);
- } else if (s->server_chr != NULL) {
+ } else {
IVSHMEM_DPRINTF("using shared memory server (socket = %s)\n",
s->server_chr->filename);
@@ -948,36 +955,6 @@ static void pci_ivshmem_realize(PCIDevice *dev, Error
**errp)
error_setg(errp, "failed to initialize interrupts");
return;
}
- } else {
- /* just map the file immediately, we're not using a server */
- int fd;
-
- IVSHMEM_DPRINTF("using shm_open (shm object = %s)\n", s->shmobj);
-
- /* try opening with O_EXCL and if it succeeds zero the memory
- * by truncating to 0 */
- if ((fd = shm_open(s->shmobj, O_CREAT|O_RDWR|O_EXCL,
- S_IRWXU|S_IRWXG|S_IRWXO)) > 0) {
- /* truncate file to length PCI device's memory */
- if (ftruncate(fd, s->ivshmem_size) != 0) {
- error_report("could not truncate shared file");
- }
-
- } else if ((fd = shm_open(s->shmobj, O_CREAT|O_RDWR,
- S_IRWXU|S_IRWXG|S_IRWXO)) < 0) {
- error_setg(errp, "could not open shared file");
- return;
- }
-
- if (check_shm_size(s, fd, errp) == -1) {
- return;
- }
-
- create_shared_memory_BAR(s, fd, attr, &err);
- if (err) {
- error_propagate(errp, err);
- return;
- }
}
if (s->role_val == IVSHMEM_PEER) {
--
2.4.3
