mem: add share parameter to memory-backend-ram
Currently only file backed memory backend can
be created with a "share" flag in order to allow
sharing guest RAM with other processes in the host.
Add the "share" flag also to RAM Memory Backend
in order to allow remapping parts of the guest RAM
to different host virtual addresses. This is needed
by the RDMA devices in order to remap non-contiguous
QEMU virtual addresses to a contiguous virtual address range.
Moved the "share" flag to the Host Memory base class,
modified phys_mem_alloc to include the new parameter
and a new interface memory_region_init_ram_shared_nomigrate.
There are no functional changes if the new flag is not used.
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
diff --git a/exec.c b/exec.c
index e8d7b33..4d8addb 100644
--- a/exec.c
+++ b/exec.c
@@ -1285,7 +1285,7 @@
uint16_t section);
static subpage_t *subpage_init(FlatView *fv, hwaddr base);
-static void *(*phys_mem_alloc)(size_t size, uint64_t *align) =
+static void *(*phys_mem_alloc)(size_t size, uint64_t *align, bool shared) =
qemu_anon_ram_alloc;
/*
@@ -1293,7 +1293,7 @@
* Accelerators with unusual needs may need this. Hopefully, we can
* get rid of it eventually.
*/
-void phys_mem_set_alloc(void *(*alloc)(size_t, uint64_t *align))
+void phys_mem_set_alloc(void *(*alloc)(size_t, uint64_t *align, bool shared))
{
phys_mem_alloc = alloc;
}
@@ -1921,7 +1921,7 @@
}
}
-static void ram_block_add(RAMBlock *new_block, Error **errp)
+static void ram_block_add(RAMBlock *new_block, Error **errp, bool shared)
{
RAMBlock *block;
RAMBlock *last_block = NULL;
@@ -1944,7 +1944,7 @@
}
} else {
new_block->host = phys_mem_alloc(new_block->max_length,
- &new_block->mr->align);
+ &new_block->mr->align, shared);
if (!new_block->host) {
error_setg_errno(errp, errno,
"cannot set up guest memory '%s'",
@@ -2049,7 +2049,7 @@
return NULL;
}
- ram_block_add(new_block, &local_err);
+ ram_block_add(new_block, &local_err, share);
if (local_err) {
g_free(new_block);
error_propagate(errp, local_err);
@@ -2091,7 +2091,7 @@
void (*resized)(const char*,
uint64_t length,
void *host),
- void *host, bool resizeable,
+ void *host, bool resizeable, bool share,
MemoryRegion *mr, Error **errp)
{
RAMBlock *new_block;
@@ -2114,7 +2114,7 @@
if (resizeable) {
new_block->flags |= RAM_RESIZEABLE;
}
- ram_block_add(new_block, &local_err);
+ ram_block_add(new_block, &local_err, share);
if (local_err) {
g_free(new_block);
error_propagate(errp, local_err);
@@ -2126,12 +2126,15 @@
RAMBlock *qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
MemoryRegion *mr, Error **errp)
{
- return qemu_ram_alloc_internal(size, size, NULL, host, false, mr, errp);
+ return qemu_ram_alloc_internal(size, size, NULL, host, false,
+ false, mr, errp);
}
-RAMBlock *qemu_ram_alloc(ram_addr_t size, MemoryRegion *mr, Error **errp)
+RAMBlock *qemu_ram_alloc(ram_addr_t size, bool share,
+ MemoryRegion *mr, Error **errp)
{
- return qemu_ram_alloc_internal(size, size, NULL, NULL, false, mr, errp);
+ return qemu_ram_alloc_internal(size, size, NULL, NULL, false,
+ share, mr, errp);
}
RAMBlock *qemu_ram_alloc_resizeable(ram_addr_t size, ram_addr_t maxsz,
@@ -2140,7 +2143,8 @@
void *host),
MemoryRegion *mr, Error **errp)
{
- return qemu_ram_alloc_internal(size, maxsz, resized, NULL, true, mr, errp);
+ return qemu_ram_alloc_internal(size, maxsz, resized, NULL, true,
+ false, mr, errp);
}
static void reclaim_ramblock(RAMBlock *block)
