A new field, attributes, was introduced in RAMBlock to link to a
RamBlockAttributes object, which centralizes all guest_memfd related
information (such as fd and shared bitmap) within a RAMBlock.
Create and initialize the RamBlockAttributes object upon ram_block_add().
Meanwhile, register the object in the target RAMBlock's MemoryRegion.
After that, guest_memfd-backed RAMBlock is associated with the
RamDiscardManager interface, and the users can execute RamDiscardManager
specific handling. For example, VFIO will register the
RamDiscardListener and get notifications when the state_change() helper
invokes.
As coordinate discarding of RAM with guest_memfd is now supported, only
block uncoordinated discard.
Signed-off-by: Chenyi Qiang <chenyi.qi...@intel.com>
---
Changes in v6:
- Squash the unblocking of cooridnate discard into this commit.
- Remove the checks in migration path.
Changes in v5:
- Revert to use RamDiscardManager interface.
- Move the object_new() into the ram_block_attribute_create()
helper.
- Add some check in migration path.
Changes in v4:
- Remove the replay operations for attribute changes which will be
handled in a listener in following patches.
- Add some comment in the error path of realize() to remind the
future development of the unified error path.
Changes in v3:
- Use ram_discard_manager_reply_populated/discarded() to set the
memory attribute and add the undo support if state_change()
failed.
- Didn't add Reviewed-by from Alexey due to the new changes in this
commit.
---
accel/kvm/kvm-all.c | 9 +++++++++
include/system/ramblock.h | 1 +
system/physmem.c | 18 ++++++++++++++++--
3 files changed, 26 insertions(+), 2 deletions(-)
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 51526d301b..3b390bbb09 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -3089,6 +3089,15 @@ int kvm_convert_memory(hwaddr start, hwaddr size, bool
to_private)
addr = memory_region_get_ram_ptr(mr) + section.offset_within_region;
rb = qemu_ram_block_from_host(addr, false, &offset);
+ ret = ram_block_attributes_state_change(RAM_BLOCK_ATTRIBUTES(mr->rdm),
+ offset, size, to_private);
+ if (ret) {
+ error_report("Failed to notify the listener the state change of "
+ "(0x%"HWADDR_PRIx" + 0x%"HWADDR_PRIx") to %s",
+ start, size, to_private ? "private" : "shared");
+ goto out_unref;
+ }
+
if (to_private) {
if (rb->page_size != qemu_real_host_page_size()) {
/*
diff --git a/include/system/ramblock.h b/include/system/ramblock.h
index 1bab9e2dac..87e847e184 100644
--- a/include/system/ramblock.h
+++ b/include/system/ramblock.h
@@ -46,6 +46,7 @@ struct RAMBlock {
int fd;
uint64_t fd_offset;
int guest_memfd;
+ RamBlockAttributes *attributes;
size_t page_size;
/* dirty bitmap used during migration */
unsigned long *bmap;
diff --git a/system/physmem.c b/system/physmem.c
index a8a9ca309e..1f1217fa0a 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -1916,7 +1916,7 @@ static void ram_block_add(RAMBlock *new_block, Error
**errp)
}
assert(new_block->guest_memfd < 0);
- ret = ram_block_discard_require(true);
+ ret = ram_block_coordinated_discard_require(true);
if (ret < 0) {
error_setg_errno(errp, -ret,
"cannot set up private guest memory: discard
currently blocked");
@@ -1931,6 +1931,19 @@ static void ram_block_add(RAMBlock *new_block, Error
**errp)
goto out_free;
}
+ new_block->attributes = ram_block_attributes_create(new_block);
+ if (!new_block->attributes) {
+ error_setg(errp, "Failed to create ram block attribute");
+ /*
+ * The error path could be unified if the rest of ram_block_add()
+ * ever develops a need to check for errors.
+ */
+ close(new_block->guest_memfd);
+ ram_block_coordinated_discard_require(false);
+ qemu_mutex_unlock_ramlist();
+ goto out_free;
+ }
+
/*
* Add a specific guest_memfd blocker if a generic one would not be
* added by ram_block_add_cpr_blocker.
@@ -2287,8 +2300,9 @@ static void reclaim_ramblock(RAMBlock *block)
}
if (block->guest_memfd >= 0) {
+ ram_block_attributes_destroy(block->attributes);
close(block->guest_memfd);
- ram_block_discard_require(false);
+ ram_block_coordinated_discard_require(false);
}
g_free(block);
--
2.43.5
