On 25.01.24 04:22, Xiaoyao Li wrote:
When memory page is converted from private to shared, the original
private memory is back'ed by guest_memfd. Introduce
ram_block_discard_guest_memfd_range() for discarding memory in
guest_memfd.
Originally-from: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Codeveloped-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
---
Changes in in v4:
- Drop ram_block_convert_range() and open code its implementation in the
next Patch.
---
include/exec/cpu-common.h | 2 ++
system/physmem.c | 23 +++++++++++++++++++++++
2 files changed, 25 insertions(+)
diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h
index fef3138d29fc..05610efa8b4f 100644
--- a/include/exec/cpu-common.h
+++ b/include/exec/cpu-common.h
@@ -175,6 +175,8 @@ typedef int (RAMBlockIterFunc)(RAMBlock *rb, void *opaque);
int qemu_ram_foreach_block(RAMBlockIterFunc func, void *opaque);
int ram_block_discard_range(RAMBlock *rb, uint64_t start, size_t length);
+int ram_block_discard_guest_memfd_range(RAMBlock *rb, uint64_t start,
+ size_t length);
#endif
diff --git a/system/physmem.c b/system/physmem.c
index 4735b0462ed9..fc59470191ef 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -3626,6 +3626,29 @@ err:
return ret;
}
+int ram_block_discard_guest_memfd_range(RAMBlock *rb, uint64_t start,
+ size_t length)
+{
+ int ret = -1;
+
+#ifdef CONFIG_FALLOCATE_PUNCH_HOLE
+ ret = fallocate(rb->guest_memfd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
+ start, length);
+
+ if (ret) {
+ ret = -errno;
+ error_report("%s: Failed to fallocate %s:%" PRIx64 " +%zx (%d)",
+ __func__, rb->idstr, start, length, ret);
+ }
+#else
+ ret = -ENOSYS;
+ error_report("%s: fallocate not available %s:%" PRIx64 " +%zx (%d)",
+ __func__, rb->idstr, start, length, ret);
+#endif
+
+ return ret;
+}
+
bool ramblock_is_pmem(RAMBlock *rb)
{
return rb->flags & RAM_PMEM;
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
--
Cheers,
David / dhildenb
