From: Chao Peng <chao.p.p...@linux.intel.com>
This new routine adds support for memory conversion between
shared/private memory for gmem fd based private ram_block.
Signed-off-by: Chao Peng <chao.p.p...@linux.intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao...@intel.com>
---
include/exec/cpu-common.h | 2 ++
softmmu/physmem.c | 61 ++++++++++++++++++++++++++++++---------
2 files changed, 50 insertions(+), 13 deletions(-)
diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h
index 87dc9a752c9a..558684b9f246 100644
--- a/include/exec/cpu-common.h
+++ b/include/exec/cpu-common.h
@@ -157,6 +157,8 @@ 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_convert_range(RAMBlock *rb, uint64_t start, size_t length,
+ bool shared_to_private);
#endif
diff --git a/softmmu/physmem.c b/softmmu/physmem.c
index 05c981e5c18e..2acc8bee5b33 100644
--- a/softmmu/physmem.c
+++ b/softmmu/physmem.c
@@ -3415,15 +3415,9 @@ int qemu_ram_foreach_block(RAMBlockIterFunc func, void
*opaque)
return ret;
}
-/*
- * Unmap pages of memory from start to start+length such that
- * they a) read as 0, b) Trigger whatever fault mechanism
- * the OS provides for postcopy.
- * The pages must be unmapped by the end of the function.
- * Returns: 0 on success, none-0 on failure
- *
- */
-int ram_block_discard_range(RAMBlock *rb, uint64_t start, size_t length)
+static int ram_block_discard_range_fd(RAMBlock *rb, uint64_t start,
+ size_t length, int fd)
+
{
int ret = -1;
@@ -3449,8 +3443,8 @@ int ram_block_discard_range(RAMBlock *rb, uint64_t start,
size_t length)
* fallocate works on hugepages and shmem
* shared anonymous memory requires madvise REMOVE
*/
- need_madvise = (rb->page_size == qemu_host_page_size);
- need_fallocate = rb->fd != -1;
+ need_madvise = (rb->page_size == qemu_host_page_size) && (rb->fd ==
fd);
+ need_fallocate = fd != -1;
if (need_fallocate) {
/* For a file, this causes the area of the file to be zero'd
* if read, and for hugetlbfs also causes it to be unmapped
@@ -3475,7 +3469,7 @@ int ram_block_discard_range(RAMBlock *rb, uint64_t start,
size_t length)
" users of the file", __func__);
}
- ret = fallocate(rb->fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
+ ret = fallocate(fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
start, length);
if (ret) {
ret = -errno;
@@ -3498,7 +3492,7 @@ int ram_block_discard_range(RAMBlock *rb, uint64_t start,
size_t length)
* fallocate'd away).
*/
#if defined(CONFIG_MADVISE)
- if (qemu_ram_is_shared(rb) && rb->fd < 0) {
+ if (qemu_ram_is_shared(rb) && fd < 0) {
ret = madvise(host_startaddr, length, QEMU_MADV_REMOVE);
} else {
ret = madvise(host_startaddr, length, QEMU_MADV_DONTNEED);
@@ -3528,6 +3522,20 @@ err:
return ret;
}
+/*
+ * Unmap pages of memory from start to start+length such that
+ * they a) read as 0, b) Trigger whatever fault mechanism
+ * the OS provides for postcopy.
+ *
+ * The pages must be unmapped by the end of the function.
+ * Returns: 0 on success, none-0 on failure.
+ */
+int ram_block_discard_range(RAMBlock *rb, uint64_t start, size_t length)
+{
+ return ram_block_discard_range_fd(rb, start, length, rb->fd);
+}
+
+
bool ramblock_is_pmem(RAMBlock *rb)
{
return rb->flags & RAM_PMEM;
@@ -3715,3 +3723,30 @@ bool ram_block_discard_is_required(void)
return qatomic_read(&ram_block_discard_required_cnt) ||
qatomic_read(&ram_block_coordinated_discard_required_cnt);
}
+
+int ram_block_convert_range(RAMBlock *rb, uint64_t start, size_t length,
+ bool shared_to_private)
+{
+ int fd;
+
+ if (!rb || rb->gmem_fd < 0) {
+ return -1;
+ }
+
+ if (!QEMU_PTR_IS_ALIGNED(start, rb->page_size) ||
+ !QEMU_PTR_IS_ALIGNED(length, rb->page_size)) {
+ return -1;
+ }
+
+ if (length > rb->max_length) {
+ return -1;
+ }
+
+ if (shared_to_private) {
+ fd = rb->fd;
+ } else {
+ fd = rb->gmem_fd;
+ }
+
+ return ram_block_discard_range_fd(rb, start, length, fd);
+}
--
2.34.1
