#include "exec/address-spaces.h"
#include "sysemu/xen-mapcache.h"
#include "trace-root.h"
+
#endif
#include "exec/cpu-all.h"
#include "qemu/rcu_queue.h"
rcu_read_unlock();
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)
+{
+ int ret = -1;
+
+ uint8_t *host_startaddr = rb->host + start;
+
+ if ((uintptr_t)host_startaddr & (rb->page_size - 1)) {
+ error_report("ram_block_discard_range: Unaligned start address: %p",
+ host_startaddr);
+ goto err;
+ }
+
+ if ((start + length) <= rb->used_length) {
+ uint8_t *host_endaddr = host_startaddr + length;
+ if ((uintptr_t)host_endaddr & (rb->page_size - 1)) {
+ error_report("ram_block_discard_range: Unaligned end address: %p",
+ host_endaddr);
+ goto err;
+ }
+
+ errno = ENOTSUP; /* If we are missing MADVISE etc */
+
+#if defined(CONFIG_MADVISE)
+ /* Note: We need the madvise MADV_DONTNEED behaviour of definitely
+ * freeing the page.
+ */
+ ret = madvise(host_startaddr, length, MADV_DONTNEED);
+#endif
+ if (ret) {
+ ret = -errno;
+ error_report("ram_block_discard_range: Failed to discard range "
+ "%s:%" PRIx64 " +%zx (%d)",
+ rb->idstr, start, length, ret);
+ }
+ } else {
+ error_report("ram_block_discard_range: Overrun block '%s' (%" PRIu64
+ "/%zx/" RAM_ADDR_FMT")",
+ rb->idstr, start, length, rb->used_length);
+ }
+
+err:
+ return ret;
+}
+
#endif
ram_addr_t offset, ram_addr_t length, void *opaque);
int qemu_ram_foreach_block(RAMBlockIterFunc func, void *opaque);
+int ram_block_discard_range(RAMBlock *rb, uint64_t start, size_t length);
#endif
int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis);
/*
- * Discard the contents of 'length' bytes from 'start'
- * We can assume that if we've been called postcopy_ram_hosttest returned true
- */
-int postcopy_ram_discard_range(MigrationIncomingState *mis, uint8_t *start,
- size_t length);
-
-/*
* Userfault requires us to mark RAM as NOHUGEPAGE prior to discard
* however leaving it until after precopy means that most of the precopy
* data is still THPd
return ret;
}
-/**
- * postcopy_ram_discard_range: Discard a range of memory.
- * We can assume that if we've been called postcopy_ram_hosttest returned true.
- *
- * @mis: Current incoming migration state.
- * @start, @length: range of memory to discard.
- *
- * returns: 0 on success.
- */
-int postcopy_ram_discard_range(MigrationIncomingState *mis, uint8_t *start,
- size_t length)
-{
- trace_postcopy_ram_discard_range(start, length);
- if (madvise(start, length, MADV_DONTNEED)) {
- error_report("%s MADV_DONTNEED: %s", __func__, strerror(errno));
- return -1;
- }
-
- return 0;
-}
-
/*
* Setup an area of RAM so that it *can* be used for postcopy later; this
* must be done right at the start prior to pre-copy.
* - we're going to get the copy from the source anyway.
* (Precopy will just overwrite this data, so doesn't need the discard)
*/
- if (postcopy_ram_discard_range(mis, host_addr, length)) {
+ if (ram_discard_range(mis, block_name, 0, length)) {
return -1;
}
return -1;
}
-int postcopy_ram_discard_range(MigrationIncomingState *mis, uint8_t *start,
- size_t length)
-{
- assert(0);
- return -1;
-}
-
int postcopy_ram_prepare_discard(MigrationIncomingState *mis)
{
assert(0);
{
int ret = -1;
+ trace_ram_discard_range(block_name, start, length);
+
rcu_read_lock();
RAMBlock *rb = qemu_ram_block_by_name(block_name);
goto err;
}
- uint8_t *host_startaddr = rb->host + start;
-
- if ((uintptr_t)host_startaddr & (qemu_host_page_size - 1)) {
- error_report("ram_discard_range: Unaligned start address: %p",
- host_startaddr);
- goto err;
- }
-
- if ((start + length) <= rb->used_length) {
- uint8_t *host_endaddr = host_startaddr + length;
- if ((uintptr_t)host_endaddr & (qemu_host_page_size - 1)) {
- error_report("ram_discard_range: Unaligned end address: %p",
- host_endaddr);
- goto err;
- }
- ret = postcopy_ram_discard_range(mis, host_startaddr, length);
- } else {
- error_report("ram_discard_range: Overrun block '%s' (%" PRIu64
- "/%zx/" RAM_ADDR_FMT")",
- block_name, start, length, rb->used_length);
- }
+ ret = ram_block_discard_range(rb, start, length);
err:
rcu_read_unlock();
migration_bitmap_sync_start(void) ""
migration_bitmap_sync_end(uint64_t dirty_pages) "dirty_pages %" PRIu64
migration_throttle(void) ""
+ram_discard_range(const char *rbname, uint64_t start, size_t len) "%s: start: %" PRIx64 " %zx"
ram_load_postcopy_loop(uint64_t addr, int flags) "@%" PRIx64 " %x"
ram_postcopy_send_discard_bitmap(void) ""
ram_save_queue_pages(const char *rbname, size_t start, size_t len) "%s: start: %zx len: %zx"
# migration/postcopy-ram.c
postcopy_discard_send_finish(const char *ramblock, int nwords, int ncmds) "%s mask words sent=%d in %d commands"
postcopy_discard_send_range(const char *ramblock, unsigned long start, unsigned long length) "%s:%lx/%lx"
-postcopy_ram_discard_range(void *start, size_t length) "%p,+%zx"
postcopy_cleanup_range(const char *ramblock, void *host_addr, size_t offset, size_t length) "%s: %p offset=%zx length=%zx"
postcopy_init_range(const char *ramblock, void *host_addr, size_t offset, size_t length) "%s: %p offset=%zx length=%zx"
postcopy_nhp_range(const char *ramblock, void *host_addr, size_t offset, size_t length) "%s: %p offset=%zx length=%zx"