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authorDavid Hildenbrand <david@redhat.com>2021-04-29 13:27:05 +0200
committerDr. David Alan Gilbert <dgilbert@redhat.com>2021-05-13 18:21:13 +0100
commit6a23f6399a1f8807447f8680f80e4d536522683e (patch)
tree033b8a712c637d071a8c7cd0e07bf24bb75cdb3d /migration
parentcc61c703b6a8b9dfdfb92d5f3fa1961f6d232926 (diff)
migration/ram: Simplify host page handling in ram_load_postcopy()
Add two new helper functions. This will come in come handy once we want to handle ram block resizes while postcopy is active. Note that ram_block_from_stream() will already print proper errors. Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com> Message-Id: <20210429112708.12291-8-david@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> dgilbert: Added brackets in host_page_from_ram_block_offset to cause uintptr_t to cast the sum, to fix armhf-cross build
Diffstat (limited to 'migration')
-rw-r--r--migration/ram.c55
1 files changed, 32 insertions, 23 deletions
diff --git a/migration/ram.c b/migration/ram.c
index e1d081d334..26ed42b87d 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -3085,6 +3085,20 @@ static inline void *host_from_ram_block_offset(RAMBlock *block,
return block->host + offset;
}
+static void *host_page_from_ram_block_offset(RAMBlock *block,
+ ram_addr_t offset)
+{
+ /* Note: Explicitly no check against offset_in_ramblock(). */
+ return (void *)QEMU_ALIGN_DOWN((uintptr_t)(block->host + offset),
+ block->page_size);
+}
+
+static ram_addr_t host_page_offset_from_ram_block_offset(RAMBlock *block,
+ ram_addr_t offset)
+{
+ return ((uintptr_t)block->host + offset) & (block->page_size - 1);
+}
+
static inline void *colo_cache_from_block_offset(RAMBlock *block,
ram_addr_t offset, bool record_bitmap)
{
@@ -3481,13 +3495,12 @@ static int ram_load_postcopy(QEMUFile *f)
MigrationIncomingState *mis = migration_incoming_get_current();
/* Temporary page that is later 'placed' */
void *postcopy_host_page = mis->postcopy_tmp_page;
- void *this_host = NULL;
+ void *host_page = NULL;
bool all_zero = true;
int target_pages = 0;
while (!ret && !(flags & RAM_SAVE_FLAG_EOS)) {
ram_addr_t addr;
- void *host = NULL;
void *page_buffer = NULL;
void *place_source = NULL;
RAMBlock *block = NULL;
@@ -3512,9 +3525,12 @@ static int ram_load_postcopy(QEMUFile *f)
if (flags & (RAM_SAVE_FLAG_ZERO | RAM_SAVE_FLAG_PAGE |
RAM_SAVE_FLAG_COMPRESS_PAGE)) {
block = ram_block_from_stream(f, flags);
+ if (!block) {
+ ret = -EINVAL;
+ break;
+ }
- host = host_from_ram_block_offset(block, addr);
- if (!host) {
+ if (!offset_in_ramblock(block, addr)) {
error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
ret = -EINVAL;
break;
@@ -3532,19 +3548,17 @@ static int ram_load_postcopy(QEMUFile *f)
* of a host page in one chunk.
*/
page_buffer = postcopy_host_page +
- ((uintptr_t)host & (block->page_size - 1));
+ host_page_offset_from_ram_block_offset(block, addr);
+ /* If all TP are zero then we can optimise the place */
if (target_pages == 1) {
- this_host = (void *)QEMU_ALIGN_DOWN((uintptr_t)host,
- block->page_size);
- } else {
+ host_page = host_page_from_ram_block_offset(block, addr);
+ } else if (host_page != host_page_from_ram_block_offset(block,
+ addr)) {
/* not the 1st TP within the HP */
- if (QEMU_ALIGN_DOWN((uintptr_t)host, block->page_size) !=
- (uintptr_t)this_host) {
- error_report("Non-same host page %p/%p",
- host, this_host);
- ret = -EINVAL;
- break;
- }
+ error_report("Non-same host page %p/%p", host_page,
+ host_page_from_ram_block_offset(block, addr));
+ ret = -EINVAL;
+ break;
}
/*
@@ -3623,16 +3637,11 @@ static int ram_load_postcopy(QEMUFile *f)
}
if (!ret && place_needed) {
- /* This gets called at the last target page in the host page */
- void *place_dest = (void *)QEMU_ALIGN_DOWN((uintptr_t)host,
- block->page_size);
-
if (all_zero) {
- ret = postcopy_place_page_zero(mis, place_dest,
- block);
+ ret = postcopy_place_page_zero(mis, host_page, block);
} else {
- ret = postcopy_place_page(mis, place_dest,
- place_source, block);
+ ret = postcopy_place_page(mis, host_page, place_source,
+ block);
}
place_needed = false;
target_pages = 0;