From a18ba2fbaf132724e81be92da42b36d8f365e66c Mon Sep 17 00:00:00 2001
From: Janosch Frank <frankja@linux.ibm.com>
Date: Thu, 11 Aug 2022 12:10:56 +0000
Subject: [PATCH 24/42] dump: Refactor dump_iterate and introduce
dump_filter_memblock_*()
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
RH-Author: Cédric Le Goater <clg@redhat.com>
RH-MergeRequest: 226: s390: Enhanced Interpretation for PCI Functions and Secure Execution guest dump
RH-Bugzilla: 1664378 2043909
RH-Acked-by: Thomas Huth <thuth@redhat.com>
RH-Acked-by: Cornelia Huck <cohuck@redhat.com>
RH-Acked-by: Jon Maloy <jmaloy@redhat.com>
RH-Commit: [24/41] 74ef470f24d9d98093c4d63730a99474587033fd
The iteration over the memblocks in dump_iterate() is hard to
understand so it's about time to clean it up. Instead of manually
grabbing the next memblock we can use QTAILQ_FOREACH to iterate over
all memblocks.
Additionally we move the calculation of the offset and length out by
introducing and using the dump_filter_memblock_*() functions. These
functions will later be used to cleanup other parts of dump.c.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220811121111.9878-4-frankja@linux.ibm.com>
(cherry picked from commit 1e8113032f5b1efc5da66382470ce4809c76f8f2)
Signed-off-by: Cédric Le Goater <clg@redhat.com>
---
dump/dump.c | 74 ++++++++++++++++++++++++++++++-----------------------
1 file changed, 42 insertions(+), 32 deletions(-)
diff --git a/dump/dump.c b/dump/dump.c
index fa787f379f..d981e843dd 100644
--- a/dump/dump.c
+++ b/dump/dump.c
@@ -592,31 +592,43 @@ static void dump_begin(DumpState *s, Error **errp)
write_elf_notes(s, errp);
}
-static int get_next_block(DumpState *s, GuestPhysBlock *block)
+static int64_t dump_filtered_memblock_size(GuestPhysBlock *block,
+ int64_t filter_area_start,
+ int64_t filter_area_length)
{
- while (1) {
- block = QTAILQ_NEXT(block, next);
- if (!block) {
- /* no more block */
- return 1;
- }
+ int64_t size, left, right;
- s->start = 0;
- s->next_block = block;
- if (s->has_filter) {
- if (block->target_start >= s->begin + s->length ||
- block->target_end <= s->begin) {
- /* This block is out of the range */
- continue;
- }
+ /* No filter, return full size */
+ if (!filter_area_length) {
+ return block->target_end - block->target_start;
+ }
- if (s->begin > block->target_start) {
- s->start = s->begin - block->target_start;
- }
+ /* calculate the overlapped region. */
+ left = MAX(filter_area_start, block->target_start);
+ right = MIN(filter_area_start + filter_area_length, block->target_end);
+ size = right - left;
+ size = size > 0 ? size : 0;
+
+ return size;
+}
+
+static int64_t dump_filtered_memblock_start(GuestPhysBlock *block,
+ int64_t filter_area_start,
+ int64_t filter_area_length)
+{
+ if (filter_area_length) {
+ /* return -1 if the block is not within filter area */
+ if (block->target_start >= filter_area_start + filter_area_length ||
+ block->target_end <= filter_area_start) {
+ return -1;
}
- return 0;
+ if (filter_area_start > block->target_start) {
+ return filter_area_start - block->target_start;
+ }
}
+
+ return 0;
}
/* write all memory to vmcore */
@@ -624,24 +636,22 @@ static void dump_iterate(DumpState *s, Error **errp)
{
ERRP_GUARD();
GuestPhysBlock *block;
- int64_t size;
-
- do {
- block = s->next_block;
+ int64_t memblock_size, memblock_start;
- size = block->target_end - block->target_start;
- if (s->has_filter) {
- size -= s->start;
- if (s->begin + s->length < block->target_end) {
- size -= block->target_end - (s->begin + s->length);
- }
+ QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
+ memblock_start = dump_filtered_memblock_start(block, s->begin, s->length);
+ if (memblock_start == -1) {
+ continue;
}
- write_memory(s, block, s->start, size, errp);
+
+ memblock_size = dump_filtered_memblock_size(block, s->begin, s->length);
+
+ /* Write the memory to file */
+ write_memory(s, block, memblock_start, memblock_size, errp);
if (*errp) {
return;
}
-
- } while (!get_next_block(s, block));
+ }
}
static void create_vmcore(DumpState *s, Error **errp)
--
2.37.3