On 7/23/25 19:31, Denis V. Lunev wrote:
On 7/23/25 19:04, Nikolai Barybin wrote:
QMP query-dump-guest-memory-capability reports win dump as available for
any x86 VM, which is false.
This patch implements proper query of vmcoreinfo and calculation of
guest note size. Based on that we can surely report whether win dump
available or not.
For further reference one may review this libvirt discussion:
https://lists.libvirt.org/archives/list/de...@lists.libvirt.org/thread/HJ3JRLWLGN3IKIC22OQ3PMZ4J3EFG5XB/#HJ3JRLWLGN3IKIC22OQ3PMZ4J3EFG5XB
[PATCH 0/4] Allow xml-configured coredump format on VM crash
Signed-off-by: Nikolai Barybin <nikolai.bary...@virtuozzo.com>
---
dump/win_dump.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 60 insertions(+)
diff --git a/dump/win_dump.c b/dump/win_dump.c
index 3162e8bd48..4bb1b28e63 100644
--- a/dump/win_dump.c
+++ b/dump/win_dump.c
@@ -14,14 +14,74 @@
#include "qemu/error-report.h"
#include "exec/cpu-defs.h"
#include "hw/core/cpu.h"
+#include "hw/misc/vmcoreinfo.h"
#include "qemu/win_dump_defs.h"
#include "win_dump.h"
#include "cpu.h"
+#include "elf.h"
#if defined(TARGET_X86_64)
+#define ELF_NOTE_SIZE(hdr_size, name_size, desc_size) \
+ ((DIV_ROUND_UP((hdr_size), 4) + \
+ DIV_ROUND_UP((name_size), 4) + \
+ DIV_ROUND_UP((desc_size), 4)) * 4)
+
bool win_dump_available(Error **errp)
{
+ uint64_t addr, note_head_size, name_size, desc_size;
+ uint32_t size;
+ uint16_t guest_format;
+ uint8_t *guest_note = NULL;
+ size_t guest_note_size = 0;
+ VMCoreInfoState *vmci = vmcoreinfo_find();
+ ArchDumpInfo dump_info = {};
+ GuestPhysBlockList blocks = {};
+ int ret;
+
+ if (!vmci || !vmci->has_vmcoreinfo)
+ return false;
+
+ ret = cpu_get_dump_info(&dump_info, &blocks);
This will not work IMHO. cpu_get_dump_info tries to operate
with a real guest memory, which is not provided. This means
that guest executable is impossible to find.
For me this is looking like Windows dump could not be enabled
after the patch.
Correction: current code will not work on 32bit guest with
more than 4Gb RAM on i386. More problems are definitely
possible on other platforms.
Den
