dump: add Windows dump format to dump-guest-memory

This patch adds Windows crashdumping feature. Now QEMU can produce ELF-dump
containing Windows crashdump header, which can help to convert to a valid
WinDbg-understandable crashdump file, or immediately create such file.
The crashdump will be obtained by joining physical memory dump and 8K header
exposed through vmcoreinfo/fw_cfg device by guest driver at BSOD time. Option
'-w' was added to dump-guest-memory command. At the moment, only x64
configuration is supported.
Suitable driver can be found at
https://github.com/virtio-win/kvm-guest-drivers-windows/tree/master/fwcfg64

Signed-off-by: Viktor Prutyanov <viktor.prutyanov@virtuozzo.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20180517162342.4330-2-viktor.prutyanov@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/hmp.c b/hmp.c
index 0da0b0ac33..41f5e39b72 100644
--- a/hmp.c
+++ b/hmp.c
@@ -2014,6 +2014,7 @@ void hmp_device_del(Monitor *mon, const QDict *qdict)
 void hmp_dump_guest_memory(Monitor *mon, const QDict *qdict)
 {
     Error *err = NULL;
+    bool win_dmp = qdict_get_try_bool(qdict, "windmp", false);
     bool paging = qdict_get_try_bool(qdict, "paging", false);
     bool zlib = qdict_get_try_bool(qdict, "zlib", false);
     bool lzo = qdict_get_try_bool(qdict, "lzo", false);
@@ -2028,12 +2029,16 @@ void hmp_dump_guest_memory(Monitor *mon, const QDict *qdict)
     enum DumpGuestMemoryFormat dump_format = DUMP_GUEST_MEMORY_FORMAT_ELF;
     char *prot;
 
-    if (zlib + lzo + snappy > 1) {
-        error_setg(&err, "only one of '-z|-l|-s' can be set");
+    if (zlib + lzo + snappy + win_dmp > 1) {
+        error_setg(&err, "only one of '-z|-l|-s|-w' can be set");
         hmp_handle_error(mon, &err);
         return;
     }
 
+    if (win_dmp) {
+        dump_format = DUMP_GUEST_MEMORY_FORMAT_WIN_DMP;
+    }
+
     if (zlib) {
         dump_format = DUMP_GUEST_MEMORY_FORMAT_KDUMP_ZLIB;
     }