5 The `-device vmcoreinfo` will create a fw_cfg entry for a guest to
11 A guest may use this fw_cfg entry to add information details to qemu
14 The entry of 16 bytes has the following layout, in little-endian::
16 #define VMCOREINFO_FORMAT_NONE 0x0
17 #define VMCOREINFO_FORMAT_ELF 0x1
19 struct FWCfgVMCoreInfo {
20 uint16_t host_format; /* formats host supports */
21 uint16_t guest_format; /* format guest supplies */
22 uint32_t size; /* size of vmcoreinfo region */
23 uint64_t paddr; /* physical address of vmcoreinfo region */
26 Only full write (of 16 bytes) are considered valid for further
27 processing of entry values.
29 A write of 0 in guest_format will disable further processing of
30 vmcoreinfo entry values & content.
32 You may write a guest_format that is not supported by the host, in
33 which case the entry data can be ignored by qemu (but you may still
34 access it through a debugger, via vmcoreinfo_realize::vmcoreinfo_state).
39 As of qemu 2.11, only VMCOREINFO_FORMAT_ELF is supported.
41 The entry gives location and size of an ELF note that is appended in
44 The note format/class must be of the target bitness and the size must
47 If the ELF note name is "VMCOREINFO", it is expected to be the Linux
48 vmcoreinfo note (see Documentation/ABI/testing/sysfs-kernel-vmcoreinfo
49 in Linux source). In this case, qemu dump code will read the content
50 as a key=value text file, looking for "NUMBER(phys_base)" key
51 value. The value is expected to be more accurate than architecture
52 guess of the value. This is useful for KASLR-enabled guest with
53 ancient tools not handling the VMCOREINFO note.