diff options
author | Peter Maydell <peter.maydell@linaro.org> | 2023-09-27 16:12:04 +0100 |
---|---|---|
committer | Peter Maydell <peter.maydell@linaro.org> | 2023-11-02 12:52:06 +0000 |
commit | 096d3ce2316253919cfcb2ac9fead1fd315b2c98 (patch) | |
tree | d20e0ae656d2015768e96d8b797e1b50c1240c9b /docs | |
parent | 6e0c849275250ff9d1b3b2ae32f6a4b1247ed745 (diff) |
docs/specs/vmcoreinfo: Convert to rST
Convert docs/specs/vmcoreinfo.txt to rST format.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20230927151205.70930-8-peter.maydell@linaro.org
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Acked-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Diffstat (limited to 'docs')
-rw-r--r-- | docs/specs/index.rst | 1 | ||||
-rw-r--r-- | docs/specs/vmcoreinfo.rst | 54 | ||||
-rw-r--r-- | docs/specs/vmcoreinfo.txt | 53 |
3 files changed, 55 insertions, 53 deletions
diff --git a/docs/specs/index.rst b/docs/specs/index.rst index 8d30968650..7a56ccb215 100644 --- a/docs/specs/index.rst +++ b/docs/specs/index.rst @@ -30,3 +30,4 @@ guest hardware that is specific to QEMU. pvpanic standard-vga virt-ctlr + vmcoreinfo diff --git a/docs/specs/vmcoreinfo.rst b/docs/specs/vmcoreinfo.rst new file mode 100644 index 0000000000..6541aa116f --- /dev/null +++ b/docs/specs/vmcoreinfo.rst @@ -0,0 +1,54 @@ +================= +VMCoreInfo device +================= + +The ``-device vmcoreinfo`` will create a ``fw_cfg`` entry for a guest to +store dump details. + +``etc/vmcoreinfo`` +================== + +A guest may use this ``fw_cfg`` entry to add information details to QEMU +dumps. + +The entry of 16 bytes has the following layout, in little-endian:: + + #define VMCOREINFO_FORMAT_NONE 0x0 + #define VMCOREINFO_FORMAT_ELF 0x1 + + struct FWCfgVMCoreInfo { + uint16_t host_format; /* formats host supports */ + uint16_t guest_format; /* format guest supplies */ + uint32_t size; /* size of vmcoreinfo region */ + uint64_t paddr; /* physical address of vmcoreinfo region */ + }; + +Only full write (of 16 bytes) are considered valid for further +processing of entry values. + +A write of 0 in ``guest_format`` will disable further processing of +vmcoreinfo entry values & content. + +You may write a ``guest_format`` that is not supported by the host, in +which case the entry data can be ignored by QEMU (but you may still +access it through a debugger, via ``vmcoreinfo_realize::vmcoreinfo_state``). + +Format & content +================ + +As of QEMU 2.11, only ``VMCOREINFO_FORMAT_ELF`` is supported. + +The entry gives location and size of an ELF note that is appended in +qemu dumps. + +The note format/class must be of the target bitness and the size must +be less than 1Mb. + +If the ELF note name is ``VMCOREINFO``, it is expected to be the Linux +vmcoreinfo note (see `the kernel documentation for its format +<https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-kernel-vmcoreinfo>`_). +In this case, qemu dump code will read the content +as a key=value text file, looking for ``NUMBER(phys_base)`` key +value. The value is expected to be more accurate than architecture +guess of the value. This is useful for KASLR-enabled guest with +ancient tools not handling the ``VMCOREINFO`` note. diff --git a/docs/specs/vmcoreinfo.txt b/docs/specs/vmcoreinfo.txt deleted file mode 100644 index bcbca6fe47..0000000000 --- a/docs/specs/vmcoreinfo.txt +++ /dev/null @@ -1,53 +0,0 @@ -================= -VMCoreInfo device -================= - -The `-device vmcoreinfo` will create a fw_cfg entry for a guest to -store dump details. - -etc/vmcoreinfo -************** - -A guest may use this fw_cfg entry to add information details to qemu -dumps. - -The entry of 16 bytes has the following layout, in little-endian:: - -#define VMCOREINFO_FORMAT_NONE 0x0 -#define VMCOREINFO_FORMAT_ELF 0x1 - - struct FWCfgVMCoreInfo { - uint16_t host_format; /* formats host supports */ - uint16_t guest_format; /* format guest supplies */ - uint32_t size; /* size of vmcoreinfo region */ - uint64_t paddr; /* physical address of vmcoreinfo region */ - }; - -Only full write (of 16 bytes) are considered valid for further -processing of entry values. - -A write of 0 in guest_format will disable further processing of -vmcoreinfo entry values & content. - -You may write a guest_format that is not supported by the host, in -which case the entry data can be ignored by qemu (but you may still -access it through a debugger, via vmcoreinfo_realize::vmcoreinfo_state). - -Format & content -**************** - -As of qemu 2.11, only VMCOREINFO_FORMAT_ELF is supported. - -The entry gives location and size of an ELF note that is appended in -qemu dumps. - -The note format/class must be of the target bitness and the size must -be less than 1Mb. - -If the ELF note name is "VMCOREINFO", it is expected to be the Linux -vmcoreinfo note (see Documentation/ABI/testing/sysfs-kernel-vmcoreinfo -in Linux source). In this case, qemu dump code will read the content -as a key=value text file, looking for "NUMBER(phys_base)" key -value. The value is expected to be more accurate than architecture -guess of the value. This is useful for KASLR-enabled guest with -ancient tools not handling the VMCOREINFO note. |