[PATCHv7 0/9] Xen: extend kexec hypercall for use with pv-ops kernels
david.vrabel at citrix.com
Thu Sep 12 15:48:58 EDT 2013
The series (for Xen 4.4) improves the kexec hypercall by making Xen
responsible for loading and relocating the image. This allows kexec
to be usable by pv-ops kernels and should allow kexec to be usable
from a HVM or PVH privileged domain.
The first patch is a simple clean-up.
Patch 2 introduces the new ABI.
Patch 3 and 4 nearly completely reimplement the kexec load, unload and
exec sub-ops. The old load_v1 sub-op is then implemented on top of
the new code.
Patch 5 calls the kexec image when dom0 crashes. This avoids having
to alter dom0 kernels to do a exec sub-op call on crash -- a
SHUTDOWN_crash by dom0 will trigger the kexec.
Patches 6 and 7 add the libxc API for the kexec calls. These have
been acked-by Ian Campbell already.
Patch 8 adds a link time check for the size of the relocate code.
Patch 9 adds myself as the maintainer for kexec in Xen.
The required patch series for kexec-tools will be posted shortly and
are available from the xen-v4 branch of:
Changes since v6:
- No longer use GUEST_HANDLE_64(), get a uniform ABI by using unions
and explicit padding.
- Only map the segments and not all of RAM.
- Add a mechanism to create mappings for use by the exec'd image (a
segment with a NULL buf handle).
- Fix a bug where a crash image's code page would by placed at machine
address 0 (instead of inside the crash region).
Changes since v5:
- Fix double free in KEXEC_load_v1 failure path.
- Only copy the relocation code and not the whole page.
- Add myself as the kexec maintainer.
Changes since v4 (v5 was not posted to the list):
- _rsvd -> _pad in one of the public ABI structures.
- Fix bug where trailing pages were not zeroed. This fixes loading a
64-bit Linux kernel using a more recent version of kexec-tools.
- Check the relocation code fits into a page at link time.
Changes since v3:
- Use paddr_t and page_to_maddr() etc. for portability.
- Add explicit padding to hypercall structures where required.
- Minor cleanup of the kexec_reloc assembly.
- Print a message before exec'ing a crash image.
- Style fixes (tabs, trailing whitespace) and typos.
- Fix a bug where using the V1 interface and unloading a image may crash.
Changes since v2:
- Provide old struct xen_kexec_load if __XEN_INTERFACE_VERSION__ < 4.3
- Adjust new struct xen_kexec_load to avoid unnecessary padding.
- Use domheap pages for the image and control pages.
- Remove the DBG() macros from the reloc code.
More information about the kexec