- An 'xc_error' struct is used to pass around error
details. Currently contains two members 'code' an enumeration of
error types, and 'message' a free text description of the specific
problem.
- The xc_get_last_error() method returns a const pointer to the
internal instance of this struct manged by libxc. By returning a
const pointer we can add extra members to the end of the struct at
any time without worrying about ABI of callers. This will let us
provide more fine-grained info if needed in the future.
- The xc_error instance is statically defined inside libxc and marked
__thread. This ensures that errors are recorded per-thread, and
that when dealing with errors we never need to call malloc - all
storage needed is statically allocated.
- The xc_clear_last_error() method resets any currently recorded
error details
- The xc_error_code_to_desc() method converts the integer error code
into a generic user facing messsage. eg "Invalid kernel". Together
with the 'message' field from xc_error, this provides the user
visible feedback. eg "Invalid kernel: Non PAE-kernel on PAE host."
- A callback can be registered with xc_set_error_handler to receive
notification whenever an error is recorded, rather than querying
for error details after the fact with xc_get_last_error
- If built with -DDEBUG set, a default error handler will be
registered which calls fprintf(stderr), thus maintaining current
behaviour of logging errors to stderr during developer builds.
- The python binding for libxc is updated to use xc_get_last_error
to pull out error details whenever appropriate, instead of
returning info based on 'errno'
- The xc_set_error method is private to libxc internals, and is used
for setting error details
- The ERROR and PERROR macros have been updated to call xc_set_error
automatically specifying XC_INTERNAL_ERROR as the error code. This
gives a generic error report for all current failure points
- Some uses of the ERROR macro have been replaced with explicit
calls to xc_set_error to enable finer grained error reporting. In
particular the code dealing with invalid kernel types uses this
to report about PAE/architecture/wordsize mismatches
The patch has been tested by calling xm create against a varietry of
config files defining invalid kernels of various kinds. It has also
been tested with libvirt talking to xend. In both cases the error
messages were propagated all the way back up the stack.
There is only one place where I need to do further work. The suspend
& restore APIs in Xend invoke external helper programs rather than
calling libxc directly. This means that error details are essentially
lost. Since there is already code in XenD which scans STDERR from
these programs I will investigate adapting this to extract actual
error messages from these helpers.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The latest ELF changes have a null pointer dereference bug when you
have neither an elf notes section nor a __xen_guest_string. This patch
checks for the existence of the __xen_guest_string prior to using it.
Please apply. Thanks,
Alex
Signed-off-by: Alex Williamson <alex.williamson@hp.com>
---
- Remove debugging statements.
- Cope better with archtectures where neither ELF notes or __xen_guest
are needed or required.
Signed-off-by: Ian Campbell <ian.campbell@xensource.com>
- use 64-bit integral types for addresses in struct domain_start_info
- use stroull() to parse 64-bit values
- remove redundant _p(a) definition and add a comment
- printf format changes for the new types
Signed-off-by: Jimi Xenidis <jimix@watson.ibm.com>
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Necessary if a long is a different size to addresses in elf
file being parsed.
From: Jimi Xenidis <jimix@watson.ibm.com>
Signed-off-by: Keir Fraser <keir@xensource.com>
pae_pgdir_above_4gb tp guests that have enabled this vmassist.
Control tools ensure all PAE page directories are below 4GB
unless the vmassist is enabled (triggered via an extended-cr3
option in guest Elf header).
Signed-off-by: Keir Fraser <keir@xensource.com>
This avoids using zero to indicate 'undefined'. Instead we use
an explicit boolean to indicate whether suitable defaults should
be used. As well as making the logic clearer (I believe) it also
avoids problems if anyone ever explicitly specifies virt_base
(and also elf_paddr_offset) as zero.
Signed-off-by: Keir Fraser <keir@xensource.com>
to prevent xend crashign (when Aravindh's latest patch is
applied) and breaks ia64. Also, ensure we set a reasonable
default for elf_paddr_offset.
Signed-off-by: Keir Fraser <keir@xensource.com>
Add a new __xen_guest header field to distinguish between kernels with
the previous use of the paddr field and the new use.
Add a new __xen_guest header field to control the kernel entry point,
since the elf header entry field now points to a physical address.
This header field is also useful for supporting alternative entry
points in kernel images which run both on xen and native.
Also add a kernel config option to control whether the resulting kernel
should include compatibility code to run on Xen 3.0.2 or whether such
code such be left out, resulting in a kernel which will only run on
newer Xen versions. Default to having compatibility enabled.
Kernels built with the new use of the elf header fields would otherwise
not work on Xen versions prior to this changeset.
Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>
xc_private.h, xc_linux_build.c, Makefile:
Add support for loading ``bin'' format images, as used by ReactOS.
Move image probing/parsing/loading code out of domain builder to allow
multiple image formats without having to duplicate the domain building
code.
xc_load_elf.c, xc_load_bin.c:
new file
xc_vmx_build.c:
Cleanup.
Signed-Off-By: Ge van Geldorp <gvg@reactos.com>
Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>
