Jan Kiszka wrote:
Anthony Liguori wrote:
Jan Kiszka wrote:
This patch prepares the QEMU cpu_watchpoint/breakpoint API to allow the
succeeding enhancements this series comes with.
First of all, it overcomes MAX_BREAKPOINTS/MAX_WATCHPOINTS by switching
to dynamically allocated data structures that are kept in linked lists.
This also allows to return a stable reference to the related objects,
required for later introduced x86 debug register support.
Breakpoints and watchpoints are stored with their full information set
and an additional flag field that makes them easily extensible for use
beyond pure guest debugging.
Finally, this restructuring lays the foundation for KVM to hook into
the debugging infrastructure, providing its own services where hardware
virtualization demands it. Once QEMUAccel is considered for merge,
those entry point should be included into its abstraction layer so that
accellerators can hook in even more cleanly.
We've merged KVM support (although not QEMUAccel), so perhaps you can
also add the KVM hooks in this series that you are thinking of?
I will check how much of my kvm patches for guest debugging can already
be ported over.
That topic is more complex - if you recall my according series - as kvm
requires kernel changes to gain full guest debugging support. I'm not
even sure if it makes sense to add support for the current kernel
interface as it is too restricted (no watchpoints, only 4 breakpoints).
However, will re-check if some patch re-ordering may help the migration.
I had a closer look meanwhile. Given the fact that there are no kvm bits
for supporting guest debugging in qemu yet and that it would take some
additional effort for me to establish this for the old interface, I
would like to skip this step and suggest a different roadmap instead:
o integrate plain qemu bits for full guest debugging (this series)
o wait for Avi to merge them into kvm-userspace
o rebase my kvm guest debugging series over kvm-userspace
(kernel bits are already up to date) and submit it for review/merge
o port stabilized kvm guest debugging over to qemu, but demanding the
new kernel ABI