request again (possibly because of compiler optimisations), by using
copies and barrier.
From XSA155:
The compiler can emit optimizations in the PV backend drivers which
can lead to double fetch vulnerabilities. Specifically the shared
memory between the frontend and backend can be fetched twice (during
which time the frontend can alter the contents) possibly leading to
arbitrary code execution in backend.
New interfaces for PV drivers:
- Xen transcedent memory
- USB IO
- SCSI IO
PCI IO improvements:
- PCI MSI support
- PCI Express AER support
New features:
- xen honors flags to be placed into guest kernel available pte bits
if enabled (for grant table)
- support for 128 vcpus
(old interface is still present and supports up to 32 vcpus)
- PCI passthrough: new hypercalls to support SR-IOV
- new hypercall for physical cpu hotplugging
- new hypercall for physical page offlining
- fixes to compile with clang
- machine check recovery mechanism
This branch was a major cleanup and rototill of many of the various OEA
cpu based PPC ports that focused on sharing as much code as possible
between the various ports to eliminate near-identical copies of files in
every tree. Additionally there is a new PIC system that unifies the
interface to interrupt code for all different OEA ppc arches. The work
for this branch was done by a variety of people, too long to list here.
TODO:
bebox still needs work to complete the transition to -renovation.
ofppc still needs a bunch of work, which I will be looking at.
ev64260 still needs to be renovated
amigappc was not attempted.
NOTES:
pmppc was removed as an arch, and moved to a evbppc target.
- kernel (both dom0 and domU) boot, console is functionnal and it can starts
software from a ramdisk
- there is no driver front-end expect console for domU yet.
- dom0 can probe devices and ex(4) work when Xen3 is booted without acpi
and apic support. But the on-board IDE doens't get interrupts.
The PCI code still needs work (it's hardcoded to mode 1). Some of this
code should be shared with ../x86
The physical insterrupt code needs to get MPBIOS and ACPI support, and
do interrupt routing to properly interract with Xen.
To enable Xen-3.0 support, add
options XEN3
to your kernel config file (this will disable Xen2 support)
Changes affecting Xen-2.0 support (no functionnal changes intended):
- get more constants from genassym for assembly code
- remove some unneeded registers move from start()
- map the shared info page from start(), and remove the pte = 0xffffffff hack
- vector.S: in hypervisor_callback() make sure %esi points to
HYPERVISOR_shared_info before accessing the info page. Remplace some
hand-written assembly with the equivalent macro defined in frameasm.h
- more debug code, dissabled by default.
while here added my copyright on some files I worked on in 2005.
Remove the padding bits from blkif_extent_t, so that the message size doesn't
change. You'll need xentools20-2.0.3nb1 if you upgrade your kernel
(the old tools didn't zero out the padding bits, and a new kernel will
interpret them as part of the device number).
