(domU only). PAE support is enabled by 'options PAE', see the new XEN3PAE_DOMU
and INSTALL_XEN3PAE_DOMU kernel config files.
See the comments in arch/i386/include/{pte.h,pmap.h} to see how it works.
In short, we still handle it as a 2-level MMU, with the second level page
directory being 4 pages in size. pmap switching is done by switching the
L2 pages in the L3 entries, instead of loading %cr3. This is almost required
by Xen, which handle the last L2 page (the one mapping 0xc0000000 - 0xffffffff)
in a very special way. But this approach should also work for native PAE
support if ever supported (in fact, the pmap should almost suport native
PAE, what's missing is bootstrap code in locore.S).
pmap_bootstrap()/init386() wants to map a few additionnal things after
first_avail that we didn't account for, before pmap_growkernel() is
used/functionnal, and if the loaded kernel is close to the end of
the last L2 slot we loose. Should fix port-xen/37761 by YAMAMOTO Takashi.
Fix a XENPRINTF() so that low debug builds again.
branch is still active and will see i386PAE support developement).
Sumary of changes:
- switch xeni386 to the x86/x86/pmap.c, and the xen/x86/x86_xpmap.c
pmap bootstrap.
- merge back most of xen/i386/ to i386/i386
- change the build to reduce diffs between i386 and amd64 in file locations
- remove include files that were identical to the i386/amd64 counterparts,
the build will find them via the xen-ma/machine link.
- make tss per-cpu. this considerably speeds up context switch for,
at least, pentium4, where ltr instruction seems very slow.
i386, xen:
- kill cpu_maxproc.
kvm86:
- adapt to per-cpu tss.
- cleanup and simplify.
- move kvm86_mp_lock to more meaningful place.
- disable preemption during a call.
ACPI wakeup code and teach it how to start the APs again. As a side
effect the CPU_START interface allows choosing between different
bootstrap codes more easily now.
- Reduce available SPL levels for hardware devices to none, vm, sched, high.
- Acquire kernel_lock only for interrupts at IPL_VM.
- Implement threaded soft interrupts.
- Replace most inline assembly with proper functions. As a side effect
this reduces the size of amd64 GENERIC by about 120kB, and i386 by a
smaller amount. Nearly all of the inlines did something slow, or something
that does not need to be fast.
- Make curcpu() and curlwp functions proper, unless __GNUC__ && _KERNEL.
In that case make them inlines. Makes curlwp LKM and preemption safe.
- Make bus_space and bus_dma more LKM friendly.
- Share a few more files between the ports.
- Other minor changes.
interface doesn't allow it), so that .e.g bus_dma_subregion() has a chance
to work. Unfortunably a stock Xen hypervisor won't allow a upper bound less
than 2^31 (2GB) so devices like bce(4) will need a hacked hypervisor to
work properly.
Patch by Slava Semushin <slava.semushin@gmail.com>
Again, this was tested by comparing obj files from a pristine and a patched
source tree against an i386/ALL kernel, and also for src/sbin/fsck_ffs,
src/sbin/fsdb and src/usr.sbin/makefs. Only changes in assert() line numbers
were detected in 'objdump -d' output.
CPUs are now configured on mainbus only in dom0, and only to know about
their APIC id. virtual CPUs are attached to hypervisor as:
vcpu* at hypervisor?
and this is what's used as curcpu(). The kernel config files needs to be
updated for this, see XEN3_DOM0 or XEN3_DOMU for examples.
XEN3_DOM0 now has acpi, MPBIOS and ioapic by default.
Note that a Xen dom0 kernel doens't have access to the lapic.
- Attempt to gracefully recover from a failed decrease_reservation or
increase_reservation, by avoiding physical memory loss.
- always store a machine address in ds_addr; this avoids some mistakes
where machine address would in some case be freed at physical address, or
mapped as physical address.
- 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.
- Define _BUS_AVAIL_END to 0xffffffff, as we don't have an easy way to
find the upper bound for our machine address space (and this can change
when we swap pages with the hypervisor).
- implement _xen_bus_dmamem_alloc_range(), which will request a contigous
set of pages to the hypervisor if the pages returned by uvm_pglistalloc()
don't fit the constraints.
We can't deal with the low/high constraints yet, because Xen doesn't offer a
way to get pages in a specific ranges of addresses.
Based on patches from Dave Thompson (in private mail), with heavy hacking
by me.
including soft interrupt, and this is way too low in some use (lots of domains,
or domains with lots of xennet, or even hardware with lots of devices at
different interrupts).
Based on idea from YAMAMOTO Takashi, keep one list of handler per-event and
one per-IPL (so the same handler is now in 2 lists). In the common case were
an event is received at low IPL, we can call the handlers quickly (there
is usually only one handler per event, unless the event is mapped to a
physical interrupt and this interrupt is shared by different devices).
Deffered events and software interrupts are handled by a bitmask (as before)
with one bit per IPL. When one IPL has an event pending all handlers for
this IPL will be called.
With this change, it is now possible to have all the 1024 events active.
While here, handle debug event in a special way: the handler is always called,
regardless of the current IPL. Make the handler print usefull informations
about events and IPL states.
Also remove code not used on Xen in files inherited from the x86 port.
- distinguish paddr_t and bus_addr_t.
for xen, use bus_addr_t in the sense of machine address.
- move _X86_BUS_DMA_PRIVATE part of bus.h into bus_private.h.
- remove special handling of xen_shm. we can always grab
machine address from pte.
- don't use managed mappings/backing objects for wired memory allocations.
save some resources like pv_entry. also fix (most of) PR/27030.
- simplify kernel memory management API.
- simplify pmap bootstrap of some ports.
- some related cleanups.
by 0x100000 (above the I/O Memory "hole") leaving all physical addresses
below unused, don't perform phys<->mach mapping for addresses below 0x100000
or beyond the real hardware's physical memory.
-> /dev/mem works now as expected and X works in domain0.
bouyer