There is little in common with user and softmmu versions of cpu_resume_signal(),
split them.
Fix coding style for the user emulator part.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
tb_invalidate_page_range() was intended to be used to invalidate an
area of a TB which the guest explicitly flushes from i-cache. However,
QEMU detects writes to code areas where TBs have been generated, so
his has never been useful.
Delete the function, adjust callers.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
This bit is never set, therefore we should not read it either.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
This mask contains all of the bits that should be ignored while single
stepping in the debugger. The mask contains 2 bits that are not currently
cleared, but are also never set. The bits are included in the mask for
consistency in handling of the CPU_INTERRUPT_TGT_EXT_N bits.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
The code changed here is an unused data type name (evt_flush_occurred).
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
The previous patch removed the need for parameter puc.
Is is now unused, so remove it.
Cc: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
This patch adds some code paths for running s390x guest OSs without the
need for KVM.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Commit 83f338f73e broke x86 hardware breakpoint emulation by moving the
debug exception handling out of cpu_exec. Fix this by moving all TCG
related bits back, only leaving the generic guest debugging parts in
cpus.c.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
CC: TeLeMan <geleman@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
All implementations are now the same, and there is only one caller,
so inline the function there.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
This patch adds support for the LatticeMico32 softcore processor by Lattice
Semiconductor.
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Mixing up TCG bits with KVM already led to problems around eflags
emulation on x86. Moreover, quite some code that TCG requires on cpu
enty/exit is useless for KVM. So dispatch between tcg_cpu_exec and
kvm_cpu_exec as early as possible.
The core logic of cpu_halted from cpu_exec is added to
kvm_arch_process_irqchip_events. Moving away from cpu_exec makes
exception_index meaningless for KVM, we can simply pass the exit reason
directly (only "EXCP_DEBUG vs. rest" is relevant).
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
To prepare splitting up KVM and TCG CPU entry/exit, move the debug
exception into cpus.c and invoke cpu_handle_debug_exception on return
from qemu_cpu_exec.
This also allows to clean up the debug request signaling: We can assign
the job of informing main-loop to qemu_system_debug_request and stop the
calling cpu directly in cpu_handle_debug_exception. That means a debug
stop will now only be signaled via debug_requested and not additionally
via vmstop_requested.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
When the CPU is in wait state, do not wake-up if an interrupt can't be
taken. This avoid host CPU running at 100% if a device (e.g. timer) has
an interrupt line left enabled.
Also factorize code to check if interrupts are enabled in
cpu_mips_hw_interrupts_pending().
Based on a patch from Edgar E. Iglesias <edgar.iglesias@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Acked-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Move the last found TB to the head of the list so it will be found more quickly next time it will be looked for.
Signed-off-by: Kirill Batuzov <batuzovk@ispras.ru>
Signed-off-by: Pavel Yushchenko <pau@ispras.ru>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
If a cpu_exit request is pending, ensure that we leave the CPU loop
quickly. For this purpose, keep the global exit_request pending until
we are about to leave tcg_cpu_exec. Also, immediately break out of the
SMP loop if the request is set, do not run till the end of the chain.
This preserves the VCPU scheduling order in SMP mode.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
If a signal hit after the env->exit_request check but before cpu_exec
updated env->current_tb, cpu_unlink_tb called from the signal hander
will not unlink the current TB. This may leave us stuck in a guest loop
if no further unlink is invoked.
Fix this by reordering current_tb update and exit_request check,
additionally enforcing the correct order via a compiler barrier.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Store tcg loop exit request on a global variable, and transfer it to
per-CPUState exit_request after assignment of cpu_single_env.
This makes exit request signal from robust. Drop the timedlock hack.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
When -d cpu logging was handled by target-foo/translate.c,
it was controled by DEBUG_DISAS, which is enabled by default.
Use the same condition in cpu_exec.
At the same time, reduce the if-deffery by assuming no flags
update is required for the target.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
ia64 has some strangenesses that need to be workaround:
- it has a __clone2() syscall instead of the using clone() one, with
different arguments, and which is not declared in the usual headers.
- ucontext.uc_sigmask is declared with type long int, while it is
actually of type sigset_t.
- uc_mcontext, uc_sigmask, uc_stack, uc_link are declared using #define,
which clashes with the target_ucontext fields. Change their names to
tuc_*, as already done for some target architectures.
The page tracking code in exec.c is used by both userspace and system
emulation. Userspace emulation uses it to track virtual pages, and
system emulation to track ram pages. Introduce a new type to hold this
kind of address.
Signed-off-by: Paul Brook <paul@codesourcery.com>
This ensures that the compiler does not move it away from
the "env = env1;" assignment. Fixes a miscompilation
on gcc 4.4, reported by Jay Foad.
Cc: <jay.foad@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This should explain a lot of the weird breakages of upstream KVM we've
seen recently (actually we should have seen it much earlier):
Stop translating eflags into TCG format when in kvm mode as we never
translate it back and rather sync this broken state into the kernel.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Since b567b38 (target-arm: remove T0 and T1, 2009-10-16) the only global
register that is used is AREG0, so the complexity of hostregs_helper.h
is unused. Use regular assignments and a compiler optimization barrier.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
The while loop will be executed exactly 0 or 1 times, depending on
env->exit_request.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
By virtue of the previous patch env->current_tb will always be NULL at
the top of cpu_exec's outermost for loop, and at the end of the innermost
while loop.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
There are three paths from the innermost while loop of cpu_exec
to the top of the outermost for loop. Two do not reset
env->current_tb. Fix this.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
cpu_check_irqs
- handle SOFTINT register TICK and STICK timer bits
- only check interrupt levels greater than PIL value
- handle preemption by higher level traps
cpu_exec
- handle CPU_INTERRUPT_HARD only if interrupts are enabled
- PIL 15 is not special level on sparcv9
Signed-off-by: Igor V. Kovalenko <igor.v.kovalenko@gmail.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Because Qemu currently requires a TCG target to exist and there are quite some
useful helpers here to lay the groundwork for out KVM target, let's create a
stub TCG emulation target for S390X CPUs.
This is required to make tcg happy. The emulation target itself won't work
though.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Problem: Our file sys-queue.h is a copy of the BSD file, but there are
some additions and it's not entirely compatible. Because of that, there have
been conflicts with system headers on BSD systems. Some hacks have been
introduced in the commits 15cc923584,
f40d753718,
96555a96d7 and
3990d09adf but the fixes were fragile.
Solution: Avoid the conflict entirely by renaming the functions and the
file. Revert the previous hacks.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
handle_cpu_signal is very nearly copy-paste code for each target, with a
few minor variations. This patch sets up appropriate defaults for a
generic handle_cpu_signal and provides overrides for particular targets
that did things differently. Fixing things like the persistent (XXX:
use sigsetjmp) should now become somewhat easier.
Previous comments on this patch suggest that the "activate soft MMU for
this block" comments refer to defunct functionality. I have removed
such blocks for the appropriate targets in this patch.
Signed-off-by: Nathan Froyd <froydnj@codesourcery.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
kqemu introduces a number of restrictions on the i386 target. The worst is that
it prevents large memory from working in the default build.
Furthermore, kqemu is fundamentally flawed in a number of ways. It relies on
the TSC as a time source which will not be reliable on a multiple processor
system in userspace. Since most modern processors are multicore, this severely
limits the utility of kqemu.
kvm is a viable alternative for people looking to accelerate qemu and has the
benefit of being supported by the upstream Linux kernel. If someone can
implement work arounds to remove the restrictions introduced by kqemu, I'm
happy to avoid and/or revert this patch.
N.B. kqemu will still function in the 0.11 series but this patch removes it from
the 0.12 series.
Paul, please Ack or Nack this patch.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
On Sun, Jul 12, 2009 at 12:09 PM, Blue Swirl<blauwirbel@gmail.com> wrote:
> On 7/12/09, Igor Kovalenko <igor.v.kovalenko@gmail.com> wrote:
>> Good trap handling is required to process interrupts.
>> This patch fixes the following:
>>
>> - sparc64 has no wim register
>> - sparc64 has no psret register, use IE bit of pstate
>> extract IE checking code to cpu_interrupts_enabled
>> - alternate globals are not available if cpu has GL feature
>> in this case bit AG of pstate is constant zero
>> - write to pstate must actually write pstate
>> even if cpu has GL feature
>>
>> Also timer interrupt is handled using do_interrupt.
>
> A bit too much for one patch. Please also remove the code instead of
> commenting out.
I now excluded timer interrupt related part.
To my mind other changes are essentially tied together.
> PUT_PSR for Sparc64 needs CC_OP = CC_OP_FLAGS; like Sparc32.
Fixed, please find attached the updated version.
--
Kind regards,
Igor V. Kovalenko
- MCE features are initialized when VCPU is intialized according to CPUID.
- A monitor command "mce" is added to inject a MCE.
- A new interrupt mask: CPU_INTERRUPT_MCE is added to inject the MCE.
aliguori: fix build for linux-user
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This should fix compilation problem in case of CONFIG_USER_ONLY.
Currently INIT/SIPI is handled in the context of CPU that sends IPI.
This patch changes this to handle them like all other events in a main
cpu exec loop. When KVM will gain thread per vcpu capability it will
be much more clear to handle those event by cpu thread itself and not
modify one cpu's state from the context of the other.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
env->interrupt_request is accessed as the bit level from both main code
and signal handler, making a race condition possible even on CISC CPU.
This causes freeze of QEMU under high load when running the dyntick
clock.
The patch below move the bit corresponding to CPU_INTERRUPT_EXIT in a
separate variable, declared as volatile sig_atomic_t, so it should be
work even on RISC CPU.
We may want to move the cpu_interrupt(env, CPU_INTERRUPT_EXIT) case in
its own function and get rid of CPU_INTERRUPT_EXIT. That can be done
later, I wanted to keep the patch short for easier review.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6728 c046a42c-6fe2-441c-8c8c-71466251a162
These are references to 'loglevel' that aren't on a simple 'if (loglevel &
X) qemu_log()' statement.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6340 c046a42c-6fe2-441c-8c8c-71466251a162
This is a large patch that changes all occurrences of logfile/loglevel
global variables to use the new qemu_log*() macros.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6338 c046a42c-6fe2-441c-8c8c-71466251a162
According to $GCC/gcc/config/rs6000/rs6000-c.c _ARCH_PPC is the
ubiquitous define which should be used to test whether gcc targets
PowerPC, on 64bit platforms _ARCH_PPC64 will be also defined.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6301 c046a42c-6fe2-441c-8c8c-71466251a162
The attached patch updates the FSF address in the GPL/LGPL boilerplate
in most GPL/LGPLed files, and also in COPYING.LIB.
Signed-off-by: Stuart Brady <stuart.brady@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6162 c046a42c-6fe2-441c-8c8c-71466251a162
shortly after an IRQ has been raised, env->exception_index will still be set
to EXCP_IRQ when cpu_io_recompile calls cpu_resume_from_signal.
This causes qemu to repeat the IRQ trap, with disasterous consequences.
I suspect this "works" most of the time because linux tends to drop back to
svc mode before doing actual IRQ processing, and be fairly
tolerant of spurious IRQ traps.
Signed-off-by: Paul Brook <paul@codesourcery.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6100 c046a42c-6fe2-441c-8c8c-71466251a162
SVM specifies that the V_IRQ mask is only to be removed, if the
interrupt that is to be delivered actually is delivered.
As of the SVM rewrite, this mask is always unmasked when the main cpu
loop is processed, leaving a corner case where calling the interrupt
handler causes a #PF. In that case (booting Linux / starting gfxboot)
the current implementation tells the VMM the interrupt is taken, even
though it is not.
This patch modifies the VIRQ unmasking to occur after do_interrupt,
making gfxboot work again.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6008 c046a42c-6fe2-441c-8c8c-71466251a162
This switches cpu_break/watchpoint_* to TAILQ wrappers, simplifying the
code and also fixing a use after release issue in
cpu_break/watchpoint_remove_all.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5799 c046a42c-6fe2-441c-8c8c-71466251a162
This patch allows to hook into the delivery of EXCP_DEBUG so that other
use beyond guest debugging becomes possible.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5745 c046a42c-6fe2-441c-8c8c-71466251a162
When one watchpoint is hit, others might have triggered as well. To
support users of the watchpoint API which need to detect such cases,
the BP_WATCHPOINT_HIT flag is introduced and maintained.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5744 c046a42c-6fe2-441c-8c8c-71466251a162
This patch refactors the way the CPU state is handled that is associated
with a TB. The basic motivation is to move more arch specific code out
of generic files. Specifically the long #ifdef clutter in tb_find_fast()
has to be overcome in order to avoid duplicating it for the gdb
watchpoint fixes (patch "Restore pc on watchpoint hits").
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5736 c046a42c-6fe2-441c-8c8c-71466251a162
as macros should be avoided when possible.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5735 c046a42c-6fe2-441c-8c8c-71466251a162
We don't need to use cpu_loop_exit() because we never use the
condition codes so everything can be folded into a single case.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5669 c046a42c-6fe2-441c-8c8c-71466251a162
Commit #5620 revealed an issue of the SSTEP_NOIRQ masking that was
applied on all interrupt sources (including internal ones) when single
stepping through the guest. Due to that commit, we now ended up in an
infinite loop when CPU_INTERRUPT_EXIT was pending on SSTEP resume. That
was due to #5620 eating all TBs while CPU_INTERRUPT_EXIT is pending, but
SSTEP_NOIRQ preventing CPU_INTERRUPT_EXIT to be processed.
What SSTEP_NOIRQ should actually do is to block the delivery of all
external, guest visible interrupts. With the fix below applied, single
stepping now works again.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5643 c046a42c-6fe2-441c-8c8c-71466251a162
This patch adds very basic KVM support. KVM is a kernel module for Linux that
allows userspace programs to make use of hardware virtualization support. It
current supports x86 hardware virtualization using Intel VT-x or AMD-V. It
also supports IA64 VT-i, PPC 440, and S390.
This patch only implements the bare minimum support to get a guest booting. It
has very little impact the rest of QEMU and attempts to integrate nicely with
the rest of QEMU.
Even though this implementation is basic, it is significantly faster than TCG.
Booting and shutting down a Linux guest:
w/TCG: 1:32.36 elapsed 84% CPU
w/KVM: 0:31.14 elapsed 59% CPU
Right now, KVM is disabled by default and must be explicitly enabled with
-enable-kvm. We can enable it by default later when we have had better
testing.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5627 c046a42c-6fe2-441c-8c8c-71466251a162
cpu_interrupt might be called while translating the TB, but before it
is linked into a potentially infinite loop and becomes env->current_tb.
Currently this can (and does) cause huge problems only when using
dyntick clock, with other (periodic) clocks host_alarm_handler will
eventually be executed resulting in a call to cpu_interrupt which will
reset the recursion of running TB and the damage is "only" latency.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5620 c046a42c-6fe2-441c-8c8c-71466251a162
* break 8 sets ERP to the current insn.
* First shot at S flag single-stepping.
* Make it easier to use the local disasm.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5445 c046a42c-6fe2-441c-8c8c-71466251a162
This patch adds check for all SH4 instructions which are
executed only in privileged mode.
(Shin-ichiro KAWASAKI)
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5224 c046a42c-6fe2-441c-8c8c-71466251a162
* Dont flush the entire qemu tlb when the $pid changes. Instead we go through
the guests TLB and choose entries that need to be flushed.
* Add env->dslot and handle delayslots at pageboundaries.
* Remove some unused code.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4450 c046a42c-6fe2-441c-8c8c-71466251a162
This patch allows the qemu backend debugger to single step an
instruction without running the hardware interrupts.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4391 c046a42c-6fe2-441c-8c8c-71466251a162
* Support both the I and D MMUs and improve the accuracy of the MMU model.
* Handle the automatic user/kernel stack pointer switching when leaving or entering user mode.
* Move the CCS evaluation into helper funcs.
* Make sure user-mode cannot change flags only writeable in kernel mode.
* More conversion of the translator into TCG.
* Handle exceptions while in a delayslot.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4299 c046a42c-6fe2-441c-8c8c-71466251a162
* Clean up the interrupt handling a bit.
* Connect some NOR flash to the test board.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4055 c046a42c-6fe2-441c-8c8c-71466251a162
allowing support of more than 2 mmu access modes.
Add backward compatibility is_user variable in targets code when needed.
Implement per target cpu_mmu_index function, avoiding duplicated code
and #ifdef TARGET_xxx in softmmu core functions.
Implement per target mmu modes definitions. As an example, add PowerPC
hypervisor mode definition and Alpha executive and kernel modes definitions.
Optimize PowerPC case, precomputing mmu_idx when MSR register changes
and using the same definition in code translation code.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3384 c046a42c-6fe2-441c-8c8c-71466251a162
move all PowerPC specific code into target-ppc/helper.c to avoid polluting
the common code in cpu-exec.c. This makes implementation of new features
(ie embedded PowerPC timers, critical interrupts, ...) easier.
This also avoid hardcoding the IRQ callback in the OpenPIC controller,
making it more easily reusable and allowing cascading.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@2542 c046a42c-6fe2-441c-8c8c-71466251a162
This is needed by OS/2 and Windows NT and some programs like VirtualPC.
This patch has been tested using OS/2 bootloader (thanks to Tero
Kaarlela).
(Jocelyn Mayer)
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@1379 c046a42c-6fe2-441c-8c8c-71466251a162
