Several functions to provide necessary access to BdrvDirtyBitmap for
block-migration.c
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
[Add the "finish" parameters. - Fam]
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 1476395910-8697-9-git-send-email-jsnow@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Functions to serialize / deserialize(restore) HBitmap. HBitmap should be
saved to linear sequence of bits independently of endianness and bitmap
array element (unsigned long) size. Therefore Little Endian is chosen.
These functions are appropriate for dirty bitmap migration, restoring
the bitmap in several steps is available. To save performance, every
step writes only the last level of the bitmap. All other levels are
restored by hbitmap_deserialize_finish() as a last step of restoring.
So, HBitmap is inconsistent while restoring.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
[Fix left shift operand to 1UL; add "finish" parameter. - Fam]
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 1476395910-8697-8-git-send-email-jsnow@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
We use a loop over bs->dirty_bitmaps to make sure the caller is
only releasing a bitmap owned by bs. Let's also assert that in this case
the caller is releasing a bitmap that does exist.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 1476395910-8697-7-git-send-email-jsnow@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
For dirty bitmap users to get the size and the name of a
BdrvDirtyBitmap.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 1476395910-8697-6-git-send-email-jsnow@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
The added group of operations enables tracking of the changed bits in
the dirty bitmap.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 1476395910-8697-5-git-send-email-jsnow@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Upon each bit toggle, the corresponding bit in the meta bitmap will be
set.
Signed-off-by: Fam Zheng <famz@redhat.com>
[Amended text inline. --js]
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 1476395910-8697-3-git-send-email-jsnow@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
HBitmap is an implementation detail of block dirty bitmap that should be hidden
from users. Introduce a BdrvDirtyBitmapIter to encapsulate the underlying
HBitmapIter.
A small difference in the interface is, before, an HBitmapIter is initialized
in place, now the new BdrvDirtyBitmapIter must be dynamically allocated because
the structure definition is in block/dirty-bitmap.c.
Two current users are converted too.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 1476395910-8697-2-git-send-email-jsnow@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
In FIFO mode there are no parallel reads, hence there is no need to
allocate separate buffers and clone the iovecs.
The two cases of quorum_aio_cb are now even more different, and
most of quorum_aio_finalize is only needed in one of them, so split
them in separate functions.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1475685327-22767-3-git-send-email-pbonzini@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This simplifies a bit the code by using the usual C "inclusive start,
exclusive end" pattern for ranges.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1475685327-22767-2-git-send-email-pbonzini@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
There are some (mostly ISP-specific) name servers who will redirect
non-existing domains to special hosts. In this case, we will get a
different error message when trying to connect to such a host, which
breaks test 162.
162 needed this specific error message so it can confirm that qemu was
indeed trying to connect to the user-specified port. However, we can
also confirm this by setting up a local NBD server on exactly that port;
so we can fix the issue by doing just that.
Reported-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
With qemu-nbd's new --fork option, we no longer need to launch it the
hacky way.
Suggested-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Using the --fork option, one can make qemu-nbd fork the worker process.
The original process will exit on error of the worker or once the worker
enters the main loop.
Suggested-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
iotest 093 contains a test that creates a throttling group with
several drives and performs I/O in all of them. This patch adds a new
test that creates a similar setup but only performs I/O in one of the
drives at the same time.
This is useful to test that the round robin algorithm is behaving
properly in these scenarios, and is specifically written using the
regression introduced in 27ccdd5259 as an example.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
In 27ccdd5259 the throttling fields were
moved from BlockDriverState to BlockBackend. However in a few cases
the code started using throttling fields from the active BlockBackend
instead of the round-robin token, making the algorithm behave
incorrectly.
This can cause starvation if there's a throttling group with several
drives but only one of them has I/O.
Cc: qemu-stable@nongnu.org
Reported-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The 'obj' result of the visitor was not properly freed, like done in
other places doing a similar job.
Signed-off-by: Pino Toscano <ptoscano@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Make raw_open for POSIX more consistent in handling errors by setting
the error object also when qemu_open fails. The error object was set
generally set in case of errors, but I guess this case was overlooked.
Do the same for win32.
Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Tested-by: Marc Hartmayer <mhartmay@linux.vnet.ibm.com> (POSIX only)
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Now that QAPI supports boxed types, we can have unions at the top level
of a command, so let's put our real options directly there for
blockdev-add instead of having a single "options" dict that contains the
real arguments.
blockdev-add is still experimental and we already made substantial
changes to the API recently, so we're free to make changes like this
one, too.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Handling this is similar to what is done to the L2 entry in the case of
compressed clusters.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
If the backing file cannot be opened when doing qemu-img rebase, the
variable 'ret' was not assigned a non-zero value, and the qemu-img
process terminated with exit code zero. Fix this.
Signed-off-by: Xu Tian <xutian@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Some SMBus operations restart the transfer to convert from
write to read mode without an intervening i2c_end_transfer().
The second call cannot fail, so the return code is unchecked,
but this causes Coverity to complain. So add some asserts
and documentation about this.
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Version 2.0 of the semihosting specification introduces new trap
instructions for AArch32: HLT 0xF000 for A32 and HLT 0x3C for T32.
Implement these (in the same way we implement the existing HLT
semihosting trap for A64).
The old traps via SVC and BKPT are unaffected.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1476792973-18508-1-git-send-email-peter.maydell@linaro.org
Drop the old Sysbus init and use instance_init and
DeviceClass::realize instead
Signed-off-by: xiaoqiang zhao <zxq_yx_007@163.com>
Message-id: 20161023091816.3839-5-zxq_yx_007@163.com
[PMM: added accidentally dropped blank line]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Drop the old Sysbus init and use instance_init and
DeviceClass::realize instead
Signed-off-by: xiaoqiang zhao <zxq_yx_007@163.com>
Message-id: 20161023091816.3839-4-zxq_yx_007@163.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Drop the old Sysbus init and use instance_init and
DeviceClass::realize instead
Signed-off-by: xiaoqiang zhao <zxq_yx_007@163.com>
Message-id: 20161023091816.3839-3-zxq_yx_007@163.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Drop the old Sysbus init and use instance_init and
DeviceClass::realize instead
Signed-off-by: xiaoqiang zhao <zxq_yx_007@163.com>
Message-id: 20161023091816.3839-2-zxq_yx_007@163.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The STM32F2XX Timer emulator uses a 16 bit prescaler value to
limit the timer clock rate. It does that by dividing the timer
frequency. If the prescaler 's->tim_psc' was set to be UINT_MAX,
it'd lead to divide by zero error. Limit prescaler value to 16
bits to avoid it.
Reported-by: Huawei PSIRT <psirt@huawei.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Message-id: 1476800269-31902-1-git-send-email-ppandit@redhat.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Change 2293c27fad (i2c: implement broadcast write) added broadcast
capability to the I2C bus, but it broke SMBus read transactions.
An SMBus read transaction does two i2c_start_transaction() calls
without an intervening i2c_end_transfer() call. This will
result in i2c_start_transfer() adding the same device to the
current_devs list twice, and then the ->event() for the same
device gets called twice in the second call to i2c_start_transfer(),
resulting in the smbus code getting confused.
Note that this happens even with pure I2C devices when simulating
SMBus over I2C.
This fix only scans the bus if the current set of devices is empty.
This means that the current set of devices stays fixed until
i2c_end_transfer() is called, which is really what you want.
This also deletes the empty check from the top of i2c_end_transfer().
It's unnecessary, and it prevents the broadcast variable from being
set to false at the end of the transaction if no devices were on
the bus.
Cc: KONRAD Frederic <fred.konrad@greensocs.com>
Cc: Alistair Francis <alistair.francis@xilinx.com>
Cc: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Cc: Kwon <hyun.kwon@xilinx.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Reviewed-by: KONRAD Frederic <fred.konrad@greensocs.com>
Tested-by: KONRAD Frederic <fred.konrad@greensocs.com>
Message-id: 1470153614-6657-1-git-send-email-minyard@acm.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
ARM A9MP processor has a peripheral timer with an auto-increment
register, which holds an increment step value. A user could set
this value to zero. When auto-increment control bit is enabled,
it leads to an infinite loop in 'a9_gtimer_update' while
updating comparator value. Remove this loop incrementing the
comparator value.
Reported-by: Li Qiang <liqiang6-s@360.cn>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Message-id: 1476733226-11635-1-git-send-email-ppandit@redhat.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This patch builds an IORT table that features a root complex node and
an ITS node. This complements the ITS description in the ACPI MADT
table and allows vhost-net on ACPI guest.
Signed-off-by: Prem Mallappa <prem.mallappa@broadcom.com>
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Message-id: 1476707466-14300-3-git-send-email-eric.auger@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
ACPI Spec 6.0 introduces IO Remapping Table Structure. This patch
introduces the definitions required to describe the IO relationship
between the PCIe root complex and the ITS.
This conforms to:
"IO Remapping Table System Software on ARM Platforms",
Document number: ARM DEN 0049B, October 2015.
Signed-off-by: Prem Mallappa <prem.mallappa@broadcom.com>
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Message-id: 1476707466-14300-2-git-send-email-eric.auger@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
ARM MPTimer is a per-CPU core timer, essential part of the ARM Cortex-A9
MPCore. Add QTests for it.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Message-id: 1c9a2f1c80f87e935b4a28919457c81b6b2256e9.1475421224.git.digetx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Current ARM MPTimer implementation uses QEMUTimer for the actual timer,
this implementation isn't complete and mostly tries to duplicate of what
generic ptimer is already doing fine.
Conversion to ptimer brings the following benefits and fixes:
- Simple timer pausing implementation
- Fixes counter value preservation after stopping the timer
- Properly handles prescaler != 0 / counter = 0 / load = 0 cases
- Code simplification and reduction
Bump VMSD to version 3, since VMState is changed and is not compatible
with the previous implementation.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Message-id: 37f378c33bb5a28d5cd71167a6bd5bff5e59cbc3.1475421224.git.digetx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The 10000 is an arbitrarily chosen value used for advancing the QEMU
time, so that ptimer's now != last. Change it to 1 to make code a bit
more readable.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Message-id: 63256eaac54c84dac7c797f41296cc49e751d09d.1475421224.git.digetx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Eric Blake suggested that use of "Author:" in the copyright text of the
files created by individuals is incorrect, replace it with "Copyright".
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Message-id: 9d8b626f462d4a5094b1945fbd763b8a2e28dd86.1475421224.git.digetx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
PTIMER_POLICY_NO_COUNTER_ROUND_DOWN makes ptimer_get_count() return the
actual counter value and not the one less.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Message-id: 0082889309b3dc66c03c8de00b8c1ef40c1e3955.1475421224.git.digetx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
For most of the timers counter starts to decrement after first period
expires. Due to rounding down performed by the ptimer_get_count, it returns
counter - 1 for the running timer, so that for the ptimer user it looks
like counter gets decremented immediately after running the timer. Add "no
counter round down" policy that provides correct behaviour for those timers.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Message-id: ef39622d0ebfdc32a0877e59ffdf6910dc3db688.1475421224.git.digetx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
PTIMER_POLICY_NO_IMMEDIATE_RELOAD makes ptimer to not to re-load
counter on setting counter value to "0" or starting to run with "0".
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Message-id: a7acf805e447cc7f637ecacbd45cca34ea3bf425.1475421224.git.digetx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Immediate counter re-load on setting (or on starting to run with)
counter = 0 is a wrong behaviour for some of the timers. Add "no
immediate reload" policy that provides correct behaviour for such timers.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Message-id: bf9385cd2550ca451d564fa46007688cee3f3d9d.1475421224.git.digetx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
PTIMER_POLICY_NO_IMMEDIATE_TRIGGER makes ptimer to not to trigger on starting
to run with / setting counter to "0".
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Message-id: 12b1e745f90fe2ca3d59197166bc3d379260f912.1475421224.git.digetx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Performing trigger on setting (or starting to run with) counter = 0 could
be a wrong behaviour for some of the timers, provide "no immediate trigger"
policy to maintain correct behaviour for such timers.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Message-id: 72c0319cf2ec599f22397b7da280c06c34dc40dd.1475421224.git.digetx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
PTIMER_POLICY_CONTINUOUS_TRIGGER makes periodic ptimer to re-trigger every
period in case of load = delta = 0.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Message-id: 7a908ab38b902d521eb959941f9efe2df8ce4297.1475421224.git.digetx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Currently, periodic timer that has load = delta = 0 performs trigger
on timer reload and stops, printing a "period zero" error message.
Introduce new policy that makes periodic timer to continuously trigger
with a period interval in case of load = 0.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Message-id: 632b23dd11055d9bd5e338d66b38fac0bd51462e.1475421224.git.digetx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
PTIMER_POLICY_WRAP_AFTER_ONE_PERIOD changes ptimer behaviour in a such way,
that it would wrap around after one period instead of doing it immediately.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Message-id: ce27bb84ed9f2b64300dd4e90f3eff235a7dcedf.1475421224.git.digetx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Currently, periodic counter wraps around immediately once counter reaches
"0", this is wrong behaviour for some of the timers, resulting in one period
being lost. Add new ptimer policy that provides correct behaviour for such
timers, so that counter stays with "0" for a one period before wrapping
around.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Message-id: f22a670cf1f4be298b31640cb5f4be1df0f20ab6.1475421224.git.digetx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Since the virt board model will never create a CPU which is
pre-ARMv7, we know that our minimum page size is 4K and can
set minimum_page_bits accordingly, for improved performance.
Note that this is a migration compatibility break, so
we introduce it only for the virt-2.8 machine and onward;
virt-2.7 continues using the old 1K pages.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Rather than defining TARGET_PAGE_BITS to always be 10,
switch to using a value picked at runtime. This allows us
to use 4K pages for modern ARM CPUs (and in particular all
64-bit CPUs) without having to drop support for the old
ARMv5 CPUs which had 1K pages.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Add a subsection to vmstate_configuration which is present
only if the guest is using a target page size which is
different from the default. This allows us to helpfully
diagnose attempts to migrate between machines which
are using different target page sizes.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Support target CPUs having a page size which isn't knownn
at compile time. To use this, the CPU implementation should:
* define TARGET_PAGE_BITS_VARY
* not define TARGET_PAGE_BITS
* define TARGET_PAGE_BITS_MIN to the smallest value it
might possibly want for TARGET_PAGE_BITS
* call set_preferred_target_page_bits() in its realize
function to indicate the actual preferred target page
size for the CPU (and report any error from it)
In CONFIG_USER_ONLY, the CPU implementation should continue
to define TARGET_PAGE_BITS appropriately for the guest
OS page size.
Machines which want to take advantage of having the page
size something larger than TARGET_PAGE_BITS_MIN must
set the MachineClass minimum_page_bits field to a value
which they guarantee will be no greater than the preferred
page size for any CPU they create.
Note that changing the target page size by setting
minimum_page_bits is a migration compatibility break
for that machine.
For debugging purposes, attempts to use TARGET_PAGE_SIZE
before it has been finally confirmed will assert.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
