The fw_cfg documentation says this of the revision key (0x0001, FW_CFG_ID):
> A 32-bit little-endian unsigned int, this item is used as an interface
> revision number, and is currently set to 1 by all QEMU architectures
> which expose a fw_cfg device.
arm/virt doesn't. It could be argued that that's an error in
"hw/arm/virt.c"; on the other hand, all of the other fw_cfg providing
boards set the interface version to 1 manually, despite the device
coming from the same, shared implementation. Therefore, instead of
adding
fw_cfg_add_i32(fw_cfg, FW_CFG_ID, 1);
to arm/virt, consolidate all such existing calls in the fw_cfg
initialization code.
Signed-off-by: Gabriel Somlo <somlo@cmu.edu>
Message-Id: <1426789244-26318-1-git-send-email-somlo@cmu.edu>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(1) Let's contemplate what device endianness means, for a memory mapped
device register (independently of QEMU -- that is, on physical hardware).
It determines the byte order that the device will put on the data bus when
the device is producing a *numerical value* for the CPU. This byte order
may differ from the CPU's own byte order, therefore when software wants to
consume the *numerical value*, it may have to swap the byte order first.
For example, suppose we have a device that exposes in a 2-byte register
the number of sheep we have to count before falling asleep. If the value
is decimal 37 (0x0025), then a big endian register will produce [0x00,
0x25], while a little endian register will produce [0x25, 0x00].
If the device register is big endian, but the CPU is little endian, the
numerical value will read as 0x2500 (decimal 9472), which software has to
byte swap before use.
However... if we ask the device about who stole our herd of sheep, and it
answers "XY", then the byte representation coming out of the register must
be [0x58, 0x59], regardless of the device register's endianness for
numeric values. And, software needs to copy these bytes into a string
field regardless of the CPU's own endianness.
(2) QEMU's device register accessor functions work with *numerical values*
exclusively, not strings:
The emulated register's read accessor function returns the numerical value
(eg. 37 decimal, 0x0025) as a *host-encoded* uint64_t. QEMU translates
this value for the guest to the endianness of the emulated device register
(which is recorded in MemoryRegionOps.endianness). Then guest code must
translate the numerical value from device register to guest CPU
endianness, before including it in any computation (see (1)).
(3) However, the data register of the fw_cfg device shall transfer strings
*only* -- that is, opaque blobs. Interpretation of any given blob is
subject to further agreement -- it can be an integer in an independently
determined byte order, or a genuine string, or an array of structs of
integers (in some byte order) and fixed size strings, and so on.
Because register emulation in QEMU is integer-preserving, not
string-preserving (see (2)), we have to jump through a few hoops.
(3a) We defined the memory mapped fw_cfg data register as
DEVICE_BIG_ENDIAN.
The particular choice is not really relevant -- we picked BE only for
consistency with the control register, which *does* transfer integers --
but our choice affects how we must host-encode values from fw_cfg strings.
(3b) Since we want the fw_cfg string "XY" to appear as the [0x58, 0x59]
array on the data register, *and* we picked DEVICE_BIG_ENDIAN, we must
compose the host (== C language) value 0x5859 in the read accessor
function.
(3c) When the guest performs the read access, the immediate uint16_t value
will be 0x5958 (in LE guests) and 0x5859 (in BE guests). However, the
uint16_t value does not matter. The only thing that matters is the byte
pattern [0x58, 0x59], which the guest code must copy into the target
string *without* any byte-swapping.
(4) Now I get to explain where I screwed up. :(
When we decided for big endian *integer* representation in the MMIO data
register -- see (3a) --, I mindlessly added an indiscriminate
byte-swizzling step to the (little endian) guest firmware.
This was a grave error -- it violates (3c) --, but I didn't realize it. I
only saw that the code I otherwise intended for fw_cfg_data_mem_read():
value = 0;
for (i = 0; i < size; ++i) {
value = (value << 8) | fw_cfg_read(s);
}
didn't produce the expected result in the guest.
In true facepalm style, instead of blaming my guest code (which violated
(3c)), I blamed my host code (which was correct). Ultimately, I coded
ldX_he_p() into fw_cfg_data_mem_read(), because that happened to work.
Obviously (...in retrospect) that was wrong. Only because my host happened
to be LE, ldX_he_p() composed the (otherwise incorrect) host value 0x5958
from the fw_cfg string "XY". And that happened to compensate for the bogus
indiscriminate byte-swizzling in my guest code.
Clearly the current code leaks the host endianness through to the guest,
which is wrong. Any device should work the same regardless of host
endianness.
The solution is to compose the host-endian representation (2) of the big
endian interpretation (3a, 3b) of the fw_cfg string, and to drop the wrong
byte-swizzling in the guest (3c).
Brown paper bag time for me.
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-id: 1420024880-15416-1-git-send-email-lersek@redhat.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
We rebase fw_cfg_init_mem() to the new function for compatibility with
current callers.
The behavior of the (big endian) multi-byte data reads is best shown
with a qtest session. Here, we are reading the first six bytes of
the UUID
$ arm-softmmu/qemu-system-arm -M virt -machine accel=qtest \
-qtest stdio -uuid 4600cb32-38ec-4b2f-8acb-81c6ea54f2d8
>>> writew 0x9020008 0x0200
<<< OK
>>> readl 0x9020000
<<< OK 0x000000004600cb32
Remember this is big endian. On big endian machines, it is stored
directly as 0x46 0x00 0xcb 0x32.
On a little endian machine, we have to first swap it, so that it becomes
0x32cb0046. When written to memory, it becomes 0x46 0x00 0xcb 0x32
again.
Reading byte-by-byte works too, of course:
>>> readb 0x9020000
<<< OK 0x0000000000000038
>>> readb 0x9020000
<<< OK 0x00000000000000ec
Here only a single byte is read at a time, so they are read in order
similar to the 1-byte data port that is already in PPC and SPARC
machines.
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1419250305-31062-8-git-send-email-pbonzini@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The "data_width" property is capable of changing the maximum valid access
size to the MMIO data register, and resizes the memory region similarly,
at device realization time.
The default value of "data_memwidth" is set so that we don't yet diverge
from "fw_cfg_data_mem_ops".
Most of the fw_cfg_mem users will stick with the default, and for them we
should continue using the statically allocated "fw_cfg_data_mem_ops". This
is beneficial for debugging because gdb can resolve pointers referencing
static objects to the names of those objects.
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1419250305-31062-7-git-send-email-pbonzini@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The standalone selector port (fw_cfg_ctl_mem_ops) is only used by big
endian guests to date (*), hence this change doesn't regress them. Paolo
and Alex have suggested / requested an explicit DEVICE_BIG_ENDIAN setting
here, for clarity.
(*) git grep -l fw_cfg_init_mem
hw/nvram/fw_cfg.c
hw/ppc/mac_newworld.c
hw/ppc/mac_oldworld.c
hw/sparc/sun4m.c
include/hw/nvram/fw_cfg.h
The standalone data port (fw_cfg_data_mem_ops) has max_access_size 1 (for
now), hence changing its endianness doesn't change behavior for existing
guest code.
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1419250305-31062-5-git-send-email-pbonzini@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Make it clear that the maximum access size to the MMIO data register
determines the full size of the memory region.
Currently the max access size is 1.
This patch doesn't change behavior.
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1419250305-31062-4-git-send-email-pbonzini@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This allows us to drop the fw_cfg_init() shim and to enforce the possible
mappings at compile time.
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1419250305-31062-3-git-send-email-pbonzini@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
We are going to introduce a wide data register for fw_cfg, but only for
the MMIO mapped device. The wide data register will also require the
tightening of endiannesses.
However we don't want to touch the I/O port mapped fw_cfg device at all.
Currently QEMU provides a single fw_cfg device type that can handle both
I/O port and MMIO mapping. This flexibility is not actually exploited by
any board in the tree, but it renders restricting the above changes to
MMIO very hard.
Therefore, let's derive two classes from TYPE_FW_CFG: TYPE_FW_CFG_IO and
TYPE_FW_CFG_MEM.
TYPE_FW_CFG_IO incorporates the base I/O port and the related combined
MemoryRegion. (NB: all boards in the tree that use the I/O port mapped
flavor opt for the combined mapping; that is, when the data port overlays
the high address byte of the selector port. Therefore we can drop the
capability to map those I/O ports separately.)
TYPE_FW_CFG_MEM incorporates the base addresses for the MMIO selector and
data registers, and their respective MemoryRegions.
The "realize" and "props" class members are specific to each new derived
class, and become unused for the base class. The base class retains the
"reset" member and the "vmsd" member, because the reset functionality and
the set of migrated data are not specific to the mapping.
The new functions fw_cfg_init_io() and fw_cfg_init_mem() expose the
possible mappings in separation. For now fw_cfg_init() is retained as a
compatibility shim that enforces the above assumptions.
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1419250305-31062-2-git-send-email-pbonzini@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
When we dynamically modify boot order, the length of
boot order will be changed, but we don't update
s->files->f[i].size with new length. This casuse
seabios read a wrong vale of qemu cfg file about
bootorder.
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We must assure that the changed bootindex can take effect
when guest is rebooted. So we introduce fw_cfg_machine_reset(),
which change the fw_cfg file's bootindex data using the new
global fw_boot_order list.
Signed-off-by: Chenliang <chenliang88@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
After previous Peter patch, they are redundant. This way we don't
assign them except when needed. Once there, there were lots of case
where the ".fields" indentation was wrong:
.fields = (VMStateField []) {
and
.fields = (VMStateField []) {
Change all the combinations to:
.fields = (VMStateField[]){
The biggest problem (appart from aesthetics) was that checkpatch complained
when we copy&pasted the code from one place to another.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Acked-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
As suffixes do not make sense for sPAPR's device tree and
there is no way to filter them out on the BusState::get_fw_dev_path()
level, let's add an ability for the external caller to specify
whether to apply suffixes or not.
We could handle suffixes in SLOF (ignored for now) but this would require
serious rework in the node opening code in SLOF, which has no obvious
benefit for the currently emulated sPAPR machine.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Replace them with uint8/32/64.
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
device_add plugs devices into suitable bus. For "real" buses, that
actually connects the device. For sysbus, the connections need to be
made separately, and device_add can't do that. The device would be
left unconnected, and could not possibly work.
Quite a few, but not all sysbus devices already set
cannot_instantiate_with_device_add_yet in their class init function.
Set it in their abstract base's class init function
sysbus_device_class_init(), and remove the now redundant assignments
from device class init functions.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marcel Apfelbaum <marcel.a@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
In an ideal world, machines can be built by wiring devices together
with configuration, not code. Unfortunately, that's not the world we
live in right now. We still have quite a few devices that need to be
wired up by code. If you try to device_add such a device, it'll fail
in sometimes mysterious ways. If you're lucky, you get an
unmysterious immediate crash.
To protect users from such badness, DeviceClass member no_user used to
make device models unavailable with -device / device_add, but that
regressed in commit 18b6dad. The device model is still omitted from
help, but is available anyway.
Attempts to fix the regression have been rejected with the argument
that the purpose of no_user isn't clear, and it's prone to misuse.
This commit clarifies no_user's purpose. Anthony suggested to rename
it cannot_instantiate_with_device_add_yet_due_to_internal_bugs, which
I shorten somewhat to keep checkpatch happy. While there, make it
bool.
Every use of cannot_instantiate_with_device_add_yet gets a FIXME
comment asking for rationale. The next few commits will clean them
all up, either by providing a rationale, or by getting rid of the use.
With that done, the regression fix is hopefully acceptable.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marcel Apfelbaum <marcel.a@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
The I/O port variant of fw_cfg is used by sparc64, which is a big-endian machine.
Firmware swaps bytes before sending them to fw_cfg, so we need to unswap them in
the device.
This is only used on sparc64 and on (little-endian) x86, so it does not affect
any other target. 32-bit Sparc and PPC all use memory-mapped fw_cfg.
Reported-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-id: 1375014954-31916-2-git-send-email-pbonzini@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
[AF: Moved sysbus_init_mmio() to instance_init, renamed variable]
Signed-off-by: Andreas Färber <afaerber@suse.de>
Use type constant if possible and avoid DO_UPCAST().
Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
[AF: Renamed parent field]
Signed-off-by: Andreas Färber <afaerber@suse.de>
Make sure we only have a single instance ever:
because if it isn't we can't find it so it's
useless anyway.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Remove some code duplication by adding a
function to look up the fw cfg file.
This way, we don't need to duplicate same strings everywhere.
Use by both fw cfg and pvpanic device.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This unbreaks cross compile builds:
configure --target-list="i386-softmmu" --cpu=i386
When building on a 64bit machine.
Reported-by: David Holsgrove <david.holsgrove@xilinx.com>
Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Message-id: 926326e96fd8685d74e9d5bf430fe4ad97a55289.1369191585.git.peter.crosthwaite@xilinx.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This lets seabios patch the corresponding SSDT entry.
Also add fw_cfg object to /machine/fw_cfg so we can reference
it elsewhere.
Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-id: 60c65d95fe2b23b12bea67099126566010a11a1a.1366945969.git.hutao@cn.fujitsu.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
