The function ppc_hash64_set_sdr1 basically checked the htabsize and set an
error if it was too big, otherwise it just stored the value in SPR_SDR1.
Given that the only function which calls ppc_hash64_set_sdr1() is
ppc_store_sdr1(), why not handle the checking in ppc_store_sdr1() to avoid
the extra function call. Note that ppc_store_sdr1() already stores the
value in SPR_SDR1 anyway, so we were doing it twice.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
[dwg: Remove unnecessary error temporary]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The pseries machine type implements the behaviour of a PAPR compliant
hypervisor, without actually executing such a hypervisor on the virtual
CPU. To do this we need some hooks in the CPU code to make hypervisor
facilities get redirected to the machine instead of emulated internally.
For hypercalls this is managed through the cpu->vhyp field, which points
to a QOM interface with a method implementing the hypercall.
For the hashed page table (HPT) - also a hypervisor resource - we use an
older hack. CPUPPCState has an 'external_htab' field which when non-NULL
indicates that the HPT is stored in qemu memory, rather than within the
guest's address space.
For consistency - and to make some future extensions easier - this merges
the external HPT mechanism into the vhyp mechanism. Methods are added
to vhyp for the basic operations the core hash MMU code needs: map_hptes()
and unmap_hptes() for reading the HPT, store_hpte() for updating it and
hpt_mask() to retrieve its size.
To match this, the pseries machine now sets these vhyp fields in its
existing vhyp class, rather than reaching into the cpu object to set the
external_htab field.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
CPUPPCState includes fields htab_base and htab_mask which store the base
address (GPA) and size (as a mask) of the guest's hashed page table (HPT).
These are set when the SDR1 register is updated.
Keeping these in sync with the SDR1 is actually a little bit fiddly, and
probably not useful for performance, since keeping them expands the size of
CPUPPCState. It also makes some upcoming changes harder to implement.
This patch removes these fields, in favour of calculating them directly
from the SDR1 contents when necessary.
This does make a change to the behaviour of attempting to write a bad value
(invalid HPT size) to the SDR1 with an mtspr instruction. Previously, the
bad value would be stored in SDR1 and could be retrieved with a later
mfspr, but the HPT size as used by the softmmu would be, clamped to the
allowed values. Now, writing a bad value is treated as a no-op. An error
message is printed in both new and old versions.
I'm not sure which behaviour, if either, matches real hardware. I don't
think it matters that much, since it's pretty clear that if an OS writes
a bad value to SDR1, it's not going to boot.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Accesses to the hashed page table (HPT) are complicated by the fact that
the HPT could be in one of three places:
1) Within guest memory - when we're emulating a full guest CPU at the
hardware level (e.g. powernv, mac99, g3beige)
2) Within qemu, but outside guest memory - when we're emulating user and
supervisor instructions within TCG, but instead of emulating
the CPU's hypervisor mode, we just emulate a hypervisor's behaviour
(pseries in TCG or KVM-PR)
3) Within the host kernel - a pseries machine using KVM-HV
acceleration. Mostly accesses to the HPT are handled by KVM,
but there are a few cases where qemu needs to access it via a
special fd for the purpose.
In order to batch accesses to the fd in case (3), we use a somewhat awkward
ppc_hash64_start_access() / ppc_hash64_stop_access() pair, which for case
(3) reads / releases several HPTEs from the kernel as a batch (usually a
whole PTEG). For cases (1) & (2) it just returns an address value. The
actual HPTE load helpers then need to interpret the returned token
differently in the 3 cases.
This patch keeps the same basic structure, but simplfiies the details.
First start_access() / stop_access() are renamed to map_hptes() and
unmap_hptes() to make their operation more obvious. Second, map_hptes()
now always returns a qemu pointer, which can always be used in the same way
by the load_hpte() helpers. In case (1) it comes from address_space_map()
in case (2) directly from qemu's HPT buffer and in case (3) from a
temporary buffer read from the KVM fd.
While we're at it, make things a bit more consistent in terms of types and
variable names: avoid variables named 'index' (it shadows index(3) which
can lead to confusing results), use 'hwaddr ptex' for HPTE indices and
uint64_t for each of the HPTE words, use ptex throughout the call stack
instead of pte_offset in some places (we still need that at the bottom
layer, but nowhere else).
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
At present the SDR1 register - the base of the system's hashed page table
(HPT) - is represented as an SPR with supervisor read and write permission.
However, on CPUs which have a hypervisor mode, the SDR1 is a hypervisor
only resource. Change the permission checking on the SPR to reflect this.
Now that this is done, we don't need to check for an external HPT executing
mtsdr1: an external HPT only applies when we're emulating the behaviour of
a hypervisor, rather than modelling the CPU's hypervisor mode internally,
so if we're permitted to execute mtsdr1, we don't have an external HPT.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
cpu_ppc_set_papr() sets up various aspects of CPU state for use with PAPR
paravirtualized guests. However, it doesn't set the virtual hypervisor,
so callers must also call cpu_ppc_set_vhyp() so that PAPR hypercalls are
handled properly. This is a bit silly, so fold setting the virtual
hypervisor into cpu_ppc_set_papr().
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
* Standardize on 'ptex' instead of 'pte_index' for HPTE index variables
for consistency and brevity
* Avoid variables named 'index'; shadowing index(3) from libc can lead to
surprising bugs if the variable is removed, because compiler errors
might not appear for remaining references
* Clarify index calculations in h_enter() - we have two cases, H_EXACT
where the exact HPTE slot is given, and !H_EXACT where we search for
an empty slot within the hash bucket. Make the calculation more
consistent between the cases.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
When a 'pseries' guest is running with KVM-HV, the guest's hashed page
table (HPT) is stored within the host kernel, so it is not directly
accessible to qemu. Most of the time, qemu doesn't need to access it:
we're using the hardware MMU, and KVM itself implements the guest
hypercalls for manipulating the HPT.
However, qemu does need access to the in-KVM HPT to implement
get_phys_page_debug() for the benefit of the gdbstub, and maybe for
other debug operations.
To allow this, 7c43bca "target-ppc: Fix page table lookup with kvm
enabled" added kvmppc_hash64_read_pteg() to target/ppc/kvm.c to read
in a batch of HPTEs from the KVM table. Unfortunately, there are a
couple of problems with this:
First, the name of the function implies it always reads a whole PTEG
from the HPT, but in fact in some cases it's used to grab individual
HPTEs (which ends up pulling 8 HPTEs, not aligned to a PTEG from the
kernel).
Second, and more importantly, the code to read the HPTEs from KVM is
simply wrong, in general. The data from the fd that KVM provides is
designed mostly for compact migration rather than this sort of one-off
access, and so needs some decoding for this purpose. The current code
will work in some cases, but if there are invalid HPTEs then it will
not get sane results.
This patch rewrite the HPTE reading function to have a simpler
interface (just read n HPTEs into a caller provided buffer), and to
correctly decode the stream from the kernel.
For consistency we also clean up the similar function for altering
HPTEs within KVM (introduced in c138593 "target-ppc: Update
ppc_hash64_store_hpte to support updating in-kernel htab").
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Some systems can already provide more than 255 hardware threads.
Bumping the QEMU limit to 1024 seems reasonable:
- it has no visible overhead in top;
- the limit itself has no effect on hot paths.
Cc: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Removes duplicate code and will be useful for consolidating flags
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
When DT node names for PCI devices are generated by SLOF,
they are generated according to the type of the device
(for instance, ethernet for virtio-net-pci device).
Node name for hotplugged devices is generated by QEMU.
This patch adds the mechanic to QEMU to create the node
name according to the device type too.
The data structure has been roughly copied from OpenBIOS/OpenHackware,
node names from SLOF.
Example:
Hotplugging some PCI cards with QEMU monitor:
device_add virtio-tablet-pci
device_add virtio-serial-pci
device_add virtio-mouse-pci
device_add virtio-scsi-pci
device_add virtio-gpu-pci
device_add ne2k_pci
device_add nec-usb-xhci
device_add intel-hda
What we can see in linux device tree:
for dir in /proc/device-tree/pci@800000020000000/*@*/; do
echo $dir
cat $dir/name
echo
done
WITHOUT this patch:
/proc/device-tree/pci@800000020000000/pci@0/
pci
/proc/device-tree/pci@800000020000000/pci@1/
pci
/proc/device-tree/pci@800000020000000/pci@2/
pci
/proc/device-tree/pci@800000020000000/pci@3/
pci
/proc/device-tree/pci@800000020000000/pci@4/
pci
/proc/device-tree/pci@800000020000000/pci@5/
pci
/proc/device-tree/pci@800000020000000/pci@6/
pci
/proc/device-tree/pci@800000020000000/pci@7/
pci
WITH this patch:
/proc/device-tree/pci@800000020000000/communication-controller@1/
communication-controller
/proc/device-tree/pci@800000020000000/display@4/
display
/proc/device-tree/pci@800000020000000/ethernet@5/
ethernet
/proc/device-tree/pci@800000020000000/input-controller@0/
input-controller
/proc/device-tree/pci@800000020000000/mouse@2/
mouse
/proc/device-tree/pci@800000020000000/multimedia-device@7/
multimedia-device
/proc/device-tree/pci@800000020000000/scsi@3/
scsi
/proc/device-tree/pci@800000020000000/usb-xhci@6/
usb-xhci
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
To allow QEMU to add PCI entries in device tree,
we must have a more exhaustive list of PCI class IDs.
This patch synchronizes as much as possible with
pci_ids.h and add some missing IDs from SLOF.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
To fix the following warnings:
In file included from /users/pranith/qemu/tcg/tcg.c:255:
/users/pranith/qemu/tcg/aarch64/tcg-target.inc.c:879:24: warning: implicit conversion from enumeration type 'TCGMemOp' (aka 'enum TCGMemOp') to different enumeration type 'TCGType' (aka 'enum TCGType')
[-Wenum-conversion]
tcg_out_cmp(s, ext, a, b, b_const);
~~~~~~~~~~~ ^~~
/users/pranith/qemu/tcg/aarch64/tcg-target.inc.c:893:36: warning: implicit conversion from enumeration type 'TCGMemOp' (aka 'enum TCGMemOp') to different enumeration type 'TCGType' (aka 'enum TCGType')
[-Wenum-conversion]
tcg_out_insn(s, 3201, CBZ, ext, a, offset);
~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~
/users/pranith/qemu/tcg/aarch64/tcg-target.inc.c:389:65: note: expanded from macro 'tcg_out_insn'
glue(tcg_out_insn_,FMT)(S, glue(glue(glue(I,FMT),_),OP), ## __VA_ARGS__)
^
/users/pranith/qemu/tcg/aarch64/tcg-target.inc.c:895:37: warning: implicit conversion from enumeration type 'TCGMemOp' (aka 'enum TCGMemOp') to different enumeration type 'TCGType' (aka 'enum TCGType')
[-Wenum-conversion]
tcg_out_insn(s, 3201, CBNZ, ext, a, offset);
~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~
/users/pranith/qemu/tcg/aarch64/tcg-target.inc.c:389:65: note: expanded from macro 'tcg_out_insn'
glue(tcg_out_insn_,FMT)(S, glue(glue(glue(I,FMT),_),OP), ## __VA_ARGS__)
^
/users/pranith/qemu/tcg/aarch64/tcg-target.inc.c:1610:27: warning: implicit conversion from enumeration type 'TCGType' (aka 'enum TCGType') to different enumeration type 'TCGMemOp' (aka 'enum TCGMemOp')
[-Wenum-conversion]
tcg_out_brcond(s, ext, a2, a0, a1, const_args[1], arg_label(args[3]));
~~~~~~~~~~~~~~ ^~~
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Message-Id: <20170217154311.13920-1-bobby.prani@gmail.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Move the fallback from qtest_add_data_func_full() to glib-compat.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Similarly to allocation, do it from an inline function. This allows
tests to only use the headers for allocation/free of timer.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
No need for strdup, fix leaks when socat is missing.
Spotted by ASAN.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: "Daniel P. Berrange" <berrange@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Spotted by ASAN.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
for building a s390-netboot.img) can be found at
http://wiki.qemu-project.org/Features/S390xNetworkBoot
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Merge remote-tracking branch 'remotes/cohuck/tags/s390x-20170228' into staging
Network boot for s390x. More information (and instructions
for building a s390-netboot.img) can be found at
http://wiki.qemu-project.org/Features/S390xNetworkBoot
# gpg: Signature made Tue 28 Feb 2017 11:27:18 GMT
# gpg: using RSA key 0xDECF6B93C6F02FAF
# gpg: Good signature from "Cornelia Huck <huckc@linux.vnet.ibm.com>"
# gpg: aka "Cornelia Huck <cornelia.huck@de.ibm.com>"
# Primary key fingerprint: C3D0 D66D C362 4FF6 A8C0 18CE DECF 6B93 C6F0 2FAF
* remotes/cohuck/tags/s390x-20170228:
pc-bios/s390-ccw.img: rebuild image
pc-bios/s390-ccw: Use the ccw bios to start the network boot
s390x/ipl: Load network boot image
s390x/ipl: Extend S390IPLState to support network boot
elf-loader: Allow late loading of elf
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Aborting on error in bdrv_append() isn't correct. This patch fixes it
and lets the callers handle failures.
Test case 085 needs a reference output update. This is caused by the
reversed order of bdrv_set_backing_hd() and change_parent_backing_link()
in bdrv_append(): When the backing file of the new node is set, the
parent nodes are still pointing to the old top, so the backing blocker
is now initialised with the node name rather than the BlockBackend name.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Not all callers of bdrv_set_backing_hd() know for sure that attaching
the backing file will be allowed by the permission system. Return the
error from the function rather than aborting.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This adds an assertion that ensures that the necessary resize permission
has been granted before bdrv_truncate() is called.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
This adds assertions that ensure that the necessary write permissions
have been granted before someone attempts to write to a node.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This is where we want to check the permissions, so we need to have the
BdrvChild around where they are stored.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Not requesting any permissions is actually correct for these test cases
because no actual I/O or other operation covered by the permission
system is performed.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
NBD can't cope with device size changes, so resize must be forbidden,
but otherwise we can tolerate anything. Depending on whether the export
is writable or not, we only require consistent reads and writes.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Request BLK_PERM_CONSISTENT_READ for the source of block migration, and
handle potential permission errors as good as we can in this place
(which is not very good, but it matches the other failure cases).
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
The HMP command 'qemu-io' is a bit tricky because it wants to work on
the original BlockBackend, but additional permissions could be required.
The details are explained in a comment in the code, but in summary, just
request whatever permissions the current qemu-io command needs.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Management tools need to be able to know about every node in the graph
and need a way to address them. Changing the graph structure was okay
because libvirt doesn't really manage the node level yet, but future
libvirt versions need to deal with both new and old version of qemu.
This new option to blockdev-commit allows the client to set a node-name
for the automatically inserted filter driver, and at the same time
serves as a witness for a future libvirt that this version of qemu does
automatically insert a filter driver.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Management tools need to be able to know about every node in the graph
and need a way to address them. Changing the graph structure was okay
because libvirt doesn't really manage the node level yet, but future
libvirt versions need to deal with both new and old version of qemu.
This new option to blockdev-mirror allows the client to set a node-name
for the automatically inserted filter driver, and at the same time
serves as a witness for a future libvirt that this version of qemu does
automatically insert a filter driver.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
The correct permissions are relatively obvious here (and explained in
code comments). For intermediate streaming, we need to reopen the top
node read-write before creating the job now because the permissions
system catches attempts to get the BLK_PERM_WRITE_UNCHANGED permission
on a read-only node.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
The mirror block job is mainly used for two different scenarios:
Mirroring to an otherwise unused, independent target node, or for active
commit where the target node is part of the backing chain of the source.
Similarly to the commit block job patch, we need to insert a new filter
node to keep the permissions correct during active commit.
Note that one change this implies is that job->blk points to
mirror_top_bs as its root now, and mirror_top_bs (rather than the actual
source node) contains the bs->job pointer. This requires qemu-img commit
to get the job by name now rather than just taking bs->job.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Acked-by: Max Reitz <mreitz@redhat.com>
In some cases, we want to remove op blockers on intermediate nodes
before the whole block job transaction has completed (because they block
restoring the final graph state during completion). Provide a function
for this.
The whole block job lifecycle is a bit messed up and it's hard to
actually do all things in the right order, but I'll leave simplifying
this for another day.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Now that the backing file child role implements .attach/.detach
callbacks, nothing prevents us from modifying the graph even if that
involves changing backing file links.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Backing files are somewhat special compared to other kinds of children
because they are attached and detached using bdrv_set_backing_hd()
rather than the normal set of functions, which does a few more things
like setting backing blockers, toggling the BDRV_O_NO_BACKING flag,
setting parent_bs->backing_file, etc.
These special features are a reason why change_parent_backing_link()
can't handle backing files yet. With abstracting the additional features
into .attach/.detach callbacks, we get a step closer to a function that
can actually deal with this.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
bdrv_append() cares about isolation of the node that it modifies, but
not about activity in some subtree below it. Instead of using the
recursive bdrv_requests_pending(), directly check bs->in_flight, which
considers only the node in question.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
The backup block job doesn't have very complicated requirements: It
needs to read from the source and write to the target, but it's fine
with either side being changed. The only restriction is that we can't
resize the image because the job uses a cached value.
qemu-iotests 055 needs to be changed because it used a target which was
already attached to a virtio-blk device. The permission system correctly
forbids this (virtio-blk can't accept another writer with its default
share-rw=off).
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
This is a little simpler than the commit block job because it's
synchronous and only commits into the immediate backing file, but
otherwise doing more or less the same.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
This is probably one of the most interesting conversions to the new
op blocker system because a commit block job intentionally leaves some
intermediate block nodes in the backing chain that aren't valid on their
own any more; only the whole chain together results in a valid view.
In order to provide the 'consistent read' permission to the parents of
the 'top' node of the commit job, a new filter block driver is inserted
above 'top' which doesn't require 'consistent read' on its backing
chain. Subsequently, the commit job can block 'consistent read' on all
intermediate nodes without causing a conflict.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Block jobs don't actually do I/O through the the reference they create
with block_job_add_bdrv(), but they might want to use the permisssion
system to express what the block job does to intermediate nodes. This
adds permissions to block_job_add_bdrv() to provide the means to request
permissions.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
When the parents' child links are updated in bdrv_append() or
bdrv_replace_in_backing_chain(), this should affect all child links of
BlockBackends or other nodes, but not on child links held for other
purposes (like for setting permissions). This patch allows to control
the behaviour per BdrvChildRole.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Instead of just telling that there was some conflict, we can be specific
and tell which permissions were in conflict and which way the conflict
is.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
For meaningful error messages in the permission system, we need to get
some human-readable description of the parent of a BdrvChild.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
This functions creates a BlockBackend internally, so the block jobs need
to tell it what they want to do with the BB.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
By default, don't allow another writer for block devices that are
attached to a guest device. For the cases where this setup is intended
(e.g. using a cluster filesystem on the disk), the new option can be
used to allow it.
This change affects only devices using DEFINE_BLOCK_PROPERTIES().
Devices directly using DEFINE_PROP_DRIVE() still accept writers
unconditionally.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
