Peter Maydell [Tue, 25 May 2021 13:44:55 +0000 (14:44 +0100)]
tests/qtest/hd-geo-test: Fix checks on mkstemp() return value
Coverity notices that the checks against mkstemp() failing in
create_qcow2_with_mbr() are wrong: mkstemp returns -1 on failure but
the check is just "g_assert(fd)". Fix to use "g_assert(fd >= 0)",
matching the correct check in create_test_img().
The e1000e_send_verify() test calls qemu_recv() but doesn't
check that the call succeeded, which annoys Coverity. Add
an explicit test check for the length of the data.
(This is a test check, not a "we assume this syscall always
succeeds", so we use g_assert_cmpint() rather than g_assert().)
Peter Maydell [Tue, 25 May 2021 13:44:53 +0000 (14:44 +0100)]
tests/qtest/bios-tables-test: Check for dup2() failure
Coverity notes that we don't check for dup2() failing. Add some
assertions so that if it does ever happen we get some indication.
(This is similar to how we handle other "don't expect this syscall to
fail" checks in this test code.)
Alexander Graf [Thu, 3 Jun 2021 13:42:41 +0000 (14:42 +0100)]
hvf: Simplify post reset/init/loadvm hooks
The hooks we have that call us after reset, init and loadvm really all
just want to say "The reference of all register state is in the QEMU
vcpu struct, please push it".
We already have a working pushing mechanism though called cpu->vcpu_dirty,
so we can just reuse that for all of the above, syncing state properly the
next time we actually execute a vCPU.
This fixes PSCI resets on ARM, as they modify CPU state even after the
post init call has completed, but before we execute the vCPU again.
To also make the scheme work for x86, we have to make sure we don't
move stale eflags into our env when the vcpu state is dirty.
Alexander Graf [Thu, 3 Jun 2021 13:09:34 +0000 (14:09 +0100)]
hvf: Introduce hvf vcpu struct
We will need more than a single field for hvf going forward. To keep
the global vcpu struct uncluttered, let's allocate a special hvf vcpu
struct, similar to how hax does it.
Alexander Graf [Thu, 3 Jun 2021 13:09:33 +0000 (14:09 +0100)]
hvf: Use cpu_synchronize_state()
There is no reason to call the hvf specific hvf_cpu_synchronize_state()
when we can just use the generic cpu_synchronize_state() instead. This
allows us to have less dependency on internal function definitions and
allows us to make hvf_cpu_synchronize_state() static.
Alexander Graf [Thu, 3 Jun 2021 13:09:32 +0000 (14:09 +0100)]
hvf: Split out common code on vcpu init and destroy
Until now, Hypervisor.framework has only been available on x86_64 systems.
With Apple Silicon shipping now, it extends its reach to aarch64. To
prepare for support for multiple architectures, let's start moving common
code out into its own accel directory.
This patch splits the vcpu init and destroy functions into a generic and
an architecture specific portion. This also allows us to move the generic
functions into the generic hvf code, removing exported functions.
Alexander Graf [Thu, 3 Jun 2021 13:09:31 +0000 (14:09 +0100)]
hvf: Move hvf internal definitions into common header
Until now, Hypervisor.framework has only been available on x86_64 systems.
With Apple Silicon shipping now, it extends its reach to aarch64. To
prepare for support for multiple architectures, let's start moving common
code out into its own accel directory.
This patch moves a few internal struct and constant defines over.
Alexander Graf [Thu, 3 Jun 2021 13:09:31 +0000 (14:09 +0100)]
hvf: Move cpu functions into common directory
Until now, Hypervisor.framework has only been available on x86_64 systems.
With Apple Silicon shipping now, it extends its reach to aarch64. To
prepare for support for multiple architectures, let's start moving common
code out into its own accel directory.
This patch moves CPU and memory operations over. While at it, make sure
the code is consumable on non-i386 systems.
Alexander Graf [Thu, 3 Jun 2021 13:09:31 +0000 (14:09 +0100)]
hvf: Move vcpu thread functions into common directory
Until now, Hypervisor.framework has only been available on x86_64 systems.
With Apple Silicon shipping now, it extends its reach to aarch64. To
prepare for support for multiple architectures, let's start moving common
code out into its own accel directory.
Alexander Graf [Thu, 3 Jun 2021 13:09:30 +0000 (14:09 +0100)]
hvf: Move assert_hvf_ok() into common directory
Until now, Hypervisor.framework has only been available on x86_64 systems.
With Apple Silicon shipping now, it extends its reach to aarch64. To
prepare for support for multiple architectures, let's start moving common
code out into its own accel directory.
This patch moves assert_hvf_ok() and introduces generic build infrastructure.
Jamie Iles [Wed, 26 May 2021 12:18:47 +0000 (13:18 +0100)]
target/arm: use raise_exception_ra for stack limit exception
The sequence cpu_restore_state() + raise_exception() is equivalent to
raise_exception_ra(), so use that instead. (In this case we never
cared about the syndrome value, because M-profile doesn't use the
syndrome; the old code was just written unnecessarily awkwardly.)
Jamie Iles [Wed, 26 May 2021 12:18:46 +0000 (13:18 +0100)]
target/arm: use raise_exception_ra for MTE check failure
Now that raise_exception_ra restores the state before raising the
exception we can use restore_exception_ra to perform the state restore +
exception raising without clobbering the syndrome.
Jamie Iles [Wed, 26 May 2021 12:18:44 +0000 (13:18 +0100)]
target/arm: fix missing exception class
The DAIF and PAC checks used raise_exception_ra to raise an exception
and unwind CPU state but raise_exception_ra is currently designed for
handling data aborts as the syndrome is partially precomputed and
encoded in the TB and then merged in merge_syn_data_abort when handling
the data abort. Using raise_exception_ra for DAIF and PAC checks
results in an empty syndrome being retrieved from data[2] in
restore_state_to_opc and setting ESR to 0. This manifested as:
target/arm: Mark LDS{MIN,MAX} as signed operations
The operands to tcg_gen_atomic_fetch_s{min,max}_i64 must
be signed, so that the inputs are properly extended.
Zero extend the result afterward, as needed.
docs: Fix installation of man pages with Sphinx 4.x
The 4.x branch of Sphinx introduces a breaking change, as generated man
pages are now written to subdirectories corresponding to the manual
section they belong to. This results in `make install` erroring out when
attempting to install the man pages, because they are not where it
expects to find them.
This patch restores the behavior of Sphinx 3.x regarding man pages.
Peter Maydell [Thu, 27 May 2021 09:51:52 +0000 (10:51 +0100)]
arm: Consistently use "Cortex-Axx", not "Cortex Axx"
The official punctuation for Arm CPU names uses a hyphen, like
"Cortex-A9". We mostly follow this, but in a few places usage
without the hyphen has crept in. Fix those so we consistently
use the same way of writing the CPU name.
This commit was created with:
git grep -z -l 'Cortex ' | xargs -0 sed -i 's/Cortex /Cortex-/'
Peter Maydell [Thu, 20 May 2021 15:28:40 +0000 (16:28 +0100)]
target/arm: Allow board models to specify initial NS VTOR
Currently we allow board models to specify the initial value of the
Secure VTOR register, using an init-svtor property on the TYPE_ARMV7M
object which is plumbed through to the CPU. Allow board models to
also specify the initial value of the Non-secure VTOR via a similar
init-nsvtor property.
Peter Maydell [Thu, 20 May 2021 15:28:36 +0000 (16:28 +0100)]
target/arm: Fix return values in fp_sysreg_checks()
The fp_sysreg_checks() function is supposed to be returning an
FPSysRegCheckResult, which is an enum with three possible values.
However, three places in the function "return false" (a hangover from
a previous iteration of the design where the function just returned a
bool). Make these return FPSysRegCheckFailed instead (for no
functional change, since both false and FPSysRegCheckFailed are
zero).
Peter Maydell [Thu, 20 May 2021 15:28:34 +0000 (16:28 +0100)]
target/arm: Move fpsp/fpdp isar check into callers of do_vfp_2op_sp/dp
The do_vfp_2op_sp() and do_vfp_2op_dp() functions currently check
whether floating point is supported via the aa32_fpdp_v2 and
aa32_fpsp_v2 isar checks. For v8.1M MVE support, the VMOV_reg trans
functions (but not any of the others) need to update this to also
allow the insn if MVE is implemented. Move the check out of the do_
function and into its callsites (which are all implemented via the
DO_VFP_2OP macro), so we have a place to change the check for the
VMOV insns.
Peter Maydell [Thu, 20 May 2021 15:28:33 +0000 (16:28 +0100)]
target/arm: Update feature checks for insns which are "MVE or FP"
Some v8M instructions are present if either the floating point
extension or MVE is implemented. Update our implementation of them
to check for MVE as well as for FP.
This is all the insns which use CheckDecodeFaults(ExtType_MveOrFp) or
CheckDecodeFaults(ExtType_MveOrDpFp) in their pseudocode, which are
essentially the loads and stores, moves and sysreg accesses, except
for VMOV_reg_sp and VMOV_reg_dp, which we handle in subsequent
patches because they need a refactor to provide a place to put the
new MVE check.
Peter Maydell [Thu, 20 May 2021 15:28:32 +0000 (16:28 +0100)]
target/arm: Add isar feature check functions for MVE
Add the isar feature check functions we will need for v8.1M MVE:
* a check for MVE present: this corresponds to the pseudocode's
CheckDecodeFaults(ExtType_Mve)
* a check for the optional floating-point part of MVE: this
corresponds to CheckDecodeFaults(ExtType_MveFp)
Peter Maydell [Thu, 3 Jun 2021 09:00:35 +0000 (10:00 +0100)]
Merge remote-tracking branch 'remotes/dg-gitlab/tags/ppc-for-6.1-20210603' into staging
ppc patch queue 2021-06-03
Next batch of ppc target patches. Highlights are:
* A fix for a regression with single-step mode
* Start of moving ppc to use decodetree
* Implementation of some POWER10 64-bit prefixed instructions
* Several cleanups to softmmu code
* Continued progress towards allowing --disable-tcg
* Fix for the POWER PEF implementation
* Fix for LPCR handling of hotplugged CPUs
* Assorted other bugfixes and cleanups
This patchset does contain a couple of changes to code outside my
normal scope of maintainership, related to the removal of cpu_dump and
cpu_statistics hooks. ppc was the last target arch implementing these
at all, and they didn't really do anything there either. The patches
should have relevant acks.
Luis Pires [Wed, 2 Jun 2021 12:51:03 +0000 (09:51 -0300)]
target/ppc: fix single-step exception regression
Commit 6086c75 (target/ppc: Replace POWERPC_EXCP_BRANCH with
DISAS_NORETURN) broke the generation of exceptions when
CPU_SINGLE_STEP or CPU_BRANCH_STEP were set, due to nip always being
reset to the address of the current instruction.
This fix leaves nip untouched when generating the exception.
Matheus Ferst [Tue, 1 Jun 2021 19:35:28 +0000 (16:35 -0300)]
target/ppc: Move cmp/cmpi/cmpl/cmpli to decodetree
Additionally, REQUIRE_64BIT when L=1 to match what is specified in The
Programming Environments Manual:
"For 32-bit implementations, the L field must be cleared, otherwise the
instruction form is invalid."
Some CPUs are known to deviate from this specification by ignoring the
L bit [1]. The stricter behavior, however, can help users that test
software with qemu, making it more likely to detect bugs that would
otherwise be silent.
If deemed necessary, a future patch can adapt this behavior based on
the specific CPU model.
[1] The 601 manual is the only one I've found that explicitly states
that the L bit is ignored, but we also observe this behavior in a 7447A
v1.2.
Implements the following PowerISA v3.1 instructions:
setbc: Set Boolean Condition
setbcr: Set Boolean Condition Reverse
setnbc: Set Negative Boolean Condition
setnbcr: Set Negative Boolean Condition Reverse
Fabiano Rosas [Tue, 1 Jun 2021 21:46:47 +0000 (18:46 -0300)]
target/ppc: powerpc_excp: Consolidade TLB miss code
The only difference in the code for Instruction fetch, Data load and
Data store TLB miss errors is that when called from an unsupported
processor (i.e. not one of 602, 603, 603e, G2, 7x5 or 74xx), they
abort with a message specific to the operation type (insn fetch, data
load/store).
If a processor does not support those interrupts we should not be
registering them in init_excp_<proc> to begin with, so that error
message would never be used.
I'm leaving the message in for completeness, but making it generic and
consolidating the three interrupts into the same case statement body.
target/ppc: overhauled and moved logic of storing fpscr
Followed the suggested overhaul to store_fpscr logic, and moved it to
cpu.c where it can be accessed in !TCG builds.
The overhaul was suggested because storing a value to fpscr should
never raise an exception, so we could remove all the mess that happened
with POWERPC_EXCP_FP.
We also moved fpscr_set_rounding_mode into cpu.c as it could now be moved
there, and it is needed when a value for the fpscr is being stored
directly.
This feature will no longer be useful as ppc moves to using decodetree
for TCG. And building with it enabled is no longer possible, due to
changes in opc_handler_t. Since the last commit that mentions it
happened in 2014, I think it is safe to remove it.
since both, PPC_DO_STATISTICS and PPC_DUMP_CPU, are obsoleted as
target/ppc moves to decodetree, we can remove this ifdef based decision
tree, and only have what is now the standard option for the macro.
Since ppc was the last architecture to collect these statistics and
it is currently phasing this collection out, the command that would query
this information is being removed.
This function requires surce code modification to be useful, which means
it probably is not used often, and the move to using decodetree means
the statistics won't even be collected anymore.
Also removed setting dump_statistics in ppc_cpu_realize, since it was
only useful when in conjunction with ppc_cpu_dump_statistics.
Created a file with stubs needed to compile disabling TCG. *_ppc_opcodes
were created to make cpu_init.c have a few less ifdefs, since they are
not needed. softmmu_resize_hpt_* have to be created because the compiler
can't automatically know they aren't used, but they should never be
reached.
excp_helper.c, mmu-hash64.c and mmu_helper.c have some function
declarations that are TCG-only, and couldn't be easily moved to a
TCG only file, so ifdefs were added around them.
We also needed ifdefs around some header files because helper-proto.h
includes trace/generated-helpers.h, which is never created when building
without TCG, and cpu_ldst.h includes tcg/tcg.h, whose containing folder
is not included as a -iquote. As future cleanup, we could change the
part of the configuration script to add those.
cpu_init.c also had a callback definition that is TCG only and could be
removed as part of a future cleanup (all the dump_statistics part is
almost never used and will become obsolete as we transition to using
decodetree).
target/ppc: used ternary operator when registering MAS
The write calback decision when registering the MAS SPR has been turned
into a ternary operation, rather than an if-then-else block.
This was done because when building without TCG, even though the
compiler will optimize away the pointers to spr_write_generic*, it
doesn't optimize away the decision and assignment to the local pointer,
creating compiler errors. This cleanup looked better than using ifdefs,
so we decided to with it.
Nicholas Piggin [Wed, 26 May 2021 09:16:25 +0000 (19:16 +1000)]
spapr: Set LPCR to current AIL mode when starting a new CPU
TCG does not keep track of AIL mode in a central place, it's based on
the current LPCR[AIL] bits. Synchronize the new CPU's LPCR to the
current LPCR in rtas_start_cpu(), similarly to the way the ILE bit is
synchronized.
Open-code the ILE setting as well now that the caller's LPCR is
available directly, there is no need for the indirection.
Without this, under both TCG and KVM, adding a POWER8/9/10 class CPU
with a new core ID after a modern Linux has booted results in the new
CPU's LPCR missing the LPCR[AIL]=0b11 setting that the other CPUs have.
This can cause crashes and unexpected behaviour.
Nicholas Piggin [Wed, 26 May 2021 09:16:24 +0000 (19:16 +1000)]
spapr: Remove stale comment about power-saving LPCR bits
Commit 47a9b551547 ("spapr: Clean up handling of LPCR power-saving exit
bits") moved this logic but did not remove the comment from the
previous location.
target/ppc: fold ppc_store_ptcr into it's only caller
ppc_store_ptcr, defined in mmu_helper.c, was only used by
helper_store_ptcr, in misc_helper.c. To avoid possible confusion,
the function was folded into the helper.
spapr: nvdimm: Fix the persistent-memory root node name in device tree
The FDT code is adding the pmem root node by name "persistent-memory"
which should have been "ibm,persistent-memory".
The linux fetches the device tree nodes by type and it has been working
correctly as the type is correct. If someone searches by its intended
name it would fail, so fix that.
spapr: nvdimm: Forward declare and move the definitions
The subsequent patches add definitions which tend to get
the compilation to cyclic dependency. So, prepare with
forward declarations, move the definitions and clean up.
spapr: Fix EEH capability issue on KVM guest for PCI passthru
With upstream kernel, especially after commit 98ba956f6a389
("powerpc/pseries/eeh: Rework device EEH PE determination") we see that KVM
guest isn't able to enable EEH option for PCI pass-through devices anymore.
So far the linux kernel was assuming pe_config_addr equal to device's
config_addr and using it to enable EEH on the PE through ibm,set-eeh-option
RTAS call. Which wasn't the correct way as per PAPR. The linux kernel
commit 98ba956f6a389 fixed this flow. With that fixed, linux now uses PE
config address returned by ibm,get-config-addr-info2 RTAS call to enable
EEH option per-PE basis instead of per-device basis. However this has
uncovered a bug in qemu where ibm,set-eeh-option is treating PE config
address as per-device config address.
Hence in qemu guest with recent kernel the ibm,set-eeh-option RTAS call
fails with -3 return value indicating that there is no PCI device exist for
the specified PE config address. The rtas_ibm_set_eeh_option call uses
pci_find_device() to get the PC device that matches specific bus and devfn
extracted from PE config address passed as argument. Thus it tries to map
the PE config address to a single specific PCI device 'bus->devices[devfn]'
which always results into checking device on slot 0 'bus->devices[0]'.
This succeeds when there is a pass-through device (vfio-pci) present on
slot 0. But in cases where there is no pass-through device present in slot
0, but present in non-zero slots, ibm,set-eeh-option call fails to enable
the EEH capability.
hw/ppc/spapr_pci_vfio.c: spapr_phb_vfio_eeh_set_option()
case RTAS_EEH_ENABLE: {
PCIHostState *phb;
PCIDevice *pdev;
/*
* The EEH functionality is enabled on basis of PCI device,
* instead of PE. We need check the validity of the PCI
* device address.
*/
phb = PCI_HOST_BRIDGE(sphb);
pdev = pci_find_device(phb->bus,
(addr >> 16) & 0xFF, (addr >> 8) & 0xFF);
if (!pdev || !object_dynamic_cast(OBJECT(pdev), "vfio-pci")) {
return RTAS_OUT_PARAM_ERROR;
}
hw/pci/pci.c:pci_find_device()
PCIDevice *pci_find_device(PCIBus *bus, int bus_num, uint8_t devfn)
{
bus = pci_find_bus_nr(bus, bus_num);
if (!bus)
return NULL;
return bus->devices[devfn];
}
This patch fixes ibm,set-eeh-option to check for presence of any PCI device
(vfio-pci) under specified bus and enable the EEH if found. The current
code already makes sure that all the devices on that bus are from same
iommu group (within same PE) and fail very early if it does not.
After this fix guest is able to find EEH capable devices and enable EEH
recovery on it.
Greg Kurz [Fri, 21 May 2021 16:07:35 +0000 (18:07 +0200)]
spapr: Don't hijack current_machine->boot_order
QEMU 6.0 moved all the -boot variables to the machine. Especially, the
removal of the boot_order static changed the handling of '-boot once'
from:
if (boot_once) {
qemu_boot_set(boot_once, &error_fatal);
qemu_register_reset(restore_boot_order, g_strdup(boot_order));
}
to
if (current_machine->boot_once) {
qemu_boot_set(current_machine->boot_once, &error_fatal);
qemu_register_reset(restore_boot_order,
g_strdup(current_machine->boot_order));
}
This means that we now register as subsequent boot order a copy
of current_machine->boot_once that was just set with the previous
call to qemu_boot_set(), i.e. we never transition away from the
once boot order.
It is certainly fragile^Wwrong for the spapr code to hijack a
field of the base machine type object like that. The boot order
rework simply turned this software boundary violation into an
actual bug.
Have the spapr code to handle that with its own field in
SpaprMachineState. Also kfree() the initial boot device
string when "once" was used.
target/ppc: reduce usage of fpscr_set_rounding_mode
It is preferable to store the current rounding mode and retore from that
than recalculating from fpscr, so we changed the behavior of do_fri and
VSX_ROUND to do it like that.
target/ppc: moved ppc_store_lpcr and ppc_store_msr to cpu.c
These functions are used in hw/ppc logic, during machine startup, which
means it must be compiled when --disable-tcg is selected, and so it has
been moved into a common code file
Peter Maydell [Wed, 2 Jun 2021 18:34:03 +0000 (19:34 +0100)]
Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging
Block layer patches
- NBD server: Fix crashes related to switching between AioContexts
- file-posix: Workaround for discard/write_zeroes on buggy filesystems
- Follow-up fixes for the reopen vs. permission changes
- quorum: Fix error handling for flush
- block-copy: Refactor copy_range handling
- docs: Describe how to use 'null-co' block driver
* remotes/kevin/tags/for-upstream:
docs/secure-coding-practices: Describe how to use 'null-co' block driver
block-copy: refactor copy_range handling
block-copy: fix block_copy_task_entry() progress update
nbd/server: Use drained block ops to quiesce the server
block-backend: add drained_poll
block: improve permission conflict error message
block: simplify bdrv_child_user_desc()
block/vvfat: inherit child_vvfat_qcow from child_of_bds
block: improve bdrv_child_get_parent_desc()
block-backend: improve blk_root_get_parent_desc()
block: document child argument of bdrv_attach_child_common()
block/file-posix: Try other fallbacks after invalid FALLOC_FL_ZERO_RANGE
block/file-posix: Fix problem with fallocate(PUNCH_HOLE) on GPFS
block: drop BlockBackendRootState::read_only
block: drop BlockDriverState::read_only
block: consistently use bdrv_is_read_only()
block/vvfat: fix vvfat_child_perm crash
block/vvfat: child_vvfat_qcow: add .get_parent_aio_context, fix crash
qemu-io-cmds: assert that we don't have .perm requested in no-blk case
block/quorum: Provide .bdrv_co_flush instead of .bdrv_co_flush_to_disk
* remotes/thuth-gitlab/tags/pull-request-2021-06-02:
configure: bump min required CLang to 6.0 / XCode 10.0
configure: bump min required GCC to 7.5.0
configure: bump min required glib version to 2.56
tests/docker: drop CentOS 7 container
tests/vm: convert centos VM recipe to CentOS 8
crypto: drop used conditional check
crypto: bump min gnutls to 3.5.18, dropping RHEL-7 support
crypto: bump min gcrypt to 1.8.0, dropping RHEL-7 support
crypto: drop back compatibility typedefs for nettle
crypto: bump min nettle to 3.4, dropping RHEL-7 support
patchew: move quick build job from CentOS 7 to CentOS 8 container
block/ssh: Bump minimum libssh version to 0.8.7
docs: fix references to docs/devel/s390-dasd-ipl.rst
docs: fix references to docs/specs/tpm.rst
docs: fix references to docs/devel/build-system.rst
docs: fix references to docs/devel/atomics.rst
docs: fix references to docs/devel/tracing.rst
docs/secure-coding-practices: Describe how to use 'null-co' block driver
Document that security reports must use 'null-co,read-zeroes=on'
because otherwise the memory is left uninitialized (which is an
on-purpose performance feature).
Currently we update s->use_copy_range and s->copy_size in
block_copy_do_copy().
It's not very good:
1. block_copy_do_copy() is intended to be a simple function, that wraps
bdrv_co_<io> functions for need of block copy. That's why we don't pass
BlockCopyTask into it. So, block_copy_do_copy() is bad place for
manipulation with generic state of block-copy process
2. We are going to make block-copy thread-safe. So, it's good to move
manipulation with state of block-copy to the places where we'll need
critical sections anyway, to not introduce extra synchronization
primitives in block_copy_do_copy().
Sergio Lopez [Wed, 2 Jun 2021 06:05:52 +0000 (08:05 +0200)]
nbd/server: Use drained block ops to quiesce the server
Before switching between AioContexts we need to make sure that we're
fully quiesced ("nb_requests == 0" for every client) when entering the
drained section.
To do this, we set "quiescing = true" for every client on
".drained_begin" to prevent new coroutines from being created, and
check if "nb_requests == 0" on ".drained_poll". Finally, once we're
exiting the drained section, on ".drained_end" we set "quiescing =
false" and call "nbd_client_receive_next_request()" to resume the
processing of new requests.
With these changes, "blk_aio_attach()" and "blk_aio_detach()" can be
reverted to be as simple as they were before f148ae7d36.
Now permissions are updated as follows:
1. do graph modifications ignoring permissions
2. do permission update
(of course, we rollback [1] if [2] fails)
So, on stage [2] we can't say which users are "old" and which are
"new" and exist only since [1]. And current error message is a bit
outdated. Let's improve it, to make everything clean.
While being here, add also a comment and some good assertions.
block/vvfat: inherit child_vvfat_qcow from child_of_bds
Recently we've fixed a crash by adding .get_parent_aio_context handler
to child_vvfat_qcow. Now we want it to support .get_parent_desc as
well. child_vvfat_qcow wants to implement own .inherit_options, it's
not bad. But omitting all other handlers is a bad idea. Let's inherit
the class from child_of_bds instead, similar to chain_child_class and
detach_by_driver_cb_class in test-bdrv-drain.c.
We have different types of parents: block nodes, block backends and
jobs. So, it makes sense to specify type together with name.
Next, this handler us used to compose an error message about permission
conflict. And permission conflict occurs in a specific place of block
graph. We shouldn't report name of parent device (as it refers another
place in block graph), but exactly and only the name of the node. So,
use bdrv_get_node_name() directly.
block: document child argument of bdrv_attach_child_common()
The logic around **child is not obvious: this reference is used not
only to return resulting child, but also to rollback NULL value on
transaction abort.
So, let's add documentation and some assertions.
While being here, drop extra declaration of bdrv_attach_child_noperm().
Thomas Huth [Thu, 27 May 2021 17:20:20 +0000 (19:20 +0200)]
block/file-posix: Try other fallbacks after invalid FALLOC_FL_ZERO_RANGE
If fallocate(... FALLOC_FL_ZERO_RANGE ...) returns EINVAL, it's likely
an indication that the file system is buggy and does not implement
unaligned accesses right. We still might be lucky with the other
fallback fallocate() calls later in this function, though, so we should
not return immediately and try the others first.
Since FALLOC_FL_ZERO_RANGE could also return EINVAL if the file descriptor
is not a regular file, we ignore this filesystem bug silently, without
printing an error message for the user.
fails for them with the following error message when the images are
stored on a GPFS file system :
qemu-img: error while writing sector 0: Invalid argument
After analyzing the strace output, it seems like the problem is in
handle_aiocb_write_zeroes(): The call to fallocate(FALLOC_FL_PUNCH_HOLE)
returns EINVAL, which can apparently happen if the file system has
a different idea of the granularity of the operation. It's arguably
a bug in GPFS, since the PUNCH_HOLE mode should not result in EINVAL
according to the man-page of fallocate(), but the file system is out
there in production and so we have to deal with it. In commit 294682cc3a
("block: workaround for unaligned byte range in fallocate()") we also
already applied the a work-around for the same problem to the earlier
fallocate(FALLOC_FL_ZERO_RANGE) call, so do it now similar with the
PUNCH_HOLE call. But instead of silently catching and returning
-ENOTSUP (which causes the caller to fall back to writing zeroes),
let's rather inform the user once about the buggy file system and
try the other fallback instead.