Convert the Neon floating point VFMA and VFMS insn to decodetree.
These are the last insns in the 3-reg-same group so we can
remove all the support/loop code from the old decoder.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200512163904.10918-18-peter.maydell@linaro.org
Convert the Neon fp VMAX/VMIN/VMAXNM/VMINNM/VRECPS/VRSQRTS 3-reg-same
insns to decodetree. (These are all the remaining non-accumulation
instructions in this group.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200512163904.10918-17-peter.maydell@linaro.org
The usual location for the env argument in the argument list of a TCG helper
is immediately after the return-value argument. recps_f32 and rsqrts_f32
differ in that they put it at the end.
Move the env argument to its usual place; this will allow us to
more easily use these helper functions with the gvec APIs.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200512163904.10918-16-peter.maydell@linaro.org
Convert the Neon integer 3-reg-same compare insns VCGE, VCGT,
VCEQ, VACGE and VACGT to decodetree.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200512163904.10918-15-peter.maydell@linaro.org
Convert the Neon integer VMUL, VMLA, and VMLS 3-reg-same inssn to
decodetree.
We don't have a gvec helper for multiply-accumulate, so VMLA and VMLS
need a loop function do_3same_fp(). This takes a reads_vd parameter
to do_3same_fp() which tells it to load the old value into vd before
calling the callback function, in the same way that the do_vfp_3op_sp()
and do_vfp_3op_dp() functions in translate-vfp.inc.c work. (The
only uses in this patch pass reads_vd == true, but later commits
will use reads_vd == false.)
This conversion fixes in passing an underdecoding for VMUL
(originally reported by Fredrik Strupe <fredrik@strupe.net>): bit 1
of the 'size' field must be 0. The old decoder didn't enforce this,
but the decodetree pattern does.
The gen_VMLA_fp_reg() function performs the addition operation
with the operands in the opposite order to the old decoder:
since Neon sets 'default NaN mode' float32_add operations are
commutative so there is no behaviour difference, but putting
them this way around matches the Arm ARM pseudocode and the
required operation order for the subtraction in gen_VMLS_fp_reg().
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200512163904.10918-14-peter.maydell@linaro.org
Convert the Neon float VPMIN, VPMAX and VPADD 3-reg-same insns to
decodetree. These are the only remaining 'pairwise' operations,
so we can delete the pairwise-specific bits of the old decoder's
for-each-element loop now.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200512163904.10918-13-peter.maydell@linaro.org
Convert the Neon VADD, VSUB, VABD 3-reg-same insns to decodetree.
We already have gvec helpers for addition and subtraction, but must
add one for fabd.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200512163904.10918-12-peter.maydell@linaro.org
Convert the Neon VQDMULH and VQRDMULH 3-reg-same insns to
decodetree. These are the last integer operations in the
3-reg-same group.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200512163904.10918-11-peter.maydell@linaro.org
Convert the Neon integer VPADD 3-reg-same insns to decodetree. These
are 'pairwise' operations. (Note that VQRDMLAH, which shares the
same primary opcode but has U=1, has already been converted.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200512163904.10918-10-peter.maydell@linaro.org
Convert the Neon integer VPMAX and VPMIN 3-reg-same insns to
decodetree. These are 'pairwise' operations.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200512163904.10918-9-peter.maydell@linaro.org
Convert the VQSHL, VRSHL and VQRSHL insns in the 3-reg-same
group to decodetree. We have already implemented the size==0b11
case of these insns; this commit handles the remaining sizes.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200512163904.10918-8-peter.maydell@linaro.org
Convert the Neon VRHADD and VHSUB 3-reg-same insns to decodetree.
(These are all the other insns in 3-reg-same which were using
GEN_NEON_INTEGER_OP() and which are not pairwise or
reversed-operands.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200512163904.10918-7-peter.maydell@linaro.org
Convert the Neon VABA and VABD insns in the 3-reg-same group to
decodetree.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200512163904.10918-6-peter.maydell@linaro.org
Convert the Neon VHADD insns in the 3-reg-same group to decodetree.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200512163904.10918-5-peter.maydell@linaro.org
Convert the 64-bit element insns in the 3-reg-same group
to decodetree. This covers VQSHL, VRSHL and VQRSHL where
size==0b11.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200512163904.10918-4-peter.maydell@linaro.org
Convert the Neon SHA instructions in the 3-reg-same group
to decodetree.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200512163904.10918-3-peter.maydell@linaro.org
Convert the Neon VQRDMLAH and VQRDMLSH insns in the 3-reg-same group
to decodetree. These don't use do_3same() because they want to
operate on VFP double registers, whose offsets are different from the
neon_reg_offset() calculations do_3same does.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200512163904.10918-2-peter.maydell@linaro.org
I and Xiang are willing to review the APEI-related patches and
volunteer as the reviewers for the HEST/GHES part.
Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
Signed-off-by: Xiang Zheng <zhengxiang9@huawei.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Message-id: 20200512030609.19593-11-gengdongjiu@huawei.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Add a SIGBUS signal handler. In this handler, it checks the SIGBUS type,
translates the host VA delivered by host to guest PA, then fills this PA
to guest APEI GHES memory, then notifies guest according to the SIGBUS
type.
When guest accesses the poisoned memory, it will generate a Synchronous
External Abort(SEA). Then host kernel gets an APEI notification and calls
memory_failure() to unmapped the affected page in stage 2, finally
returns to guest.
Guest continues to access the PG_hwpoison page, it will trap to KVM as
stage2 fault, then a SIGBUS_MCEERR_AR synchronous signal is delivered to
Qemu, Qemu records this error address into guest APEI GHES memory and
notifes guest using Synchronous-External-Abort(SEA).
In order to inject a vSEA, we introduce the kvm_inject_arm_sea() function
in which we can setup the type of exception and the syndrome information.
When switching to guest, the target vcpu will jump to the synchronous
external abort vector table entry.
The ESR_ELx.DFSC is set to synchronous external abort(0x10), and the
ESR_ELx.FnV is set to not valid(0x1), which will tell guest that FAR is
not valid and hold an UNKNOWN value. These values will be set to KVM
register structures through KVM_SET_ONE_REG IOCTL.
Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
Signed-off-by: Xiang Zheng <zhengxiang9@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Xiang Zheng <zhengxiang9@huawei.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Message-id: 20200512030609.19593-10-gengdongjiu@huawei.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
kvm_arch_on_sigbus_vcpu() error injection uses source_id as
index in etc/hardware_errors to find out Error Status Data
Block entry corresponding to error source. So supported source_id
values should be assigned here and not be changed afterwards to
make sure that guest will write error into expected Error Status
Data Block.
Before QEMU writes a new error to ACPI table, it will check whether
previous error has been acknowledged. If not acknowledged, the new
errors will be ignored and not be recorded. For the errors section
type, QEMU simulate it to memory section error.
Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
Signed-off-by: Xiang Zheng <zhengxiang9@huawei.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-id: 20200512030609.19593-9-gengdongjiu@huawei.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
kvm_hwpoison_page_add() and kvm_unpoison_all() will both
be used by X86 and ARM platforms, so moving them into
"accel/kvm/kvm-all.c" to avoid duplicate code.
For architectures that don't use the poison-list functionality
the reset handler will harmlessly do nothing, so let's register
the kvm_unpoison_all() function in the generic kvm_init() function.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
Signed-off-by: Xiang Zheng <zhengxiang9@huawei.com>
Acked-by: Xiang Zheng <zhengxiang9@huawei.com>
Message-id: 20200512030609.19593-8-gengdongjiu@huawei.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Record the GHEB address via fw_cfg file, when recording
a error to CPER, it will use this address to find out
Generic Error Data Entries and write the error.
In order to avoid migration failure, make hardware
error table address to a part of GED device instead
of global variable, then this address will be migrated
to target QEMU.
Acked-by: Xiang Zheng <zhengxiang9@huawei.com>
Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-id: 20200512030609.19593-7-gengdongjiu@huawei.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This patch builds Hardware Error Source Table(HEST) via fw_cfg blobs.
Now it only supports ARMv8 SEA, a type of Generic Hardware Error
Source version 2(GHESv2) error source. Afterwards, we can extend
the supported types if needed. For the CPER section, currently it
is memory section because kernel mainly wants userspace to handle
the memory errors.
This patch follows the spec ACPI 6.2 to build the Hardware Error
Source table. For more detailed information, please refer to
document: docs/specs/acpi_hest_ghes.rst
build_ghes_hw_error_notification() helper will help to add Hardware
Error Notification to ACPI tables without using packed C structures
and avoid endianness issues as API doesn't need explicit conversion.
Signed-off-by: Xiang Zheng <zhengxiang9@huawei.com>
Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-id: 20200512030609.19593-6-gengdongjiu@huawei.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This patch builds error_block_address and read_ack_register fields
in hardware errors table , the error_block_address points to Generic
Error Status Block(GESB) via bios_linker. The max size for one GESB
is 1kb, For more detailed information, please refer to
document: docs/specs/acpi_hest_ghes.rst
Now we only support one Error source, if necessary, we can extend to
support more.
Suggested-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Xiang Zheng <zhengxiang9@huawei.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-id: 20200512030609.19593-5-gengdongjiu@huawei.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
RAS Virtualization feature is not supported now, so
add a RAS machine option and disable it by default.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
Signed-off-by: Xiang Zheng <zhengxiang9@huawei.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Message-id: 20200512030609.19593-3-gengdongjiu@huawei.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The little end UUID is used in many places, so make
NVDIMM_UUID_LE to a common macro to convert the UUID
to a little end array.
Reviewed-by: Xiang Zheng <zhengxiang9@huawei.com>
Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
Message-id: 20200512030609.19593-2-gengdongjiu@huawei.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Sonora Pass is a 2 socket x86 motherboard designed by Facebook
and supported by OpenBMC. Strapping configuration was obtained
from hardware and i2c configuration is based on dts found at:
1633c87b8b/arch/arm/boot/dts/aspeed-bmc-facebook-sonorapass.dts
Booted a test image of http://github.com/facebook/openbmc to login
prompt.
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Reviewed-by: Amithash Prasad <amithash@fb.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
[PMM: fixed block comment style nit]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Include 64-bit element size in preparation for SVE2.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200513163245.17915-17-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Include 64-bit element size in preparation for SVE2.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200513163245.17915-16-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Must clear the tail for AdvSIMD when SVE is enabled.
Fixes: ca40a6e6e3
Cc: qemu-stable@nongnu.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200513163245.17915-15-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Pass a pointer directly to env->vfp.qc[0], rather than env.
This will allow SVE2, which does not modify QC, to pass a
pointer to dummy storage.
Change the return type of inl_qrdml.h_s16 to match the
sense of the operation: signed.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200513163245.17915-14-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Provide a functional interface for the vector expansion.
This fits better with the existing set of helpers that
we provide for other operations.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200513163245.17915-13-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
These operations do not touch fp_status.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200513163245.17915-12-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Provide a functional interface for the vector expansion.
This fits better with the existing set of helpers that
we provide for other operations.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200513163245.17915-11-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Provide a functional interface for the vector expansion.
This fits better with the existing set of helpers that
we provide for other operations.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200513163245.17915-10-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Rather than perform the argument swap during code generation,
perform it during decode. This means it doesn't have to be
special cased later, and we can share code with aarch64 code
generation. Hopefully the decode comment addresses any confusion
that might arise in between.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200513163245.17915-9-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Provide a functional interface for the vector expansion.
This fits better with the existing set of helpers that
we provide for other operations.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200513163245.17915-8-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Provide a functional interface for the vector expansion.
This fits better with the existing set of helpers that
we provide for other operations.
Macro-ize the 5 nearly identical comparisons.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200513163245.17915-7-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Now that we've converted all cases to gvec, there is quite a bit
of dead code at the end of the function. Remove it.
Sink the call to gen_gvec_fn2i to the end, loading a function
pointer within the switch statement.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200513163245.17915-6-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
In 1dc8425e55, while converting to gvec, I added an extra range check
against the shift count. This was unnecessary because the encoding of
the shift count produces 0 to the element size - 1.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200513163245.17915-5-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The functions eliminate duplication of the special cases for
this operation. They match up with the GVecGen2iFn typedef.
Add out-of-line helpers. We got away with only having inline
expanders because the neon vector size is only 16 bytes, and
we know that the inline expansion will always succeed.
When we reuse this for SVE, tcg-gvec-op may decide to use an
out-of-line helper due to longer vector lengths.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200513163245.17915-4-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Create vectorized versions of handle_shri_with_rndacc
for shift+round and shift+round+accumulate. Add out-of-line
helpers in preparation for longer vector lengths from SVE.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200513163245.17915-3-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The functions eliminate duplication of the special cases for
this operation. They match up with the GVecGen2iFn typedef.
Add out-of-line helpers. We got away with only having inline
expanders because the neon vector size is only 16 bytes, and
we know that the inline expansion will always succeed.
When we reuse this for SVE, tcg-gvec-op may decide to use an
out-of-line helper due to longer vector lengths.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200513163245.17915-2-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
GDB's remote protocol requires M-profile cores to use the feature
name 'org.gnu.gdb.arm.m-profile' instead of the 'org.gnu.gdb.arm.core'
feature used for A- and R-profile cores. We weren't doing this, which
meant GDB treated our M-profile cores like A-profile ones. This mostly
doesn't matter, but for instance means that it doesn't correctly
handle backtraces where an M-profile exception frame is involved.
Ship a copy of GDB's arm-m-profile.xml and use it on the M-profile
cores. The integer registers have the same offsets as the
arm-core.xml, but register 25 is the M-profile XPSR rather than the
A-profile CPSR, so we need to update arm_cpu_gdb_read_register() and
arm_cpu_gdb_write_register() to handle XSPR reads and writes.
Fixes: https://bugs.launchpad.net/qemu/+bug/1877136
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20200507134755.13997-1-peter.maydell@linaro.org
If delivery of some 9pfs response fails for some reason, log the
error message by mentioning the 9P protocol reply type, not by
client's request type. The latter could be misleading that the
error occurred already when handling the request input.
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Message-Id: <ad0e5a9b6abde52502aa40b30661d29aebe1590a.1589132512.git.qemu_oss@crudebyte.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
QEMU's local 9pfs server passes through O_NOATIME from the client. If
the QEMU process doesn't have permissions to use O_NOATIME (namely, it
does not own the file nor have the CAP_FOWNER capability), the open will
fail. This causes issues when from the client's point of view, it
believes it has permissions to use O_NOATIME (e.g., a process running as
root in the virtual machine). Additionally, overlayfs on Linux opens
files on the lower layer using O_NOATIME, so in this case a 9pfs mount
can't be used as a lower layer for overlayfs (cf.
dabfe19719/vmtest/onoatimehack.c
and https://github.com/NixOS/nixpkgs/issues/54509).
Luckily, O_NOATIME is effectively a hint, and is often ignored by, e.g.,
network filesystems. open(2) notes that O_NOATIME "may not be effective
on all filesystems. One example is NFS, where the server maintains the
access time." This means that we can honor it when possible but fall
back to ignoring it.
Acked-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Message-Id: <e9bee604e8df528584693a4ec474ded6295ce8ad.1587149256.git.osandov@fb.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
The docs are ambiguous about the difference (or actually their
equality) between options '-virtfs' vs. '-fsdev'. So clarify that
'-virtfs' is actually just a convenience shortcut for its
generalized form '-fsdev' in conjunction with '-device virtio-9p-pci'.
And as we're at it, also be a bit more descriptive what 9pfs is
actually used for.
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <208f1fceffce2feaf7c900b29e326b967dce7762.1585661532.git.qemu_oss@crudebyte.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
As suggested by Greg, let's upgrade myself as co-maintainer of 9pfs.
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <E1jEYz4-0004pt-Cs@lizzy.crudebyte.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
