The function reads the parents list, so it needs to hold the graph lock.

This happens to result in BlockDriver.bdrv_set_perm() to be called with
the graph lock held. For consistency, make it the same for all of the
BlockDriver callbacks for updating permissions and annotate the function
pointers with GRAPH_RDLOCK_PTR.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-15-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

The function reads the parents list, so it needs to hold the graph lock.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-14-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Instead of taking the writer lock internally, require callers to already
hold it when calling bdrv_attach_child_common(). These callers will
typically already hold the graph lock once the locking work is
completed, which means that they can't call functions that take it
internally.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-13-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

In previous patches, we changed some transactionable functions to be
marked as GRAPH_WRLOCK, but required that tran_finalize() is still
called without the lock. This was because all callbacks that can be in
the same transaction need to follow the same convention.

Now that we don't have conflicting requirements any more, we can switch
all of the transaction callbacks to be declared GRAPH_WRLOCK, too, and
call tran_finalize() with the lock held.

Document for each of these transactionable functions that the lock needs
to be held when completing the transaction, and make sure that all
callers down to the place where the transaction is finalised actually
have the writer lock.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-12-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Instead of taking the writer lock internally, require callers to already
hold it when calling bdrv_attach_child_common(). These callers will
typically already hold the graph lock once the locking work is
completed, which means that they can't call functions that take it
internally.

Note that the transaction callbacks still take the lock internally, so
tran_finalize() must be called without the lock held. This is because
bdrv_append() also calls bdrv_replace_node_noperm(), which currently
requires the transaction callbacks to be called unlocked. In the next
step, both of them can be switched to locked tran_finalize() calls
together.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-11-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Instead of taking the writer lock internally, require callers to already
hold it when calling bdrv_replace_child_tran(). These callers will
typically already hold the graph lock once the locking work is
completed, which means that they can't call functions that take it
internally.

While a graph lock is held, polling is not allowed. Therefore draining
the necessary nodes can no longer be done in bdrv_remove_child() and
bdrv_replace_node_noperm(), but the callers must already make sure that
they are drained.

Note that the transaction callbacks still take the lock internally, so
tran_finalize() must be called without the lock held. This is because
bdrv_append() also calls bdrv_attach_child_noperm(), which currently
requires to be called unlocked. Once it changes, the transaction
callbacks can be changed, too.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-10-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Instead of taking the writer lock internally, require callers to already
hold it when calling bdrv_replace_child_noperm(). These callers will
typically already hold the graph lock once the locking work is
completed, which means that they can't call functions that take it
internally.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-9-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Don't assume specific parameter names like 'bs' or 'blk' in the
generated code, but use the actual name.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-8-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Add a new wrapper type for GRAPH_WRLOCK functions that should be called
from coroutine context.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-7-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

bdrv_unref() is called by a lot of places that need to hold the graph
lock (it naturally happens in the context of operations that change the
graph). However, bdrv_unref() takes the graph writer lock internally, so
it can't actually be called while already holding a graph lock without
causing a deadlock.

bdrv_unref() also can't just become GRAPH_WRLOCK because it drains the
node before closing it, and draining requires that the graph is
unlocked.

The solution is to defer deleting the node until we don't hold the lock
any more and draining is possible again.

Note that keeping images open for longer than necessary can create
problems, too: You can't open an image again before it is really closed
(if image locking didn't prevent it, it would cause corruption).
Reopening an image immediately happens at least during bdrv_open() and
bdrv_co_create().

In order to solve this problem, make sure to run the deferred unref in
bdrv_graph_wrunlock(), i.e. the first possible place where we can drain
again. This is also why bdrv_schedule_unref() is marked GRAPH_WRLOCK.

The output of iotest 051 is updated because the additional polling
changes the order of HMP output, resulting in a new "(qemu)" prompt in
the test output that was previously on a separate line and filtered out.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230911094620.45040-6-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

The documentation for bdrv_append() says that the caller must hold the
AioContext lock for bs_top. Change all callers to actually adhere to the
contract.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-5-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

When the permission related BlockDriver callbacks are called, we are in
the middle of an operation traversing the block graph. Polling in such a
place is a very bad idea because the graph could change in unexpected
ways. In the future, callers will also hold the graph lock, which is
likely to turn polling into a deadlock.

So we need to get rid of calls to functions like bdrv_getlength() or
bdrv_truncate() there as these functions poll internally. They are
currently used so that when no parent has write/resize permissions on
the image any more, the preallocate filter drops the extra preallocated
area in the image file and gives up write/resize permissions itself.

In order to achieve this without polling in .bdrv_check_perm, don't
immediately truncate the image, but only schedule a BH to do so. The
filter keeps the write/resize permissions a bit longer now until the BH
has executed.

There is one case in which delaying doesn't work: Reopening the image
read-only. In this case, bs->file will likely be reopened read-only,
too, so keeping write permissions a bit longer on it doesn't work. But
we can already cover this case in preallocate_reopen_prepare() and not
rely on the permission updates for it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-4-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

It's essentially the same code in preallocate_check_perm() and
preallocate_close(), except that the latter ignores errors.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-3-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

This field has been unused since commit 72373e40 ('block:
bdrv_reopen_multiple: refresh permissions on updated graph').
Remove it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-2-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Hi,

"Host Memory Backends" and "Memory devices" queue ("mem"):
- Support and document VM templating with R/O files using a new "rom"
  parameter for memory-backend-file
- Some cleanups and fixes around NVDIMMs and R/O file handling for guest
  RAM
- Optimize ioeventfd updates by skipping address spaces that are not
  applicable

# -----BEGIN PGP SIGNATURE-----
#
# iQJFBAABCAAvFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAmUJdykRHGRhdmlkQHJl
# ZGhhdC5jb20ACgkQTd4Q9wD/g1pf2w//akOUoYMuamySGjXtKLVyMKZkjIys+Ama
# k2C0xzsWAHBP572ezwHi8uxf5j9kzAjsw6GxDZ7FAamD9MhiohkEvkecloBx6f/c
# q3fVHblBNkG7v2urtf4+6PJtJvhzOST2SFXfWeYhO/vaA04AYCDgexv82JN3gA6B
# OS8WyOX62b8wILPSY2GLZ8IqpE9XnOYZwzVBn6YB1yo7ZkYEfXO6cA8nykNuNcOE
# vppqDo7uVIX6317FWj8ygxmzFfOaj0WT2MT2XFzEIDfg8BInQN8HC4mTn0hcVKMa
# N1y+eZH733CQKT+uNBRZ5YOeljOi4d6gEEyvkkA/L7e5D3Qg9hIdvHb4uryCFSWX
# Vt07OP1XLBwCZFobOC6sg+2gtTZJxxYK89e6ZzEd0454S24w5bnEteRAaCGOP0XL
# ww9xYULqhtZs55UC4rvZHJwdUAk1fIY4VqynwkeQXegvz6BxedNeEkJiiEU0Tizx
# N2VpsxAJ7H/LLSFeZoCRESo4azrH6U4n7S/eS1tkCniFqibfe2yIQCDoJVfb42ec
# gfg/vThCrDwHkIHzkMmoV8NndA7Q7SIkyMfYeEEBeZMeg8JzYll4DJEw/jQCacxh
# KRUa+AZvGlTJUq0mkvyOVfLki+iaehoIUuY1yvMrmdWijPO8n3YybmP9Ljhr8VdR
# 9MSYZe+I2v8=
# =iraT
# -----END PGP SIGNATURE-----
# gpg: Signature made Tue 19 Sep 2023 06:25:45 EDT
# gpg:                using RSA key 1BD9CAAD735C4C3A460DFCCA4DDE10F700FF835A
# gpg:                issuer "david@redhat.com"
# gpg: Good signature from "David Hildenbrand <david@redhat.com>" [unknown]
# gpg:                 aka "David Hildenbrand <davidhildenbrand@gmail.com>" [full]
# gpg:                 aka "David Hildenbrand <hildenbr@in.tum.de>" [unknown]
# gpg: WARNING: The key's User ID is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 1BD9 CAAD 735C 4C3A 460D  FCCA 4DDE 10F7 00FF 835A

* tag 'mem-2023-09-19' of https://github.com/davidhildenbrand/qemu

:
  memory: avoid updating ioeventfds for some address_space
  machine: Improve error message when using default RAM backend id
  softmmu/physmem: Hint that "readonly=on,rom=off" exists when opening file R/W for private mapping fails
  docs: Start documenting VM templating
  docs: Don't mention "-mem-path" in multi-process.rst
  softmmu/physmem: Never return directories from file_ram_open()
  softmmu/physmem: Fail creation of new files in file_ram_open() with readonly=true
  softmmu/physmem: Bail out early in ram_block_discard_range() with readonly files
  softmmu/physmem: Remap with proper protection in qemu_ram_remap()
  backends/hostmem-file: Add "rom" property to support VM templating with R/O files
  softmmu/physmem: Distinguish between file access mode and mmap protection
  nvdimm: Reject writing label data to ROM instead of crashing QEMU

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

edk2: update to edk2-stable202308

v2: include acpi test data updates

# -----BEGIN PGP SIGNATURE-----
#
# iQIzBAABCgAdFiEEoDKM/7k6F6eZAf59TLbY7tPocTgFAmUIUYUACgkQTLbY7tPo
# cTiPgQ/9Hfn4ooawA2k7i4KB5mAdNMhG1TYmR05hjIPur8S+UBhfHx3Qdv/lojzr
# 9hRkXsi3CpV8E/t7sA/ZUVbc17ukBrJvL2VbW1nGqPZytiNqmU/2HOZEd88WByyg
# O1UYg9FZ1JbrqVbFkrE7Y0CHJmrr4EDWRxEGd7ITPDbR4UEuiQUm7+TeHIbQFCll
# T5vNxkCBP6smY9n/OEMZHX964D7906pBflHSjzpLPV/mXBrlM/rDNtPXA6dcIquh
# cCOndACPpenM8ngtgbW2gvDkkflXv4gtLozJR8XE8O434HmCviUjcxGW6L7nelcZ
# +madon48CZ/5AJUvC09R3xuzWHOBuLOn21O3ooprnCBFWAgCtaMEDWwNbgf1Pig3
# PgwOd1HeiQTKRuNCFDwNX1GJRN7Cyq6tY+ALQal3glDmWEMiyihUHViSsqux3c01
# RAkyyOJAMOZ6+MbZ4HMWNVI9pKRTYY7IDxg3NWSvlCD3KmDuDt8YBuQftZMN+T8X
# yMSa1wQda7ATlrsjUZL5LsEYO3qkho4ybffiFFDVz8QR/sO0TQg9uw6mggIghLAh
# GsSUE9SpVZmu+1lZYV/+/KomGeyNlhfchgIVPApMLQS3j0kDgVeNsrsjfbDgCqsn
# q3Ame+Roul54cv437F02ugt6JoxP76gNXXn8KdZPIDqOHWxMeS0=
# =Grjx
# -----END PGP SIGNATURE-----
# gpg: Signature made Mon 18 Sep 2023 09:32:53 EDT
# gpg:                using RSA key A0328CFFB93A17A79901FE7D4CB6D8EED3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>" [full]
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>" [full]
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>" [full]
# Primary key fingerprint: A032 8CFF B93A 17A7 9901  FE7D 4CB6 D8EE D3E8 7138

* tag 'firmware/edk2-20230918-pull-request' of https://gitlab.com/kraxel/qemu

:
  tests/acpi: disallow virt/SSDT.memhp updates
  tests/acpi: update virt/SSDT.memhp
  edk2: update binaries to edk2-stable202308
  edk2: update submodule to edk2-stable202308
  edk2: workaround edk-stable202308 bug
  edk2: update build config
  edk2: update build script
  tests/acpi: allow virt/SSDT.memhp updates

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

ppc patch queue for 2023-09-18:

In this short queue we're making two important changes:

- Nicholas Piggin is now the qemu-ppc maintainer. Cédric Le Goater and
Daniel Barboza will act as backup during Nick's transition to this new
role.

- Support for NVIDIA V100 GPU with NVLink2 is dropped from qemu-ppc.
Linux removed the same support back in 5.13, we're following suit now.

A xive Coverity fix is also included.

# -----BEGIN PGP SIGNATURE-----
#
# iIwEABYKADQWIQQX6/+ZI9AYAK8oOBk82cqW3gMxZAUCZQhPnBYcZGFuaWVsaGI0
# MTNAZ21haWwuY29tAAoJEDzZypbeAzFk5QUBAJJNnCtv/SPP6bQVNGMgtfI9sz2z
# MEttDa7SINyLCiVxAP0Y9z8ZHEj6vhztTX0AAv2QubCKWIVbJZbPV5RWrHCEBQ==
# =y3nh
# -----END PGP SIGNATURE-----
# gpg: Signature made Mon 18 Sep 2023 09:24:44 EDT
# gpg:                using EDDSA key 17EBFF9923D01800AF2838193CD9CA96DE033164
# gpg:                issuer "danielhb413@gmail.com"
# gpg: Good signature from "Daniel Henrique Barboza <danielhb413@gmail.com>" [unknown]
# gpg: WARNING: The key's User ID is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 17EB FF99 23D0 1800 AF28  3819 3CD9 CA96 DE03 3164

* tag 'pull-ppc-20230918' of https://gitlab.com/danielhb/qemu

:
  spapr: Remove support for NVIDIA V100 GPU with NVLink2
  ppc/xive: Fix uint32_t overflow
  MAINTAINERS: Nick Piggin PPC maintainer, other PPC changes

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

# -----BEGIN PGP SIGNATURE-----
# Version: GnuPG v1
#
# iQEcBAABAgAGBQJlB/SLAAoJEO8Ells5jWIR7EQH/1kAbxHcSGJXDOgQAXJ/rOZi
# UKn3ugJzD0Hxd4Xz8cvdVLM+9/JoEEOK1uB+NIG7Ask/gA5D7eUYzaLtp1OJ8VNO
# mamfKmn3EIBWJoLSHH19TKzfW2tGMJHQ0Nj+sbDQRkK5f2c7hwLTRXa1EmlJd4dB
# VoVzX4OiJtrQyv4OVmpP/PSETXJDvYYX/DNcRl9/3ccKtQW/wVDI3YzrMzXrsgyc
# w9ItJi8k+19mVH6RgQwciqRvTbVMdzkOxqvU//LY0TxnjsHfbyHr+KlNAa2WTY2N
# QgpAlMZhHqUG6/XXAs0o2VEtA66zmw932Xfy/CZUEcdGWfkG/9CEVfbuT4CKGY4=
# =tF7K
# -----END PGP SIGNATURE-----
# gpg: Signature made Mon 18 Sep 2023 02:56:11 EDT
# gpg:                using RSA key EF04965B398D6211
# gpg: Good signature from "Jason Wang (Jason Wang on RedHat) <jasowang@redhat.com>" [full]
# Primary key fingerprint: 215D 46F4 8246 689E C77F  3562 EF04 965B 398D 6211

* tag 'net-pull-request' of https://github.com/jasowang/qemu

:
  net/tap: Avoid variable-length array
  net/dump: Avoid variable length array
  hw/net/rocker: Avoid variable length array
  hw/net/fsl_etsec/rings.c: Avoid variable length array
  net: add initial support for AF_XDP network backend
  tests: bump libvirt-ci for libasan and libxdp
  e1000e: rename e1000e_ba_state and e1000e_write_hdr_to_rx_buffers
  igb: packet-split descriptors support
  igb: add IPv6 extended headers traffic detection
  igb: RX payload guest writting refactoring
  igb: RX descriptors guest writting refactoring
  igb: rename E1000E_RingInfo_st
  igb: remove TCP ACK detection
  virtio-net: Add support for USO features
  virtio-net: Add USO flags to vhost support.
  tap: Add check for USO features
  tap: Add USO support to tap device.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

*: Delete checks for old host definitions
tcg/loongarch64: Generate LSX instructions
fpu: Add conversions between bfloat16 and [u]int8
fpu: Handle m68k extended precision denormals properly
accel/tcg: Improve cputlb i/o organization
accel/tcg: Simplify tlb_plugin_lookup
accel/tcg: Remove false-negative halted assertion
tcg: Add gvec compare with immediate and scalar operand
tcg/aarch64: Emit BTI insns at jump landing pads

[Resolved conflict between CPUINFO_PMULL and CPUINFO_BTI.
--Stefan]

* tag 'pull-tcg-20230915-2' of https://gitlab.com/rth7680/qemu

: (39 commits)
  tcg: Map code_gen_buffer with PROT_BTI
  tcg/aarch64: Emit BTI insns at jump landing pads
  util/cpuinfo-aarch64: Add CPUINFO_BTI
  tcg: Add tcg_out_tb_start backend hook
  fpu: Handle m68k extended precision denormals properly
  fpu: Add conversions between bfloat16 and [u]int8
  accel/tcg: Introduce do_st16_mmio_leN
  accel/tcg: Introduce do_ld16_mmio_beN
  accel/tcg: Merge io_writex into do_st_mmio_leN
  accel/tcg: Merge io_readx into do_ld_mmio_beN
  accel/tcg: Replace direct use of io_readx/io_writex in do_{ld,st}_1
  accel/tcg: Merge cpu_transaction_failed into io_failed
  plugin: Simplify struct qemu_plugin_hwaddr
  accel/tcg: Use CPUTLBEntryFull.phys_addr in io_failed
  accel/tcg: Split out io_prepare and io_failed
  accel/tcg: Simplify tlb_plugin_lookup
  target/arm: Use tcg_gen_gvec_cmpi for compare vs 0
  tcg: Add gvec compare with immediate and scalar operand
  tcg/loongarch64: Implement 128-bit load & store
  tcg/loongarch64: Lower rotli_vec to vrotri
  ...

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

When updating ioeventfds, we need to iterate all address spaces,
but some address spaces do not register eventfd_add|del call when
memory_listener_register() and they do nothing when updating ioeventfds.
So we can skip these AS in address_space_update_ioeventfds().

The overhead of memory_region_transaction_commit() can be significantly
reduced. For example, a VM with 8 vhost net devices and each one has
64 vectors, can reduce the time spent on memory_region_transaction_commit by 20%.

Message-ID: <20230830032906.12488-1-hongmianquan@bytedance.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: hongmianquan <hongmianquan@bytedance.com>
Signed-off-by: David Hildenbrand <david@redhat.com>

For migration purposes, users might want to reuse the default RAM
backend id, but specify a different memory backend.

For example, to reuse "pc.ram" on q35, one has to set
    -machine q35,memory-backend=pc.ram
Only then, can a memory backend with the id "pc.ram" be created
manually.

Let's improve the error message by improving the hint. Use
error_append_hint() -- which in turn requires ERRP_GUARD().

Message-ID: <20230906120503.359863-12-david@redhat.com>
Suggested-by: ThinerLogoer <logoerthiner1@163.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Mario Casquero <mcasquer@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>

softmmu/physmem: Hint that "readonly=on,rom=off" exists when opening file R/W for private mapping fails

It's easy to miss that memory-backend-file with "share=off" (default)
will always try opening the file R/W as default, and fail if we don't
have write permissions to the file.

In that case, the user has to explicit specify "readonly=on,rom=off" to
get usable RAM, for example, for VM templating.

Let's hint that '-object memory-backend-file,readonly=on,rom=off,...'
exists to consume R/O files in a private mapping to create writable RAM,
but only if we have permissions to open the file read-only.

Message-ID: <20230906120503.359863-11-david@redhat.com>
Suggested-by: ThinerLogoer <logoerthiner1@163.com>
Signed-off-by: David Hildenbrand <david@redhat.com>

Let's add some details about VM templating, focusing on the VM memory
configuration only.

There is much more to VM templating (VM state? block devices?), but I leave
that as future work.

Message-ID: <20230906120503.359863-10-david@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: David Hildenbrand <david@redhat.com>

"-mem-path" corresponds to "memory-backend-file,share=off" and,
therefore, creates a private COW mapping of the file. For multi-proces
QEMU, we need proper shared file-backed memory.

Let's make that clearer.

Message-ID: <20230906120503.359863-9-david@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>

open() does not fail on directories when opening them readonly (O_RDONLY).

Currently, we succeed opening such directories and fail later during
mmap(), resulting in a misleading error message.

$ ./qemu-system-x86_64 \
    -object memory-backend-file,id=ram0,mem-path=tmp,readonly=true,size=1g
 qemu-system-x86_64: unable to map backing store for guest RAM: No such device

To identify directories and handle them accordingly in file_ram_open()
also when readonly=true was specified, detect if we just opened a directory
using fstat() instead. Then, fail file_ram_open() right away, similarly
to how we now fail if the file does not exist and we want to open the
file readonly.

With this change, we get a nicer error message:
 qemu-system-x86_64: can't open backing store tmp for guest RAM: Is a directory

Note that the only memory-backend-file will end up calling
memory_region_init_ram_from_file() -> qemu_ram_alloc_from_file() ->
file_ram_open().

Message-ID: <20230906120503.359863-8-david@redhat.com>
Reported-by: Thiner Logoer <logoerthiner1@163.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Tested-by: Mario Casquero <mcasquer@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>

Currently, if a file does not exist yet, file_ram_open() will create new
empty file and open it writable. However, it even does that when
readonly=true was specified.

Specifying O_RDONLY instead to create a new readonly file would
theoretically work, however, ftruncate() will refuse to resize the new
empty file and we'll get a warning:
    ftruncate: Invalid argument
And later eventually more problems when actually mmap'ing that file and
accessing it.

If someone intends to let QEMU open+mmap a file read-only, better
create+resize+fill that file ahead of time outside of QEMU context.

We'll now fail with:
./qemu-system-x86_64 \
    -object memory-backend-file,id=ram0,mem-path=tmp,readonly=true,size=1g
qemu-system-x86_64: can't open backing store tmp for guest RAM: No such file or directory

All use cases of readonly files (R/O NVDIMMs, VM templating) work on
existing files, so silently creating new files might just hide user
errors when accidentally specifying a non-existent file.

Note that the only memory-backend-file will end up calling
memory_region_init_ram_from_file() -> qemu_ram_alloc_from_file() ->
file_ram_open().

Move error reporting to the single caller.

Message-ID: <20230906120503.359863-7-david@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>

fallocate() will fail, let's print a nicer error message.

Message-ID: <20230906120503.359863-6-david@redhat.com>
Suggested-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>

Let's remap with the proper protection that we can derive from
RAM_READONLY.

Message-ID: <20230906120503.359863-5-david@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: David Hildenbrand <david@redhat.com>

For now, "share=off,readonly=on" would always result in us opening the
file R/O and mmap'ing the opened file MAP_PRIVATE R/O -- effectively
turning it into ROM.

Especially for VM templating, "share=off" is a common use case. However,
that use case is impossible with files that lack write permissions,
because "share=off,readonly=on" will not give us writable RAM.

The sole user of ROM via memory-backend-file are R/O NVDIMMs, but as we
have users (Kata Containers) that rely on the existing behavior --
malicious VMs should not be able to consume COW memory for R/O NVDIMMs --
we cannot change the semantics of "share=off,readonly=on"

So let's add a new "rom" property with on/off/auto values. "auto" is
the default and what most people will use: for historical reasons, to not
change the old semantics, it defaults to the value of the "readonly"
property.

For VM templating, one can now use:
    -object memory-backend-file,share=off,readonly=on,rom=off,...

But we'll disallow:
    -object memory-backend-file,share=on,readonly=on,rom=off,...
because we would otherwise get an error when trying to mmap the R/O file
shared and writable. An explicit error message is cleaner.

We will also disallow for now:
    -object memory-backend-file,share=off,readonly=off,rom=on,...
    -object memory-backend-file,share=on,readonly=off,rom=on,...
It's not harmful, but also not really required for now.

Alternatives that were abandoned:
* Make "unarmed=on" for the NVDIMM set the memory region container
  readonly. We would still see a change of ROM->RAM and possibly run
  into memslot limits with vhost-user. Further, there might be use cases
  for "unarmed=on" that should still allow writing to that memory
  (temporary files, system RAM, ...).
* Add a new "readonly=on/off/auto" parameter for NVDIMMs. Similar issues
  as with "unarmed=on".
* Make "readonly" consume "on/off/file" instead of being a 'bool' type.
  This would slightly changes the behavior of the "readonly" parameter:
  values like true/false (as accepted by a 'bool'type) would no longer be
  accepted.

Message-ID: <20230906120503.359863-4-david@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>

There is a difference between how we open a file and how we mmap it,
and we want to support writable private mappings of readonly files. Let's
define RAM_READONLY and RAM_READONLY_FD flags, to replace the single
"readonly" parameter for file-related functions.

In memory_region_init_ram_from_fd() and memory_region_init_ram_from_file(),
initialize mr->readonly based on the new RAM_READONLY flag.

While at it, add some RAM_* flags we missed to add to the list of accepted
flags in the documentation of some functions.

No change in functionality intended. We'll make use of both flags next
and start setting them independently for memory-backend-file.

Message-ID: <20230906120503.359863-3-david@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>

Currently, when using a true R/O NVDIMM (ROM memory backend) with a label
area, the VM can easily crash QEMU by trying to write to the label area,
because the ROM memory is mmap'ed without PROT_WRITE.

    [root@vm-0 ~]# ndctl disable-region region0
    disabled 1 region
    [root@vm-0 ~]# ndctl zero-labels nmem0
    -> QEMU segfaults

Let's remember whether we have a ROM memory backend and properly
reject the write request:

    [root@vm-0 ~]# ndctl disable-region region0
    disabled 1 region
    [root@vm-0 ~]# ndctl zero-labels nmem0
    zeroed 0 nmem

In comparison, on a system with a R/W NVDIMM:

    [root@vm-0 ~]# ndctl disable-region region0
    disabled 1 region
    [root@vm-0 ~]# ndctl zero-labels nmem0
    zeroed 1 nmem

For ACPI, just return "unsupported", like if no label exists. For spapr,
return "H_P2", similar to when no label area exists.

Could we rely on the "unarmed" property? Maybe, but it looks cleaner to
only disallow what certainly cannot work.

After all "unarmed=on" primarily means: cannot accept persistent writes. In
theory, there might be setups where devices with "unarmed=on" set could
be used to host non-persistent data (temporary files, system RAM, ...); for
example, in Linux, admins can overwrite the "readonly" setting and still
write to the device -- which will work as long as we're not using ROM.
Allowing writing label data in such configurations can make sense.

Message-ID: <20230906120503.359863-2-david@redhat.com>
Fixes: dbd730e8 ("nvdimm: check -object memory-backend-file, readonly=on option")
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>

Unify implementation of carry-less multiply.
Accelerate carry-less multiply for 64x64->128.

# -----BEGIN PGP SIGNATURE-----
#
# iQFRBAABCgA7FiEEekgeeIaLTbaoWgXAZN846K9+IV8FAmUEiPodHHJpY2hhcmQu
# aGVuZGVyc29uQGxpbmFyby5vcmcACgkQZN846K9+IV/akgf/XkiIeErWJr1YXSbS
# YPQtCsDAfIrqn3RiyQ2uwSn2eeuwVqTFFPGER04YegRDK8dyO874JBfvOwmBT70J
# I/aU8Z4BbRyNu9nfaCtFMlXQH9KArAKcAds1PnshfcnI5T2yBloZ1sAU97IuJFZk
# Uuz96H60+ohc4wzaUiPqPhXQStgZeSYwwAJB0s25DhCckdea0udRCAJ1tQTVpxkM
# wIFef1SHPoM6DtMzFKHLLUH6VivSlHjqx8GqFusa7pVqfQyDzNBfwvDl1F/bkE07
# yTocQEkV3QnZvIplhqUxAaZXIFZr9BNk7bDimMjHW6z3pNPN3T8zRn4trNjxbgPV
# jqzAtg==
# =8nnk
# -----END PGP SIGNATURE-----
# gpg: Signature made Fri 15 Sep 2023 12:40:26 EDT
# gpg:                using RSA key 7A481E78868B4DB6A85A05C064DF38E8AF7E215F
# gpg:                issuer "richard.henderson@linaro.org"
# gpg: Good signature from "Richard Henderson <richard.henderson@linaro.org>" [full]
# Primary key fingerprint: 7A48 1E78 868B 4DB6 A85A  05C0 64DF 38E8 AF7E 215F

* tag 'pull-crypto-20230915' of https://gitlab.com/rth7680/qemu

:
  host/include/aarch64: Implement clmul.h
  host/include/i386: Implement clmul.h
  target/ppc: Use clmul_64
  target/s390x: Use clmul_64
  target/i386: Use clmul_64
  target/arm: Use clmul_64
  crypto: Add generic 64-bit carry-less multiply routine
  target/ppc: Use clmul_32* routines
  target/s390x: Use clmul_32* routines
  target/arm: Use clmul_32* routines
  crypto: Add generic 32-bit carry-less multiply routines
  target/ppc: Use clmul_16* routines
  target/s390x: Use clmul_16* routines
  target/arm: Use clmul_16* routines
  crypto: Add generic 16-bit carry-less multiply routines
  target/ppc: Use clmul_8* routines
  target/s390x: Use clmul_8* routines
  target/arm: Use clmul_8* routines
  crypto: Add generic 8-bit carry-less multiply routines

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

The edk2 update caused an address change:

 DefinitionBlock ("", "SSDT", 1, "BOCHS ", "NVDIMM", 0x00000001)
 {
     Scope (\_SB)
     {
         Device (NVDR)
         {
             Name (_HID, "ACPI0012" /* NVDIMM Root Device */)  // _HID: Hardware ID
             [ ... ]
         }
     }

-    Name (MEMA, 0x43D10000)
+    Name (MEMA, 0x43C90000)
 }

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

New stable release was tagged in August 2023,
update the edk2 submodule to it.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

Set PCD to workaround two fixes missing the release.
https://github.com/tianocore/edk2/commit/8b66f9df1bb0fd5ebb743944d41cb33178cf2fdd
https://github.com/tianocore/edk2/commit/020cc9e2e7053bb62247b0babbbe80cb855592e5



Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

risc-v switched to use split code/vars images like the other archs.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

Sync with latest version from gitlab.com/kraxel/edk2-build-config

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>