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ASoC: SOF: Intel: optimize block_write() and write64() / read64() - #365

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ASoC: SOF: Intel: optimize block_write() and write64() / read64()#365
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@keyonjie

@keyonjie keyonjie commented Dec 4, 2018

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This is aimed to fix #353 , tested on byt and apl.

For write64() and read64(), switch to use writeq() and readq().
For block_write(), optimize the connection of fragment bytes.

And apply these changes to all BYT/HSW/BDW/SKL+ platforms.

Signed-off-by: Keyon Jie yang.jie@linux.intel.com

For write64() and read64(), switch to use writeq() and readq().
For block_write(), optimize the connection of fragment bytes.

And apply these changes to all BYT/HSW/BDW/SKL+ platforms.

Signed-off-by: Keyon Jie <yang.jie@linux.intel.com>
Comment thread sound/soc/sof/intel/hsw.c
*/
__ioread32_copy(&tmp, dest + m * 4, 1);

tmp |= *(u32 *)(src_byte + m * 4) & ((1 << (8 * n)) - 1);

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@keyonjie what you have here is correct and i've tested it to work.
But I have a suggestion to improve the readability.

tmp |= *(u32 *)(src_byte + m * 4) & GENMASK(31, 32 - n * 8 );

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@ranj063 is the GENMASK arguments correct? For n=1 this should be 1<<8-1, so 0xFF

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@ranj063 @plbossart the mask is start from bit 0, so for n > 0, it should be GENMASK((8 * n) - 1, 0). But we can't use GENMASK if the mask is 0.

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oops looks like I misunderstood it. Yes but maybe like @plbossart said it is better to leave the array as it is definitely easier to follow.

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The readq/writeq changes are fine.
The rest of the code is horrible to read and I don't see what it optimizes. I prefer the simple array notation...

Comment thread sound/soc/sof/intel/hda.c

dst_byte = (u8 *)&tmp;
for (i = 0; i < n; i++)
dst_byte[i] = src_byte[m * 4 + i];

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I honestly prefer this array notation over all the rest. I don't see the point of complex formulas that aren't readable. Let the compiler work for you...

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@plbossart This is actually from Andy Shevchenko's comment. @keyonjie takes sick leave today. I will revert this part if you prefer the original one.

  • if (n) {
  •    for (i = 0; i < n; i++)
    
  •    	tmp |= (u32)*(src_byte + m * 4 + i) << (i * 8);
    

I suppose src_byte is aligned on 32-bit.

Why not just

tmp = *(u32 *)src_byte & ((1 << (8 * n)) - 1);

1 -> 0xff
2 -> 0xffff
3 -> 0xffffff

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Can you just use the array solution everywhere? It's not like this pointer arithmetic and masks gain us anything.

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@plbossart this was what Andy suggested and I think it is good as it remove usage of for loop, and it actually improve efficiency?

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Sorry @keyonjie I think we have to consider about @plbossart 's opinion. So, I made a PR which contains the readq/writeq change only.

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Ah, I missed the fact that the loop was gone. So yes indeed it's simpler without a loop, thanks for pushing back. Please add a new PR to improve this (I'd like something more readable though)

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Hi @bardliao can you help change it and create new PR to replace this one, my comment is:

  1. add '#include <linux/io.h>' to those changed files, 0-day complaint about this.
  2. add 'tmp &= ~((1 << (8 * n)) - 1))' before line 'tmp |= *(u32 *)(src_byte + m * 4) & ((1 << (8 * n)) - 1);'.

@keyonjie

keyonjie commented Dec 6, 2018

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as @bardliao's PR merged, let me close this one and send a new PR to remove the loop.

@keyonjie keyonjie closed this Dec 6, 2018
plbossart pushed a commit that referenced this pull request May 3, 2024
The delete set command does not rely on the transaction object for
element removal, therefore, a combination of delete element + delete set
from the abort path could result in restoring twice the refcount of the
mapping.

Check for inactive element in the next generation for the delete element
command in the abort path, skip restoring state if next generation bit
has been already cleared. This is similar to the activate logic using
the set walk iterator.

[ 6170.286929] ------------[ cut here ]------------
[ 6170.286939] WARNING: CPU: 6 PID: 790302 at net/netfilter/nf_tables_api.c:2086 nf_tables_chain_destroy+0x1f7/0x220 [nf_tables]
[ 6170.287071] Modules linked in: [...]
[ 6170.287633] CPU: 6 PID: 790302 Comm: kworker/6:2 Not tainted 6.9.0-rc3+ #365
[ 6170.287768] RIP: 0010:nf_tables_chain_destroy+0x1f7/0x220 [nf_tables]
[ 6170.287886] Code: df 48 8d 7d 58 e8 69 2e 3b df 48 8b 7d 58 e8 80 1b 37 df 48 8d 7d 68 e8 57 2e 3b df 48 8b 7d 68 e8 6e 1b 37 df 48 89 ef eb c4 <0f> 0b 48 83 c4 08 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 0f
[ 6170.287895] RSP: 0018:ffff888134b8fd08 EFLAGS: 00010202
[ 6170.287904] RAX: 0000000000000001 RBX: ffff888125bffb28 RCX: dffffc0000000000
[ 6170.287912] RDX: 0000000000000003 RSI: ffffffffa20298ab RDI: ffff88811ebe4750
[ 6170.287919] RBP: ffff88811ebe4700 R08: ffff88838e812650 R09: fffffbfff0623a55
[ 6170.287926] R10: ffffffff8311d2af R11: 0000000000000001 R12: ffff888125bffb10
[ 6170.287933] R13: ffff888125bffb10 R14: dead000000000122 R15: dead000000000100
[ 6170.287940] FS:  0000000000000000(0000) GS:ffff888390b00000(0000) knlGS:0000000000000000
[ 6170.287948] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 6170.287955] CR2: 00007fd31fc00710 CR3: 0000000133f60004 CR4: 00000000001706f0
[ 6170.287962] Call Trace:
[ 6170.287967]  <TASK>
[ 6170.287973]  ? __warn+0x9f/0x1a0
[ 6170.287986]  ? nf_tables_chain_destroy+0x1f7/0x220 [nf_tables]
[ 6170.288092]  ? report_bug+0x1b1/0x1e0
[ 6170.287986]  ? nf_tables_chain_destroy+0x1f7/0x220 [nf_tables]
[ 6170.288092]  ? report_bug+0x1b1/0x1e0
[ 6170.288104]  ? handle_bug+0x3c/0x70
[ 6170.288112]  ? exc_invalid_op+0x17/0x40
[ 6170.288120]  ? asm_exc_invalid_op+0x1a/0x20
[ 6170.288132]  ? nf_tables_chain_destroy+0x2b/0x220 [nf_tables]
[ 6170.288243]  ? nf_tables_chain_destroy+0x1f7/0x220 [nf_tables]
[ 6170.288366]  ? nf_tables_chain_destroy+0x2b/0x220 [nf_tables]
[ 6170.288483]  nf_tables_trans_destroy_work+0x588/0x590 [nf_tables]

Fixes: 5910544 ("netfilter: nf_tables: revisit chain/object refcounting from elements")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
plbossart pushed a commit that referenced this pull request May 3, 2024
…ent path

Check for table dormant flag otherwise netdev release event path tries
to unregister an already unregistered hook.

[524854.857999] ------------[ cut here ]------------
[524854.858010] WARNING: CPU: 0 PID: 3386599 at net/netfilter/core.c:501 __nf_unregister_net_hook+0x21a/0x260
[...]
[524854.858848] CPU: 0 PID: 3386599 Comm: kworker/u32:2 Not tainted 6.9.0-rc3+ #365
[524854.858869] Workqueue: netns cleanup_net
[524854.858886] RIP: 0010:__nf_unregister_net_hook+0x21a/0x260
[524854.858903] Code: 24 e8 aa 73 83 ff 48 63 43 1c 83 f8 01 0f 85 3d ff ff ff e8 98 d1 f0 ff 48 8b 3c 24 e8 8f 73 83 ff 48 63 43 1c e9 26 ff ff ff <0f> 0b 48 83 c4 18 48 c7 c7 00 68 e9 82 5b 5d 41 5c 41 5d 41 5e 41
[524854.858914] RSP: 0018:ffff8881e36d79e0 EFLAGS: 00010246
[524854.858926] RAX: 0000000000000000 RBX: ffff8881339ae790 RCX: ffffffff81ba524a
[524854.858936] RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff8881c8a16438
[524854.858945] RBP: ffff8881c8a16438 R08: 0000000000000001 R09: ffffed103c6daf34
[524854.858954] R10: ffff8881e36d79a7 R11: 0000000000000000 R12: 0000000000000005
[524854.858962] R13: ffff8881c8a16000 R14: 0000000000000000 R15: ffff8881351b5a00
[524854.858971] FS:  0000000000000000(0000) GS:ffff888390800000(0000) knlGS:0000000000000000
[524854.858982] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[524854.858991] CR2: 00007fc9be0f16f4 CR3: 00000001437cc004 CR4: 00000000001706f0
[524854.859000] Call Trace:
[524854.859006]  <TASK>
[524854.859013]  ? __warn+0x9f/0x1a0
[524854.859027]  ? __nf_unregister_net_hook+0x21a/0x260
[524854.859044]  ? report_bug+0x1b1/0x1e0
[524854.859060]  ? handle_bug+0x3c/0x70
[524854.859071]  ? exc_invalid_op+0x17/0x40
[524854.859083]  ? asm_exc_invalid_op+0x1a/0x20
[524854.859100]  ? __nf_unregister_net_hook+0x6a/0x260
[524854.859116]  ? __nf_unregister_net_hook+0x21a/0x260
[524854.859135]  nf_tables_netdev_event+0x337/0x390 [nf_tables]
[524854.859304]  ? __pfx_nf_tables_netdev_event+0x10/0x10 [nf_tables]
[524854.859461]  ? packet_notifier+0xb3/0x360
[524854.859476]  ? _raw_spin_unlock_irqrestore+0x11/0x40
[524854.859489]  ? dcbnl_netdevice_event+0x35/0x140
[524854.859507]  ? __pfx_nf_tables_netdev_event+0x10/0x10 [nf_tables]
[524854.859661]  notifier_call_chain+0x7d/0x140
[524854.859677]  unregister_netdevice_many_notify+0x5e1/0xae0

Fixes: d54725c ("netfilter: nf_tables: support for multiple devices per netdev hook")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
oder-chiou pushed a commit to oder-chiou/linux-soundwire that referenced this pull request May 5, 2026
Matt reported a splat at msk close time:

    BUG: sleeping function called from invalid context at net/mptcp/protocol.c:2877
    in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 155, name: packetdrill
    preempt_count: 201, expected: 0
    RCU nest depth: 0, expected: 0
    4 locks held by packetdrill/155:
    #0: ffff888001536990 (&sb->s_type->i_mutex_key#6){+.+.}-{3:3}, at: __sock_release (net/socket.c:650)
    thesofproject#1: ffff88800b498130 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_close (net/mptcp/protocol.c:2973)
    thesofproject#2: ffff88800b49a130 (sk_lock-AF_INET/1){+.+.}-{0:0}, at: __mptcp_close_ssk (net/mptcp/protocol.c:2363)
    thesofproject#3: ffff88800b49a0b0 (slock-AF_INET){+...}-{2:2}, at: __lock_sock_fast (include/net/sock.h:1820)
    Preemption disabled at:
    0x0
    CPU: 1 PID: 155 Comm: packetdrill Not tainted 6.1.0-rc5 thesofproject#365
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
    Call Trace:
    <TASK>
    dump_stack_lvl (lib/dump_stack.c:107 (discriminator 4))
    __might_resched.cold (kernel/sched/core.c:9891)
    __mptcp_destroy_sock (include/linux/kernel.h:110)
    __mptcp_close (net/mptcp/protocol.c:2959)
    mptcp_subflow_queue_clean (include/net/sock.h:1777)
    __mptcp_close_ssk (net/mptcp/protocol.c:2363)
    mptcp_destroy_common (net/mptcp/protocol.c:3170)
    mptcp_destroy (include/net/sock.h:1495)
    __mptcp_destroy_sock (net/mptcp/protocol.c:2886)
    __mptcp_close (net/mptcp/protocol.c:2959)
    mptcp_close (net/mptcp/protocol.c:2974)
    inet_release (net/ipv4/af_inet.c:432)
    __sock_release (net/socket.c:651)
    sock_close (net/socket.c:1367)
    __fput (fs/file_table.c:320)
    task_work_run (kernel/task_work.c:181 (discriminator 1))
    exit_to_user_mode_prepare (include/linux/resume_user_mode.h:49)
    syscall_exit_to_user_mode (kernel/entry/common.c:130)
    do_syscall_64 (arch/x86/entry/common.c:87)
    entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)

We can't call mptcp_close under the 'fast' socket lock variant, replace
it with a sock_lock_nested() as the relevant code is already under the
listening msk socket lock protection.

Reported-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Closes: multipath-tcp/mptcp_net-next#316
Fixes: 30e51b9 ("mptcp: fix unreleased socket in accept queue")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
oder-chiou pushed a commit to oder-chiou/linux-soundwire that referenced this pull request May 5, 2026
Extend the netkit selftests to specify and validate the {head,tail}room
on the netdevice:

  # ./vmtest.sh -- ./test_progs -t netkit
  [...]
  ./test_progs -t netkit
  [    1.174147] bpf_testmod: loading out-of-tree module taints kernel.
  [    1.174585] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel
  [    1.422307] tsc: Refined TSC clocksource calibration: 3407.983 MHz
  [    1.424511] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x311fc3e5084, max_idle_ns: 440795359833 ns
  [    1.428092] clocksource: Switched to clocksource tsc
  thesofproject#363     tc_netkit_basic:OK
  thesofproject#364     tc_netkit_device:OK
  thesofproject#365     tc_netkit_multi_links:OK
  thesofproject#366     tc_netkit_multi_opts:OK
  thesofproject#367     tc_netkit_neigh_links:OK
  thesofproject#368     tc_netkit_pkt_type:OK
  thesofproject#369     tc_netkit_scrub:OK
  Summary: 7/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/bpf/20241220234658.490686-3-daniel@iogearbox.net
ujfalusi pushed a commit to ujfalusi/sof-linux that referenced this pull request Jul 29, 2026
[WARNING]
When running test cases with injected errors or shutdown, e.g.
generic/388 or generic/475, there is a chance that the following kernel
warning is triggered:

  BTRFS info (device dm-2): first mount of filesystem d8a19a28-3232-4809-b0df-38df83e71bff
  BTRFS info (device dm-2): using crc32c checksum algorithm
  BTRFS info (device dm-2): checking UUID tree
  BTRFS info (device dm-2): turning on async discard
  BTRFS info (device dm-2): enabling free space tree
  BTRFS critical (device dm-2 state E): emergency shutdown
  ------------[ cut here ]------------
  WARNING: extent_io.c:1742 at extent_writepage_io+0x437/0x520 [btrfs], CPU#2: kworker/u43:2/651591
  CPU: 2 UID: 0 PID: 651591 Comm: kworker/u43:2 Tainted: G        W  OE       7.0.0-rc6-custom+ thesofproject#365 PREEMPT(full)  5804053f02137e627472d94b5128cc9fcb110e88
  RIP: 0010:extent_writepage_io+0x437/0x520 [btrfs]
  Call Trace:
   <TASK>
   extent_write_cache_pages+0x2a5/0x820 [btrfs 70299925d0856939e93b17d480651713b3cbba58]
   btrfs_writepages+0x74/0x130 [btrfs 70299925d0856939e93b17d480651713b3cbba58]
   do_writepages+0xd0/0x160
   __writeback_single_inode+0x42/0x340
   writeback_sb_inodes+0x22d/0x580
   wb_writeback+0xc6/0x360
   wb_workfn+0xbd/0x470
   process_one_work+0x198/0x3b0
   worker_thread+0x1c8/0x330
   kthread+0xee/0x120
   ret_from_fork+0x2a6/0x330
   ret_from_fork_asm+0x11/0x20
   </TASK>
  ---[ end trace 0000000000000000 ]---
  BTRFS error (device dm-2 state E): root 5 ino 259 folio 1323008 is marked dirty without notifying the fs
  BTRFS error (device dm-2 state E): failed to submit blocks, root=5 inode=259 folio=1323008 submit_bitmap=0: -117
  BTRFS info (device dm-2 state E): last unmount of filesystem d8a19a28-3232-4809-b0df-38df83e71bff

[CAUSE]
Inside btrfs we have the following pattern in several locations, for
example inside btrfs_dirty_folio():

	btrfs_clear_extent_bit(&inode->io_tree, start_pos, end_of_last_block,
			       EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
			       cached);

	ret = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
					extra_bits, cached);
	if (ret)
		return ret;

However btrfs_set_extent_delalloc() can return IO errors other than -ENOMEM
through the following callchain:

 btrfs_set_extent_delalloc()
 \- btrfs_find_new_delalloc_bytes()
    \- btrfs_get_extent()
       \- btrfs_lookup_file_extent()
          \- btrfs_search_slot()

When such IO error happened, the previous btrfs_clear_extent_bit() has
cleared the EXTENT_DELALLOC for the range, and we're expecting
btrfs_set_extent_delalloc() to re-set EXTENT_DELALLOC.

But since btrfs_set_extent_delalloc() failed before
btrfs_set_extent_bit(), EXTENT_DELALLOC flag is no longer present.

And if the folio range is dirty before entering
btrfs_set_extent_delalloc(), we got a dirty folio but no EXTENT_DELALLOC
flag now.

Then we hit the folio writeback:

  extent_writepage()
  |- writepage_delalloc()
  |  No ordered extent is created, as there is no EXTENT_DELALLOC set
  |  for the folio range.
  |  This also means the folio has no ordered flag set.
  |
  |- extent_writepage_io()
     \- if (unlikely(!folio_test_ordered(folio))
        Now we hit the warning.

[FIX]
Introduce a new helper, btrfs_reset_extent_delalloc() to replace the
currently open-coded btrfs_clear_extent_bit() +
btrfs_set_extent_delalloc() combination.

Instead of calling btrfs_clear_extent_bit() first, update
EXTENT_DELALLOC_NEW first, as that part can fail due to metadata IO,
meanwhile btrfs_clear_extent_bit() and btrfs_set_extent_bit() won't
return any error but retry memory allocation until succeeded.

This allows us to fail early without clearing EXTENT_DELALLOC bit, so
even if that new btrfs_reset_extent_delalloc() failed before touching
EXTENT_DELALLOC, the existing dirty range will still have their old
EXTENT_DELALLOC flag present, thus avoid the warning.

CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
ujfalusi pushed a commit to ujfalusi/sof-linux that referenced this pull request Jul 29, 2026
…et_unaligned()

Drop a BUG_ON() that has been reachable since it was first added, way back
in 2009, and instead use get_unaligned() to perform potentially-unaligned
accesses.

For a given store, KVM x86's emulator tracks the entire value in the
destination operand, x86_emulate_ctxt.dst.  If the destination is memory,
and the target splits multiple pages and/or is emulated MMIO, then KVM
handles each fragment independently.  E.g. on a page split starting at page
offset 0xffc, KVM writes 4 bytes to the first page, then the remaining
bytes to the second page, using ctxt->dst as the source for both (with
appropriate offsets).

If the destination splits a page *and* hits emulated MMIO on the second
page, then KVM will complete the write to the first page, then emulate the
MMIO access to the second page.  If there is a datamatch-enabled ioeventfd
at offset 0 of the second page, then KVM will process the remainder of the
store as a potential ioeventfd signal.

Putting it all together, if the guest emits a store that splits a page
starting at page offset N, and the second page has a datamatch-enabled
ioeventfd at offset 0, then KVM will check for datamatch using
&dst.valptr[N] as the source.  Due to dst (and thus dst.valptr) being
32-byte aligned, if N is not aligned to @len, the BUG_ON() fires.

E.g. with a 16-byte store at page offset 0xffc, to an ioeventfd of len 8,
all initial checks in ioeventfd_in_range() will succeed, and the BUG_ON()
fires due to @Val being 4-byte aligned, but not 8-byte aligned.

  ------------[ cut here ]------------
  kernel BUG at arch/x86/kvm/../../../virt/kvm/eventfd.c:783!
  Oops: invalid opcode: 0000 [thesofproject#1] SMP
  CPU: 0 UID: 1000 PID: 615 Comm: repro Not tainted 7.1.0-rc2-ff238429d1ea thesofproject#365 PREEMPT
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  RIP: 0010:ioeventfd_write+0x6c/0x70 [kvm]
  Call Trace:
   <TASK>
   __kvm_io_bus_write+0x85/0xb0 [kvm]
   kvm_io_bus_write+0x53/0x80 [kvm]
   vcpu_mmio_write+0x66/0xf0 [kvm]
   emulator_read_write_onepage+0x12a/0x540 [kvm]
   emulator_read_write+0x109/0x2b0 [kvm]
   x86_emulate_insn+0x4f8/0xfb0 [kvm]
   x86_emulate_instruction+0x181/0x790 [kvm]
   kvm_mmu_page_fault+0x313/0x630 [kvm]
   vmx_handle_exit+0x18a/0x590 [kvm_intel]
   kvm_arch_vcpu_ioctl_run+0xc81/0x1c90 [kvm]
   kvm_vcpu_ioctl+0x2d5/0x970 [kvm]
   __x64_sys_ioctl+0x8a/0xd0
   do_syscall_64+0xb7/0x890
   entry_SYSCALL_64_after_hwframe+0x4b/0x53
  RIP: 0033:0x7f19c931a9bf
   </TASK>
  Modules linked in: kvm_intel kvm irqbypass
  ---[ end trace 0000000000000000 ]---

In a perfect world, the fix would be to simply delete the BUG_ON(), as KVM
x86 doesn't perform alignment checks on "normal" memory accesses at CPL0.
Sadly, C99 ruins all the fun; while the x86 architecture plays nice,
dereferencing an unaligned pointer directly is undefined behavior in C,
e.g. triggers splats when running with CONFIG_UBSAN_ALIGNMENT=y.

Fixes: d34e6b1 ("KVM: add ioeventfd support")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260612225241.678509-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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upstream: revisit io read/write routines

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