<feed xmlns='http://www.w3.org/2005/Atom'>
<title>blaster4385/linux-IllusionX/arch/powerpc, branch v6.12.10</title>
<subtitle>Linux kernel with personal config changes for arch linux</subtitle>
<id>http://git.tablaster.dev/blaster4385/linux-IllusionX/atom?h=v6.12.10</id>
<link rel='self' href='http://git.tablaster.dev/blaster4385/linux-IllusionX/atom?h=v6.12.10'/>
<link rel='alternate' type='text/html' href='http://git.tablaster.dev/blaster4385/linux-IllusionX/'/>
<updated>2025-01-02T09:34:15Z</updated>
<entry>
<title>powerpc/pseries/vas: Add close() callback in vas_vm_ops struct</title>
<updated>2025-01-02T09:34:15Z</updated>
<author>
<name>Haren Myneni</name>
<email>haren@linux.ibm.com</email>
</author>
<published>2024-12-14T05:17:58Z</published>
<link rel='alternate' type='text/html' href='http://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=6d9cd27105459f169993a4c5f216499a946dbf34'/>
<id>urn:sha1:6d9cd27105459f169993a4c5f216499a946dbf34</id>
<content type='text'>
[ Upstream commit 05aa156e156ef3168e7ab8a68721945196495c17 ]

The mapping VMA address is saved in VAS window struct when the
paste address is mapped. This VMA address is used during migration
to unmap the paste address if the window is active. The paste
address mapping will be removed when the window is closed or with
the munmap(). But the VMA address in the VAS window is not updated
with munmap() which is causing invalid access during migration.

The KASAN report shows:
[16386.254991] BUG: KASAN: slab-use-after-free in reconfig_close_windows+0x1a0/0x4e8
[16386.255043] Read of size 8 at addr c00000014a819670 by task drmgr/696928

[16386.255096] CPU: 29 UID: 0 PID: 696928 Comm: drmgr Kdump: loaded Tainted: G    B              6.11.0-rc5-nxgzip #2
[16386.255128] Tainted: [B]=BAD_PAGE
[16386.255148] Hardware name: IBM,9080-HEX Power11 (architected) 0x820200 0xf000007 of:IBM,FW1110.00 (NH1110_016) hv:phyp pSeries
[16386.255181] Call Trace:
[16386.255202] [c00000016b297660] [c0000000018ad0ac] dump_stack_lvl+0x84/0xe8 (unreliable)
[16386.255246] [c00000016b297690] [c0000000006e8a90] print_report+0x19c/0x764
[16386.255285] [c00000016b297760] [c0000000006e9490] kasan_report+0x128/0x1f8
[16386.255309] [c00000016b297880] [c0000000006eb5c8] __asan_load8+0xac/0xe0
[16386.255326] [c00000016b2978a0] [c00000000013f898] reconfig_close_windows+0x1a0/0x4e8
[16386.255343] [c00000016b297990] [c000000000140e58] vas_migration_handler+0x3a4/0x3fc
[16386.255368] [c00000016b297a90] [c000000000128848] pseries_migrate_partition+0x4c/0x4c4
...

[16386.256136] Allocated by task 696554 on cpu 31 at 16377.277618s:
[16386.256149]  kasan_save_stack+0x34/0x68
[16386.256163]  kasan_save_track+0x34/0x80
[16386.256175]  kasan_save_alloc_info+0x58/0x74
[16386.256196]  __kasan_slab_alloc+0xb8/0xdc
[16386.256209]  kmem_cache_alloc_noprof+0x200/0x3d0
[16386.256225]  vm_area_alloc+0x44/0x150
[16386.256245]  mmap_region+0x214/0x10c4
[16386.256265]  do_mmap+0x5fc/0x750
[16386.256277]  vm_mmap_pgoff+0x14c/0x24c
[16386.256292]  ksys_mmap_pgoff+0x20c/0x348
[16386.256303]  sys_mmap+0xd0/0x160
...

[16386.256350] Freed by task 0 on cpu 31 at 16386.204848s:
[16386.256363]  kasan_save_stack+0x34/0x68
[16386.256374]  kasan_save_track+0x34/0x80
[16386.256384]  kasan_save_free_info+0x64/0x10c
[16386.256396]  __kasan_slab_free+0x120/0x204
[16386.256415]  kmem_cache_free+0x128/0x450
[16386.256428]  vm_area_free_rcu_cb+0xa8/0xd8
[16386.256441]  rcu_do_batch+0x2c8/0xcf0
[16386.256458]  rcu_core+0x378/0x3c4
[16386.256473]  handle_softirqs+0x20c/0x60c
[16386.256495]  do_softirq_own_stack+0x6c/0x88
[16386.256509]  do_softirq_own_stack+0x58/0x88
[16386.256521]  __irq_exit_rcu+0x1a4/0x20c
[16386.256533]  irq_exit+0x20/0x38
[16386.256544]  interrupt_async_exit_prepare.constprop.0+0x18/0x2c
...

[16386.256717] Last potentially related work creation:
[16386.256729]  kasan_save_stack+0x34/0x68
[16386.256741]  __kasan_record_aux_stack+0xcc/0x12c
[16386.256753]  __call_rcu_common.constprop.0+0x94/0xd04
[16386.256766]  vm_area_free+0x28/0x3c
[16386.256778]  remove_vma+0xf4/0x114
[16386.256797]  do_vmi_align_munmap.constprop.0+0x684/0x870
[16386.256811]  __vm_munmap+0xe0/0x1f8
[16386.256821]  sys_munmap+0x54/0x6c
[16386.256830]  system_call_exception+0x1a0/0x4a0
[16386.256841]  system_call_vectored_common+0x15c/0x2ec

[16386.256868] The buggy address belongs to the object at c00000014a819670
                which belongs to the cache vm_area_struct of size 168
[16386.256887] The buggy address is located 0 bytes inside of
                freed 168-byte region [c00000014a819670, c00000014a819718)

[16386.256915] The buggy address belongs to the physical page:
[16386.256928] page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x14a81
[16386.256950] memcg:c0000000ba430001
[16386.256961] anon flags: 0x43ffff800000000(node=4|zone=0|lastcpupid=0x7ffff)
[16386.256975] page_type: 0xfdffffff(slab)
[16386.256990] raw: 043ffff800000000 c00000000501c080 0000000000000000 5deadbee00000001
[16386.257003] raw: 0000000000000000 00000000011a011a 00000001fdffffff c0000000ba430001
[16386.257018] page dumped because: kasan: bad access detected

This patch adds close() callback in vas_vm_ops vm_operations_struct
which will be executed during munmap() before freeing VMA. The VMA
address in the VAS window is set to NULL after holding the window
mmap_mutex.

Fixes: 37e6764895ef ("powerpc/pseries/vas: Add VAS migration handler")
Signed-off-by: Haren Myneni &lt;haren@linux.ibm.com&gt;
Signed-off-by: Madhavan Srinivasan &lt;maddy@linux.ibm.com&gt;
Link: https://patch.msgid.link/20241214051758.997759-1-haren@linux.ibm.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>powerpc/prom_init: Fixup missing powermac #size-cells</title>
<updated>2024-12-14T19:04:09Z</updated>
<author>
<name>Michael Ellerman</name>
<email>mpe@ellerman.id.au</email>
</author>
<published>2024-11-26T02:57:10Z</published>
<link rel='alternate' type='text/html' href='http://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=296a109fa77110ba5267fe0e90a26005eecc2726'/>
<id>urn:sha1:296a109fa77110ba5267fe0e90a26005eecc2726</id>
<content type='text'>
[ Upstream commit cf89c9434af122f28a3552e6f9cc5158c33ce50a ]

On some powermacs `escc` nodes are missing `#size-cells` properties,
which is deprecated and now triggers a warning at boot since commit
045b14ca5c36 ("of: WARN on deprecated #address-cells/#size-cells
handling").

For example:

  Missing '#size-cells' in /pci@f2000000/mac-io@c/escc@13000
  WARNING: CPU: 0 PID: 0 at drivers/of/base.c:133 of_bus_n_size_cells+0x98/0x108
  Hardware name: PowerMac3,1 7400 0xc0209 PowerMac
  ...
  Call Trace:
    of_bus_n_size_cells+0x98/0x108 (unreliable)
    of_bus_default_count_cells+0x40/0x60
    __of_get_address+0xc8/0x21c
    __of_address_to_resource+0x5c/0x228
    pmz_init_port+0x5c/0x2ec
    pmz_probe.isra.0+0x144/0x1e4
    pmz_console_init+0x10/0x48
    console_init+0xcc/0x138
    start_kernel+0x5c4/0x694

As powermacs boot via prom_init it's possible to add the missing
properties to the device tree during boot, avoiding the warning. Note
that `escc-legacy` nodes are also missing `#size-cells` properties, but
they are skipped by the macio driver, so leave them alone.

Depends-on: 045b14ca5c36 ("of: WARN on deprecated #address-cells/#size-cells handling")
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Reviewed-by: Rob Herring &lt;robh@kernel.org&gt;
Signed-off-by: Madhavan Srinivasan &lt;maddy@linux.ibm.com&gt;
Link: https://patch.msgid.link/20241126025710.591683-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>powerpc: Adjust adding stack protector flags to KBUILD_CLAGS for clang</title>
<updated>2024-12-09T09:41:10Z</updated>
<author>
<name>Nathan Chancellor</name>
<email>nathan@kernel.org</email>
</author>
<published>2024-10-09T19:26:09Z</published>
<link rel='alternate' type='text/html' href='http://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=ac04ef405da998a791e21afbf21e6671dd6f84b5'/>
<id>urn:sha1:ac04ef405da998a791e21afbf21e6671dd6f84b5</id>
<content type='text'>
commit bee08a9e6ab03caf14481d97b35a258400ffab8f upstream.

After fixing the HAVE_STACKPROTECTER checks for clang's in-progress
per-task stack protector support [1], the build fails during prepare0
because '-mstack-protector-guard-offset' has not been added to
KBUILD_CFLAGS yet but the other '-mstack-protector-guard' flags have.

  clang: error: '-mstack-protector-guard=tls' is used without '-mstack-protector-guard-offset', and there is no default
  clang: error: '-mstack-protector-guard=tls' is used without '-mstack-protector-guard-offset', and there is no default
  make[4]: *** [scripts/Makefile.build:229: scripts/mod/empty.o] Error 1
  make[4]: *** [scripts/Makefile.build:102: scripts/mod/devicetable-offsets.s] Error 1

Mirror other architectures and add all '-mstack-protector-guard' flags
to KBUILD_CFLAGS atomically during stack_protector_prepare, which
resolves the issue and allows clang's implementation to fully work with
the kernel.

Cc: stable@vger.kernel.org # 6.1+
Link: https://github.com/llvm/llvm-project/pull/110928 [1]
Reviewed-by: Keith Packard &lt;keithp@keithp.com&gt;
Tested-by: Keith Packard &lt;keithp@keithp.com&gt;
Signed-off-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://patch.msgid.link/20241009-powerpc-fix-stackprotector-test-clang-v2-2-12fb86b31857@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>powerpc: Fix stack protector Kconfig test for clang</title>
<updated>2024-12-09T09:41:10Z</updated>
<author>
<name>Nathan Chancellor</name>
<email>nathan@kernel.org</email>
</author>
<published>2024-10-09T19:26:08Z</published>
<link rel='alternate' type='text/html' href='http://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=fab0610d646a4a3d00f67d0e9d599036181346ff'/>
<id>urn:sha1:fab0610d646a4a3d00f67d0e9d599036181346ff</id>
<content type='text'>
commit 46e1879deea22eed31e9425d58635895fc0e8040 upstream.

Clang's in-progress per-task stack protector support [1] does not work
with the current Kconfig checks because '-mstack-protector-guard-offset'
is not provided, unlike all other architecture Kconfig checks.

  $ fd Kconfig -x rg -l mstack-protector-guard-offset
  ./arch/arm/Kconfig
  ./arch/riscv/Kconfig
  ./arch/arm64/Kconfig

This produces an error from clang, which is interpreted as the flags not
being supported at all when they really are.

  $ clang --target=powerpc64-linux-gnu \
          -mstack-protector-guard=tls \
          -mstack-protector-guard-reg=r13 \
          -c -o /dev/null -x c /dev/null
  clang: error: '-mstack-protector-guard=tls' is used without '-mstack-protector-guard-offset', and there is no default

This argument will always be provided by the build system, so mirror
other architectures and use '-mstack-protector-guard-offset=0' for
testing support, which fixes the issue for clang and does not regress
support with GCC.

Even with the first problem addressed, the 32-bit test continues to fail
because Kbuild uses the powerpc64le-linux-gnu target for clang and
nothing flips the target to 32-bit, resulting in an error about an
invalid register valid:

  $ clang --target=powerpc64le-linux-gnu \
          -mstack-protector-guard=tls
          -mstack-protector-guard-reg=r2 \
          -mstack-protector-guard-offset=0 \
          -x c -c -o /dev/null /dev/null
  clang: error: invalid value 'r2' in 'mstack-protector-guard-reg=', expected one of: r13

While GCC allows arbitrary registers, the implementation of
'-mstack-protector-guard=tls' in LLVM shares the same code path as the
user space thread local storage implementation, which uses a fixed
register (2 for 32-bit and 13 for 62-bit), so the command line parsing
enforces this limitation.

Use the Kconfig macro '$(m32-flag)', which expands to '-m32' when
supported, in the stack protector support cc-option call to properly
switch the target to a 32-bit one, which matches what happens in Kbuild.
While the 64-bit macro does not strictly need it, add the equivalent
64-bit option for symmetry.

Cc: stable@vger.kernel.org # 6.1+
Link: https://github.com/llvm/llvm-project/pull/110928 [1]
Reviewed-by: Keith Packard &lt;keithp@keithp.com&gt;
Tested-by: Keith Packard &lt;keithp@keithp.com&gt;
Signed-off-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://patch.msgid.link/20241009-powerpc-fix-stackprotector-test-clang-v2-1-12fb86b31857@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>powerpc/vdso: Drop -mstack-protector-guard flags in 32-bit files with clang</title>
<updated>2024-12-09T09:41:02Z</updated>
<author>
<name>Nathan Chancellor</name>
<email>nathan@kernel.org</email>
</author>
<published>2024-10-30T18:41:37Z</published>
<link rel='alternate' type='text/html' href='http://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=d63516b1e0d34e1ceed5f146d3043b54c82c6ab2'/>
<id>urn:sha1:d63516b1e0d34e1ceed5f146d3043b54c82c6ab2</id>
<content type='text'>
commit d677ce521334d8f1f327cafc8b1b7854b0833158 upstream.

Under certain conditions, the 64-bit '-mstack-protector-guard' flags may
end up in the 32-bit vDSO flags, resulting in build failures due to the
structure of clang's argument parsing of the stack protector options,
which validates the arguments of the stack protector guard flags
unconditionally in the frontend, choking on the 64-bit values when
targeting 32-bit:

  clang: error: invalid value 'r13' in 'mstack-protector-guard-reg=', expected one of: r2
  clang: error: invalid value 'r13' in 'mstack-protector-guard-reg=', expected one of: r2
  make[3]: *** [arch/powerpc/kernel/vdso/Makefile:85: arch/powerpc/kernel/vdso/vgettimeofday-32.o] Error 1
  make[3]: *** [arch/powerpc/kernel/vdso/Makefile:87: arch/powerpc/kernel/vdso/vgetrandom-32.o] Error 1

Remove these flags by adding them to the CC32FLAGSREMOVE variable, which
already handles situations similar to this. Additionally, reformat and
align a comment better for the expanding CONFIG_CC_IS_CLANG block.

Cc: stable@vger.kernel.org # v6.1+
Signed-off-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://patch.msgid.link/20241030-powerpc-vdso-drop-stackp-flags-clang-v1-1-d95e7376d29c@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>powerpc/pseries: Fix KVM guest detection for disabling hardlockup detector</title>
<updated>2024-12-05T13:02:43Z</updated>
<author>
<name>Gautam Menghani</name>
<email>gautam@linux.ibm.com</email>
</author>
<published>2024-11-08T09:48:37Z</published>
<link rel='alternate' type='text/html' href='http://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=58d6473042e8ef117ad0d339bd782ed6854d3bf1'/>
<id>urn:sha1:58d6473042e8ef117ad0d339bd782ed6854d3bf1</id>
<content type='text'>
commit 44e5d21e6d3fd2a1fed7f0327cf72e99397e2eaf upstream.

As per the kernel documentation[1], hardlockup detector should
be disabled in KVM guests as it may give false positives. On
PPC, hardlockup detector is enabled inside KVM guests because
disable_hardlockup_detector() is marked as early_initcall and it
relies on kvm_guest static key (is_kvm_guest()) which is initialized
later during boot by check_kvm_guest(), which is a core_initcall.
check_kvm_guest() is also called in pSeries_smp_probe(), which is called
before initcalls, but it is skipped if KVM guest does not have doorbell
support or if the guest is launched with SMT=1.

Call check_kvm_guest() in disable_hardlockup_detector() so that
is_kvm_guest() check goes through fine and hardlockup detector can be
disabled inside the KVM guest.

[1]: Documentation/admin-guide/sysctl/kernel.rst

Fixes: 633c8e9800f3 ("powerpc/pseries: Enable hardlockup watchdog for PowerVM partitions")
Cc: stable@vger.kernel.org # v5.14+
Signed-off-by: Gautam Menghani &lt;gautam@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://patch.msgid.link/20241108094839.33084-1-gautam@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>powerpc/kexec: Fix return of uninitialized variable</title>
<updated>2024-12-05T13:02:14Z</updated>
<author>
<name>Zhang Zekun</name>
<email>zhangzekun11@huawei.com</email>
</author>
<published>2024-09-30T07:56:28Z</published>
<link rel='alternate' type='text/html' href='http://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=55fdcd1f4aaafd8a0eed7256093306f50235075c'/>
<id>urn:sha1:55fdcd1f4aaafd8a0eed7256093306f50235075c</id>
<content type='text'>
[ Upstream commit 83b5a407fbb73e6965adfb4bd0a803724bf87f96 ]

of_property_read_u64() can fail and leave the variable uninitialized,
which will then be used. Return error if reading the property failed.

Fixes: 2e6bd221d96f ("powerpc/kexec_file: Enable early kernel OPAL calls")
Signed-off-by: Zhang Zekun &lt;zhangzekun11@huawei.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://patch.msgid.link/20240930075628.125138-1-zhangzekun11@huawei.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>KVM: PPC: Book3S HV: Fix kmv -&gt; kvm typo</title>
<updated>2024-12-05T13:02:14Z</updated>
<author>
<name>Kajol Jain</name>
<email>kjain@linux.ibm.com</email>
</author>
<published>2024-11-14T08:50:20Z</published>
<link rel='alternate' type='text/html' href='http://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=ac8f0486370400f090b993c5ba83b3f603634345'/>
<id>urn:sha1:ac8f0486370400f090b993c5ba83b3f603634345</id>
<content type='text'>
[ Upstream commit 590d2f9347f7974d7954400e5d937672fd844a8b ]

Fix typo in the following kvm function names from:

 kmvhv_counters_tracepoint_regfunc -&gt; kvmhv_counters_tracepoint_regfunc
 kmvhv_counters_tracepoint_unregfunc -&gt; kvmhv_counters_tracepoint_unregfunc

Fixes: e1f288d2f9c6 ("KVM: PPC: Book3S HV nestedv2: Add support for reading VPA counters for pseries guests")
Reported-by: Madhavan Srinivasan &lt;maddy@linux.ibm.com&gt;
Reviewed-by: Ritesh Harjani (IBM) &lt;ritesh.list@gmail.com&gt;
Reviewed-by: Amit Machhiwal &lt;amachhiw@linux.ibm.com&gt;
Signed-off-by: Kajol Jain &lt;kjain@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://patch.msgid.link/20241114085020.1147912-1-kjain@linux.ibm.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>powerpc/sstep: make emulate_vsx_load and emulate_vsx_store static</title>
<updated>2024-12-05T13:02:14Z</updated>
<author>
<name>Michal Suchanek</name>
<email>msuchanek@suse.de</email>
</author>
<published>2024-10-01T13:03:49Z</published>
<link rel='alternate' type='text/html' href='http://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=607324864d903a28a09659d27d7fae3ace7a4e05'/>
<id>urn:sha1:607324864d903a28a09659d27d7fae3ace7a4e05</id>
<content type='text'>
[ Upstream commit a26c4dbb3d9c1821cb0fc11cb2dbc32d5bf3463b ]

These functions are not used outside of sstep.c

Fixes: 350779a29f11 ("powerpc: Handle most loads and stores in instruction emulation code")
Signed-off-by: Michal Suchanek &lt;msuchanek@suse.de&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://patch.msgid.link/20241001130356.14664-1-msuchanek@suse.de
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>KVM: PPC: Book3S HV: Avoid returning to nested hypervisor on pending doorbells</title>
<updated>2024-12-05T13:02:13Z</updated>
<author>
<name>Gautam Menghani</name>
<email>gautam@linux.ibm.com</email>
</author>
<published>2024-11-09T06:32:57Z</published>
<link rel='alternate' type='text/html' href='http://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=5c1adda2d5e97acf1896f5c5dab8164958cd99ad'/>
<id>urn:sha1:5c1adda2d5e97acf1896f5c5dab8164958cd99ad</id>
<content type='text'>
[ Upstream commit 26686db69917399fa30e3b3135360771e90f83ec ]

Commit 6398326b9ba1 ("KVM: PPC: Book3S HV P9: Stop using vc-&gt;dpdes")
dropped the use of vcore-&gt;dpdes for msgsndp / SMT emulation. Prior to that
commit, the below code at L1 level (see [1] for terminology) was
responsible for setting vc-&gt;dpdes for the respective L2 vCPU:

if (!nested) {
	kvmppc_core_prepare_to_enter(vcpu);
	if (vcpu-&gt;arch.doorbell_request) {
		vc-&gt;dpdes = 1;
		smp_wmb();
		vcpu-&gt;arch.doorbell_request = 0;
	}

L1 then sent vc-&gt;dpdes to L0 via kvmhv_save_hv_regs(), and while
servicing H_ENTER_NESTED at L0, the below condition at L0 level made sure
to abort and go back to L1 if vcpu-&gt;arch.doorbell_request = 1 so that L1
sets vc-&gt;dpdes as per above if condition:

} else if (vcpu-&gt;arch.pending_exceptions ||
	   vcpu-&gt;arch.doorbell_request ||
	   xive_interrupt_pending(vcpu)) {
	vcpu-&gt;arch.ret = RESUME_HOST;
	goto out;
}

This worked fine since vcpu-&gt;arch.doorbell_request was used more like a
flag and vc-&gt;dpdes was used to pass around the doorbell state. But after
Commit 6398326b9ba1 ("KVM: PPC: Book3S HV P9: Stop using vc-&gt;dpdes"),
vcpu-&gt;arch.doorbell_request is the only variable used to pass around
doorbell state.
With the plumbing for handling doorbells for nested guests updated to use
vcpu-&gt;arch.doorbell_request over vc-&gt;dpdes, the above "else if" stops
doorbells from working correctly as L0 aborts execution of L2 and
instead goes back to L1.

Remove vcpu-&gt;arch.doorbell_request from the above "else if" condition as
it is no longer needed for L0 to correctly handle the doorbell status
while running L2.

[1] Terminology
1. L0 : PowerNV linux running with HV privileges
2. L1 : Pseries KVM guest running on top of L0
2. L2 : Nested KVM guest running on top of L1

Fixes: 6398326b9ba1 ("KVM: PPC: Book3S HV P9: Stop using vc-&gt;dpdes")
Signed-off-by: Gautam Menghani &lt;gautam@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://patch.msgid.link/20241109063301.105289-4-gautam@linux.ibm.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
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