[ Upstream commit ffa0b64e3be58519ae472ea29a1a1ad681e32f48 ]
mpe: On 64-bit Book3E vmalloc space starts at 0x8000000000000000.
Because of the way __pa() works we have:
__pa(0x8000000000000000) == 0, and therefore
virt_to_pfn(0x8000000000000000) == 0, and therefore
virt_addr_valid(0x8000000000000000) == true
Which is wrong, virt_addr_valid() should be false for vmalloc space.
In fact all vmalloc addresses that alias with a valid PFN will return
true from virt_addr_valid(). That can cause bugs with hardened usercopy
as described below by Kefeng Wang:
When running ethtool eth0 on 64-bit Book3E, a BUG occurred:
usercopy: Kernel memory exposure attempt detected from SLUB object not in SLUB page?! (offset 0, size 1048)!
kernel BUG at mm/usercopy.c:99
...
usercopy_abort+0x64/0xa0 (unreliable)
__check_heap_object+0x168/0x190
__check_object_size+0x1a0/0x200
dev_ethtool+0x2494/0x2b20
dev_ioctl+0x5d0/0x770
sock_do_ioctl+0xf0/0x1d0
sock_ioctl+0x3ec/0x5a0
__se_sys_ioctl+0xf0/0x160
system_call_exception+0xfc/0x1f0
system_call_common+0xf8/0x200
The code shows below,
data = vzalloc(array_size(gstrings.len, ETH_GSTRING_LEN));
copy_to_user(useraddr, data, gstrings.len * ETH_GSTRING_LEN))
The data is alloced by vmalloc(), virt_addr_valid(ptr) will return true
on 64-bit Book3E, which leads to the panic.
As commit 4dd7554a64 ("powerpc/64: Add VIRTUAL_BUG_ON checks for __va
and __pa addresses") does, make sure the virt addr above PAGE_OFFSET in
the virt_addr_valid() for 64-bit, also add upper limit check to make
sure the virt is below high_memory.
Meanwhile, for 32-bit PAGE_OFFSET is the virtual address of the start
of lowmem, high_memory is the upper low virtual address, the check is
suitable for 32-bit, this will fix the issue mentioned in commit
602946ec2f90 ("powerpc: Set max_mapnr correctly") too.
On 32-bit there is a similar problem with high memory, that was fixed in
commit 602946ec2f90 ("powerpc: Set max_mapnr correctly"), but that
commit breaks highmem and needs to be reverted.
We can't easily fix __pa(), we have code that relies on its current
behaviour. So for now add extra checks to virt_addr_valid().
For 64-bit Book3S the extra checks are not necessary, the combination of
virt_to_pfn() and pfn_valid() should yield the correct result, but they
are harmless.
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Add additional change log detail]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220406145802.538416-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7c5ed82b800d8615cdda00729e7b62e5899f0b13 ]
On large config LPARs (having 192 and more cores), Linux fails to boot
due to insufficient memory in the first memblock. It is due to the
memory reservation for the crash kernel which starts at 128MB offset of
the first memblock. This memory reservation for the crash kernel doesn't
leave enough space in the first memblock to accommodate other essential
system resources.
The crash kernel start address was set to 128MB offset by default to
ensure that the crash kernel get some memory below the RMA region which
is used to be of size 256MB. But given that the RMA region size can be
512MB or more, setting the crash kernel offset to mid of RMA size will
leave enough space for the kernel to allocate memory for other system
resources.
Since the above crash kernel offset change is only applicable to the LPAR
platform, the LPAR feature detection is pushed before the crash kernel
reservation. The rest of LPAR specific initialization will still
be done during pseries_probe_fw_features as usual.
This patch is dependent on changes to paca allocation for boot CPU. It
expect boot CPU to discover 1T segment support which is introduced by
the patch posted here:
https://lists.ozlabs.org/pipermail/linuxppc-dev/2022-January/239175.html
Reported-by: Abdul haleem <abdhalee@linux.vnet.ibm.com>
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220204085601.107257-1-sourabhjain@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 17846485dff91acce1ad47b508b633dffc32e838 ]
T1040RDB has two RTL8211E-VB phys which requires setting
of internal delays for correct work.
Changing the phy-connection-type property to `rgmii-id`
will fix this issue.
Signed-off-by: Maxim Kiselev <bigunclemax@gmail.com>
Reviewed-by: Maxim Kochetkov <fido_max@inbox.ru>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211230151123.1258321-1-bigunclemax@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 8667d0d64dd1f84fd41b5897fd87fa9113ae05e3 upstream.
Building tinyconfig with gcc (Debian 11.2.0-16) and assembler (Debian
2.37.90.20220207) the following build error shows up:
{standard input}: Assembler messages:
{standard input}:1190: Error: unrecognized opcode: `stbcix'
{standard input}:1433: Error: unrecognized opcode: `lwzcix'
{standard input}:1453: Error: unrecognized opcode: `stbcix'
{standard input}:1460: Error: unrecognized opcode: `stwcix'
{standard input}:1596: Error: unrecognized opcode: `stbcix'
...
Rework to add assembler directives [1] around the instruction. Going
through them one by one shows that the changes should be safe. Like
__get_user_atomic_128_aligned() is only called in p9_hmi_special_emu(),
which according to the name is specific to power9. And __raw_rm_read*()
are only called in things that are powernv or book3s_hv specific.
[1] https://sourceware.org/binutils/docs/as/PowerPC_002dPseudo.html#PowerPC_002dPseudo
Cc: stable@vger.kernel.org
Co-developed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
[mpe: Make commit subject more descriptive]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220224162215.3406642-2-anders.roxell@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8219d31effa7be5dbc7ff915d7970672e028c701 upstream.
Building tinyconfig with gcc (Debian 11.2.0-16) and assembler (Debian
2.37.90.20220207) the following build error shows up:
{standard input}: Assembler messages:
{standard input}:10576: Error: unrecognized opcode: `stbcx.'
{standard input}:10680: Error: unrecognized opcode: `lharx'
{standard input}:10694: Error: unrecognized opcode: `lbarx'
Rework to add assembler directives [1] around the instruction. The
problem with this might be that we can trick a power6 into
single-stepping through an stbcx. for instance, and it will execute that
in kernel mode.
[1] https://sourceware.org/binutils/docs/as/PowerPC_002dPseudo.html#PowerPC_002dPseudo
Fixes: 350779a29f ("powerpc: Handle most loads and stores in instruction emulation code")
Cc: stable@vger.kernel.org # v4.14+
Co-developed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220224162215.3406642-3-anders.roxell@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a633cb1edddaa643fadc70abc88f89a408fa834a upstream.
Looks like there been a copy paste mistake when added the instruction
'stbcx' twice and one was probably meant to be 'sthcx'. Changing to
'sthcx' from 'stbcx'.
Fixes: 350779a29f ("powerpc: Handle most loads and stores in instruction emulation code")
Cc: stable@vger.kernel.org # v4.14+
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220224162215.3406642-1-anders.roxell@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 3fd46e551f67f4303c3276a0d6cd20baf2d192c4 ]
mpc8xx_pic_init() should return -ENOMEM instead of 0 when
irq_domain_add_linear() return NULL. This cause mpc8xx_pics_init to continue
executing even if mpc8xx_pic_host is NULL.
Fixes: cc76404fea ("powerpc/8xx: Fix possible device node reference leak")
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220223070223.26845-1-hbh25y@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit fa1321b11bd01752f5be2415e74a0e1a7c378262 ]
'gtm' will *always* be set by list_for_each_entry().
It is incorrect to assume that the iterator value will be NULL if the
list is empty.
Instead of checking the pointer it should be checked if
the list is empty.
Fixes: 83ff9dcf37 ("powerpc/sysdev: implement FSL GTM support")
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220228142434.576226-1-jakobkoschel@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2863dd2db23e0407f6c50b8ba5c0e55abef894f1 ]
When CONFIG_GENERIC_CPU=y (true for all our defconfigs) we pass
-mcpu=powerpc64 to the compiler, even when we're building a 32-bit
kernel.
This happens because we have an ifdef CONFIG_PPC_BOOK3S_64/else block in
the Makefile that was written before 32-bit supported GENERIC_CPU. Prior
to that the else block only applied to 64-bit Book3E.
The GCC man page says -mcpu=powerpc64 "[specifies] a pure ... 64-bit big
endian PowerPC ... architecture machine [type], with an appropriate,
generic processor model assumed for scheduling purposes."
It's unclear how that interacts with -m32, which we are also passing,
although obviously -m32 is taking precedence in some sense, as the
32-bit kernel only contains 32-bit instructions.
This was noticed by inspection, not via any bug reports, but it does
affect code generation. Comparing before/after code generation, there
are some changes to instruction scheduling, and the after case (with
-mcpu=powerpc64 removed) the compiler seems more keen to use r8.
Fix it by making the else case only apply to Book3E 64, which excludes
32-bit.
Fixes: 0e00a8c9fd ("powerpc: Allow CPU selection also on PPC32")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220215112858.304779-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0198322379c25215b2778482bf1221743a76e2b5 ]
Trace IMC (In-Memory collection counters) in powerpc is useful for
application level profiling.
For trace_imc, presently task context (task_ctx_nr) is set to
perf_hw_context. But perf_hw_context should only be used for CPU PMU.
See commit 2665784850 ("perf/core: Verify we have a single
perf_hw_context PMU").
So for trace_imc, even though it is per thread PMU, it is preferred to
use sw_context in order to be able to do application level monitoring.
Hence change the task_ctx_nr to use perf_sw_context.
Fixes: 012ae24484 ("powerpc/perf: Trace imc PMU functions")
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
[mpe: Update subject & incorporate notes into change log, reflow comment]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220202041837.65968-1-atrajeev@linux.vnet.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b99234b918c6e36b9aa0a5b2981e86b6bd11f8e2 ]
The MMIO emulation code for vector instructions is duplicated between
VSX and VMX. When emulating VMX we should check the VMX copy size
instead of the VSX one.
Fixes: acc9eb9305 ("KVM: PPC: Reimplement LOAD_VMX/STORE_VMX instruction ...")
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220125215655.1026224-3-farosas@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit fe663df7825811358531dc2e8a52d9eaa5e3515e upstream.
Building tinyconfig with gcc (Debian 11.2.0-16) and assembler (Debian
2.37.90.20220207) the following build error shows up:
{standard input}: Assembler messages:
{standard input}:2088: Error: unrecognized opcode: `ptesync'
make[3]: *** [/builds/linux/scripts/Makefile.build:287: arch/powerpc/lib/sstep.o] Error 1
Add the 'ifdef CONFIG_PPC64' around the 'ptesync' in function
'emulate_update_regs()' to like it is in 'analyse_instr()'. Since it looks like
it got dropped inadvertently by commit 3cdfcbfd32 ("powerpc: Change
analyse_instr so it doesn't modify *regs").
A key detail is that analyse_instr() will never recognise lwsync or
ptesync on 32-bit (because of the existing ifdef), and as a result
emulate_update_regs() should never be called with an op specifying
either of those on 32-bit. So removing them from emulate_update_regs()
should be a nop in terms of runtime behaviour.
Fixes: 3cdfcbfd32 ("powerpc: Change analyse_instr so it doesn't modify *regs")
Cc: stable@vger.kernel.org # v4.14+
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
[mpe: Add last paragraph of change log mentioning analyse_instr() details]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220211005113.1361436-1-anders.roxell@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bba496656a73fc1d1330b49c7f82843836e9feb1 upstream.
Boot fails with GCC latent entropy plugin enabled.
This is due to early boot functions trying to access 'latent_entropy'
global data while the kernel is not relocated at its final
destination yet.
As there is no way to tell GCC to use PTRRELOC() to access it,
disable latent entropy plugin in early_32.o and feature-fixups.o and
code-patching.o
Fixes: 38addce8b6 ("gcc-plugins: Add latent_entropy plugin")
Cc: stable@vger.kernel.org # v4.9+
Reported-by: Erhard Furtner <erhard_f@mailbox.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215217
Link: https://lore.kernel.org/r/2bac55483b8daf5b1caa163a45fa5f9cdbe18be4.1640178426.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0d375d610fa96524e2ee2b46830a46a7bfa92a9f upstream.
This block is used in (at least) T1024 and T1040, including their
variants like T1023 etc.
Fixes: d55ad2967d ("powerpc/mpc85xx: Create dts components for the FSL QorIQ DPAA FMan")
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e89257e28e844f5d1d39081bb901d9f1183a7705 upstream.
Clang warns:
arch/powerpc/platforms/cell/pervasive.c:81:2: error: unannotated fall-through between switch labels
case SRR1_WAKEEE:
^
arch/powerpc/platforms/cell/pervasive.c:81:2: note: insert 'break;' to avoid fall-through
case SRR1_WAKEEE:
^
break;
1 error generated.
Clang is more pedantic than GCC, which does not warn when failing
through to a case that is just break or return. Clang's version is more
in line with the kernel's own stance in deprecated.rst. Add athe missing
break to silence the warning.
Fixes: 6e83985b0f ("powerpc/cbe: Do not process external or decremeter interrupts from sreset")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211207110228.698956-1-anders.roxell@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 219572d2fc4135b5ce65c735d881787d48b10e71 ]
Kdump can be triggered after panic_notifers since commit f06e5153f4
("kernel/panic.c: add "crash_kexec_post_notifiers" option for kdump
after panic_notifers") introduced crash_kexec_post_notifiers option.
But using this option would mean smp_send_stop(), that marks all other
CPUs as offline, gets called before kdump is triggered. As a result,
kdump routines fail to save other CPUs' registers. To fix this, kdump
friendly crash_smp_send_stop() function was introduced with kernel
commit 0ee59413c9 ("x86/panic: replace smp_send_stop() with kdump
friendly version in panic path"). Override this kdump friendly weak
function to handle crash_kexec_post_notifiers option appropriately
on powerpc.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
[Fixed signature of crash_stop_this_cpu() - reported by lkp@intel.com]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211207103719.91117-1-hbathini@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 792020907b11c6f9246c21977cab3bad985ae4b6 ]
H_COPY_TOFROM_GUEST is an hcall for an upper level VM to access its nested
VMs memory. The userspace can trigger WARN_ON_ONCE(!(gfp & __GFP_NOWARN))
in __alloc_pages() by constructing a tiny VM which only does
H_COPY_TOFROM_GUEST with a too big GPR9 (number of bytes to copy).
This silences the warning by adding __GFP_NOWARN.
Spotted by syzkaller.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210901084550.1658699-1-aik@ozlabs.ru
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a4ac0d249a5db80e79d573db9e4ad29354b643a8 ]
setup_profiling_timer() is only needed when CONFIG_PROFILING is enabled.
Fixes the following W=1 warning when CONFIG_PROFILING=n:
linux/arch/powerpc/kernel/smp.c:1638:5: error: no previous prototype for ‘setup_profiling_timer’
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211124093254.1054750-5-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5dad4ba68a2483fc80d70b9dc90bbe16e1f27263 ]
It is possible for all CPUs to miss the pending cpumask becoming clear,
and then nobody resetting it, which will cause the lockup detector to
stop working. It will eventually expire, but watchdog_smp_panic will
avoid doing anything if the pending mask is clear and it will never be
reset.
Order the cpumask clear vs the subsequent test to close this race.
Add an extra check for an empty pending mask when the watchdog fires and
finds its bit still clear, to try to catch any other possible races or
bugs here and keep the watchdog working. The extra test in
arch_touch_nmi_watchdog is required to prevent the new warning from
firing off.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Debugged-by: Laurent Dufour <ldufour@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211110025056.2084347-2-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a1d2b210ffa52d60acabbf7b6af3ef7e1e69cda0 ]
for_each_node_by_type performs an of_node_get on each iteration, so
a break out of the loop requires an of_node_put.
A simplified version of the semantic patch that fixes this problem is as
follows (http://coccinelle.lip6.fr):
// <smpl>
@@
local idexpression n;
expression e;
@@
for_each_node_by_type(n,...) {
...
(
of_node_put(n);
|
e = n
|
+ of_node_put(n);
? break;
)
...
}
... when != n
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1448051604-25256-6-git-send-email-Julia.Lawall@lip6.fr
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a841fd009e51c8c0a8f07c942e9ab6bb48da8858 ]
for_each_node_by_name performs an of_node_get on each iteration, so
a break out of the loop requires an of_node_put.
A simplified version of the semantic patch that fixes this problem is as
follows (http://coccinelle.lip6.fr):
// <smpl>
@@
expression e,e1;
local idexpression n;
@@
for_each_node_by_name(n, e1) {
... when != of_node_put(n)
when != e = n
(
return n;
|
+ of_node_put(n);
? return ...;
)
...
}
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1448051604-25256-7-git-send-email-Julia.Lawall@lip6.fr
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7d405a939ca960162eb30c1475759cb2fdf38f8c ]
for_each_compatible_node performs an of_node_get on each iteration, so
a break out of the loop requires an of_node_put.
A simplified version of the semantic patch that fixes this problem is as
follows (http://coccinelle.lip6.fr):
// <smpl>
@@
local idexpression n;
expression e;
@@
for_each_compatible_node(n,...) {
...
(
of_node_put(n);
|
e = n
|
+ of_node_put(n);
? break;
)
...
}
... when != n
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1448051604-25256-4-git-send-email-Julia.Lawall@lip6.fr
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f6e82647ff71d427d4148964b71f239fba9d7937 ]
for_each_compatible_node performs an of_node_get on each iteration, so
a break out of the loop requires an of_node_put.
A simplified version of the semantic patch that fixes this problem is as
follows (http://coccinelle.lip6.fr):
// <smpl>
@@
expression e;
local idexpression n;
@@
@@
local idexpression n;
expression e;
@@
for_each_compatible_node(n,...) {
...
(
of_node_put(n);
|
e = n
|
+ of_node_put(n);
? break;
)
...
}
... when != n
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1448051604-25256-2-git-send-email-Julia.Lawall@lip6.fr
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b149d5d45ac9171ed699a256f026c8ebef901112 ]
Commit df1f679d19ed ("powerpc/powermac: Add missing
lockdep_register_key()") fixed a problem that was causing a WARNING.
There are two other places in the same file with the same problem
originating from commit 9e607f7274 ("i2c_powermac: shut up lockdep
warning").
Add missing lockdep_register_key()
Fixes: 9e607f7274 ("i2c_powermac: shut up lockdep warning")
Reported-by: Erhard Furtner <erhard_f@mailbox.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Depends-on: df1f679d19ed ("powerpc/powermac: Add missing lockdep_register_key()")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=200055
Link: https://lore.kernel.org/r/2c7e421874e21b2fb87813d768cf662f630c2ad4.1638984999.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 869fb7e5aecbc163003f93f36dcc26d0554319f6 ]
prom_getprop() can return PROM_ERROR. Binary operator can not identify
it.
Fixes: 94d2dde738 ("[POWERPC] Efika: prune fixups and make them more carefull")
Signed-off-by: Peiwei Hu <jlu.hpw@foxmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/tencent_BA28CC6897B7C95A92EB8C580B5D18589105@qq.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit cf0b0e3712f7af90006f8317ff27278094c2c128 upstream.
The POWER9 ERAT flush instruction is a SLBIA with IH=7, which is a
reserved value on POWER7/8. On POWER8 this invalidates the SLB entries
above index 0, similarly to SLBIA IH=0.
If the SLB entries are invalidated, and then the guest is bypassed, the
host SLB does not get re-loaded, so the bolted entries above 0 will be
lost. This can result in kernel stack access causing a SLB fault.
Kernel stack access causing a SLB fault was responsible for the infamous
mega bug (search "Fix SLB reload bug"). Although since commit
48e7b76957 ("powerpc/64s/hash: Convert SLB miss handlers to C") that
starts using the kernel stack in the SLB miss handler, it might only
result in an infinite loop of SLB faults. In any case it's a bug.
Fix this by only executing the instruction on >= POWER9 where IH=7 is
defined not to invalidate the SLB. POWER7/8 don't require this ERAT
flush.
Fixes: 5008711259 ("KVM: PPC: Book3S HV: Invalidate ERAT when flushing guest TLB entries")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211119031627.577853-1-npiggin@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit dae581864609d36fb58855fd59880b4941ce9d14 ]
kvmppc_h_set_dabr(), and kvmppc_h_set_xdabr() which jumps into
it, need to use _GLOBAL_TOC to setup the kernel TOC pointer, because
kvmppc_h_set_dabr() uses LOAD_REG_ADDR() to load dawr_force_enable.
When called from hcall_try_real_mode() we have the kernel TOC in r2,
established near the start of kvmppc_interrupt_hv(), so there is no
issue.
But they can also be called from kvmppc_pseries_do_hcall() which is
module code, so the access ends up happening with the kvm-hv module's
r2, which will not point at dawr_force_enable and could even cause a
fault.
With the current code layout and compilers we haven't observed a fault
in practice, the load hits somewhere in kvm-hv.ko and silently returns
some bogus value.
Note that we we expect p8/p9 guests to use the DAWR, but SLOF uses
h_set_dabr() to test if sc1 works correctly, see SLOF's
lib/libhvcall/brokensc1.c.
Fixes: c1fe190c06 ("powerpc: Add force enable of DAWR on P9 option")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Link: https://lore.kernel.org/r/20210923151031.72408-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit fef071be57dc43679a32d5b0e6ee176d6f12e9f2 ]
In dcr-low.S we use cmpli with three arguments, instead of four
arguments as defined in the ISA:
cmpli cr0,r3,1024
This appears to be a PPC440-ism, looking at the "PPC440x5 CPU Core
User’s Manual" it shows cmpli having no L field, but implied to be 0 due
to the core being 32-bit. It mentions that the ISA defines four
arguments and recommends using cmplwi.
It also corresponds to the old POWER instruction set, which had no L
field there, a reserved bit instead.
dcr-low.S is only built 32-bit, because it is only built when
DCR_NATIVE=y, which is only selected by 40x and 44x. Looking at the
generated code (with gcc/gas) we see cmplwi as expected.
Although gas is happy with the 3-argument version when building for
32-bit, the LLVM assembler is not and errors out with:
arch/powerpc/sysdev/dcr-low.S:27:10: error: invalid operand for instruction
cmpli 0,%r3,1024; ...
^
Switch to the cmplwi extended opcode, which avoids any confusion when
reading the ISA, fixes the issue with the LLVM assembler, and also means
the code could be built 64-bit in future (though that's very unlikely).
Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
BugLink: https://github.com/ClangBuiltLinux/linux/issues/1419
Link: https://lore.kernel.org/r/20211014024424.528848-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit aed2886a5e9ffc8269a4220bff1e9e030d3d2eb1 ]
Fixes build warnings:
Warning (unit_address_vs_reg): /memory: node has a reg or ranges property, but no unit name
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211013220532.24759-4-agust@denx.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
upstream commit b7540d62509453263604a155bf2d5f0ed450cba2
Emit similar instruction sequences to commit a048a07d7f
("powerpc/64s: Add support for a store forwarding barrier at kernel
entry/exit") when encountering BPF_NOSPEC.
Mitigations are enabled depending on what the firmware advertises. In
particular, we do not gate these mitigations based on current settings,
just like in x86. Due to this, we don't need to take any action if
mitigations are enabled or disabled at runtime.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/956570cbc191cd41f8274bed48ee757a86dac62a.1633464148.git.naveen.n.rao@linux.vnet.ibm.com
[adjust macros to account for commits 0654186510, 3a18123791 and ef909ba954145e.
adjust security feature checks to account for commit 84ed26fd00c514]
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
upstream commit 030905920f32e91a52794937f67434ac0b3ea41a
Add a helper to return the stf_barrier type for the current processor.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/3bd5d7f96ea1547991ac2ce3137dc2b220bae285.1633464148.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
upstream commit 5855c4c1f415ca3ba1046e77c0b3d3dfc96c9025
We aren't handling subtraction involving an immediate value of
0x80000000 properly. Fix the same.
Fixes: 156d0e290e ("powerpc/ebpf/jit: Implement JIT compiler for extended BPF")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Fold in fix from Naveen to use imm <= 32768]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/fc4b1276eb10761fd7ce0814c8dd089da2815251.1633464148.git.naveen.n.rao@linux.vnet.ibm.com
[adjust macros to account for commits 0654186510 and 3a18123791]
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
upstream commit 3832ba4e283d7052b783dab8311df7e3590fed93
Add checks to ensure that we never emit branch instructions with
truncated branch offsets.
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Tested-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/71d33a6b7603ec1013c9734dd8bdd4ff5e929142.1633464148.git.naveen.n.rao@linux.vnet.ibm.com
[include header, drop ppc32 changes]
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
upstream commit 4549c3ea3160fa8b3f37dfe2f957657bb265eda9
Add a helper to check if a given offset is within the branch range for a
powerpc conditional branch instruction, and update some sites to use the
new helper.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/442b69a34ced32ca346a0d9a855f3f6cfdbbbd41.1633464148.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 290fe8aa69ef5c51c778c0bb33f8ef0181c769f5 ]
Early exits from for_each_compatible_node() should decrement the
node reference counter. Reported by Coccinelle:
./arch/powerpc/platforms/44x/fsp2.c:206:1-25: WARNING: Function
"for_each_compatible_node" should have of_node_put() before return
around line 218.
Fixes: 7813043e1b ("powerpc/44x/fsp2: Add irq error handlers")
Signed-off-by: Bixuan Cui <cuibixuan@linux.alibaba.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1635406102-88719-1-git-send-email-cuibixuan@linux.alibaba.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 3c2172c1c47b4079c29f0e6637d764a99355ebcd upstream.
When the field described in mpc85xx_smp_guts_ids[] is not configured in
dtb, the mpc85xx_setup_pmc() does not assign a value to the "guts"
variable. As a result, the oops is triggered when
mpc85xx_freeze_time_base() is executed.
Fixes: 56f1ba2807 ("powerpc/mpc85xx: refactor the PM operations")
Cc: stable@vger.kernel.org # v4.6+
Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210929033646.39630-2-nixiaoming@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8bbc9d822421d9ac8ff9ed26a3713c9afc69d6c8 upstream.
Only ignore the operation if dividing by 1.
Fixes: 156d0e290e ("powerpc/ebpf/jit: Implement JIT compiler for extended BPF")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Tested-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c674ca18c3046885602caebb326213731c675d06.1633464148.git.naveen.n.rao@linux.vnet.ibm.com
[cascardo: use PPC_LI instead of EMIT(PPC_RAW_LI)]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 496c5fe25c377ddb7815c4ce8ecfb676f051e9b6 upstream.
In isa206_idle_insn_mayloss() we store various registers into the stack
red zone, which is allowed.
However inside the IDLE_STATE_ENTER_SEQ_NORET macro we save r2 again,
to 0(r1), which corrupts the stack back chain.
We used to do the same in isa206_idle_insn_mayloss() itself, but we
fixed that in 73287caa9210 ("powerpc64/idle: Fix SP offsets when saving
GPRs"), however we missed that the macro also corrupts the back chain.
Corrupting the back chain is bad for debuggability but doesn't
necessarily cause a bug.
However we recently changed the stack handling in some KVM code, and it
now relies on the stack back chain being valid when it returns. The
corruption causes that code to return with r1 pointing somewhere in
kernel data, at some point LR is restored from the stack and we branch
to NULL or somewhere else invalid.
Only affects Power8 hosts running KVM guests, with dynamic_mt_modes
enabled (which it is by default).
The fixes tag below points to the commit that changed the KVM stack
handling, exposing this bug. The actual corruption of the back chain has
always existed since 948cf67c47 ("powerpc: Add NAP mode support on
Power7 in HV mode").
Fixes: 9b4416c5095c ("KVM: PPC: Book3S HV: Fix stack handling in idle_kvm_start_guest()")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211020094826.3222052-1-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit cdeb5d7d890e14f3b70e8087e745c4a6a7d9f337 upstream.
We call idle_kvm_start_guest() from power7_offline() if the thread has
been requested to enter KVM. We pass it the SRR1 value that was returned
from power7_idle_insn() which tells us what sort of wakeup we're
processing.
Depending on the SRR1 value we pass in, the KVM code might enter the
guest, or it might return to us to do some host action if the wakeup
requires it.
If idle_kvm_start_guest() is able to handle the wakeup, and enter the
guest it is supposed to indicate that by returning a zero SRR1 value to
us.
That was the behaviour prior to commit 10d91611f4 ("powerpc/64s:
Reimplement book3s idle code in C"), however in that commit the
handling of SRR1 was reworked, and the zeroing behaviour was lost.
Returning from idle_kvm_start_guest() without zeroing the SRR1 value can
confuse the host offline code, causing the guest to crash and other
weirdness.
Fixes: 10d91611f4 ("powerpc/64s: Reimplement book3s idle code in C")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211015133929.832061-2-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9b4416c5095c20e110c82ae602c254099b83b72f upstream.
In commit 10d91611f4 ("powerpc/64s: Reimplement book3s idle code in
C") kvm_start_guest() became idle_kvm_start_guest(). The old code
allocated a stack frame on the emergency stack, but didn't use the
frame to store anything, and also didn't store anything in its caller's
frame.
idle_kvm_start_guest() on the other hand is written more like a normal C
function, it creates a frame on entry, and also stores CR/LR into its
callers frame (per the ABI). The problem is that there is no caller
frame on the emergency stack.
The emergency stack for a given CPU is allocated with:
paca_ptrs[i]->emergency_sp = alloc_stack(limit, i) + THREAD_SIZE;
So emergency_sp actually points to the first address above the emergency
stack allocation for a given CPU, we must not store above it without
first decrementing it to create a frame. This is different to the
regular kernel stack, paca->kstack, which is initialised to point at an
initial frame that is ready to use.
idle_kvm_start_guest() stores the backchain, CR and LR all of which
write outside the allocation for the emergency stack. It then creates a
stack frame and saves the non-volatile registers. Unfortunately the
frame it creates is not large enough to fit the non-volatiles, and so
the saving of the non-volatile registers also writes outside the
emergency stack allocation.
The end result is that we corrupt whatever is at 0-24 bytes, and 112-248
bytes above the emergency stack allocation.
In practice this has gone unnoticed because the memory immediately above
the emergency stack happens to be used for other stack allocations,
either another CPUs mc_emergency_sp or an IRQ stack. See the order of
calls to irqstack_early_init() and emergency_stack_init().
The low addresses of another stack are the top of that stack, and so are
only used if that stack is under extreme pressue, which essentially
never happens in practice - and if it did there's a high likelyhood we'd
crash due to that stack overflowing.
Still, we shouldn't be corrupting someone else's stack, and it is purely
luck that we aren't corrupting something else.
To fix it we save CR/LR into the caller's frame using the existing r1 on
entry, we then create a SWITCH_FRAME_SIZE frame (which has space for
pt_regs) on the emergency stack with the backchain pointing to the
existing stack, and then finally we switch to the new frame on the
emergency stack.
Fixes: 10d91611f4 ("powerpc/64s: Reimplement book3s idle code in C")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211015133929.832061-1-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 73287caa9210ded6066833195f4335f7f688a46b upstream.
The idle entry/exit code saves/restores GPRs in the stack "red zone"
(Protected Zone according to PowerPC64 ELF ABI v2). However, the offset
used for the first GPR is incorrect and overwrites the back chain - the
Protected Zone actually starts below the current SP. In practice this is
probably not an issue, but it's still incorrect so fix it.
Also expand the comments to explain why using the stack "red zone"
instead of creating a new stackframe is appropriate here.
Signed-off-by: Christopher M. Riedl <cmr@codefail.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210206072342.5067-1-cmr@codefail.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6f779e1d359b8d5801f677c1d49dcfa10bf95674 upstream.
When an interrupt is passed through, the KVM XIVE device calls the
set_vcpu_affinity() handler which raises the P bit to mask the
interrupt and to catch any in-flight interrupts while routing the
interrupt to the guest.
On the guest side, drivers (like some Intels) can request at probe
time some MSIs and call synchronize_irq() to check that there are no
in flight interrupts. This will call the XIVE get_irqchip_state()
handler which will always return true as the interrupt P bit has been
set on the host side and lock the CPU in an infinite loop.
Fix that by discarding disabled interrupts in get_irqchip_state().
Fixes: da15c03b04 ("powerpc/xive: Implement get_irqchip_state method for XIVE to fix shutdown race")
Cc: stable@vger.kernel.org #v5.4+
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Tested-by: seeteena <s1seetee@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211011070203.99726-1-clg@kaod.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit eed183abc0d3b8adb64fd1363b7cea7986cd58d6 ]
Property phy-connection-type contains invalid value "sgmii-2500" per scheme
defined in file ethernet-controller.yaml.
Correct phy-connection-type value should be "2500base-x".
Signed-off-by: Pali Rohár <pali@kernel.org>
Fixes: 84e0f1c138 ("powerpc/mpc85xx: Add MDIO bus muxing support to the board device tree(s)")
Acked-by: Scott Wood <oss@buserror.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 267cdfa21385d78c794768233678756e32b39ead upstream.
POWER9 DD2.2 and 2.3 hardware implements a "fake-suspend" mode where
certain TM instructions executed in HV=0 mode cause softpatch interrupts
so the hypervisor can emulate them and prevent problematic processor
conditions. In this fake-suspend mode, the treclaim. instruction does
not modify registers.
Unfortunately the rfscv instruction executed by the guest do not
generate softpatch interrupts, which can cause the hypervisor to lose
track of the fake-suspend mode, and it can execute this treclaim. while
not in fake-suspend mode. This modifies GPRs and crashes the hypervisor.
It's not trivial to disable scv in the guest with HFSCR now, because
they assume a POWER9 has scv available. So this fix saves and restores
checkpointed registers across the treclaim.
Fixes: 7854f7545b ("KVM: PPC: Book3S: Rework TM save/restore code and make it C-callable")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210908101718.118522-2-npiggin@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 1d78dfde33a02da1d816279c2e3452978b7abd39 ]
Since commit e1a1ef84cd ("KVM: PPC: Book3S: Allocate guest TCEs on
demand too"), pages for TCE tables for KVM guests are allocated only
when needed. This allows skipping any update when clearing TCEs. This
works mostly fine as TCE updates are handled when the MMU is enabled.
The realmode handlers fail with H_TOO_HARD when pages are not yet
allocated, except when clearing a TCE in which case KVM prints a warning
and proceeds to dereference a NULL pointer, which crashes the host OS.
This has not been caught so far as the change in commit e1a1ef84cd is
reasonably new, and POWER9 runs mostly radix which does not use realmode
handlers. With hash, the default TCE table is memset() by QEMU when the
machine is reset which triggers page faults and the KVM TCE device's
kvm_spapr_tce_fault() handles those with MMU on. And the huge DMA
windows are not cleared by VMs which instead successfully create a DMA
window big enough to map the VM memory 1:1 and then VMs just map
everything without clearing.
This started crashing now as commit 381ceda88c4c ("powerpc/pseries/iommu:
Make use of DDW for indirect mapping") added a mode when a dymanic DMA
window not big enough to map the VM memory 1:1 but it is used anyway,
and the VM now is the first (i.e. not QEMU) to clear a just created
table. Note that upstream QEMU needs to be modified to trigger the VM to
trigger the host OS crash.
This replaces WARN_ON_ONCE_RM() with a check and return, and adds
another warning if TCE is not being cleared.
Fixes: e1a1ef84cd ("KVM: PPC: Book3S: Allocate guest TCEs on demand too")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210827040706.517652-1-aik@ozlabs.ru
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1782663897945a5cf28e564ba5eed730098e9aa4 ]
After the L1 saves its PMU SPRs but before loading the L2's PMU SPRs,
switch the pmcregs_in_use field in the L1 lppaca to the value advertised
by the L2 in its VPA. On the way out of the L2, set it back after saving
the L2 PMU registers (if they were in-use).
This transfers the PMU liveness indication between the L1 and L2 at the
points where the registers are not live.
This fixes the nested HV bug for which a workaround was added to the L0
HV by commit 63279eeb7f ("KVM: PPC: Book3S HV: Always save guest pmu
for guest capable of nesting"), which explains the problem in detail.
That workaround is no longer required for guests that include this bug
fix.
Fixes: 360cae3137 ("KVM: PPC: Book3S HV: Nested guest entry via hypercall")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Link: https://lore.kernel.org/r/20210811160134.904987-10-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
