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Commit bb1520d581a3 ("s390/mm: start kernel with DAT enabled") did not
implement direct map accounting in the early page table setup code. In
result the reported values are bogus now:
$cat /proc/meminfo
...
DirectMap4k: 5120 kB
DirectMap1M: 18446744073709546496 kB
DirectMap2G: 0 kB
Fix this by adding the missing accounting. The result looks sane again:
$cat /proc/meminfo
...
DirectMap4k: 6156 kB
DirectMap1M: 2091008 kB
DirectMap2G: 6291456 kB
Fixes: bb1520d581a3 ("s390/mm: start kernel with DAT enabled")
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Architectures generally use the "direct map" wording for mapping the whole
physical memory. Use that wording as well in arch/s390/boot/vmem.c, instead
of "one to one" in order to avoid confusion.
This also matches what is already done in arch/s390/mm/vmem.c.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Use proper quoting for the variables and explicitly distinguish between
command options and positional arguments.
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Simplify pr_err() statement into one line and omit return statement.
No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
When the KASLR is enabled, randomize the base address of the amode31 image
within the first 2 GB, similar to the approach taken for the vmlinux
image. This makes it harder to predict the location of amode31 data
and code.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Improve the distribution algorithm of random base address to ensure
a uniformity among all suitable addresses. To generate a random value
once, and to build a continuous range in which every value is suitable,
count all the suitable addresses (referred to as positions) that can be
used as a base address. The positions are counted by iterating over the
usable memory ranges. For each range that is big enough to accommodate
the image, count all the suitable addresses where the image can be placed,
while taking reserved memory ranges into consideration.
A new function "iterate_valid_positions()" has dual purpose. Firstly, it
is called to count the positions in a given memory range, and secondly,
to convert a random position back to an address.
"get_random_base()" has been replaced with more generic
"randomize_within_range()" which now could be called for randomizing
base addresses not just for the kernel image.
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The special amode31 part of the kernel must always remain below 2Gb. Place
it just under vmlinux.default_lma by default, which makes it easier to
debug amode31 as its default lma is known 0x10000 - 0x3000 (currently,
amode31's size is 3 pages). This location is always available as it is
originally occupied by the vmlinux archive.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The current modification of the default_lma is illogical and should be
avoided. It would be more appropriate to introduce and utilize a new
variable vmlinux_lma instead, so that default_lma remains unchanged and
at its original "default" value of 0x100000.
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Struct s390_ctrset_read userdata is filled by ioctl_read operation
using put_user/copy_to_user. However, the ctrset->data value access
is not performed anywhere during the ioctl_read operation.
Remove unnecessary copy_from_user() call.
No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Suggested-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
When function cfset_all_copy() fails, also log the bad return code
in the debug statement (when turned on).
No functional change
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
This is the s390 variant of commit 7dfac3c5f40e ("arm64: module: create
module allocations without exec permissions"):
"The core code manages the executable permissions of code regions of
modules explicitly. It is no longer necessary to create the module vmalloc
regions with RWX permissions. So create them with RW- permissions instead,
which is preferred from a security perspective."
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The ftrace code assumes at two places that module_alloc() returns
executable memory. While this is currently true, this will be changed
with a subsequent patch to follow other architectures which implement
ARCH_HAS_STRICT_MODULE_RWX.
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Given that set_memory_rox() and set_memory_rwnx() exist, it is possible
to get rid of all open coded __set_memory() usages and replace them with
proper helper calls everywhere.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Given that set_memory_rox() is implemented, provide also set_memory_rwnx().
This allows to get rid of all open coded __set_memory() usages in s390
architecture code.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Provide the s390 specific native set_memory_rox() implementation to avoid
frequent set_memory_ro(); set_memory_x() call pairs.
This is the s390 variant of commit 60463628c9e0 ("x86/mm: Implement native
set_memory_rox()").
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diag 308 subcodes expect a physical address as their parameter.
This currently is not a bug, but in the future physical and virtual
addresses might differ.
Fix the confusion by doing a virtual-to-physical conversion in the
exported diag308() and leave the assembly wrapper __diag308() alone.
Note that several callers pass NULL as addr, so check for the case when
NULL is passed and pass 0 to hardware since virt_to_phys(0) might be
nonzero.
Suggested-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Randomize the load address of modules in the kernel to make KASLR effective
for modules.
This is the s390 variant of commit e2b32e678513 ("x86, kaslr: randomize
module base load address").
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Just like other architectures provide a kaslr_enabled() function, instead
of directly accessing a global variable.
Also pass the renamed __kaslr_enabled variable from the decompressor to the
kernel, so that kalsr_enabled() is available there too. This will be used
by a subsequent patch which randomizes the module base load address.
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Commit dfe843dce775 ("s390/checksum: support GENERIC_CSUM, enable it for
KASAN") switched s390 to use the generic checksum functions, so that KASAN
instrumentation also works checksum functions by avoiding architecture
specific inline assemblies.
There is however the problem that the generic csum_partial() function
returns a 32 bit value with a 16 bit folded checksum, while the original
s390 variant does not fold to 16 bit. This in turn causes that the
ipib_checksum in lowcore contains different values depending on kernel
config options.
The ipib_checksum is used by system dumpers to verify if pointers in
lowcore point to valid data. Verification is done by comparing checksum
values. The system dumpers still use 32 bit checksum values which are not
folded, and therefore the checksum verification fails (incorrectly).
Symptom is that reboot after dump does not work anymore when a KASAN
instrumented kernel is dumped.
Fix this by not using the generic checksum implementation. Instead add an
explicit kasan_check_read() so that KASAN knows about the read access from
within the inline assembly.
Reported-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Fixes: dfe843dce775 ("s390/checksum: support GENERIC_CSUM, enable it for KASAN")
Tested-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Add the internal logic to check for autoquiesce triggers and handle
them.
Quiesce and resume are functions that tell Linux to stop/resume
issuing I/Os to a specific DASD.
The DASD driver allows a manual quiesce/resume via ioctl.
Autoquiesce will define an amount of triggers that will lead to
an automatic quiesce if a certain event occurs.
There is no automatic resume.
All events will be reported via DASD Extended Error Reporting (EER)
if configured.
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Link: https://lore.kernel.org/r/20230405142017.2446986-3-sth@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Attempt VMA lock-based page fault handling first, and fall back to the
existing mmap_lock-based handling if that fails.
This is the s390 variant of "x86/mm: try VMA lock-based page fault handling
first".
Link: https://lkml.kernel.org/r/20230314132808.1266335-1-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Now that the SRCU Kconfig option is unconditionally selected, there is
no longer any point in selecting it. Therefore, remove the "select SRCU"
Kconfig statements from the various KVM Kconfig files.
Acked-by: Sean Christopherson <seanjc@google.com> (x86)
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <kvm@vger.kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org> (arm64)
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Anup Patel <anup@brainfault.org> (riscv)
Acked-by: Heiko Carstens <hca@linux.ibm.com> (s390)
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
* Hide KVM_CAP_IRQFD_RESAMPLE if XIVE is enabled
s390:
* Fix handling of external interrupts in protected guests
x86:
* Resample the pending state of IOAPIC interrupts when unmasking them
* Fix usage of Hyper-V "enlightened TLB" on AMD
* Small fixes to real mode exceptions
* Suppress pending MMIO write exits if emulator detects exception
Documentation:
* Fix rST syntax
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"PPC:
- Hide KVM_CAP_IRQFD_RESAMPLE if XIVE is enabled
s390:
- Fix handling of external interrupts in protected guests
x86:
- Resample the pending state of IOAPIC interrupts when unmasking them
- Fix usage of Hyper-V "enlightened TLB" on AMD
- Small fixes to real mode exceptions
- Suppress pending MMIO write exits if emulator detects exception
Documentation:
- Fix rST syntax"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
docs: kvm: x86: Fix broken field list
KVM: PPC: Make KVM_CAP_IRQFD_RESAMPLE platform dependent
KVM: s390: pv: fix external interruption loop not always detected
KVM: nVMX: Do not report error code when synthesizing VM-Exit from Real Mode
KVM: x86: Clear "has_error_code", not "error_code", for RM exception injection
KVM: x86: Suppress pending MMIO write exits if emulator detects exception
KVM: x86/ioapic: Resample the pending state of an IRQ when unmasking
KVM: irqfd: Make resampler_list an RCU list
KVM: SVM: Flush Hyper-V TLB when required
Add support for the stackleak feature. Whenever the kernel returns to user
space the kernel stack is filled with a poison value.
Enabling this feature is quite expensive: e.g. after instrumenting the
getpid() system call function to have a 4kb stack the result is an
increased runtime of the system call by a factor of 3.
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
As preparation for the stackleak feature move on_thread_stack() to
processor.h like x86.
Also make it __always_inline, and slightly optimize it by reading
current task's kernel stack pointer from lowcore.
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Allocate early async stack like other early stacks and get rid of
arch_early_irq_init(). This way the async stack is allocated earlier,
and handled like all other stacks.
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
There is no user left of call_on_stack_noreturn() - remove it.
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
s390 is the only architecture which switches from the initial stack to a
later on allocated different stack for the first process.
This is (at least) problematic for the stackleak feature, which instruments
functions to save the current stackpointer within the task structure of the
running process.
The stackleak code compares stack pointers of the current process - and
doesn't expect that the kernel stack of a task can change. Even though the
stackleak feature itself will not cause any harm, the assumption about
kernel stacks being consistent is there, and only s390 doesn't follow that.
Therefore switch back to use init_thread_union, just like all other
architectures.
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Make sure the lowcore kernel stack pointer reflects the kernel stack of the
current task as early as possible, instead of having a NULL pointer there.
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Make STACK_INIT_OFFSET also available for assembler code, and
use it everywhere instead of open-coding it at several places.
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The pattern for all in_<type>_stack() functions is the same; especially
also the size of all stacks is the same. Simplify the code by passing only
the stack address to the generic in_stack() helper, which then can assume a
THREAD_SIZE sized stack.
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Currently, exception tables are marked as ro_after_init. However,
since they are sorted during compile time using scripts/sorttable,
they can be moved to RO_DATA using the RO_EXCEPTION_TABLE_ALIGN macro,
which is specifically designed for this purpose.
Suggested-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Since commit 4efd417f298b ("s390: raise minimum supported machine
generation to z10"), the long-displacement facility is assumed and
required for the kernel. Clean up a couple of places in the entry code,
where long-displacement could be used directly instead of using a base
register.
However, there are still a few other places where a base register has
to be used to extend short-displacement for the second lowcore page
access. Notably, boot/head.S still has to be built for z900, and in
mcck_int_handler, spt and lbear, which don't have long-displacements,
but need to access save areas at the second lowcore page.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Heiko Carstens says:
===================
There are a couple of oddities within the s390 uaccess library
functions. Therefore cleanup the whole uaccess.c file.
There is no functional change, only improved readability. The output
of "objdump -Dr" was always compared before/after each patch to make
sure that the generated object file is identical, if that could be
expected. Therefore the series also includes more patches than really
required to cleanup the code.
Furthermore the kunit usercopy tests also still pass.
===================
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
In order to get uaccess.c (nearly) checkpatch warning free remove an
extra blank line:
CHECK: Blank lines aren't necessary before a close brace '}'
+
+}
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Get rid of the not needed val local variable and pass the constant
value directly as operand value. In addition this turns the val
operand into an input operand, since it is not changed within the
inline assemblies.
This in turn requires also to add the earlyclobber contraint modifier
to all output operands, since the (former) val operand is used after
all output variants have been modified.
The usercopy kunit tests still pass after this change.
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Rename tmp1 and tmp2 variables to more meaningful val (for value) and rem
(for remainder).
Except for debug sections the output of "objdump -Dr" of the uaccess object
file is identical before/after this change.
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Rename and sort labels in uaccess inline assemblies to increase
readability. In addition have only one EX_TABLE entry per line - also to
increase readability.
Except for debug sections the output of "objdump -Dr" of the uaccess object
file is identical before/after this change.
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Improve readability of the uaccess inline assemblies by using symbolic
names for all input and output operands.
Except for debug sections the output of "objdump -Dr" of the uaccess object
file is identical before/after this change.
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
We need the fixes in here for testing, as well as the driver core
changes for documentation updates to build on.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When introduced, IRQFD resampling worked on POWER8 with XICS. However
KVM on POWER9 has never implemented it - the compatibility mode code
("XICS-on-XIVE") misses the kvm_notify_acked_irq() call and the native
XIVE mode does not handle INTx in KVM at all.
This moved the capability support advertising to platforms and stops
advertising it on XIVE, i.e. POWER9 and later.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Anup Patel <anup@brainfault.org>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20220504074807.3616813-1-aik@ozlabs.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
s390 can do more fine-grained handling of spurious TLB protection faults,
when there also is the PTE pointer available.
Therefore, pass on the PTE pointer to flush_tlb_fix_spurious_fault() as an
additional parameter.
This will add no functional change to other architectures, but those with
private flush_tlb_fix_spurious_fault() implementations need to be made
aware of the new parameter.
Link: https://lkml.kernel.org/r/20230306161548.661740-1-gerald.schaefer@linux.ibm.com
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64]
Acked-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc]
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
To determine whether the guest has caused an external interruption loop
upon code 20 (external interrupt) intercepts, the ext_new_psw needs to
be inspected to see whether external interrupts are enabled.
Under non-PV, ext_new_psw can simply be taken from guest lowcore. Under
PV, KVM can only access the encrypted guest lowcore and hence the
ext_new_psw must not be taken from guest lowcore.
handle_external_interrupt() incorrectly did that and hence was not able
to reliably tell whether an external interruption loop is happening or
not. False negatives cause spurious failures of my kvm-unit-test
for extint loops[1] under PV.
Since code 20 is only caused under PV if and only if the guest's
ext_new_psw is enabled for external interrupts, false positive detection
of a external interruption loop can not happen.
Fix this issue by instead looking at the guest PSW in the state
description. Since the PSW swap for external interrupt is done by the
ultravisor before the intercept is caused, this reliably tells whether
the guest is enabled for external interrupts in the ext_new_psw.
Also update the comments to explain better what is happening.
[1] https://lore.kernel.org/kvm/20220812062151.1980937-4-nrb@linux.ibm.com/
Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Fixes: 201ae986ead7 ("KVM: s390: protvirt: Implement interrupt injection")
Link: https://lore.kernel.org/r/20230213085520.100756-2-nrb@linux.ibm.com
Message-Id: <20230213085520.100756-2-nrb@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Add missing earlyclobber annotation to size, to, and tmp2 operands of the
__clear_user() inline assembly since they are modified or written to before
the last usage of all input operands. This can lead to incorrect register
allocation for the inline assembly.
Fixes: 6c2a9e6df604 ("[S390] Use alternative user-copy operations for new hardware.")
Reported-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/all/20230321122514.1743889-3-mark.rutland@arm.com/
Cc: stable@vger.kernel.org
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
