summaryrefslogtreecommitdiff
AgeCommit message (Collapse)AuthorFilesLines
2024-11-13s390/cpcmd: Convert to use flag output macrosHeiko Carstens1-5/+5
Use flag output macros in inline asm to allow for better code generation if the compiler has support for the flag output constraint. Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-13s390/topology: Convert to use flag output macrosHeiko Carstens1-7/+8
Use flag output macros in inline asm to allow for better code generation if the compiler has support for the flag output constraint. Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-13s390/time: Convert to use flag output macrosHeiko Carstens1-15/+17
Use flag output macros in inline asm to allow for better code generation if the compiler has support for the flag output constraint. Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-13s390/pageattr: Convert to use flag output macrosHeiko Carstens1-4/+5
Use flag output macros in inline asm to allow for better code generation if the compiler has support for the flag output constraint. Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-13s390/sthyi: Convert to use flag output macrosHeiko Carstens1-5/+5
Use flag output macros in inline asm to allow for better code generation if the compiler has support for the flag output constraint. Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-13s390/asm: Helper macros for flag output operand handlingHeiko Carstens2-2/+48
Since gcc supports flag out operands for inline assemblies there is always the question when this feature should be used and if it is worth all the ifdefs that come with that. In order to avoid that provide similar macros like x86 which can be used for all inline assemblies which extract the condition code. Depending on compiler features the generated code will either always contain an ipm+srl instruction pair, which extracts the condition code, or alternatively let the compiler handle this completely. Suggested-by: Juergen Christ <jchrist@linux.ibm.com> Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-13s390/cio: Externalize full CMG characteristicsPeter Oberparleiter4-20/+39
The current "measurement_chars" CHPID sysfs attribute exposes only a limited, validity-filtered portion of data from the associated Channel- Measurements Characteristics Block (CMCB). New machine models add data that is relevant for userspace tooling to the "header"-portion of the CMCB. This data that is not currently accessible to userspace. To prevent having to add new sysfs attributes whenever a new bit of data is added to the CMCB "header", add a new sysfs attribute named "measurement_chars_full" that exposes the full, unfiltered CMCB. Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com> Reviewed-by: Vineeth Vijayan <vneethv@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-12s390/syscalls: Convert filechk to if_changedMasahiro Yamada1-11/+14
The filechk macro always executes the syscalltbl script (and discards the output if there are no changes). Using if_changed is more efficient because it avoids running the script when the target is up-to-date and the command remains unchanged. All other architectures use if_changed for generating syscall headers. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20241111134603.2063226-3-masahiroy@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-12s390/syscalls: Remove unnecessary argument of filechk_syshdrMasahiro Yamada1-3/+3
The filechk_syshdr macro receives $@ in both cases, making the argument redundant. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20241111134603.2063226-2-masahiroy@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-12s390/syscalls: Avoid creation of arch/arch/ directoryMasahiro Yamada1-1/+1
Building the kernel with ARCH=s390 creates a weird arch/arch/ directory. $ find arch/arch arch/arch arch/arch/s390 arch/arch/s390/include arch/arch/s390/include/generated arch/arch/s390/include/generated/asm arch/arch/s390/include/generated/uapi arch/arch/s390/include/generated/uapi/asm The root cause is 'targets' in arch/s390/kernel/syscalls/Makefile, where the relative path is incorrect. Strictly speaking, 'targets' was not necessary in the first place because this Makefile uses 'filechk' instead of 'if_changed'. However, this commit keeps it, as it will be useful when converting 'filechk' to 'if_changed' later. Fixes: 5c75824d915e ("s390/syscalls: add Makefile to generate system call header files") Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20241111134603.2063226-1-masahiroy@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-12s390/perf_cpum_cf: Convert to use local64_try_cmpxchg()Heiko Carstens1-4/+4
Convert local64_cmpxchg() usages to local64_try_cmpxchg() in order to generate slightly better code. Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-12s390/perf_cpum_sf: Convert to use try_cmpxchg128()Heiko Carstens1-15/+9
Convert cmpxchg128() usages to try_cmpxchg128() in order to generate slightly better code. Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-12s390/atomic: Remove __atomic_cmpxchg() variantsHeiko Carstens1-75/+0
With users converted to the standard arch_cmpxchg() variants, remove the now unused __atomic_cmpxchg() and __atomic_cmpxchg_bool() variants. Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-12s390/locking: Use arch_try_cmpxchg() instead of __atomic_cmpxchg_bool()Heiko Carstens2-11/+14
Use arch_try_cmpxchg() instead of __atomic_cmpxchg_bool() everywhere. This generates the same code like before, but uses the standard cmpxchg() implementation instead of a custom __atomic_cmpxchg_bool(). Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-12s390/preempt: Use arch_try_cmpxchg() instead of __atomic_cmpxchg()Heiko Carstens1-5/+4
Use arch_try_cmpxchg() instead of __atomic_cmpxchg() in preempt_count_set() to generate similar or better code, depending in compiler features. Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-12s390/atomic: Provide arch_atomic_try_cmpxchg()Heiko Carstens1-0/+12
Since gcc 14 flag output operands are supported also for s390. Provide an arch_atomic try_cmpxchg() implementation so that all existing atomic_try_cmpxchg() usages generate slightly better code, if compiled with gcc 14 or newer. Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-12s390/cmpxchg: Use arch_cmpxchg() instead of __atomic_cmpxchg()Heiko Carstens1-2/+2
Use arch_cmpxchg() instead of __atomic_cmpxchg() for the arch_atomic_cmpxchg() implementations. arch_cmpxchg() generates the same code and doesn't need a cast like it is required for arch_atomic64_cmpxchg(). Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-12s390/atomic: Convert arch_atomic_xchg() to C functionHeiko Carstens1-2/+10
Convert the arch_atomic_xchg define to a C function so that proper type checking is provided. Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-12s390/cmpxchg: Provide arch_try_cmpxchg128()Heiko Carstens1-0/+19
Since gcc 14 flag output operands are supported also for s390. Provide an arch_try_cmpxchg128() implementation so that all existing try_cmpxchg128() variants provide slightly better code, if compiled with gcc 14 or newer. Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-12s390/cmpxchg: Provide arch_cmpxchg128_local()Heiko Carstens1-0/+1
Just like x86 and arm64 provide a trivial arch_cmpxchg128_local() implementation by mapping it to arch_cmpxchg128(). Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-12s390/cmpxchg: Implement arch_xchg() with arch_try_cmpxchg()Heiko Carstens1-71/+81
Get rid of the arch_xchg() inline assemblies by converting the inline assemblies to C functions which make use of arch_try_cmpxchg(). With flag output operand support the generated code is at least as good as the previous version. Without it is slightly worse, however getting rid of all the inline assembly code is worth it. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-12s390/cmpxchg: Provide arch_try_cmpxchg()Heiko Carstens2-0/+64
Since gcc 14 flag output operands are supported also for s390. Provide an arch_try_cmpxchg() implementation so that all existing try_cmpxchg() variants provide slightly better code, if compiled with gcc 14 or newer. Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-12s390/cmpxchg: Convert one and two byte case inline assemblies to CHeiko Carstens1-89/+73
Rewrite __cmpxchg() in order to get rid of the large inline assemblies. Convert the one and two byte inline assemblies to C functions. The generated code of the new implementation is nearly as good or bad as the old variant, but easier to read. Note that the new variants are quite close to the generic cmpxchg_emu_u8() implementation, however a conversion to the generic variant will not follow since with mm/vmstat.c there is heavy user of one byte cmpxchg(). A not inlined variant would have a negative performance impact. Also note that the calls within __arch_cmpxchg() come with rather pointless "& 0xff..." operations. They exist only to avoid false positive sparse warnings like "warning: cast truncates bits from constant value ...". Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-12s390/dump: Add firmware sysfs attribute for dump area sizeAlexander Egorenkov1-1/+19
Dump tools from s390-tools such as zipl need to know the correct dump area size of the machine they run on in order to be able to create valid standalone dumper images. Therefore, allow it to be obtained through the new sysfs read-only attribute /sys/firmware/dump/dump_area_size. Suggested-by: Heiko Carstens <hca@linux.ibm.com> Suggested-by: Peter Oberparleiter <oberpar@linux.ibm.com> Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com> Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-12s390/con3270: Use NULL instead of 0 for pointersHeiko Carstens1-2/+2
Get rid of sparse warnings: CHECK drivers/s390/char/con3270.c drivers/s390/char/con3270.c:531:15: warning: Using plain integer as NULL pointer drivers/s390/char/con3270.c:749:15: warning: Using plain integer as NULL pointer Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-07s390/pci: Add header guards and includes to internal headersNiklas Schnelle2-0/+7
While pci_iov.h has include guards it doesn't include the necessary header for struct zpci_dev, pci_bus.h on the other hand lacks even basic include guards. This isn't only fragile and breaks convention but also confuses tooling such as clang-analyzer. Add both include guards and the necessary includes. Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Reviewed-by: Gerd Bayer <gbayer@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-07s390/uvdevice: Fix and slightly improve kernel-doc commentHeiko Carstens1-12/+20
Fix incorrect kernel-doc comment style, add missing return statement, fix incorrect parameter name, and add some additional consistency across all kernel-doc comments. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-07s390/uvdevice: Support longer secret listsSteffen Eiden1-19/+50
Enable the list IOCTL to provide lists longer than one page (85 entries). The list IOCTL now accepts any argument length in page granularity. It fills the argument up to this length with entries until the list ends. User space unaware of this enhancement will still receive one page of data and an uv_rc 0x0100. Signed-off-by: Steffen Eiden <seiden@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20241104153609.1361388-1-seiden@linux.ibm.com Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Message-ID: <20241104153609.1361388-1-seiden@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-07s390/sparsemem: Provide phys_to_target_node() with CONFIG_NUMAHeiko Carstens1-0/+8
Add a trival phys_to_target_node() implementation which always returns 0 if CONFIG_NUMA is enabled, since the s390 NUMA implementation only supports node 0. This is similar to memory_add_physaddr_to_nid() in order to avoid runtime warnings. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-07s390/configs: Enable CONFIG_VIRTIO_MEMHeiko Carstens2-0/+2
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-07Merge branch 'virtio-mem' into featuresHeiko Carstens7-18/+98
David Hildenbrand says: ==================== virtio-mem: s390 support Let's finally add s390 support for virtio-mem; my last RFC was sent 4 years ago, and a lot changed in the meantime. The latest QEMU series is available at [1], which contains some more details and a usage example on s390 (last patch). There is not too much in here: The biggest part is querying a new diag(500) STORAGE_LIMIT hypercall to obtain the proper "max_physmem_end". The last three patches are not strictly required but certainly nice-to-have. Note that -- in contrast to standby memory -- virtio-mem memory must be configured to be automatically onlined as soon as hotplugged. The easiest approach is using the "memhp_default_state=" kernel parameter or by using proper udev rules. More details can be found at [2]. I have reviving+upstreaming a systemd service to handle configuring that on my todo list, but for some reason I keep getting distracted ... I tested various things, including: * Various memory hotplug/hotunplug combinations * Device hotplug/hotunplug * /proc/iomem output * reboot * kexec * kdump: make sure we properly enter the "kdump mode" in the virtio-mem driver kdump support for virtio-mem memory on s390 will be sent out separately. v2 -> v3 * "s390/kdump: make is_kdump_kernel() consistently return "true" in kdump environments only" -> Sent out separately [3] * "s390/physmem_info: query diag500(STORAGE LIMIT) to support QEMU/KVM memory devices" -> No query function for diag500 for now. -> Update comment above setup_ident_map_size(). -> Optimize/rewrite diag500_storage_limit() [Heiko] -> Change handling in detect_physmem_online_ranges [Alexander] -> Improve documentation. * "s390/sparsemem: provide memory_add_physaddr_to_nid() with CONFIG_NUMA" -> Added after testing on systems with CONFIG_NUMA=y v1 -> v2: * Document the new diag500 subfunction * Use "s390" instead of "s390x" consistently [1] https://lkml.kernel.org/r/20241008105455.2302628-1-david@redhat.com [2] https://virtio-mem.gitlab.io/user-guide/user-guide-linux.html [3] https://lkml.kernel.org/r/20241023090651.1115507-1-david@redhat.com ==================== Link: https://lore.kernel.org/r/20241025141453.1210600-1-david@redhat.com/ Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-07s390/sparsemem: Provide memory_add_physaddr_to_nid() with CONFIG_NUMADavid Hildenbrand1-0/+8
virtio-mem uses memory_add_physaddr_to_nid() to determine the NID to use for memory it adds. We currently fallback to the dummy implementation in mm/numa.c with CONFIG_NUMA, which will end up triggering an undesired pr_info_once(): Unknown online node for memory at 0x100000000, assuming node 0 On s390, we map all cpus and memory to node 0, so let's add a simple memory_add_physaddr_to_nid() implementation that does exactly that, but without complaining. Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Tested-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20241025141453.1210600-8-david@redhat.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-07s390/sparsemem: Reduce section size to 128 MiBDavid Hildenbrand1-1/+1
Ever since commit 421c175c4d609 ("[S390] Add support for memory hot-add.") we've been using a section size of 256 MiB on s390 and 32 MiB on s390. Before that, we were using a section size of 32 MiB on both architectures. Now that we have a new mechanism to expose additional memory to a VM -- virtio-mem -- reduce the section size to 128 MiB to allow for more flexibility and reduce the metadata overhead when dealing with hot(un)plug granularity smaller than 256 MiB. 128 MiB has been used by x86-64 since the very beginning. arm64 with 4k base pages switched to 128 MiB as well: it's just big enough on these architectures to allows for using a huge page (2 MiB) in the vmemmap in sane setups with sizeof(struct page) == 64 bytes and a huge page mapping in the direct mapping, while still allowing for small hot(un)plug granularity. For s390, we could even switch to a 64 MiB section size, as our huge page size is 1 MiB: but the smaller the section size, the more sections we'll have to manage especially on bigger machines. Making it consistent with x86-64 and arm64 feels like the right thing for now. Note that the smallest memory hot(un)plug granularity is also limited by the memory block size, determined by extracting the memory increment size from SCLP. Under QEMU/KVM, implementing virtio-mem, we expose 0; therefore, we'll end up with a memory block size of 128 MiB with a 128 MiB section size. Tested-by: Mario Casquero <mcasquer@redhat.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: David Hildenbrand <david@redhat.com> Tested-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20241025141453.1210600-7-david@redhat.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-07lib/Kconfig.debug: Default STRICT_DEVMEM to "y" on s390David Hildenbrand1-1/+1
virtio-mem currently depends on !DEVMEM | STRICT_DEVMEM. Let's default STRICT_DEVMEM to "y" just like we do for arm64 and x86. There could be ways in the future to filter access to virtio-mem device memory even without STRICT_DEVMEM, but for now let's just keep it simple. Tested-by: Mario Casquero <mcasquer@redhat.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: David Hildenbrand <david@redhat.com> Tested-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20241025141453.1210600-6-david@redhat.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-07virtio-mem: s390 supportDavid Hildenbrand1-6/+6
Now that s390 code is prepared for memory devices that reside above the maximum storage increment exposed through SCLP, everything is in place to unlock virtio-mem support. As virtio-mem in Linux currently supports logically onlining/offlining memory in pageblock granularity, we have an effective hot(un)plug granularity of 1 MiB on s390. As virito-mem adds/removes individual Linux memory blocks (256MB), we will currently never use gigantic pages in the identity mapping. It is worth noting that neither storage keys nor storage attributes (e.g., data / nodat) are touched when onlining memory blocks, which is good because we are not supposed to touch these parts for unplugged device blocks that are logically offline in Linux. We will currently never initialize storage keys for virtio-mem memory -- IOW, storage_key_init_range() is never called. It could be added in the future when plugging device blocks. But as that function essentially does nothing without modifying the code (changing PAGE_DEFAULT_ACC), that's just fine for now. kexec should work as intended and just like on other architectures that support virtio-mem: we will never place kexec binaries on virtio-mem memory, and never indicate virtio-mem memory to the 2nd kernel. The device driver in the 2nd kernel can simply reset the device -- turning all memory unplugged, to then start plugging memory and adding them to Linux, without causing trouble because the memory is already used elsewhere. The special s390 kdump mode, whereby the 2nd kernel creates the ELF core header, won't currently dump virtio-mem memory. The virtio-mem driver has a special kdump mode, from where we can detect memory ranges to dump. Based on this, support for dumping virtio-mem memory can be added in the future fairly easily. Acked-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Mario Casquero <mcasquer@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Tested-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20241025141453.1210600-5-david@redhat.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-07s390/physmem_info: Query diag500(STORAGE LIMIT) to support QEMU/KVM memory ↵David Hildenbrand3-3/+54
devices To support memory devices under QEMU/KVM, such as virtio-mem, we have to prepare our kernel virtual address space accordingly and have to know the highest possible physical memory address we might see later: the storage limit. The good old SCLP interface is not suitable for this use case. In particular, memory owned by memory devices has no relationship to storage increments, it is always detected using the device driver, and unaware OSes (no driver) must never try making use of that memory. Consequently this memory is located outside of the "maximum storage increment"-indicated memory range. Let's use our new diag500 STORAGE_LIMIT subcode to query this storage limit that can exceed the "maximum storage increment", and use the existing interfaces (i.e., SCLP) to obtain information about the initial memory that is not owned+managed by memory devices. If a hypervisor does not support such memory devices, the address exposed through diag500 STORAGE_LIMIT will correspond to the maximum storage increment exposed through SCLP. To teach kdump on s390 to include memory owned by memory devices, there will be ways to query the relevant memory ranges from the device via a driver running in special kdump mode (like virtio-mem already implements to filter /proc/vmcore access so we don't end up reading from unplugged device blocks). Update setup_ident_map_size(), to clarify that there can be more than just online and standby memory. Tested-by: Mario Casquero <mcasquer@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Tested-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20241025141453.1210600-4-david@redhat.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-07Documentation: s390-diag.rst: Document diag500(STORAGE LIMIT) subfunctionDavid Hildenbrand1-0/+17
Let's document our new diag500 subfunction that can be implemented by userspace. Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Eric Farman <farman@linux.ibm.com> Tested-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20241025141453.1210600-3-david@redhat.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-07Documentation: s390-diag.rst: Make diag500 a generic KVM hypercallDavid Hildenbrand1-7/+11
Let's make it a generic KVM hypercall, allowing other subfunctions to be more independent of virtio. While at it, document that unsupported/unimplemented subfunctions result in a SPECIFICATION exception. This is a preparation for documenting a new subfunction. Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Eric Farman <farman@linux.ibm.com> Tested-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20241025141453.1210600-2-david@redhat.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-07s390/kvm: Mask extra bits from program interrupt codeClaudio Imbrenda2-2/+2
The program interrupt code has some extra bits that are sometimes set by hardware for various reasons; those bits should be ignored when the program interrupt number is needed for interrupt handling. Fixes: 05066cafa925 ("s390/mm/fault: Handle guest-related program interrupts in KVM") Reported-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Tested-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20241031120316.25462-1-imbrenda@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-31s390/kvm: Initialize uninitialized flags variableClaudio Imbrenda1-1/+1
The flags variable was being used uninitialized. Initialize it to 0 as expected. For some reason neither gcc nor clang reported a warning. Fixes: 05066cafa925 ("s390/mm/fault: Handle guest-related program interrupts in KVM") Reported-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20241030161906.85476-1-imbrenda@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-31s390/cpum_sf: Fix and protect memory allocation of SDBs with mutexThomas Richter1-1/+1
Reservation of the PMU hardware is done at first event creation and is protected by a pair of mutex_lock() and mutex_unlock(). After reservation of the PMU hardware the memory required for the PMUs the event is to be installed on is allocated by allocate_buffers() and alloc_sampling_buffer(). This done outside of the mutex protection. Without mutex protection two or more concurrent invocations of perf_event_init() may run in parallel. This can lead to allocation of Sample Data Blocks (SDBs) multiple times for the same PMU. Prevent this and protect memory allocation of SDBs by mutex. Fixes: 8a6fe8f21ec4 ("s390/cpum_sf: Use refcount_t instead of atomic_t") Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Reviewed-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-29s390/mm: Cleanup fault error handlingHeiko Carstens1-10/+4
Combine the two VM_FAULT_ERROR checks in do_exception() and move them to the exit path, similar to x86. Also remove a random blank line. Suggested-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-29s390/mm: Convert to LOCK_MM_AND_FIND_VMAHeiko Carstens2-11/+3
With the gmap code gone s390 can be easily converted to LOCK_MM_AND_FIND_VMA like it has been done for most other architectures. Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Link: https://lore.kernel.org/r/20241022120601.167009-12-imbrenda@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-29s390/mm: Get rid of fault type switch statementsHeiko Carstens1-48/+22
With GMAP_FAULT fault type gone, there are only KERNEL_FAULT and USER_FAULT fault types left. Therefore there is no need for any fault type switch statements left. Rename get_fault_type() into is_kernel_fault() and let it return a boolean value. Change all switch statements to if statements. This removes quite a bit of code. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Link: https://lore.kernel.org/r/20241022120601.167009-11-imbrenda@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-29s390/mm: Simplify get_fault_type()Heiko Carstens1-9/+2
With the gmap code gone get_fault_type() can be simplified: - every fault with user_mode(regs) == true must be a fault in user address space - every fault with user_mode(regs) == false is only a fault in user address space if the used address space is the secondary address space - every other fault is within the kernel address space Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Link: https://lore.kernel.org/r/20241022120601.167009-10-imbrenda@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-29s390: Remove gmap pointer from lowcoreClaudio Imbrenda2-3/+1
Remove the gmap pointer from lowcore, since it is not used anymore. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Steffen Eiden <seiden@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20241022120601.167009-9-imbrenda@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-29s390/mm/gmap: Remove gmap_{en,dis}able()Claudio Imbrenda2-34/+0
Remove gmap_enable(), gmap_disable(), and gmap_get_enabled() since they do not have any users anymore. Suggested-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20241022120601.167009-8-imbrenda@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-29s390/kvm: Stop using gmap_{en,dis}able()Claudio Imbrenda3-11/+2
Stop using gmap_enable(), gmap_disable(), gmap_get_enabled(). The correct guest ASCE is passed as a parameter of sie64a(), there is no need to save the current gmap in lowcore. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by: Steffen Eiden <seiden@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20241022120601.167009-7-imbrenda@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-29s390/mm/fault: Handle guest-related program interrupts in KVMClaudio Imbrenda8-157/+143
Any program interrupt that happens in the host during the execution of a KVM guest will now short circuit the fault handler and return to KVM immediately. Guest fault handling (including pfault) will happen entirely inside KVM. When sie64a() returns zero, current->thread.gmap_int_code will contain the program interrupt number that caused the exit, or zero if the exit was not caused by a host program interrupt. KVM will now take care of handling all guest faults in vcpu_post_run(). Since gmap faults will not be visible by the rest of the kernel, remove GMAP_FAULT, the linux fault handlers for secure execution faults, the exception table entries for the sie instruction, the nop padding after the sie instruction, and all other references to guest faults from the s390 code. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Co-developed-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20241022120601.167009-6-imbrenda@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-29s390/mm/gmap: Fix __gmap_fault() return codeClaudio Imbrenda1-6/+5
Errors in fixup_user_fault() were masked and -EFAULT was returned for any error, including out of memory. Fix this by returning the correct error code. This means that in many cases the error code will be propagated all the way to userspace. Suggested-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Link: https://lore.kernel.org/r/20241022120601.167009-5-imbrenda@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>