kernel.git/arch/s390/kernel/entry.S, branch linux-6.4.y

s390/entry: use SYM* macros instead of ENTRY(), etc.

2023-04-19T15:24:18Z

Consistently use the SYM* family of macros instead of the deprecated ENTRY(), ENDPROC(), etc. family of macros. Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390: enable HAVE_ARCH_STACKLEAK

2023-04-04T16:34:56Z

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 Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/stack: use STACK_INIT_OFFSET where possible

2023-04-04T16:34:55Z

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 Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/entry: rely on long-displacement facility

2023-04-04T16:34:54Z

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 Signed-off-by: Vasily Gorbik

s390/bp: remove __bpon()

2023-03-13T08:16:42Z

There is no point in changing branch prediction state of a cpu shortly before it enters stop state. Therefore remove __bpon(). Acked-by: Alexander Gordeev Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/bp: remove TIF_ISOLATE_BP

2023-03-13T08:16:42Z

TIF_ISOLATE_BP is unused since it was introduced with commit 6b73044b2b00 ("s390: run user space and KVM guests with modified branch prediction"). Given that there is no use case remove it again. Acked-by: Alexander Gordeev Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/bp: add missing BPENTER to program check handler

2023-03-13T08:16:42Z

When leaving interpretive execution because of a program check BPENTER should be called like it is done on interrupt exit as well. Acked-by: Alexander Gordeev Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/mcck: cleanup user process termination path

2023-02-28T12:19:05Z

If a machine check interrupt hits while user process is running __s390_handle_mcck() helper function is called directly from the interrupt handler and terminates the current process by calling make_task_dead() routine. The make_task_dead() is not allowed to be called from interrupt context which forces the machine check handler switch to the kernel stack and enable local interrupts first. The __s390_handle_mcck() could also be called to service pending work, but this time from the external interrupts handler. It is the machine check handler that establishes the work and schedules the external interrupt, therefore the machine check interrupt itself should be disabled while reading out the corresponding variable: local_mcck_disable(); mcck = *this_cpu_ptr(&cpu_mcck); memset(this_cpu_ptr(&cpu_mcck), 0, sizeof(mcck)); local_mcck_enable(); However, local_mcck_disable() does not have effect when __s390_handle_mcck() is called directly form the machine check handler, since the machine check interrupt is still disabled. Therefore, it is not the opening bracket to the following local_mcck_enable() function. Simplify the user process termination flow by scheduling the external interrupt and killing the affected process from the interrupt context. Assume a kernel-generated signal is always delivered and ignore a value returned by do_send_sig_info() funciton. Reviewed-by: Heiko Carstens Reviewed-by: Sven Schnelle Signed-off-by: Alexander Gordeev Signed-off-by: Heiko Carstens

s390/entry: remove toolchain dependent micro-optimization

2023-02-14T10:45:40Z

Get rid of CONFIG_AS_IS_LLVM in entry.S to make the code a bit more readable. This removes a micro-optimization, but given that the llvm IAS limitation will likely stay, just use the version that works with llvm. See commit 4c25f0ff6336 ("s390/entry: workaround llvm's IAS limitations") for further details. Signed-off-by: Heiko Carstens

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2022-12-15T19:12:21Z

Pull kvm updates from Paolo Bonzini: "ARM64: - Enable the per-vcpu dirty-ring tracking mechanism, together with an option to keep the good old dirty log around for pages that are dirtied by something other than a vcpu. - Switch to the relaxed parallel fault handling, using RCU to delay page table reclaim and giving better performance under load. - Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping option, which multi-process VMMs such as crosvm rely on (see merge commit 382b5b87a97d: "Fix a number of issues with MTE, such as races on the tags being initialised vs the PG_mte_tagged flag as well as the lack of support for VM_SHARED when KVM is involved. Patches from Catalin Marinas and Peter Collingbourne"). - Merge the pKVM shadow vcpu state tracking that allows the hypervisor to have its own view of a vcpu, keeping that state private. - Add support for the PMUv3p5 architecture revision, bringing support for 64bit counters on systems that support it, and fix the no-quite-compliant CHAIN-ed counter support for the machines that actually exist out there. - Fix a handful of minor issues around 52bit VA/PA support (64kB pages only) as a prefix of the oncoming support for 4kB and 16kB pages. - Pick a small set of documentation and spelling fixes, because no good merge window would be complete without those. s390: - Second batch of the lazy destroy patches - First batch of KVM changes for kernel virtual != physical address support - Removal of a unused function x86: - Allow compiling out SMM support - Cleanup and documentation of SMM state save area format - Preserve interrupt shadow in SMM state save area - Respond to generic signals during slow page faults - Fixes and optimizations for the non-executable huge page errata fix. - Reprogram all performance counters on PMU filter change - Cleanups to Hyper-V emulation and tests - Process Hyper-V TLB flushes from a nested guest (i.e. from a L2 guest running on top of a L1 Hyper-V hypervisor) - Advertise several new Intel features - x86 Xen-for-KVM: - Allow the Xen runstate information to cross a page boundary - Allow XEN_RUNSTATE_UPDATE flag behaviour to be configured - Add support for 32-bit guests in SCHEDOP_poll - Notable x86 fixes and cleanups: - One-off fixes for various emulation flows (SGX, VMXON, NRIPS=0). - Reinstate IBPB on emulated VM-Exit that was incorrectly dropped a few years back when eliminating unnecessary barriers when switching between vmcs01 and vmcs02. - Clean up vmread_error_trampoline() to make it more obvious that params must be passed on the stack, even for x86-64. - Let userspace set all supported bits in MSR_IA32_FEAT_CTL irrespective of the current guest CPUID. - Fudge around a race with TSC refinement that results in KVM incorrectly thinking a guest needs TSC scaling when running on a CPU with a constant TSC, but no hardware-enumerated TSC frequency. - Advertise (on AMD) that the SMM_CTL MSR is not supported - Remove unnecessary exports Generic: - Support for responding to signals during page faults; introduces new FOLL_INTERRUPTIBLE flag that was reviewed by mm folks Selftests: - Fix an inverted check in the access tracking perf test, and restore support for asserting that there aren't too many idle pages when running on bare metal. - Fix build errors that occur in certain setups (unsure exactly what is unique about the problematic setup) due to glibc overriding static_assert() to a variant that requires a custom message. - Introduce actual atomics for clear/set_bit() in selftests - Add support for pinning vCPUs in dirty_log_perf_test. - Rename the so called "perf_util" framework to "memstress". - Add a lightweight psuedo RNG for guest use, and use it to randomize the access pattern and write vs. read percentage in the memstress tests. - Add a common ucall implementation; code dedup and pre-work for running SEV (and beyond) guests in selftests. - Provide a common constructor and arch hook, which will eventually be used by x86 to automatically select the right hypercall (AMD vs. Intel). - A bunch of added/enabled/fixed selftests for ARM64, covering memslots, breakpoints, stage-2 faults and access tracking. - x86-specific selftest changes: - Clean up x86's page table management. - Clean up and enhance the "smaller maxphyaddr" test, and add a related test to cover generic emulation failure. - Clean up the nEPT support checks. - Add X86_PROPERTY_* framework to retrieve multi-bit CPUID values. - Fix an ordering issue in the AMX test introduced by recent conversions to use kvm_cpu_has(), and harden the code to guard against similar bugs in the future. Anything that tiggers caching of KVM's supported CPUID, kvm_cpu_has() in this case, effectively hides opt-in XSAVE features if the caching occurs before the test opts in via prctl(). Documentation: - Remove deleted ioctls from documentation - Clean up the docs for the x86 MSR filter. - Various fixes" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (361 commits) KVM: x86: Add proper ReST tables for userspace MSR exits/flags KVM: selftests: Allocate ucall pool from MEM_REGION_DATA KVM: arm64: selftests: Align VA space allocator with TTBR0 KVM: arm64: Fix benign bug with incorrect use of VA_BITS KVM: arm64: PMU: Fix period computation for 64bit counters with 32bit overflow KVM: x86: Advertise that the SMM_CTL MSR is not supported KVM: x86: remove unnecessary exports KVM: selftests: Fix spelling mistake "probabalistic" -> "probabilistic" tools: KVM: selftests: Convert clear/set_bit() to actual atomics tools: Drop "atomic_" prefix from atomic test_and_set_bit() tools: Drop conflicting non-atomic test_and_{clear,set}_bit() helpers KVM: selftests: Use non-atomic clear/set bit helpers in KVM tests perf tools: Use dedicated non-atomic clear/set bit helpers tools: Take @bit as an "unsigned long" in {clear,set}_bit() helpers KVM: arm64: selftests: Enable single-step without a "full" ucall() KVM: x86: fix APICv/x2AVIC disabled when vm reboot by itself KVM: Remove stale comment about KVM_REQ_UNHALT KVM: Add missing arch for KVM_CREATE_DEVICE and KVM_{SET,GET}_DEVICE_ATTR KVM: Reference to kvm_userspace_memory_region in doc and comments KVM: Delete all references to removed KVM_SET_MEMORY_ALIAS ioctl ...