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2023-11-06arch/arm64: Add lazy preempt supportAnders Roxell1-0/+1
arm64 is missing support for PREEMPT_RT. The main feature which is lacking is support for lazy preemption. The arch-specific entry code, thread information structure definitions, and associated data tables have to be extended to provide this support. Then the Kconfig file has to be extended to indicate the support is available, and also to indicate that support for full RT preemption is now available. Signed-off-by: Anders Roxell <anders.roxell@linaro.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2021-07-28arm64: mte: rename gcr_user_excl to mte_ctrlPeter Collingbourne1-1/+1
We are going to use this field to store more data. To prepare for that, rename it and change the users to rely on the bit position of gcr_user_excl in mte_ctrl. Link: https://linux-review.googlesource.com/id/Ie1fd18e480100655f5d22137f5b22f4f3a9f9e2e Signed-off-by: Peter Collingbourne <pcc@google.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20210727205300.2554659-2-pcc@google.com Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-06-29Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-0/+2
Pull kvm updates from Paolo Bonzini: "This covers all architectures (except MIPS) so I don't expect any other feature pull requests this merge window. ARM: - Add MTE support in guests, complete with tag save/restore interface - Reduce the impact of CMOs by moving them in the page-table code - Allow device block mappings at stage-2 - Reduce the footprint of the vmemmap in protected mode - Support the vGIC on dumb systems such as the Apple M1 - Add selftest infrastructure to support multiple configuration and apply that to PMU/non-PMU setups - Add selftests for the debug architecture - The usual crop of PMU fixes PPC: - Support for the H_RPT_INVALIDATE hypercall - Conversion of Book3S entry/exit to C - Bug fixes S390: - new HW facilities for guests - make inline assembly more robust with KASAN and co x86: - Allow userspace to handle emulation errors (unknown instructions) - Lazy allocation of the rmap (host physical -> guest physical address) - Support for virtualizing TSC scaling on VMX machines - Optimizations to avoid shattering huge pages at the beginning of live migration - Support for initializing the PDPTRs without loading them from memory - Many TLB flushing cleanups - Refuse to load if two-stage paging is available but NX is not (this has been a requirement in practice for over a year) - A large series that separates the MMU mode (WP/SMAP/SMEP etc.) from CR0/CR4/EFER, using the MMU mode everywhere once it is computed from the CPU registers - Use PM notifier to notify the guest about host suspend or hibernate - Support for passing arguments to Hyper-V hypercalls using XMM registers - Support for Hyper-V TLB flush hypercalls and enlightened MSR bitmap on AMD processors - Hide Hyper-V hypercalls that are not included in the guest CPUID - Fixes for live migration of virtual machines that use the Hyper-V "enlightened VMCS" optimization of nested virtualization - Bugfixes (not many) Generic: - Support for retrieving statistics without debugfs - Cleanups for the KVM selftests API" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (314 commits) KVM: x86: rename apic_access_page_done to apic_access_memslot_enabled kvm: x86: disable the narrow guest module parameter on unload selftests: kvm: Allows userspace to handle emulation errors. kvm: x86: Allow userspace to handle emulation errors KVM: x86/mmu: Let guest use GBPAGES if supported in hardware and TDP is on KVM: x86/mmu: Get CR4.SMEP from MMU, not vCPU, in shadow page fault KVM: x86/mmu: Get CR0.WP from MMU, not vCPU, in shadow page fault KVM: x86/mmu: Drop redundant rsvd bits reset for nested NPT KVM: x86/mmu: Optimize and clean up so called "last nonleaf level" logic KVM: x86: Enhance comments for MMU roles and nested transition trickiness KVM: x86/mmu: WARN on any reserved SPTE value when making a valid SPTE KVM: x86/mmu: Add helpers to do full reserved SPTE checks w/ generic MMU KVM: x86/mmu: Use MMU's role to determine PTTYPE KVM: x86/mmu: Collapse 32-bit PAE and 64-bit statements for helpers KVM: x86/mmu: Add a helper to calculate root from role_regs KVM: x86/mmu: Add helper to update paging metadata KVM: x86/mmu: Don't update nested guest's paging bitmasks if CR0.PG=0 KVM: x86/mmu: Consolidate reset_rsvds_bits_mask() calls KVM: x86/mmu: Use MMU role_regs to get LA57, and drop vCPU LA57 helper KVM: x86/mmu: Get nested MMU's root level from the MMU's role ...
2021-06-24Merge branch 'for-next/smccc' into for-next/coreWill Deacon1-0/+9
Add support for versions v1.2 and 1.3 of the SMC calling convention. * for-next/smccc: arm64: smccc: Support SMCCC v1.3 SVE register saving hint arm64: smccc: Add support for SMCCCv1.2 extended input/output registers
2021-06-24Merge branch 'for-next/ptrauth' into for-next/coreWill Deacon1-0/+4
Allow Pointer Authentication to be configured independently for kernel and userspace. * for-next/ptrauth: arm64: Conditionally configure PTR_AUTH key of the kernel. arm64: Add ARM64_PTR_AUTH_KERNEL config option
2021-06-22KVM: arm64: Save/restore MTE registersSteven Price1-0/+2
Define the new system registers that MTE introduces and context switch them. The MTE feature is still hidden from the ID register as it isn't supported in a VM yet. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Steven Price <steven.price@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210621111716.37157-4-steven.price@arm.com
2021-06-15arm64: Conditionally configure PTR_AUTH key of the kernel.Daniel Kiss1-0/+2
If the kernel is not compiled with CONFIG_ARM64_PTR_AUTH_KERNEL=y, then no PACI/AUTI instructions are expected while the kernel is running so the kernel's key will not be used. Write of a system registers is expensive therefore avoid if not required. Signed-off-by: Daniel Kiss <daniel.kiss@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20210613092632.93591-3-daniel.kiss@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-06-15arm64: Add ARM64_PTR_AUTH_KERNEL config optionDaniel Kiss1-0/+2
This patch add the ARM64_PTR_AUTH_KERNEL config and deals with the build aspect of it. Userspace support has no dependency on the toolchain therefore all toolchain checks and build flags are controlled the new config option. The default config behavior will not be changed. Signed-off-by: Daniel Kiss <daniel.kiss@arm.com> Acked-by: Will Deacon <will@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20210613092632.93591-2-daniel.kiss@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-05-27arm64: smp: initialize cpu offset earlierMark Rutland1-0/+1
Now that we have a consistent place to initialize CPU context registers early in the boot path, let's also initialize the per-cpu offset here. This makes the primary and secondary boot paths more consistent, and allows for the use of per-cpu operations earlier, which will be necessary for instrumentation with KCSAN. Note that smp_prepare_boot_cpu() still needs to re-initialize CPU0's offset as immediately prior to this the per-cpu areas may be reallocated, and hence the boot-time offset may be stale. A comment is added to make this clear. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Suzuki Poulose <suzuki.poulose@arm.com> Cc: Will Deacon <will@kernel.org> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20210520115031.18509-7-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-05-27arm64: smp: remove stack from secondary_dataMark Rutland1-1/+0
When we boot a secondary CPU, we pass it a task and a stack to use. As the stack is always the task's stack, which can be derived from the task, let's have the secondary CPU derive this itself and avoid passing redundant information. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Suzuki Poulose <suzuki.poulose@arm.com> Cc: Will Deacon <will@kernel.org> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20210520115031.18509-5-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-05-26arm64: smccc: Add support for SMCCCv1.2 extended input/output registersSudeep Holla1-0/+9
SMCCC v1.2 allows x8-x17 to be used as parameter registers and x4—x17 to be used as result registers in SMC64/HVC64. Arm Firmware Framework for Armv8-A specification makes use of x0-x7 as parameter and result registers. There are other users like Hyper-V who intend to use beyond x0-x7 as well. Current SMCCC interface in the kernel just use x0-x7 as parameter and x0-x3 as result registers as required by SMCCCv1.0. Let us add new interface to support this extended set of input/output registers namely x0-x17 as both parameter and result registers. Acked-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Cc: Will Deacon <will@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20210518163618.43950-1-sudeep.holla@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2021-05-01Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-0/+3
Pull kvm updates from Paolo Bonzini: "This is a large update by KVM standards, including AMD PSP (Platform Security Processor, aka "AMD Secure Technology") and ARM CoreSight (debug and trace) changes. ARM: - CoreSight: Add support for ETE and TRBE - Stage-2 isolation for the host kernel when running in protected mode - Guest SVE support when running in nVHE mode - Force W^X hypervisor mappings in nVHE mode - ITS save/restore for guests using direct injection with GICv4.1 - nVHE panics now produce readable backtraces - Guest support for PTP using the ptp_kvm driver - Performance improvements in the S2 fault handler x86: - AMD PSP driver changes - Optimizations and cleanup of nested SVM code - AMD: Support for virtual SPEC_CTRL - Optimizations of the new MMU code: fast invalidation, zap under read lock, enable/disably dirty page logging under read lock - /dev/kvm API for AMD SEV live migration (guest API coming soon) - support SEV virtual machines sharing the same encryption context - support SGX in virtual machines - add a few more statistics - improved directed yield heuristics - Lots and lots of cleanups Generic: - Rework of MMU notifier interface, simplifying and optimizing the architecture-specific code - a handful of "Get rid of oprofile leftovers" patches - Some selftests improvements" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (379 commits) KVM: selftests: Speed up set_memory_region_test selftests: kvm: Fix the check of return value KVM: x86: Take advantage of kvm_arch_dy_has_pending_interrupt() KVM: SVM: Skip SEV cache flush if no ASIDs have been used KVM: SVM: Remove an unnecessary prototype declaration of sev_flush_asids() KVM: SVM: Drop redundant svm_sev_enabled() helper KVM: SVM: Move SEV VMCB tracking allocation to sev.c KVM: SVM: Explicitly check max SEV ASID during sev_hardware_setup() KVM: SVM: Unconditionally invoke sev_hardware_teardown() KVM: SVM: Enable SEV/SEV-ES functionality by default (when supported) KVM: SVM: Condition sev_enabled and sev_es_enabled on CONFIG_KVM_AMD_SEV=y KVM: SVM: Append "_enabled" to module-scoped SEV/SEV-ES control variables KVM: SEV: Mask CPUID[0x8000001F].eax according to supported features KVM: SVM: Move SEV module params/variables to sev.c KVM: SVM: Disable SEV/SEV-ES if NPT is disabled KVM: SVM: Free sev_asid_bitmap during init if SEV setup fails KVM: SVM: Zero out the VMCB array used to track SEV ASID association x86/sev: Drop redundant and potentially misleading 'sev_enabled' KVM: x86: Move reverse CPUID helpers to separate header file KVM: x86: Rename GPR accessors to make mode-aware variants the defaults ...
2021-04-15Merge branch 'for-next/pac-set-get-enabled-keys' into for-next/coreCatalin Marinas1-4/+1
* for-next/pac-set-get-enabled-keys: : Introduce arm64 prctl(PR_PAC_{SET,GET}_ENABLED_KEYS). arm64: pac: Optimize kernel entry/exit key installation code paths arm64: Introduce prctl(PR_PAC_{SET,GET}_ENABLED_KEYS) arm64: mte: make the per-task SCTLR_EL1 field usable elsewhere
2021-04-13arm64: pac: Optimize kernel entry/exit key installation code pathsPeter Collingbourne1-4/+0
The kernel does not use any keys besides IA so we don't need to install IB/DA/DB/GA on kernel exit if we arrange to install them on task switch instead, which we can expect to happen an order of magnitude less often. Furthermore we can avoid installing the user IA in the case where the user task has IA disabled and just leave the kernel IA installed. This also lets us avoid needing to install IA on kernel entry. On an Apple M1 under a hypervisor, the overhead of kernel entry/exit has been measured to be reduced by 15.6ns in the case where IA is enabled, and 31.9ns in the case where IA is disabled. Signed-off-by: Peter Collingbourne <pcc@google.com> Link: https://linux-review.googlesource.com/id/Ieddf6b580d23c9e0bed45a822dabe72d2ffc9a8e Link: https://lore.kernel.org/r/2d653d055f38f779937f2b92f8ddd5cf9e4af4f4.1616123271.git.pcc@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-04-13arm64: Introduce prctl(PR_PAC_{SET,GET}_ENABLED_KEYS)Peter Collingbourne1-0/+1
This change introduces a prctl that allows the user program to control which PAC keys are enabled in a particular task. The main reason why this is useful is to enable a userspace ABI that uses PAC to sign and authenticate function pointers and other pointers exposed outside of the function, while still allowing binaries conforming to the ABI to interoperate with legacy binaries that do not sign or authenticate pointers. The idea is that a dynamic loader or early startup code would issue this prctl very early after establishing that a process may load legacy binaries, but before executing any PAC instructions. This change adds a small amount of overhead to kernel entry and exit due to additional required instruction sequences. On a DragonBoard 845c (Cortex-A75) with the powersave governor, the overhead of similar instruction sequences was measured as 4.9ns when simulating the common case where IA is left enabled, or 43.7ns when simulating the uncommon case where IA is disabled. These numbers can be seen as the worst case scenario, since in more realistic scenarios a better performing governor would be used and a newer chip would be used that would support PAC unlike Cortex-A75 and would be expected to be faster than Cortex-A75. On an Apple M1 under a hypervisor, the overhead of the entry/exit instruction sequences introduced by this patch was measured as 0.3ns in the case where IA is left enabled, and 33.0ns in the case where IA is disabled. Signed-off-by: Peter Collingbourne <pcc@google.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Link: https://linux-review.googlesource.com/id/Ibc41a5e6a76b275efbaa126b31119dc197b927a5 Link: https://lore.kernel.org/r/d6609065f8f40397a4124654eb68c9f490b4d477.1616123271.git.pcc@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-04-13Merge remote-tracking branch 'arm64/for-next/neon-softirqs-disabled' into ↵Marc Zyngier1-0/+2
kvmarm-master/next Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-04-12arm64: fpsimd: run kernel mode NEON with softirqs disabledArd Biesheuvel1-0/+2
Kernel mode NEON can be used in task or softirq context, but only in a non-nesting manner, i.e., softirq context is only permitted if the interrupt was not taken at a point where the kernel was using the NEON in task context. This means all users of kernel mode NEON have to be aware of this limitation, and either need to provide scalar fallbacks that may be much slower (up to 20x for AES instructions) and potentially less safe, or use an asynchronous interface that defers processing to a later time when the NEON is guaranteed to be available. Given that grabbing and releasing the NEON is cheap, we can relax this restriction, by increasing the granularity of kernel mode NEON code, and always disabling softirq processing while the NEON is being used in task context. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20210302090118.30666-4-ardb@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-03-19KVM: arm64: Set host stage 2 using kvm_nvhe_init_paramsQuentin Perret1-0/+3
Move the registers relevant to host stage 2 enablement to kvm_nvhe_init_params to prepare the ground for enabling it in later patches. Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210319100146.1149909-22-qperret@google.com
2021-02-09arm64: Honor VHE being disabled from the command-lineMarc Zyngier1-0/+3
Finally we can check whether VHE is disabled on the command line, and not enable it if that's the user's wish. Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: David Brazdil <dbrazdil@google.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20210208095732.3267263-16-maz@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-01-13arm64: rename S_FRAME_SIZE to PT_REGS_SIZEJianlin Lv1-1/+1
S_FRAME_SIZE is the size of the pt_regs structure, no longer the size of the kernel stack frame, the name is misleading. In keeping with arm32, rename S_FRAME_SIZE to PT_REGS_SIZE. Signed-off-by: Jianlin Lv <Jianlin.Lv@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20210112015813.2340969-1-Jianlin.Lv@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-12-22arm64: mte: switch GCR_EL1 in kernel entry and exitVincenzo Frascino1-0/+3
When MTE is present, the GCR_EL1 register contains the tags mask that allows to exclude tags from the random generation via the IRG instruction. With the introduction of the new Tag-Based KASAN API that provides a mechanism to reserve tags for special reasons, the MTE implementation has to make sure that the GCR_EL1 setting for the kernel does not affect the userspace processes and viceversa. Save and restore the kernel/user mask in GCR_EL1 in kernel entry and exit. Link: https://lkml.kernel.org/r/578b03294708cc7258fad0dc9c2a2e809e5a8214.1606161801.git.andreyknvl@google.com Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Co-developed-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Marco Elver <elver@google.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-04KVM: arm64: Init MAIR/TCR_EL2 from params structDavid Brazdil1-0/+2
MAIR_EL2 and TCR_EL2 are currently initialized from their _EL1 values. This will not work once KVM starts intercepting PSCI ON/SUSPEND SMCs and initializing EL2 state before EL1 state. Obtain the EL1 values during KVM init and store them in the init params struct. The struct will stay in memory and can be used when booting new cores. Take the opportunity to move copying the T0SZ value from idmap_t0sz in KVM init rather than in .hyp.idmap.text. This avoids the need for the idmap_t0sz symbol alias. Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201202184122.26046-12-dbrazdil@google.com
2020-12-04KVM: arm64: Move hyp-init params to a per-CPU structDavid Brazdil1-0/+3
Once we start initializing KVM on newly booted cores before the rest of the kernel, parameters to __do_hyp_init will need to be provided by EL2 rather than EL1. At that point it will not be possible to pass its three arguments directly because PSCI_CPU_ON only supports one context argument. Refactor __do_hyp_init to accept its parameters in a struct. This prepares the code for KVM booting cores as well as removes any limits on the number of __do_hyp_init arguments. Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201202184122.26046-11-dbrazdil@google.com
2020-12-02arm64: uaccess: remove set_fs()Mark Rutland1-2/+1
Now that the uaccess primitives dont take addr_limit into account, we have no need to manipulate this via set_fs() and get_fs(). Remove support for these, along with some infrastructure this renders redundant. We no longer need to flip UAO to access kernel memory under KERNEL_DS, and head.S unconditionally clears UAO for all kernel configurations via an ERET in init_kernel_el. Thus, we don't need to dynamically flip UAO, nor do we need to context-switch it. However, we still need to adjust PAN during SDEI entry. Masking of __user pointers no longer needs to use the dynamic value of addr_limit, and can use a constant derived from the maximum possible userspace task size. A new TASK_SIZE_MAX constant is introduced for this, which is also used by core code. In configurations supporting 52-bit VAs, this may include a region of unusable VA space above a 48-bit TTBR0 limit, but never includes any portion of TTBR1. Note that TASK_SIZE_MAX is an exclusive limit, while USER_DS and KERNEL_DS were inclusive limits, and is converted to a mask by subtracting one. As the SDEI entry code repurposes the otherwise unnecessary pt_regs::orig_addr_limit field to store the TTBR1 of the interrupted context, for now we rename that to pt_regs::sdei_ttbr1. In future we can consider factoring that out. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: James Morse <james.morse@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201202131558.39270-10-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-07-07KVM: arm64: Make struct kvm_regs userspace-onlyMarc Zyngier1-2/+1
struct kvm_regs is used by userspace to indicate which register gets accessed by the {GET,SET}_ONE_REG API. But as we're about to refactor the layout of the in-kernel register structures, we need the kernel to move away from it. Let's make kvm_regs userspace only, and let the kernel map it to its own internal representation. Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-06-04Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-1/+1
Pull kvm updates from Paolo Bonzini: "ARM: - Move the arch-specific code into arch/arm64/kvm - Start the post-32bit cleanup - Cherry-pick a few non-invasive pre-NV patches x86: - Rework of TLB flushing - Rework of event injection, especially with respect to nested virtualization - Nested AMD event injection facelift, building on the rework of generic code and fixing a lot of corner cases - Nested AMD live migration support - Optimization for TSC deadline MSR writes and IPIs - Various cleanups - Asynchronous page fault cleanups (from tglx, common topic branch with tip tree) - Interrupt-based delivery of asynchronous "page ready" events (host side) - Hyper-V MSRs and hypercalls for guest debugging - VMX preemption timer fixes s390: - Cleanups Generic: - switch vCPU thread wakeup from swait to rcuwait The other architectures, and the guest side of the asynchronous page fault work, will come next week" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (256 commits) KVM: selftests: fix rdtsc() for vmx_tsc_adjust_test KVM: check userspace_addr for all memslots KVM: selftests: update hyperv_cpuid with SynDBG tests x86/kvm/hyper-v: Add support for synthetic debugger via hypercalls x86/kvm/hyper-v: enable hypercalls regardless of hypercall page x86/kvm/hyper-v: Add support for synthetic debugger interface x86/hyper-v: Add synthetic debugger definitions KVM: selftests: VMX preemption timer migration test KVM: nVMX: Fix VMX preemption timer migration x86/kvm/hyper-v: Explicitly align hcall param for kvm_hyperv_exit KVM: x86/pmu: Support full width counting KVM: x86/pmu: Tweak kvm_pmu_get_msr to pass 'struct msr_data' in KVM: x86: announce KVM_FEATURE_ASYNC_PF_INT KVM: x86: acknowledgment mechanism for async pf page ready notifications KVM: x86: interrupt based APF 'page ready' event delivery KVM: introduce kvm_read_guest_offset_cached() KVM: rename kvm_arch_can_inject_async_page_present() to kvm_arch_can_dequeue_async_page_present() KVM: x86: extend struct kvm_vcpu_pv_apf_data with token info Revert "KVM: async_pf: Fix #DF due to inject "Page not Present" and "Page Ready" exceptions simultaneously" KVM: VMX: Replace zero-length array with flexible-array ...
2020-05-28Merge branch 'for-next/scs' into for-next/coreWill Deacon1-0/+4
Support for Clang's Shadow Call Stack in the kernel (Sami Tolvanen and Will Deacon) * for-next/scs: arm64: entry-ftrace.S: Update comment to indicate that x18 is live scs: Move DEFINE_SCS macro into core code scs: Remove references to asm/scs.h from core code scs: Move scs_overflow_check() out of architecture code arm64: scs: Use 'scs_sp' register alias for x18 scs: Move accounting into alloc/free functions arm64: scs: Store absolute SCS stack pointer value in thread_info efi/libstub: Disable Shadow Call Stack arm64: scs: Add shadow stacks for SDEI arm64: Implement Shadow Call Stack arm64: Disable SCS for hypervisor code arm64: vdso: Disable Shadow Call Stack arm64: efi: Restore register x18 if it was corrupted arm64: Preserve register x18 when CPU is suspended arm64: Reserve register x18 from general allocation with SCS scs: Disable when function graph tracing is enabled scs: Add support for stack usage debugging scs: Add page accounting for shadow call stack allocations scs: Add support for Clang's Shadow Call Stack (SCS)
2020-05-18arm64: scs: Store absolute SCS stack pointer value in thread_infoWill Deacon1-1/+1
Storing the SCS information in thread_info as a {base,offset} pair introduces an additional load instruction on the ret-to-user path, since the SCS stack pointer in x18 has to be converted back to an offset by subtracting the base. Replace the offset with the absolute SCS stack pointer value instead and avoid the redundant load. Tested-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2020-05-16KVM: arm64: Kill off CONFIG_KVM_ARM_HOSTWill Deacon1-1/+1
CONFIG_KVM_ARM_HOST is just a proxy for CONFIG_KVM, so remove it in favour of the latter. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Fuad Tabba <tabba@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200505154520.194120-2-tabba@google.com
2020-05-15arm64: Implement Shadow Call StackSami Tolvanen1-0/+4
This change implements shadow stack switching, initial SCS set-up, and interrupt shadow stacks for arm64. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Will Deacon <will@kernel.org>
2020-04-28arm64: simplify ptrauth initializationMark Rutland1-3/+0
Currently __cpu_setup conditionally initializes the address authentication keys and enables them in SCTLR_EL1, doing so differently for the primary CPU and secondary CPUs, and skipping this work for CPUs returning from an idle state. For the latter case, cpu_do_resume restores the keys and SCTLR_EL1 value after the MMU has been enabled. This flow is rather difficult to follow, so instead let's move the primary and secondary CPU initialization into their respective boot paths. By following the example of cpu_do_resume and doing so once the MMU is enabled, we can always initialize the keys from the values in thread_struct, and avoid the machinery necessary to pass the keys in secondary_data or open-coding initialization for the boot CPU. This means we perform an additional RMW of SCTLR_EL1, but we already do this in the cpu_do_resume path, and for other features in cpufeature.c, so this isn't a major concern in a bringup path. Note that even while the enable bits are clear, the key registers are accessible. As this now renders the argument to __cpu_setup redundant, let's also remove that entirely. Future extensions can follow a similar approach to initialize values that differ for primary/secondary CPUs. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Reviewed-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20200423101606.37601-3-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2020-03-18arm64: initialize and switch ptrauth kernel keysKristina Martsenko1-0/+5
Set up keys to use pointer authentication within the kernel. The kernel will be compiled with APIAKey instructions, the other keys are currently unused. Each task is given its own APIAKey, which is initialized during fork. The key is changed during context switch and on kernel entry from EL0. The keys for idle threads need to be set before calling any C functions, because it is not possible to enter and exit a function with different keys. Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> [Amit: Modified secondary cores key structure, comments] Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-18arm64: install user ptrauth keys at kernel exit timeKristina Martsenko1-0/+11
As we're going to enable pointer auth within the kernel and use a different APIAKey for the kernel itself, so move the user APIAKey switch to EL0 exception return. The other 4 keys could remain switched during task switch, but are also moved to keep things consistent. Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: James Morse <james.morse@arm.com> Reviewed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> [Amit: commit msg, re-positioned the patch, comments] Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-11-06arm64: asm-offsets: add S_FPMark Rutland1-0/+1
So that assembly code can more easily manipulate the FP (x29) within a pt_regs, add an S_FP asm-offsets definition. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Torsten Duwe <duwe@suse.de> Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Tested-by: Torsten Duwe <duwe@suse.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org>
2019-06-26arm64: vdso: Remove unnecessary asm-offsets.c definitionsCatalin Marinas1-39/+0
Since the VDSO code has moved to C from assembly, there is no need to define and maintain the corresponding asm offsets. Fixes: 28b1a824a4f4 ("arm64: vdso: Substitute gettimeofday() with C implementation") Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@vger.kernel.org Cc: linux-kselftest@vger.kernel.org Cc: Will Deacon <will.deacon@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Russell King <linux@armlinux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@mips.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Mark Salyzyn <salyzyn@android.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Huw Davies <huw@codeweavers.com> Cc: Shijith Thotton <sthotton@marvell.com> Cc: Andre Przywara <andre.przywara@arm.com> Link: https://lkml.kernel.org/r/20190624135812.GC29120@arrakis.emea.arm.com
2019-06-22arm64: compat: Generate asm offsets for signalsVincenzo Frascino1-0/+6
Update asm-offsets for arm64 to generate the correct offsets for compat signals. They will be useful for the implementation of the compat sigreturn trampolines in vDSO context. Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Shijith Thotton <sthotton@marvell.com> Tested-by: Andre Przywara <andre.przywara@arm.com> Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@vger.kernel.org Cc: linux-kselftest@vger.kernel.org Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Russell King <linux@armlinux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@mips.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Mark Salyzyn <salyzyn@android.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Huw Davies <huw@codeweavers.com> Link: https://lkml.kernel.org/r/20190621095252.32307-9-vincenzo.frascino@arm.com
2019-06-22arm64: vdso: Substitute gettimeofday() with C implementationVincenzo Frascino1-11/+22
To take advantage of the commonly defined vdso interface for gettimeofday() the architectural code requires an adaptation. Re-implement the gettimeofday VDSO in C in order to use lib/vdso. With the new implementation arm64 gains support for CLOCK_BOOTTIME and CLOCK_TAI. [ tglx: Reformatted the function line breaks ] Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Shijith Thotton <sthotton@marvell.com> Tested-by: Andre Przywara <andre.przywara@arm.com> Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@vger.kernel.org Cc: linux-kselftest@vger.kernel.org Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Russell King <linux@armlinux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@mips.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Mark Salyzyn <salyzyn@android.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Huw Davies <huw@codeweavers.com> Link: https://lkml.kernel.org/r/20190621095252.32307-5-vincenzo.frascino@arm.com
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234Thomas Gleixner1-12/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not see http www gnu org licenses extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 503 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Enrico Weigelt <info@metux.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-17Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-0/+7
Pull KVM updates from Paolo Bonzini: "ARM: - support for SVE and Pointer Authentication in guests - PMU improvements POWER: - support for direct access to the POWER9 XIVE interrupt controller - memory and performance optimizations x86: - support for accessing memory not backed by struct page - fixes and refactoring Generic: - dirty page tracking improvements" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (155 commits) kvm: fix compilation on aarch64 Revert "KVM: nVMX: Expose RDPMC-exiting only when guest supports PMU" kvm: x86: Fix L1TF mitigation for shadow MMU KVM: nVMX: Disable intercept for FS/GS base MSRs in vmcs02 when possible KVM: PPC: Book3S: Remove useless checks in 'release' method of KVM device KVM: PPC: Book3S HV: XIVE: Fix spelling mistake "acessing" -> "accessing" KVM: PPC: Book3S HV: Make sure to load LPID for radix VCPUs kvm: nVMX: Set nested_run_pending in vmx_set_nested_state after checks complete tests: kvm: Add tests for KVM_SET_NESTED_STATE KVM: nVMX: KVM_SET_NESTED_STATE - Tear down old EVMCS state before setting new state tests: kvm: Add tests for KVM_CAP_MAX_VCPUS and KVM_CAP_MAX_CPU_ID tests: kvm: Add tests to .gitignore KVM: Introduce KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 KVM: Fix kvm_clear_dirty_log_protect off-by-(minus-)one KVM: Fix the bitmap range to copy during clear dirty KVM: arm64: Fix ptrauth ID register masking logic KVM: x86: use direct accessors for RIP and RSP KVM: VMX: Use accessors for GPRs outside of dedicated caching logic KVM: x86: Omit caching logic for always-available GPRs kvm, x86: Properly check whether a pfn is an MMIO or not ...
2019-04-24arm64: KVM: Encapsulate kvm_cpu_context in kvm_host_dataAndrew Murray1-0/+1
The virt/arm core allocates a kvm_cpu_context_t percpu, at present this is a typedef to kvm_cpu_context and is used to store host cpu context. The kvm_cpu_context structure is also used elsewhere to hold vcpu context. In order to use the percpu to hold additional future host information we encapsulate kvm_cpu_context in a new structure and rename the typedef and percpu to match. Signed-off-by: Andrew Murray <andrew.murray@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-24KVM: arm/arm64: Context-switch ptrauth registersMark Rutland1-0/+6
When pointer authentication is supported, a guest may wish to use it. This patch adds the necessary KVM infrastructure for this to work, with a semi-lazy context switch of the pointer auth state. Pointer authentication feature is only enabled when VHE is built in the kernel and present in the CPU implementation so only VHE code paths are modified. When we schedule a vcpu, we disable guest usage of pointer authentication instructions and accesses to the keys. While these are disabled, we avoid context-switching the keys. When we trap the guest trying to use pointer authentication functionality, we change to eagerly context-switching the keys, and enable the feature. The next time the vcpu is scheduled out/in, we start again. However the host key save is optimized and implemented inside ptrauth instruction/register access trap. Pointer authentication consists of address authentication and generic authentication, and CPUs in a system might have varied support for either. Where support for either feature is not uniform, it is hidden from guests via ID register emulation, as a result of the cpufeature framework in the host. Unfortunately, address authentication and generic authentication cannot be trapped separately, as the architecture provides a single EL2 trap covering both. If we wish to expose one without the other, we cannot prevent a (badly-written) guest from intermittently using a feature which is not uniformly supported (when scheduled on a physical CPU which supports the relevant feature). Hence, this patch expects both type of authentication to be present in a cpu. This switch of key is done from guest enter/exit assembly as preparation for the upcoming in-kernel pointer authentication support. Hence, these key switching routines are not implemented in C code as they may cause pointer authentication key signing error in some situations. Signed-off-by: Mark Rutland <mark.rutland@arm.com> [Only VHE, key switch in full assembly, vcpu_has_ptrauth checks , save host key in ptrauth exception trap] Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Cc: Christoffer Dall <christoffer.dall@arm.com> Cc: kvmarm@lists.cs.columbia.edu [maz: various fixups] Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-16arm64: vdso: Fix clock_getres() for CLOCK_REALTIMEVincenzo Frascino1-1/+1
clock_getres() in the vDSO library has to preserve the same behaviour of posix_get_hrtimer_res(). In particular, posix_get_hrtimer_res() does: sec = 0; ns = hrtimer_resolution; where 'hrtimer_resolution' depends on whether or not high resolution timers are enabled, which is a runtime decision. The vDSO incorrectly returns the constant CLOCK_REALTIME_RES. Fix this by exposing 'hrtimer_resolution' in the vDSO datapage and returning that instead. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> [will: Use WRITE_ONCE(), move adr off COARSE path, renumber labels, use 'w' reg] Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-02-06arm64: Make PMR part of task contextJulien Thierry1-0/+1
In order to replace PSR.I interrupt disabling/enabling with ICC_PMR_EL1 interrupt masking, ICC_PMR_EL1 needs to be saved/restored when taking/returning from an exception. This mimics the way hardware saves and restores PSR.I bit in spsr_el1 for exceptions and ERET. Add PMR to the registers to save in the pt_regs struct upon kernel entry, and restore it before ERET. Also, initialize it to a sane value when creating new tasks. Signed-off-by: Julien Thierry <julien.thierry@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-01-21arm64: asm-offsets: remove unused offsetsAndrew Murray1-20/+0
There are a number of offsets defined in asm-offsets.c which no longer have any users. Let's clean this up by removing them. All the remaining offsets are in use. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Andrew Murray <andrew.murray@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-12-12arm64: enable per-task stack canariesArd Biesheuvel1-0/+3
This enables the use of per-task stack canary values if GCC has support for emitting the stack canary reference relative to the value of sp_el0, which holds the task struct pointer in the arm64 kernel. The $(eval) extends KBUILD_CFLAGS at the moment the make rule is applied, which means asm-offsets.o (which we rely on for the offset value) is built without the arguments, and everything built afterwards has the options set. Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-05-31arm64: KVM: Handle guest's ARCH_WORKAROUND_2 requestsMarc Zyngier1-0/+1
In order to forward the guest's ARCH_WORKAROUND_2 calls to EL3, add a small(-ish) sequence to handle it at EL2. Special care must be taken to track the state of the guest itself by updating the workaround flags. We also rely on patching to enable calls into the firmware. Note that since we need to execute branches, this always executes after the Spectre-v2 mitigation has been applied. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-04-11arm64: assembler: add macros to conditionally yield the NEON under PREEMPTArd Biesheuvel1-0/+3
Add support macros to conditionally yield the NEON (and thus the CPU) that may be called from the assembler code. In some cases, yielding the NEON involves saving and restoring a non trivial amount of context (especially in the CRC folding algorithms), and so the macro is split into three, and the code in between is only executed when the yield path is taken, allowing the context to be preserved. The third macro takes an optional label argument that marks the resume path after a yield has been performed. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-19KVM: arm64: Avoid storing the vcpu pointer on the stackChristoffer Dall1-0/+1
We already have the percpu area for the host cpu state, which points to the VCPU, so there's no need to store the VCPU pointer on the stack on every context switch. We can be a little more clever and just use tpidr_el2 for the percpu offset and load the VCPU pointer from the host context. This has the benefit of being able to retrieve the host context even when our stack is corrupted, and it has a potential performance benefit because we trade a store plus a load for an mrs and a load on a round trip to the guest. This does require us to calculate the percpu offset without including the offset from the kernel mapping of the percpu array to the linear mapping of the array (which is what we store in tpidr_el1), because a PC-relative generated address in EL2 is already giving us the hyp alias of the linear mapping of a kernel address. We do this in __cpu_init_hyp_mode() by using kvm_ksym_ref(). The code that accesses ESR_EL2 was previously using an alternative to use the _EL1 accessor on VHE systems, but this was actually unnecessary as the _EL1 accessor aliases the ESR_EL2 register on VHE, and the _EL2 accessor does the same thing on both systems. Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-01-16KVM: arm64: Handle RAS SErrors from EL2 on guest exitJames Morse1-0/+1
We expect to have firmware-first handling of RAS SErrors, with errors notified via an APEI method. For systems without firmware-first, add some minimal handling to KVM. There are two ways KVM can take an SError due to a guest, either may be a RAS error: we exit the guest due to an SError routed to EL2 by HCR_EL2.AMO, or we take an SError from EL2 when we unmask PSTATE.A from __guest_exit. The current SError from EL2 code unmasks SError and tries to fence any pending SError into a single instruction window. It then leaves SError unmasked. With the v8.2 RAS Extensions we may take an SError for a 'corrected' error, but KVM is only able to handle SError from EL2 if they occur during this single instruction window... The RAS Extensions give us a new instruction to synchronise and consume SErrors. The RAS Extensions document (ARM DDI0587), '2.4.1 ESB and Unrecoverable errors' describes ESB as synchronising SError interrupts generated by 'instructions, translation table walks, hardware updates to the translation tables, and instruction fetches on the same PE'. This makes ESB equivalent to KVMs existing 'dsb, mrs-daifclr, isb' sequence. Use the alternatives to synchronise and consume any SError using ESB instead of unmasking and taking the SError. Set ARM_EXIT_WITH_SERROR_BIT in the exit_code so that we can restart the vcpu if it turns out this SError has no impact on the vcpu. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-13arm64: kernel: Add arch-specific SDEI entry code and CPU maskingJames Morse1-0/+5
The Software Delegated Exception Interface (SDEI) is an ARM standard for registering callbacks from the platform firmware into the OS. This is typically used to implement RAS notifications. Such notifications enter the kernel at the registered entry-point with the register values of the interrupted CPU context. Because this is not a CPU exception, it cannot reuse the existing entry code. (crucially we don't implicitly know which exception level we interrupted), Add the entry point to entry.S to set us up for calling into C code. If the event interrupted code that had interrupts masked, we always return to that location. Otherwise we pretend this was an IRQ, and use SDEI's complete_and_resume call to return to vbar_el1 + offset. This allows the kernel to deliver signals to user space processes. For KVM this triggers the world switch, a quick spin round vcpu_run, then back into the guest, unless there are pending signals. Add sdei_mask_local_cpu() calls to the smp_send_stop() code, this covers the panic() code-path, which doesn't invoke cpuhotplug notifiers. Because we can interrupt entry-from/exit-to another EL, we can't trust the value in sp_el0 or x29, even if we interrupted the kernel, in this case the code in entry.S will save/restore sp_el0 and use the value in __entry_task. When we have VMAP stacks we can interrupt the stack-overflow test, which stirs x0 into sp, meaning we have to have our own VMAP stacks. For now these are allocated when we probe the interface. Future patches will add refcounting hooks to allow the arch code to allocate them lazily. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>