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2021-04-13Merge remote-tracking branch 'arm64/for-next/vhe-only' into kvmarm-master/nextMarc Zyngier
Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-04-08arm64: Get rid of CONFIG_ARM64_VHEMarc Zyngier
CONFIG_ARM64_VHE was introduced with ARMv8.1 (some 7 years ago), and has been enabled by default for almost all that time. Given that newer systems that are VHE capable are finally becoming available, and that some systems are even incapable of not running VHE, drop the configuration altogether. Anyone willing to stick to non-VHE on VHE hardware for obscure reasons should use the 'kvm-arm.mode=nvhe' command-line option. Suggested-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20210408131010.1109027-4-maz@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-04-08arm64: Cope with CPUs stuck in VHE modeMarc Zyngier
It seems that the CPUs part of the SoC known as Apple M1 have the terrible habit of being stuck with HCR_EL2.E2H==1, in violation of the architecture. Try and work around this deplorable state of affairs by detecting the stuck bit early and short-circuit the nVHE dance. Additional filtering code ensures that attempts at switching to nVHE from the command-line are also ignored. It is still unknown whether there are many more such nuggets to be found... Reported-by: Hector Martin <marcan@marcan.st> Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210408131010.1109027-3-maz@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-04-06arm64: KVM: Enable access to TRBE support for hostSuzuki K Poulose
For a nvhe host, the EL2 must allow the EL1&0 translation regime for TraceBuffer (MDCR_EL2.E2TB == 0b11). This must be saved/restored over a trip to the guest. Also, before entering the guest, we must flush any trace data if the TRBE was enabled. And we must prohibit the generation of trace while we are in EL1 by clearing the TRFCR_EL1. For vhe, the EL2 must prevent the EL1 access to the Trace Buffer. The MDCR_EL2 bit definitions for TRBE are available here : https://developer.arm.com/documentation/ddi0601/2020-12/AArch64-Registers/ Cc: Will Deacon <will@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210405164307.1720226-8-suzuki.poulose@arm.com Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
2021-02-24arm64: Add missing ISB after invalidating TLB in enter_vheMarc Zyngier
Although there has been a bit of back and forth on the subject, it appears that invalidating TLBs requires an ISB instruction after the TLBI/DSB sequence when FEAT_ETS is not implemented by the CPU. From the bible: | In an implementation that does not implement FEAT_ETS, a TLB | maintenance instruction executed by a PE, PEx, can complete at any | time after it is issued, but is only guaranteed to be finished for a | PE, PEx, after the execution of DSB by the PEx followed by a Context | synchronization event Add the missing ISB in enter_vhe(), just in case. Fixes: f359182291c7 ("arm64: Provide an 'upgrade to VHE' stub hypercall") Suggested-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20210224093738.3629662-4-maz@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-02-24arm64: VHE: Enable EL2 MMU from the idmapMarc Zyngier
Enabling the MMU requires the write to SCTLR_ELx (and the ISB that follows) to live in some identity-mapped memory. Otherwise, the translation will result in something totally unexpected (either fetching the wrong instruction stream, or taking a fault of some sort). This is exactly what happens in mutate_to_vhe(), as this code lives in the .hyp.text section, which isn't identity-mapped. With the right configuration, this explodes badly. Extract the MMU-enabling part of mutate_to_vhe(), and move it to its own function that lives in the idmap. This ensures nothing bad happens. Fixes: f359182291c7 ("arm64: Provide an 'upgrade to VHE' stub hypercall") Reported-by: "kernelci.org bot" <bot@kernelci.org> Tested-by: Guillaume Tucker <guillaume.tucker@collabora.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210224093738.3629662-2-maz@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-02-12Merge branch 'for-next/misc' into for-next/coreWill Deacon
Miscellaneous arm64 changes for 5.12. * for-next/misc: arm64: Make CPU_BIG_ENDIAN depend on ld.bfd or ld.lld 13.0.0+ arm64: vmlinux.ld.S: add assertion for tramp_pg_dir offset arm64: vmlinux.ld.S: add assertion for reserved_pg_dir offset arm64/ptdump:display the Linear Mapping start marker arm64: ptrace: Fix missing return in hw breakpoint code KVM: arm64: Move __hyp_set_vectors out of .hyp.text arm64: Include linux/io.h in mm/mmap.c arm64: cacheflush: Remove stale comment arm64: mm: Remove unused header file arm64/sparsemem: reduce SECTION_SIZE_BITS arm64/mm: Add warning for outside range requests in vmemmap_populate() arm64: Drop workaround for broken 'S' constraint with GCC 4.9
2021-02-09arm64: Honor VHE being disabled from the command-lineMarc Zyngier
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>
2021-02-09arm64: Move VHE-specific SPE setup to mutate_to_vhe()Marc Zyngier
There isn't much that a VHE kernel needs on top of whatever has been done for nVHE, so let's move the little we need to the VHE stub (the SPE setup), and drop the init_el2_state macro. No expected functional change. 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/20210208095732.3267263-8-maz@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-02-09arm64: Initialise as nVHE before switching to VHEMarc Zyngier
As we are aiming to be able to control whether we enable VHE or not, let's always drop down to EL1 first, and only then upgrade to VHE if at all possible. This means that if the kernel is booted at EL2, we always start with a nVHE init, drop to EL1 to initialise the the kernel, and only then upgrade the kernel EL to EL2 if possible (the process is obviously shortened for secondary CPUs). The resume path is handled similarly to a secondary CPU boot. 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/20210208095732.3267263-6-maz@kernel.org [will: Avoid calling switch_to_vhe twice on kaslr path] Signed-off-by: Will Deacon <will@kernel.org>
2021-02-08arm64: Provide an 'upgrade to VHE' stub hypercallMarc Zyngier
As we are about to change the way a VHE system boots, let's provide the core helper, in the form of a stub hypercall that enables VHE and replicates the full EL1 context at EL2, thanks to EL1 and VHE-EL2 being extremely similar. On exception return, the kernel carries on at EL2. Fancy! Nothing calls this new hypercall yet, so no functional change. 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/20210208095732.3267263-5-maz@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-01-28KVM: arm64: Move __hyp_set_vectors out of .hyp.textQuentin Perret
The .hyp.text section is supposed to be reserved for the nVHE EL2 code. However, there is currently one occurrence of EL1 executing code located in .hyp.text when calling __hyp_{re}set_vectors(), which happen to sit next to the EL2 stub vectors. While not a problem yet, such patterns will cause issues when removing the host kernel from the TCB, so a cleaner split would be preferable. Fix this by delimiting the end of the .hyp.text section in hyp-stub.S. Acked-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Quentin Perret <qperret@google.com> Link: https://lore.kernel.org/r/20210128173850.2478161-1-qperret@google.com Signed-off-by: Will Deacon <will@kernel.org>
2020-05-04arm64: kernel: Convert to modern annotations for assembly functionsMark Brown
In an effort to clarify and simplify the annotation of assembly functions in the kernel new macros have been introduced. These replace ENTRY and ENDPROC and also add a new annotation for static functions which previously had no ENTRY equivalent. Update the annotations in the core kernel code to the new macros. Signed-off-by: Mark Brown <broonie@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20200501115430.37315-3-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-03-24arm64: use mov_q instead of literal ldrRemi Denis-Courmont
In practice, this requires only 2 instructions, or even only 1 for the idmap_pg_dir size (with 4 or 64 KiB pages). Only the MAIR values needed more than 2 instructions and it was already converted to mov_q by 95b3f74bec203804658e17f86fe20755bb8abcb9. Signed-off-by: Remi Denis-Courmont <remi.denis.courmont@huawei.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com>
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234Thomas Gleixner
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>
2019-02-01arm64: hyp-stub: Forbid kprobing of the hyp-stubJames Morse
The hyp-stub is loaded by the kernel's early startup code at EL2 during boot, before KVM takes ownership later. The hyp-stub's text is part of the regular kernel text, meaning it can be kprobed. A breakpoint in the hyp-stub causes the CPU to spin in el2_sync_invalid. Add it to the __hyp_text. Signed-off-by: James Morse <james.morse@arm.com> Cc: stable@vger.kernel.org Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-04-09arm64: hyp-stub: Zero x0 on successful stub handlingMarc Zyngier
We now return HVC_STUB_ERR when a stub hypercall fails, but we leave whatever was in x0 on success. Zeroing it on return seems like a good idea. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09arm64: hyp-stub/KVM: Kill __hyp_get_vectorsMarc Zyngier
Nobody is using __hyp_get_vectors anymore, so let's remove both implementations (hyp-stub and KVM). Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09arm64: hyp-stub: Implement HVC_RESET_VECTORS stub hypercallMarc Zyngier
Let's define a new stub hypercall that resets the HYP configuration to its default: hyp-stub vectors, and MMU disabled. Of course, for the hyp-stub itself, this is a trivial no-op. Hypervisors will have a bit more work to do. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09arm64: hyp-stub: Define a return value for failed stub callsMarc Zyngier
Define a standard return value to be returned when a hyp stub call fails, and make KVM use it for ARM_EXCEPTION_HYP_GONE (instead of using a KVM-specific value). Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09arm64: hyp-stub: Don't save lr in the EL1 codeMarc Zyngier
The EL2 code is not corrupting lr anymore, so don't bother preserving it in the EL1 trampoline code. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09arm64: hyp-stub: Stop pointlessly clobbering lrMarc Zyngier
When entering the kernel hyp stub, we check whether or not we've made it here through an HVC instruction, clobbering lr (aka x30) in the process. This is completely pointless, as HVC is the only way to get here (all traps to EL2 are disabled, no interrupt override is applied). So let's remove this bit of code whose only point is to corrupt a valuable register. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2016-06-27arm64: Add back cpu reset routinesGeoff Levand
Commit 68234df4ea79 ("arm64: kill flush_cache_all()") removed the global arm64 routines cpu_reset() and cpu_soft_restart() needed by the arm64 kexec and kdump support. Add back a simplified version of cpu_soft_restart() with some changes needed for kexec in the new files cpu_reset.S, and cpu_reset.h. When a CPU is reset it needs to be put into the exception level it had when it entered the kernel. Update cpu_soft_restart() to accept an argument which signals if the reset address should be entered at EL1 or EL2, and add a new hypercall HVC_SOFT_RESTART which is used for the EL2 switch. Signed-off-by: Geoff Levand <geoff@infradead.org> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-04-28arm64: hyp/kvm: Make hyp-stub reject kvm_call_hyp()James Morse
A later patch implements kvm_arch_hardware_disable(), to remove kvm from el2, and re-instate the hyp-stub. This can happen while guests are running, particularly when kvm_reboot() calls kvm_arch_hardware_disable() on each cpu. This can interrupt a guest, remove kvm, then allow the guest to be scheduled again. This causes kvm_call_hyp() to be run against the hyp-stub. Change the hyp-stub to return a new exception type when this happens, and add code to kvm's handle_exit() to tell userspace we failed to enter the guest. Signed-off-by: James Morse <james.morse@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-28arm64: hyp/kvm: Make hyp-stub extensibleGeoff Levand
The existing arm64 hcall implementations are limited in that they only allow for two distinct hcalls; with the x0 register either zero or not zero. Also, the API of the hyp-stub exception vector routines and the KVM exception vector routines differ; hyp-stub uses a non-zero value in x0 to implement __hyp_set_vectors, whereas KVM uses it to implement kvm_call_hyp. To allow for additional hcalls to be defined and to make the arm64 hcall API more consistent across exception vector routines, change the hcall implementations to reserve all x0 values below 0xfff for hcalls such as {s,g}et_vectors(). Define two new preprocessor macros HVC_GET_VECTORS, and HVC_SET_VECTORS to be used as hcall type specifiers and convert the existing __hyp_get_vectors() and __hyp_set_vectors() routines to use these new macros when executing an HVC call. Also, change the corresponding hyp-stub and KVM el1_sync exception vector routines to use these new macros. Signed-off-by: Geoff Levand <geoff@infradead.org> [Merged two hcall patches, moved immediate value from esr to x0, use lr as a scratch register, changed limit to 0xfff] Signed-off-by: James Morse <james.morse@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-28arm64: kvm: Move lr save/restore from do_el2_call into EL1James Morse
Today the 'hvc' calling KVM or the hyp-stub is expected to preserve all registers. KVM saves/restores the registers it needs on the EL2 stack using do_el2_call(). The hyp-stub has no stack, later patches need to be able to be able to clobber the link register. Move the link register save/restore to the the call sites. Signed-off-by: James Morse <james.morse@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-07-08irqchip: gic-v3: Initial support for GICv3Marc Zyngier
The Generic Interrupt Controller (version 3) offers services that are similar to GICv2, with a number of additional features: - Affinity routing based on the CPU MPIDR (ARE) - System register for the CPU interfaces (SRE) - Support for more that 8 CPUs - Locality-specific Peripheral Interrupts (LPIs) - Interrupt Translation Services (ITS) This patch adds preliminary support for GICv3 with ARE and SRE, non-secure mode only. It relies on higher exception levels to grant ARE and SRE access. Support for LPI and ITS will be added at a later time. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jason Cooper <jason@lakedaemon.net> Reviewed-by: Zi Shen Lim <zlim@broadcom.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Tirumalesh Chalamarla <tchalamarla@cavium.com> Reviewed-by: Yun Wu <wuyun.wu@huawei.com> Reviewed-by: Zhen Lei <thunder.leizhen@huawei.com> Tested-by: Tirumalesh Chalamarla<tchalamarla@cavium.com> Tested-by: Radha Mohan Chintakuntla <rchintakuntla@cavium.com> Acked-by: Radha Mohan Chintakuntla <rchintakuntla@cavium.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Link: https://lkml.kernel.org/r/1404140510-5382-3-git-send-email-marc.zyngier@arm.com Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2012-12-05arm64: add hypervisor stubMarc Zyngier
If booted in EL2, install an dummy hypervisor whose only purpose is to be replaced by a full fledged one. A minimal API allows to: - obtain the current HYP vectors (__hyp_get_vectors) - set new HYP vectors (__hyp_set_vectors) Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>