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2020-03-24arm: Remove 32bit KVM host supportMarc Zyngier1-175/+0
That's it. Remove all references to KVM itself, and document that although it is no more, the ABI between SVC and HYP still exists. Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Will Deacon <will@kernel.org> Acked-by: Vladimir Murzin <vladimir.murzin@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Christoffer Dall <christoffer.dall@arm.com>
2019-10-21KVM: arm/arm64: Factor out hypercall handling from PSCI codeChristoffer Dall1-1/+1
We currently intertwine the KVM PSCI implementation with the general dispatch of hypercall handling, which makes perfect sense because PSCI is the only category of hypercalls we support. However, as we are about to support additional hypercalls, factor out this functionality into a separate hypercall handler file. Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> [steven.price@arm.com: rebased] Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Steven Price <steven.price@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266Thomas Gleixner1-13/+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 write to the free software foundation 51 franklin street fifth floor boston ma 02110 1301 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 67 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141333.953658117@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-07arm/arm64: KVM: Advertise SMCCC v1.1Marc Zyngier1-1/+1
The new SMC Calling Convention (v1.1) allows for a reduced overhead when calling into the firmware, and provides a new feature discovery mechanism. Make it visible to KVM guests. Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-07arm/arm64: KVM: Consolidate the PSCI include filesMarc Zyngier1-1/+1
As we're about to update the PSCI support, and because I'm lazy, let's move the PSCI include file to include/kvm so that both ARM architectures can find it. Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-07arm: KVM: Fix SMCCC handling of unimplemented SMC/HVC callsMarc Zyngier1-2/+11
KVM doesn't follow the SMCCC when it comes to unimplemented calls, and inject an UNDEF instead of returning an error. Since firmware calls are now used for security mitigation, they are becoming more common, and the undef is counter productive. Instead, let's follow the SMCCC which states that -1 must be returned to the caller when getting an unknown function number. Cc: <stable@vger.kernel.org> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-08-08KVM: arm: implements the kvm_arch_vcpu_in_kernel()Longpeng(Mike)1-1/+1
This implements the kvm_arch_vcpu_in_kernel() for ARM, and adjusts the calls to kvm_vcpu_on_spin(). Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-08KVM: add spinlock optimization frameworkLongpeng(Mike)1-1/+1
If a vcpu exits due to request a user mode spinlock, then the spinlock-holder may be preempted in user mode or kernel mode. (Note that not all architectures trap spin loops in user mode, only AMD x86 and ARM/ARM64 currently do). But if a vcpu exits in kernel mode, then the holder must be preempted in kernel mode, so we should choose a vcpu in kernel mode as a more likely candidate for the lock holder. This introduces kvm_arch_vcpu_in_kernel() to decide whether the vcpu is in kernel-mode when it's preempted. kvm_vcpu_on_spin's new argument says the same of the spinning VCPU. Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-15Merge branch 'kvmarm-master/master' into HEADMarc Zyngier1-2/+2
2017-06-04KVM: arm/arm64: properly use vcpu requestsAndrew Jones1-0/+1
arm/arm64 already has one VCPU request used when setting pause, but it doesn't properly check requests in VCPU RUN. Check it and also make sure we set vcpu->mode at the appropriate time (before the check) and with the appropriate barriers. See Documentation/virtual/kvm/vcpu-requests.rst. Also make sure we don't leave any vcpu requests we don't intend to handle later set in the request bitmap. If we don't clear them, then kvm_request_pending() may return true when it shouldn't. Using VCPU requests properly fixes a small race where pause could get set just as a VCPU was entering guest mode. Signed-off-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-05-15KVM: arm: plug potential guest hardware debug leakageZhichao Huang1-2/+2
Hardware debugging in guests is not intercepted currently, it means that a malicious guest can bring down the entire machine by writing to the debug registers. This patch enable trapping of all debug registers, preventing the guests to access the debug registers. This includes access to the debug mode(DBGDSCR) in the guest world all the time which could otherwise mess with the host state. Reads return 0 and writes are ignored (RAZ_WI). The result is the guest cannot detect any working hardware based debug support. As debug exceptions are still routed to the guest normal debug using software based breakpoints still works. To support debugging using hardware registers we need to implement a debug register aware world switch as well as special trapping for registers that may affect the host state. Cc: stable@vger.kernel.org Signed-off-by: Zhichao Huang <zhichao.huang@linaro.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09ARM: KVM: Gracefully handle hyp-stubs being restored from under our feetMarc Zyngier1-0/+8
Should kvm_reboot() be invoked while guest is running, an IPI wil be issued, forcing the guest to exit and HYP being reset to the stubs. We will then try to reenter the guest, only to get an error (HVC_STUB_ERR). This patch allows this case to be gracefully handled by exiting the run loop. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-03-07arm: KVM: Survive unknown traps from guestsMark Rutland1-7/+12
Currently we BUG() if we see a HSR.EC value we don't recognise. As configurable disables/enables are added to the architecture (controlled by RES1/RES0 bits respectively), with associated synchronous exceptions, it may be possible for a guest to trigger exceptions with classes that we don't recognise. While we can't service these exceptions in a manner useful to the guest, we can avoid bringing down the host. Per ARM DDI 0406C.c, all currently unallocated HSR EC encodings are reserved, and per ARM DDI 0487A.k_iss10775, page G6-4395, EC values within the range 0x00 - 0x2c are reserved for future use with synchronous exceptions, and EC values within the range 0x2d - 0x3f may be used for either synchronous or asynchronous exceptions. The patch makes KVM handle any unknown EC by injecting an UNDEFINED exception into the guest, with a corresponding (ratelimited) warning in the host dmesg. We could later improve on this with with a new (opt-in) exit to the host userspace. Cc: Dave Martin <dave.martin@arm.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-09-08arm: KVM: Drop unreachable HYP abort handlersMarc Zyngier1-27/+0
Both data and prefetch aborts occuring in HYP lead to a well deserved panic. Let's get rid of these silly handlers. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-08arm: KVM: Inject a Virtual Abort if it was pendingMarc Zyngier1-0/+19
If we have caught an Abort whilst exiting, we've tagged the exit code with the pending information. In that case, let's re-inject the error into the guest, after having adjusted the PC if required. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-08arm: KVM: Add HYP async abort handlerMarc Zyngier1-0/+3
If we've exited the guest because it has triggered an asynchronous abort, a possible course of action is to let it know it screwed up by giving it a Virtual Abort to chew on. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-02-29ARM: KVM: Remove handling of ARM_EXCEPTION_DATA/PREF_ABORTMarc Zyngier1-2/+0
These are now handled as a panic, so there is little point in keeping them around. Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29ARM: KVM: Remove unused hyp_pc fieldMarc Zyngier1-5/+0
This field was never populated, and the panic code already does something similar. Delete the related code. Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-14KVM: arm/arm64: Count guest exit due to various reasonsAmit Tomar1-0/+3
It would add guest exit statistics to debugfs, this can be helpful while measuring KVM performance. [ Renamed some of the field names - Christoffer ] Signed-off-by: Amit Singh Tomar <amittomer25@gmail.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-01-15ARM: KVM: extend WFI tracepoint to differentiate between wfi and wfeAndre Przywara1-3/+5
Currently the trace printk talks about "wfi" only, though the trace point triggers both on wfi and wfe traps. Add a parameter to differentiate between the two. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Wei Huang <wei@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-08-29arm/arm64: KVM: Complete WFI/WFE instructionsChristoffer Dall1-0/+2
The architecture specifies that when the processor wakes up from a WFE or WFI instruction, the instruction is considered complete, however we currrently return to EL1 (or EL0) at the WFI/WFE instruction itself. While most guests may not be affected by this because their local exception handler performs an exception returning setting the event bit or with an interrupt pending, some guests like UEFI will get wedged due this little mishap. Simply skip the instruction when we have completed the emulation. Cc: <stable@vger.kernel.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-04-30ARM/ARM64: KVM: Make kvm_psci_call() return convention more flexibleAnup Patel1-3/+7
Currently, the kvm_psci_call() returns 'true' or 'false' based on whether the PSCI function call was handled successfully or not. This does not help us emulate system-level PSCI functions where the actual emulation work will be done by user space (QEMU or KVMTOOL). Examples of such system-level PSCI functions are: PSCI v0.2 SYSTEM_OFF and SYSTEM_RESET. This patch updates kvm_psci_call() to return three types of values: 1) > 0 (success) 2) = 0 (success but exit to user space) 3) < 0 (errors) Signed-off-by: Anup Patel <anup.patel@linaro.org> Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-01-09KVM: ARM: Remove duplicate includeSachin Kamat1-2/+0
trace.h was included twice. Remove duplicate inclusion. Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-10-18KVM: ARM: Update comments for kvm_handle_wfiChristoffer Dall1-6/+8
Update comments to reflect what is really going on and add the TWE bit to the comments in kvm_arm.h. Also renames the function to kvm_handle_wfx like is done on arm64 for consistency and uber-correctness. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-10-18ARM: KVM: Yield CPU when vcpu executes a WFEMarc Zyngier1-1/+5
On an (even slightly) oversubscribed system, spinlocks are quickly becoming a bottleneck, as some vcpus are spinning, waiting for a lock to be released, while the vcpu holding the lock may not be running at all. This creates contention, and the observed slowdown is 40x for hackbench. No, this isn't a typo. The solution is to trap blocking WFEs and tell KVM that we're now spinning. This ensures that other vpus will get a scheduling boost, allowing the lock to be released more quickly. Also, using CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT slightly improves the performance when the VM is severely overcommited. Quick test to estimate the performance: hackbench 1 process 1000 2xA15 host (baseline): 1.843s 2xA15 guest w/o patch: 2.083s 4xA15 guest w/o patch: 80.212s 8xA15 guest w/o patch: Could not be bothered to find out 2xA15 guest w/ patch: 2.102s 4xA15 guest w/ patch: 3.205s 8xA15 guest w/ patch: 6.887s So we go from a 40x degradation to 1.5x in the 2x overcommit case, which is vaguely more acceptable. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-06-26ARM: KVM: Don't handle PSCI calls via SMCDave P Martin1-3/+0
Currently, kvmtool unconditionally declares that HVC should be used to call PSCI, so the function numbers in the DT tell the guest nothing about the function ID namespace or calling convention for SMC. We already assume that the guest will examine and honour the DT, since there is no way it could possibly guess the KVM-specific PSCI function IDs otherwise. So let's not encourage guests to violate what's specified in the DT by using SMC to make the call. [ Modified to apply to top of kvm/arm tree - Christoffer ] Signed-off-by: Dave P Martin <Dave.Martin@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
2013-05-03Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-armLinus Torvalds1-0/+164
Pull ARM updates from Russell King: "The major items included in here are: - MCPM, multi-cluster power management, part of the infrastructure required for ARMs big.LITTLE support. - A rework of the ARM KVM code to allow re-use by ARM64. - Error handling cleanups of the IS_ERR_OR_NULL() madness and fixes of that stuff for arch/arm - Preparatory patches for Cortex-M3 support from Uwe Kleine-König. There is also a set of three patches in here from Hugh/Catalin to address freeing of inappropriate page tables on LPAE. You already have these from akpm, but they were already part of my tree at the time he sent them, so unfortunately they'll end up with duplicate commits" * 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (77 commits) ARM: EXYNOS: remove unnecessary use of IS_ERR_VALUE() ARM: IMX: remove unnecessary use of IS_ERR_VALUE() ARM: OMAP: use consistent error checking ARM: cleanup: OMAP hwmod error checking ARM: 7709/1: mcpm: Add explicit AFLAGS to support v6/v7 multiplatform kernels ARM: 7700/2: Make cpu_init() notrace ARM: 7702/1: Set the page table freeing ceiling to TASK_SIZE ARM: 7701/1: mm: Allow arch code to control the user page table ceiling ARM: 7703/1: Disable preemption in broadcast_tlb*_a15_erratum() ARM: mcpm: provide an interface to set the SMP ops at run time ARM: mcpm: generic SMP secondary bringup and hotplug support ARM: mcpm_head.S: vlock-based first man election ARM: mcpm: Add baremetal voting mutexes ARM: mcpm: introduce helpers for platform coherency exit/setup ARM: mcpm: introduce the CPU/cluster power API ARM: multi-cluster PM: secondary kernel entry code ARM: cacheflush: add synchronization helpers for mixed cache state accesses ARM: cpu hotplug: remove majority of cache flushing from platforms ARM: smp: flush L1 cache in cpu_die() ARM: tegra: remove tegra specific cpu_disable() ...
2013-03-07ARM: KVM: move kvm_handle_wfi to handle_exit.cMarc Zyngier1-0/+19
It has little to do in emulate.c these days... Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2013-03-07KVM: ARM: Reintroduce trace_kvm_hvcChristoffer Dall1-0/+5
This one got lost in the move to handle_exit, so let's reintroduce it using an accessor to the immediate value field like the other ones. Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
2013-03-07ARM: KVM: move exit handler selection to a separate fileMarc Zyngier1-0/+140
The exit handler selection code cannot be shared with arm64 (two different modes, more exception classes...). Move it to a separate file (handle_exit.c). Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>