summaryrefslogtreecommitdiffstats
path: root/arch/arm64/kvm/debug.c (follow)
Commit message (Collapse)AuthorAgeFilesLines
* KVM: arm64: debug: fix kernel-doc warningsRandy Dunlap2024-02-011-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change one "/**" comment to a common "/*" comment since the comment is not in kernel-doc format. Add description for the @vcpu function parameter. These changes prevent warnings: debug.c:27: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst * save/restore_guest_debug_regs debug.c:27: warning: missing initial short description on line: * save/restore_guest_debug_regs debug.c:149: warning: Function parameter or struct member 'vcpu' not described in 'kvm_arm_reset_debug_ptr' Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Oliver Upton <oliver.upton@linux.dev> Cc: James Morse <james.morse@arm.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Zenghui Yu <yuzenghui@huawei.com> Cc: linux-arm-kernel@lists.infradead.org Cc: kvmarm@lists.linux.dev Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Zenghui Yu <yuzenghui@huawei.com> Link: https://lore.kernel.org/r/20240117230714.31025-2-rdunlap@infradead.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
* arm64/sysreg: Rename TRBIDR_EL1 fields per auto-gen tools formatAnshuman Khandual2023-06-141-1/+1
| | | | | | | | | | | | | | | | | | | | This renames TRBIDR_EL1 register fields per auto-gen tools format without causing any functional change in the TRBE driver. Cc: Will Deacon <will@kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Rob Herring <robh@kernel.org> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: James Morse <james.morse@arm.com> Cc: kvmarm@lists.linux.dev Cc: coresight@lists.linaro.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Link: https://lore.kernel.org/r/20230614065949.146187-8-anshuman.khandual@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: Drop SYS_ from SPE register definesRob Herring2023-01-191-1/+1
| | | | | | | | | | | | | | | | | | We currently have a non-standard SYS_ prefix in the constants generated for the SPE register bitfields. Drop this in preparation for automatic register definition generation. The SPE mask defines were unshifted, and the SPE register field enumerations were shifted. The autogenerated defines are the opposite, so make the necessary adjustments. No functional changes. Tested-by: James Clark <james.clark@arm.com> Signed-off-by: Rob Herring <robh@kernel.org> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Link: https://lore.kernel.org/r/20220825-arm-spe-v8-7-v4-2-327f860daf28@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
* Merge branch kvm-arm64/single-step-async-exception into kvmarm-master/nextMarc Zyngier2022-09-191-1/+33
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * kvm-arm64/single-step-async-exception: : . : Single-step fixes from Reiji Watanabe: : : "This series fixes two bugs of single-step execution enabled by : userspace, and add a test case for KVM_GUESTDBG_SINGLESTEP to : the debug-exception test to verify the single-step behavior." : . KVM: arm64: selftests: Add a test case for KVM_GUESTDBG_SINGLESTEP KVM: arm64: selftests: Refactor debug-exceptions to make it amenable to new test cases KVM: arm64: Clear PSTATE.SS when the Software Step state was Active-pending KVM: arm64: Preserve PSTATE.SS for the guest while single-step is enabled Signed-off-by: Marc Zyngier <maz@kernel.org>
| * KVM: arm64: Clear PSTATE.SS when the Software Step state was Active-pendingReiji Watanabe2022-09-191-1/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While userspace enables single-step, if the Software Step state at the last guest exit was "Active-pending", clear PSTATE.SS on guest entry to restore the state. Currently, KVM sets PSTATE.SS to 1 on every guest entry while userspace enables single-step for the vCPU (with KVM_GUESTDBG_SINGLESTEP). It means KVM always makes the vCPU's Software Step state "Active-not-pending" on the guest entry, which lets the VCPU perform single-step (then Software Step exception is taken). This could cause extra single-step (without returning to userspace) if the Software Step state at the last guest exit was "Active-pending" (i.e. the last exit was triggered by an asynchronous exception after the single-step is performed, but before the Software Step exception is taken. See "Figure D2-3 Software step state machine" and "D2.12.7 Behavior in the active-pending state" in ARM DDI 0487I.a for more info about this behavior). Fix this by clearing PSTATE.SS on guest entry if the Software Step state at the last exit was "Active-pending" so that KVM restore the state (and the exception is taken before further single-step is performed). Fixes: 337b99bf7edf ("KVM: arm64: guest debug, add support for single-step") Signed-off-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220917010600.532642-3-reijiw@google.com
| * KVM: arm64: Preserve PSTATE.SS for the guest while single-step is enabledReiji Watanabe2022-09-191-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Preserve the PSTATE.SS value for the guest while userspace enables single-step (i.e. while KVM manipulates the PSTATE.SS) for the vCPU. Currently, while userspace enables single-step for the vCPU (with KVM_GUESTDBG_SINGLESTEP), KVM sets PSTATE.SS to 1 on every guest entry, not saving its original value. When userspace disables single-step, KVM doesn't restore the original value for the subsequent guest entry (use the current value instead). Exception return instructions copy PSTATE.SS from SPSR_ELx.SS only in certain cases when single-step is enabled (and set it to 0 in other cases). So, the value matters only when the guest enables single-step (and when the guest's Software step state isn't affected by single-step enabled by userspace, practically), though. Fix this by preserving the original PSTATE.SS value while userspace enables single-step, and restoring the value once it is disabled. This fix modifies the behavior of GET_ONE_REG/SET_ONE_REG for the PSTATE.SS while single-step is enabled by userspace. Presently, GET_ONE_REG/SET_ONE_REG gets/sets the current PSTATE.SS value, which KVM will override on the next guest entry (i.e. the value userspace gets/sets is not used for the next guest entry). With this patch, GET_ONE_REG/SET_ONE_REG will get/set the guest's preserved value, which KVM will preserve and try to restore after single-step is disabled. Fixes: 337b99bf7edf ("KVM: arm64: guest debug, add support for single-step") Signed-off-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220917010600.532642-2-reijiw@google.com
* | arm64/sysreg: Add _EL1 into ID_AA64DFR0_EL1 definition namesMark Brown2022-09-161-2/+2
| | | | | | | | | | | | | | | | | | | | | | Normally we include the full register name in the defines for fields within registers but this has not been followed for ID registers. In preparation for automatic generation of defines add the _EL1s into the defines for ID_AA64DFR0_EL1 to follow the convention. No functional changes. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20220910163354.860255-3-broonie@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* | arm64/sysreg: Align field names in ID_AA64DFR0_EL1 with architectureMark Brown2022-09-161-2/+2
|/ | | | | | | | | | | | The naming scheme the architecture uses for the fields in ID_AA64DFR0_EL1 does not align well with kernel conventions, using as it does a lot of MixedCase in various arrangements. In preparation for automatically generating the defines for this register rename the defines used to match what is in the architecture. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20220910163354.860255-2-broonie@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* KVM: arm64: Move vcpu debug/SPE/TRBE flags to the input flag setMarc Zyngier2022-06-291-13/+12
| | | | | | | | | | | The three debug flags (which deal with the debug registers, SPE and TRBE) all are input flags to the hypervisor code. Move them into the input set and convert them to the new accessors. Reviewed-by: Fuad Tabba <tabba@google.com> Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
* KVM: arm64: Emulate the OS LockOliver Upton2022-02-081-4/+22
| | | | | | | | | | | | | | | The OS lock blocks all debug exceptions at every EL. To date, KVM has not implemented the OS lock for its guests, despite the fact that it is mandatory per the architecture. Simple context switching between the guest and host is not appropriate, as its effects are not constrained to the guest context. Emulate the OS Lock by clearing MDE and SS in MDSCR_EL1, thereby blocking all but software breakpoint instructions. Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220203174159.2887882-5-oupton@google.com
* KVM: arm64: MDCR_EL2 is a 64-bit registerFuad Tabba2021-08-201-1/+1
| | | | | | | | | | | | Fix the places in KVM that treat MDCR_EL2 as a 32-bit register. More recent features (e.g., FEAT_SPEv1p2) use bits above 31. No functional change intended. Acked-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/20210817081134.2918285-4-tabba@google.com
* Merge branch 'kvm-arm64/debug-5.13' into kvmarm-master/nextMarc Zyngier2021-04-131-28/+61
|\ | | | | | | Signed-off-by: Marc Zyngier <maz@kernel.org>
| * KVM: arm64: Initialize VCPU mdcr_el2 before loading itAlexandru Elisei2021-04-071-28/+60
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a VCPU is created, the kvm_vcpu struct is initialized to zero in kvm_vm_ioctl_create_vcpu(). On VHE systems, the first time vcpu.arch.mdcr_el2 is loaded on hardware is in vcpu_load(), before it is set to a sensible value in kvm_arm_setup_debug() later in the run loop. The result is that KVM executes for a short time with MDCR_EL2 set to zero. This has several unintended consequences: * Setting MDCR_EL2.HPMN to 0 is constrained unpredictable according to ARM DDI 0487G.a, page D13-3820. The behavior specified by the architecture in this case is for the PE to behave as if MDCR_EL2.HPMN is set to a value less than or equal to PMCR_EL0.N, which means that an unknown number of counters are now disabled by MDCR_EL2.HPME, which is zero. * The host configuration for the other debug features controlled by MDCR_EL2 is temporarily lost. This has been harmless so far, as Linux doesn't use the other fields, but that might change in the future. Let's avoid both issues by initializing the VCPU's mdcr_el2 field in kvm_vcpu_vcpu_first_run_init(), thus making sure that the MDCR_EL2 register has a consistent value after each vcpu_load(). Fixes: d5a21bcc2995 ("KVM: arm64: Move common VHE/non-VHE trap config in separate functions") Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210407144857.199746-3-alexandru.elisei@arm.com
* | arm64: KVM: Enable access to TRBE support for hostSuzuki K Poulose2021-04-071-4/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | KVM: arm64: Move SPE availability check to VCPU loadSuzuki K Poulose2021-04-071-0/+23
|/ | | | | | | | | | | | | | | | | | At the moment, we check the availability of SPE on the given CPU (i.e, SPE is implemented and is allowed at the host) during every guest entry. This can be optimized a bit by moving the check to vcpu_load time and recording the availability of the feature on the current CPU via a new flag. This will also be useful for adding the TRBE support. Cc: Marc Zyngier <maz@kernel.org> Cc: Will Deacon <will@kernel.org> Cc: Alexandru Elisei <Alexandru.Elisei@arm.com> Cc: James Morse <james.morse@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/20210405164307.1720226-7-suzuki.poulose@arm.com Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
* KVM: arm64: Disable guest access to trace filter controlsSuzuki K Poulose2021-03-241-0/+2
| | | | | | | | | | | | | | | | | | Disable guest access to the Trace Filter control registers. We do not advertise the Trace filter feature to the guest (ID_AA64DFR0_EL1: TRACE_FILT is cleared) already, but the guest can still access the TRFCR_EL1 unless we trap it. This will also make sure that the guest cannot fiddle with the filtering controls set by a nvhe host. Cc: Marc Zyngier <maz@kernel.org> Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210323120647.454211-3-suzuki.poulose@arm.com
* KVM: arm64: Write arch.mdcr_el2 changes since last vcpu_load on VHEAndrew Murray2020-01-221-1/+5
| | | | | | | | | | | | | | | | | | | | | | | On VHE systems arch.mdcr_el2 is written to mdcr_el2 at vcpu_load time to set options for self-hosted debug and the performance monitors extension. Unfortunately the value of arch.mdcr_el2 is not calculated until kvm_arm_setup_debug() in the run loop after the vcpu has been loaded. This means that the initial brief iterations of the run loop use a zero value of mdcr_el2 - until the vcpu is preempted. This also results in a delay between changes to vcpu->guest_debug taking effect. Fix this by writing to mdcr_el2 in kvm_arm_setup_debug() on VHE systems when a change to arch.mdcr_el2 has been detected. Fixes: d5a21bcc2995 ("KVM: arm64: Move common VHE/non-VHE trap config in separate functions") Cc: <stable@vger.kernel.org> # 4.17.x- Suggested-by: James Morse <james.morse@arm.com> Acked-by: Will Deacon <will@kernel.org> Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Andrew Murray <andrew.murray@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234Thomas Gleixner2019-06-191-12/+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>
* arm/arm64: KVM: Introduce kvm_call_hyp_ret()Marc Zyngier2019-02-191-1/+1
| | | | | | | | | | | Until now, we haven't differentiated between HYP calls that have a return value and those who don't. As we're about to change this, introduce kvm_call_hyp_ret(), and change all call sites that actually make use of a return value. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
* arm64: KVM: Consistently advance singlestep when emulating instructionsMark Rutland2018-12-181-21/+0
| | | | | | | | | | | | | | | | | | | | | | | | | When we emulate a guest instruction, we don't advance the hardware singlestep state machine, and thus the guest will receive a software step exception after a next instruction which is not emulated by the host. We bodge around this in an ad-hoc fashion. Sometimes we explicitly check whether userspace requested a single step, and fake a debug exception from within the kernel. Other times, we advance the HW singlestep state rely on the HW to generate the exception for us. Thus, the observed step behaviour differs for host and guest. Let's make this simpler and consistent by always advancing the HW singlestep state machine when we skip an instruction. Thus we can rely on the hardware to generate the singlestep exception for us, and never need to explicitly check for an active-pending step, nor do we need to fake a debug exception from the guest. Cc: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* KVM: arm64: Repurpose vcpu_arch.debug_flags for general-purpose flagsDave Martin2018-05-251-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In struct vcpu_arch, the debug_flags field is used to store debug-related flags about the vcpu state. Since we are about to add some more flags related to FPSIMD and SVE, it makes sense to add them to the existing flags field rather than adding new fields. Since there is only one debug_flags flag defined so far, there is plenty of free space for expansion. In preparation for adding more flags, this patch renames the debug_flags field to simply "flags", and updates comments appropriately. The flag definitions are also moved to <asm/kvm_host.h>, since their presence in <asm/kvm_asm.h> was for purely historical reasons: these definitions are not used from asm any more, and not very likely to be as more Hyp asm is migrated to C. KVM_ARM64_DEBUG_DIRTY_SHIFT has not been used since commit 1ea66d27e7b0 ("arm64: KVM: Move away from the assembly version of the world switch"), so this patch gets rid of that too. No functional change. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Acked-by: Christoffer Dall <christoffer.dall@arm.com> [maz: fixed minor conflict] Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* KVM: arm64: Rewrite system register accessors to read/write functionsChristoffer Dall2018-03-191-9/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently we access the system registers array via the vcpu_sys_reg() macro. However, we are about to change the behavior to some times modify the register file directly, so let's change this to two primitives: * Accessor macros vcpu_write_sys_reg() and vcpu_read_sys_reg() * Direct array access macro __vcpu_sys_reg() The accessor macros should be used in places where the code needs to access the currently loaded VCPU's state as observed by the guest. For example, when trapping on cache related registers, a write to a system register should go directly to the VCPU version of the register. The direct array access macro can be used in places where the VCPU is known to never be running (for example userspace access) or for registers which are never context switched (for example all the PMU system registers). This rewrites all users of vcpu_sys_regs to one of the macros described above. No functional change. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* KVM: arm64: Move debug dirty flag calculation out of world switchChristoffer Dall2018-03-191-0/+5
| | | | | | | | | | | | | There is no need to figure out inside the world-switch if we should save/restore the debug registers or not, we might as well do that in the higher level debug setup code, making it easier to optimize down the line. Reviewed-by: Julien Thierry <julien.thierry@arm.com> 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>
* KVM: arm/arm64: debug: Introduce helper for single-stepAlex Bennée2017-11-291-0/+21
| | | | | | | | | | | After emulating instructions we may want return to user-space to handle single-step debugging. Introduce a helper function, which, if single-step is enabled, sets the run structure for return and returns true. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
* arm64: KVM: Save/restore the host SPE state when entering/leaving a VMWill Deacon2017-02-021-0/+6
| | | | | | | | | | | | | | | | The SPE buffer is virtually addressed, using the page tables of the CPU MMU. Unusually, this means that the EL0/1 page table may be live whilst we're executing at EL2 on non-VHE configurations. When VHE is in use, we can use the same property to profile the guest behind its back. This patch adds the relevant disabling and flushing code to KVM so that the host can make use of SPE without corrupting guest memory, and any attempts by a guest to use SPE will result in a trap. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Alex Bennée <alex.bennee@linaro.org> Cc: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
* KVM: arm64: add trace points for guest_debug debugAlex Bennée2015-07-211-1/+35
| | | | | | | | | | | | | This includes trace points for: kvm_arch_setup_guest_debug kvm_arch_clear_guest_debug I've also added some generic register setting trace events and also a trace point to dump the array of hardware registers. Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* KVM: arm64: enable KVM_CAP_SET_GUEST_DEBUGAlex Bennée2015-07-211-5/+35
| | | | | | | | | | Finally advertise the KVM capability for SET_GUEST_DEBUG. Once arm support is added this check can be moved to the common kvm_vm_ioctl_check_extension() code. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* KVM: arm64: introduce vcpu->arch.debug_ptrAlex Bennée2015-07-211-0/+9
| | | | | | | | | | | | | | | | | | This introduces a level of indirection for the debug registers. Instead of using the sys_regs[] directly we store registers in a structure in the vcpu. The new kvm_arm_reset_debug_ptr() sets the debug ptr to the guest context. Because we no longer give the sys_regs offset for the sys_reg_desc->reg field, but instead the index into a debug-specific struct we need to add a number of additional trap functions for each register. Also as the generic generic user-space access code no longer works we have introduced a new pair of function pointers to the sys_reg_desc structure to override the generic code when needed. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* KVM: arm64: guest debug, add support for single-stepAlex Bennée2015-07-211-4/+64
| | | | | | | | | | | | | | | | | | | This adds support for single-stepping the guest. To do this we need to manipulate the guests PSTATE.SS and MDSCR_EL1.SS bits to trigger stepping. We take care to preserve MDSCR_EL1 and trap access to it to ensure we don't affect the apparent state of the guest. As we have to enable trapping of all software debug exceptions we suppress the ability of the guest to single-step itself. If we didn't we would have to deal with the exception arriving while the guest was in kernelspace when the guest is expecting to single-step userspace. This is something we don't want to unwind in the kernel. Once the host is no longer debugging the guest its ability to single-step userspace is restored. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* KVM: arm64: guest debug, add SW break point supportAlex Bennée2015-07-211-0/+3
| | | | | | | | | | | | | | | | | | | | | | | This adds support for SW breakpoints inserted by userspace. We do this by trapping all guest software debug exceptions to the hypervisor (MDCR_EL2.TDE). The exit handler sets an exit reason of KVM_EXIT_DEBUG with the kvm_debug_exit_arch structure holding the exception syndrome information. It will be up to userspace to extract the PC (via GET_ONE_REG) and determine if the debug event was for a breakpoint it inserted. If not userspace will need to re-inject the correct exception restart the hypervisor to deliver the debug exception to the guest. Any other guest software debug exception (e.g. single step or HW assisted breakpoints) will cause an error and the VM to be killed. This is addressed by later patches which add support for the other debug types. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* KVM: arm: introduce kvm_arm_init/setup/clear_debugAlex Bennée2015-07-211-0/+81
This is a precursor for later patches which will need to do more to setup debug state before entering the hyp.S switch code. The existing functionality for setting mdcr_el2 has been moved out of hyp.S and now uses the value kept in vcpu->arch.mdcr_el2. As the assembler used to previously mask and preserve MDCR_EL2.HPMN I've had to add a mechanism to save the value of mdcr_el2 as a per-cpu variable during the initialisation code. The kernel never sets this number so we are assuming the bootcode has set up the correct value here. This also moves the conditional setting of the TDA bit from the hyp code into the C code which is currently used for the lazy debug register context switch code. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>