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2022-09-14KVM: arm64: Add a visibility bit to ignore user writesOliver Upton1-0/+7
We're about to ignore writes to AArch32 ID registers on AArch64-only systems. Add a bit to indicate a register is handled as write ignore when accessed from userspace. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220913094441.3957645-6-oliver.upton@linux.dev
2022-09-14KVM: arm64: Spin off helper for calling visibility hookOliver Upton1-8/+11
No functional change intended. Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220913094441.3957645-5-oliver.upton@linux.dev
2022-07-17KVM: arm64: Descope kvm_arm_sys_reg_{get,set}_reg()Marc Zyngier1-1/+2
Having kvm_arm_sys_reg_get_reg and co in kvm_host.h gives the impression that these functions are free to be called from anywhere. Not quite. They really are tied to out internal sysreg handling, and they would be better off in the sys_regs.h header, which is private. kvm_host.h could also get a bit of a diet, so let's just do that. Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-07-17KVM: arm64: Get rid of find_reg_by_id()Marc Zyngier1-5/+0
This helper doesn't have a user anymore, let's get rid of it. Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-07-17KVM: arm64: Consolidate sysreg userspace accessesMarc Zyngier1-2/+2
Until now, the .set_user and .get_user callbacks have to implement (directly or not) the userspace memory accesses. Although this gives us maximem flexibility, this is also a maintenance burden, making it hard to audit, and I'd feel much better if it was all located in a single place. So let's do just that, simplifying most of the function signatures in the process (the callbacks are now only concerned with the data itself, and not with userspace). Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-07-17KVM: arm64: Introduce generic get_user/set_user helpers for system registersMarc Zyngier1-0/+6
The userspace access to the system registers is done using helpers that hardcode the table that is looked up. extract some generic helpers from this, moving the handling of hidden sysregs into the core code. Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-07-17KVM: arm64: Add get_reg_by_id() as a sys_reg_desc retrieving helperMarc Zyngier1-0/+4
find_reg_by_id() requires a sys_reg_param as input, which most users provide as a on-stack variable, but don't make any use of the result. Provide a helper that doesn't have this requirement and simplify the callers (all but one). Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-05-03KVM: arm64: Hide AArch32 PMU registers when not availableAlexandru Elisei1-1/+1
commit 11663111cd49 ("KVM: arm64: Hide PMU registers from userspace when not available") hid the AArch64 PMU registers from userspace and guest when the PMU VCPU feature was not set. Do the same when the PMU registers are accessed by an AArch32 guest. While we're at it, rename the previously unused AA32_ZEROHIGH to AA32_DIRECT to match the behavior of get_access_mask(). Now that KVM emulates ID_DFR0 and hides the PMU from the guest when the feature is not set, it is safe to inject to inject an undefined exception when the PMU is not present, as that corresponds to the architected behaviour. Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> [Oliver - Add AA32_DIRECT to match the zero value of the enum] Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220503060205.2823727-7-oupton@google.com
2022-05-03KVM: arm64: Wire up CP15 feature registers to their AArch64 equivalentsOliver Upton1-0/+7
KVM currently does not trap ID register accesses from an AArch32 EL1. This is painful for a couple of reasons. Certain unimplemented features are visible to AArch32 EL1, as we limit PMU to version 3 and the debug architecture to v8.0. Additionally, we attempt to paper over heterogeneous systems by using register values that are safe system-wide. All this hard work is completely sidestepped because KVM does not set TID3 for AArch32 guests. Fix up handling of CP15 feature registers by simply rerouting to their AArch64 aliases. Punt setting HCR_EL2.TID3 to a later change, as we need to fix up the oddball CP10 feature registers still. Signed-off-by: Oliver Upton <oupton@google.com> Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220503060205.2823727-4-oupton@google.com
2021-08-20KVM: arm64: Refactor sys_regs.h,c for nVHE reuseFuad Tabba1-0/+31
Refactor sys_regs.h and sys_regs.c to make it easier to reuse common code. It will be used in nVHE in a later patch. Note that the refactored code uses __inline_bsearch for find_reg instead of bsearch to avoid copying the bsearch code for nVHE. 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/20210817081134.2918285-6-tabba@google.com
2020-11-27Merge branch 'kvm-arm64/copro-no-more' into kvmarm-master/nextMarc Zyngier1-2/+7
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-11-10KVM: arm64: Drop is_aarch32 trap attributeMarc Zyngier1-1/+0
is_aarch32 is only used once, and can be trivially replaced by testing Op0 instead. Drop it. Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-11-10KVM: arm64: Drop is_32bit trap attributeMarc Zyngier1-1/+0
The is_32bit attribute is now completely unused, drop it. Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-11-10KVM: arm64: Add AArch32 mapping annotationMarc Zyngier1-0/+7
In order to deal with the few AArch32 system registers that map to only a particular half of their AArch64 counterpart (such as DFAR and IFAR being colocated in FAR_EL1), let's add an optional annotation to the sysreg descriptor structure, indicating whether a register maps to the upper or lower 32bits of a register. Nothing is using these annotation yet. Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-11-06KVM: arm64: Check RAZ visibility in ID register accessorsAndrew Jones1-0/+10
The instruction encodings of ID registers are preallocated. Until an encoding is assigned a purpose the register is RAZ. KVM's general ID register accessor functions already support both paths, RAZ or not. If for each ID register we can determine if it's RAZ or not, then all ID registers can build on the general functions. The register visibility function allows us to check whether a register should be completely hidden or not, extending it to also report when the register should be RAZ or not allows us to use it for ID registers as well. Check for RAZ visibility in the ID register accessor functions, allowing the RAZ case to be handled in a generic way for all system registers. The new REG_RAZ flag will be used in a later patch. This patch has no intended functional change. Signed-off-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201105091022.15373-4-drjones@redhat.com
2020-11-06KVM: arm64: Consolidate REG_HIDDEN_GUEST/USERAndrew Jones1-14/+4
REG_HIDDEN_GUEST and REG_HIDDEN_USER are always used together. Consolidate them into a single REG_HIDDEN flag. We can always add another flag later if some register needs to expose itself differently to the guest than it does to userspace. No functional change intended. Signed-off-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201105091022.15373-3-drjones@redhat.com
2019-12-06KVM: arm64: Sanely ratelimit sysreg messagesMark Rutland1-2/+15
Currently kvm_pr_unimpl() is ratelimited, so print_sys_reg_instr() won't spam the console. However, someof its callers try to print some contextual information with kvm_err(), which is not ratelimited. This means that in some cases the context may be printed without the sysreg encoding, which isn't all that useful. Let's ensure that both are consistently printed together and ratelimited, by refactoring print_sys_reg_instr() so that some callers can provide it with an arbitrary format string. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20191205180652.18671-2-mark.rutland@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>
2019-03-29KVM: arm64: Support runtime sysreg visibility filteringDave Martin1-0/+25
Some optional features of the Arm architecture add new system registers that are not present in the base architecture. Where these features are optional for the guest, the visibility of these registers may need to depend on some runtime configuration, such as a flag passed to KVM_ARM_VCPU_INIT. For example, ZCR_EL1 and ID_AA64ZFR0_EL1 need to be hidden if SVE is not enabled for the guest, even though these registers may be present in the hardware and visible to the host at EL2. Adding special-case checks all over the place for individual registers is going to get messy as the number of conditionally- visible registers grows. In order to help solve this problem, this patch adds a new sysreg method visibility() that can be used to hook in any needed runtime visibility checks. This method can currently return REG_HIDDEN_USER to inhibit enumeration and ioctl access to the register for userspace, and REG_HIDDEN_GUEST to inhibit runtime access by the guest using MSR/MRS. Wrappers are added to allow these flags to be conveniently queried. This approach allows a conditionally modified view of individual system registers such as the CPU ID registers, in addition to completely hiding register where appropriate. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-19arm64: KVM: Add trapped system register access tracepointMarc Zyngier1-0/+4
We're pretty blind when it comes to system register tracing, and rely on the ESR value displayed by kvm_handle_sys, which isn't much. Instead, let's add an actual name to the sysreg entries, so that we can finally print it as we're about to perform the access itself. The new tracepoint is conveniently called kvm_sys_access. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19KVM: arm64: Rewrite system register accessors to read/write functionsChristoffer Dall1-2/+2
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>
2017-04-09Merge remote-tracking branch 'rutland/kvm/common-sysreg' into next-fixChristoffer Dall1-0/+5
2017-04-09arm64: KVM: Make unexpected reads from WO registers inject an undefMarc Zyngier1-18/+0
Reads from write-only system registers are generally confined to EL1 and not propagated to EL2 (that's what the architecture mantates). In order to be sure that we have a sane behaviour even in the unlikely event that we have a broken system, we still handle it in KVM. In that case, let's inject an undef into the guest. Let's also remove write_to_read_only which isn't used anywhere. Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-03-22KVM: arm64: add SYS_DESC()Mark Rutland1-0/+5
This patch adds a macro enabling us to initialise sys_reg_desc structures based on common sysreg encoding definitions in <asm/sysreg.h>. Subsequent patches will use this to simplify the KVM code. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: kvmarm@lists.cs.columbia.edu
2017-01-30KVM: arm/arm64: vgic: Introduce find_reg_by_id()Vijaya Kumar K1-0/+4
In order to implement vGICv3 CPU interface access, we will need to perform table lookup of system registers. We would need both index_to_params() and find_reg() exported for that purpose, but instead we export a single function which combines them both. Signed-off-by: Pavel Fedin <p.fedin@samsung.com> Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@cavium.com> Reviewed-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-04arm64: KVM: Correctly handle zero register in system register accessesPavel Fedin1-2/+2
System register accesses also use zero register for Rt == 31, and therefore using it will also result in getting SP value instead. This patch makes them also using new accessors, introduced by the previous patch. Since register value is no longer directly associated with storage inside vCPU context structure, we introduce a dedicated storage for it in struct sys_reg_params. This refactor also gets rid of "massive hack" in kvm_handle_cp_64(). Signed-off-by: Pavel Fedin <p.fedin@samsung.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-04arm64: KVM: Remove const from struct sys_reg_paramsPavel Fedin1-2/+2
Further rework is going to introduce a dedicated storage for transfer register value in struct sys_reg_params. Before doing this we have to remove 'const' modifiers from it in all accessor functions and their callers. Signed-off-by: Pavel Fedin <p.fedin@samsung.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-07-21KVM: arm64: introduce vcpu->arch.debug_ptrAlex Bennée1-0/+6
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>
2014-03-03arm64: KVM: allows discrimination of AArch32 sysreg accessMarc Zyngier1-0/+2
The current handling of AArch32 trapping is slightly less than perfect, as it is not possible (from a handler point of view) to distinguish it from an AArch64 access, nor to tell a 32bit from a 64bit access either. Fix this by introducing two additional flags: - is_aarch32: true if the access was made in AArch32 mode - is_32bit: true if is_aarch32 == true and a MCR/MRC instruction was used to perform the access (as opposed to MCRR/MRRC). This allows a handler to cover all the possible conditions in which a system register gets trapped. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-06-07arm64: KVM: system register handlingMarc Zyngier1-0/+138
Provide 64bit system register handling, modeled after the cp15 handling for ARM. Reviewed-by: Christopher Covington <cov@codeaurora.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>