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2019-07-05KVM: arm64: Consume pending SError as early as possibleJames Morse
On systems with v8.2 we switch the 'vaxorcism' of guest SError with an alternative sequence that uses the ESB-instruction, then reads DISR_EL1. This saves the unmasking and remasking of asynchronous exceptions. We do this after we've saved the guest registers and restored the host's. Any SError that becomes pending due to this will be accounted to the guest, when it actually occurred during host-execution. Move the ESB-instruction as early as possible. Any guest SError will become pending due to this ESB-instruction and then consumed to DISR_EL1 before the host touches anything. This lets us account for host/guest SError precisely on the guest exit exception boundary. Because the ESB-instruction now lands in the preamble section of the vectors, we need to add it to the unpatched indirect vectors too, and to any sequence that may be patched in over the top. The ESB-instruction always lives in the head of the vectors, to be before any memory write. Whereas the register-store always lives in the tail. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-07-05KVM: arm64: Abstract the size of the HYP vectors pre-ambleJames Morse
The EL2 vector hardening feature causes KVM to generate vectors for each type of CPU present in the system. The generated sequences already do some of the early guest-exit work (i.e. saving registers). To avoid duplication the generated vectors branch to the original vector just after the preamble. This size is hard coded. Adding new instructions to the HYP vector causes strange side effects, which are difficult to debug as the affected code is patched in at runtime. Add KVM_VECTOR_PREAMBLE to tell kvm_patch_vector_branch() how big the preamble is. The valid_vect macro can then validate this at build time. Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@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>
2019-04-24arm64: KVM: Encapsulate kvm_cpu_context in kvm_host_dataAndrew Murray
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>
2018-12-19arm/arm64: KVM: Add ARM_EXCEPTION_IS_TRAP macroMarc Zyngier
32 and 64bit use different symbols to identify the traps. 32bit has a fine grained approach (prefetch abort, data abort and HVC), while 64bit is pretty happy with just "trap". This has been fine so far, except that we now need to decode some of that in tracepoints that are common to both architectures. Introduce ARM_EXCEPTION_IS_TRAP which abstracts the trap symbols and make the tracepoint use it. Acked-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-19KVM: arm/arm64: Fixup the kvm_exit tracepointChristoffer Dall
The kvm_exit tracepoint strangely always reported exits as being IRQs. This seems to be because either the __print_symbolic or the tracepoint macros use a variable named idx. Take this chance to update the fields in the tracepoint to reflect the concepts in the arm64 architecture that we pass to the tracepoint and move the exception type table to the same location and header files as the exits code. We also clear out the exception code to 0 for IRQ exits (which translates to UNKNOWN in text) to make it slighyly less confusing to parse the trace output. Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-10-19KVM: arm64: Safety check PSTATE when entering guest and handle ILChristoffer Dall
This commit adds a paranoid check when entering the guest to make sure we don't attempt running guest code in an equally or more privilged mode than the hypervisor. We also catch other accidental programming of the SPSR_EL2 which results in an illegal exception return and report this safely back to the user. Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-10-01kvm: arm64: Configure VTCR_EL2 per VMSuzuki K Poulose
Add support for setting the VTCR_EL2 per VM, rather than hard coding a value at boot time per CPU. This would allow us to tune the stage2 page table parameters per VM in the later changes. We compute the VTCR fields based on the system wide sanitised feature registers, except for the hardware management of Access Flags (VTCR_EL2.HA). It is fine to run a system with a mix of CPUs that may or may not update the page table Access Flags. Since the bit is RES0 on CPUs that don't support it, the bit should be ignored on them. Suggested-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <cdall@kernel.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-06-12Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Paolo Bonzini: "Small update for KVM: ARM: - lazy context-switching of FPSIMD registers on arm64 - "split" regions for vGIC redistributor s390: - cleanups for nested - clock handling - crypto - storage keys - control register bits x86: - many bugfixes - implement more Hyper-V super powers - implement lapic_timer_advance_ns even when the LAPIC timer is emulated using the processor's VMX preemption timer. - two security-related bugfixes at the top of the branch" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (79 commits) kvm: fix typo in flag name kvm: x86: use correct privilege level for sgdt/sidt/fxsave/fxrstor access KVM: x86: pass kvm_vcpu to kvm_read_guest_virt and kvm_write_guest_virt_system KVM: x86: introduce linear_{read,write}_system kvm: nVMX: Enforce cpl=0 for VMX instructions kvm: nVMX: Add support for "VMWRITE to any supported field" kvm: nVMX: Restrict VMX capability MSR changes KVM: VMX: Optimize tscdeadline timer latency KVM: docs: nVMX: Remove known limitations as they do not exist now KVM: docs: mmu: KVM support exposing SLAT to guests kvm: no need to check return value of debugfs_create functions kvm: Make VM ioctl do valloc for some archs kvm: Change return type to vm_fault_t KVM: docs: mmu: Fix link to NPT presentation from KVM Forum 2008 kvm: x86: Amend the KVM_GET_SUPPORTED_CPUID API documentation KVM: x86: hyperv: declare KVM_CAP_HYPERV_TLBFLUSH capability KVM: x86: hyperv: simplistic HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE}_EX implementation KVM: x86: hyperv: simplistic HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE} implementation KVM: introduce kvm_make_vcpus_request_mask() API KVM: x86: hyperv: do rep check for each hypercall separately ...
2018-06-02arm64: KVM: Move VCPU_WORKAROUND_2_FLAG macros to the top of the fileCatalin Marinas
This is to avoid potential merging conflicts between commit 55e3748e8902 ("arm64: KVM: Add ARCH_WORKAROUND_2 support for guests") and the KVM tree. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-31arm64: KVM: Add ARCH_WORKAROUND_2 support for guestsMarc Zyngier
In order to offer ARCH_WORKAROUND_2 support to guests, we need a bit of infrastructure. Let's add a flag indicating whether or not the guest uses SSBD mitigation. Depending on the state of this flag, allow KVM to disable ARCH_WORKAROUND_2 before entering the guest, and enable it when exiting it. Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> 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>
2018-05-31arm64: KVM: Add HYP per-cpu accessorsMarc Zyngier
As we're going to require to access per-cpu variables at EL2, let's craft the minimum set of accessors required to implement reading a per-cpu variable, relying on tpidr_el2 to contain the per-cpu offset. Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> 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>
2018-05-25KVM: arm64: Repurpose vcpu_arch.debug_flags for general-purpose flagsDave Martin
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>
2018-05-20arm64: KVM: Use lm_alias() for kvm_ksym_ref()Mark Rutland
For historical reasons, we open-code lm_alias() in kvm_ksym_ref(). Let's use lm_alias() to avoid duplication and make things clearer. As we have to pull this from <linux/mm.h> (which is not safe for inclusion in assembly), we may as well move the kvm_ksym_ref() definition into the existing !__ASSEMBLY__ block. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Christoffer Dall <christoffer.dall@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: kvmarm@lists.cs.columbia.edu Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-04-11arm64: KVM: Use SMCCC_ARCH_WORKAROUND_1 for Falkor BP hardeningShanker Donthineni
The function SMCCC_ARCH_WORKAROUND_1 was introduced as part of SMC V1.1 Calling Convention to mitigate CVE-2017-5715. This patch uses the standard call SMCCC_ARCH_WORKAROUND_1 for Falkor chips instead of Silicon provider service ID 0xC2001700. Cc: <stable@vger.kernel.org> # 4.14+ Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org> [maz: reworked errata framework integration] Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-28Revert "arm64: KVM: Use SMCCC_ARCH_WORKAROUND_1 for Falkor BP hardening"Marc Zyngier
Creates far too many conflicts with arm64/for-next/core, to be resent post -rc1. This reverts commit f9f5dc19509bbef6f5e675346f1a7d7b846bdb12. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19arm64: KVM: Use SMCCC_ARCH_WORKAROUND_1 for Falkor BP hardeningShanker Donthineni
The function SMCCC_ARCH_WORKAROUND_1 was introduced as part of SMC V1.1 Calling Convention to mitigate CVE-2017-5715. This patch uses the standard call SMCCC_ARCH_WORKAROUND_1 for Falkor chips instead of Silicon provider service ID 0xC2001700. Cc: <stable@vger.kernel.org> # 4.14+ Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19KVM: arm64: Introduce VHE-specific kvm_vcpu_runChristoffer Dall
So far this is mostly (see below) a copy of the legacy non-VHE switch function, but we will start reworking these functions in separate directions to work on VHE and non-VHE in the most optimal way in later patches. The only difference after this patch between the VHE and non-VHE run functions is that we omit the branch-predictor variant-2 hardening for QC Falkor CPUs, because this workaround is specific to a series of non-VHE ARMv8.0 CPUs. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19KVM: arm64: Avoid storing the vcpu pointer on the stackChristoffer Dall
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>
2018-01-08arm64: Implement branch predictor hardening for FalkorShanker Donthineni
Falkor is susceptible to branch predictor aliasing and can theoretically be attacked by malicious code. This patch implements a mitigation for these attacks, preventing any malicious entries from affecting other victim contexts. Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org> [will: fix label name when !CONFIG_KVM and remove references to MIDR_FALKOR] Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-11-06KVM: arm/arm64: Move timer save/restore out of the hyp codeChristoffer Dall
As we are about to be lazy with saving and restoring the timer registers, we prepare by moving all possible timer configuration logic out of the hyp code. All virtual timer registers can be programmed from EL1 and since the arch timer is always a level triggered interrupt we can safely do this with interrupts disabled in the host kernel on the way to the guest without taking vtimer interrupts in the host kernel (yet). The downside is that the cntvoff register can only be programmed from hyp mode, so we jump into hyp mode and back to program it. This is also safe, because the host kernel doesn't use the virtual timer in the KVM code. It may add a little performance performance penalty, but only until following commits where we move this operation to vcpu load/put. Signed-off-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2017-04-09arm64: KVM: Convert __cpu_reset_hyp_mode to using __hyp_reset_vectorsMarc Zyngier
We are now able to use the hyp stub to reset HYP mode. Time to kiss __kvm_hyp_reset goodbye, and use __hyp_reset_vectors. 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>
2017-04-09KVM: arm/arm64: vgic: Defer touching GICH_VMCR to vcpu_load/putChristoffer Dall
We don't have to save/restore the VMCR on every entry to/from the guest, since on GICv2 we can access the control interface from EL1 and on VHE systems with GICv3 we can access the control interface from KVM running in EL2. GICv3 systems without VHE becomes the rare case, which has to save/restore the register on each round trip. Note that userspace accesses may see out-of-date values if the VCPU is running while accessing the VGIC state via the KVM device API, but this is already the case and it is up to userspace to quiesce the CPUs before reading the CPU registers from the GIC for an up-to-date view. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2016-11-04arm/arm64: KVM: Perform local TLB invalidation when multiplexing vcpus on a ↵Marc Zyngier
single CPU Architecturally, TLBs are private to the (physical) CPU they're associated with. But when multiple vcpus from the same VM are being multiplexed on the same CPU, the TLBs are not private to the vcpus (and are actually shared across the VMID). Let's consider the following scenario: - vcpu-0 maps PA to VA - vcpu-1 maps PA' to VA If run on the same physical CPU, vcpu-1 can hit TLB entries generated by vcpu-0 accesses, and access the wrong physical page. The solution to this is to keep a per-VM map of which vcpu ran last on each given physical CPU, and invalidate local TLBs when switching to a different vcpu from the same VM. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-09-08arm64: KVM: Allow an exit code to be tagged with an SErrorMarc Zyngier
Similarily to EL1, an asynchronous abort can be triggered whilst running at EL2. But instead of making that a new error code, we need to communicate it to the rest of KVM together with the exit reason. So let's hijack a single bit that allows the exception code to be tagged with a "pending SError" information. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-08arm64: KVM: Add exception code to report EL1 asynchronous abortsMarc Zyngier
So far, we don't have a code to indicate that we've taken an asynchronous abort from EL1. Let's add one. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-05-16Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: - virt_to_page/page_address optimisations - support for NUMA systems described using device-tree - support for hibernate/suspend-to-disk - proper support for maxcpus= command line parameter - detection and graceful handling of AArch64-only CPUs - miscellaneous cleanups and non-critical fixes * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (92 commits) arm64: do not enforce strict 16 byte alignment to stack pointer arm64: kernel: Fix incorrect brk randomization arm64: cpuinfo: Missing NULL terminator in compat_hwcap_str arm64: secondary_start_kernel: Remove unnecessary barrier arm64: Ensure pmd_present() returns false after pmd_mknotpresent() arm64: Replace hard-coded values in the pmd/pud_bad() macros arm64: Implement pmdp_set_access_flags() for hardware AF/DBM arm64: Fix typo in the pmdp_huge_get_and_clear() definition arm64: mm: remove unnecessary EXPORT_SYMBOL_GPL arm64: always use STRICT_MM_TYPECHECKS arm64: kvm: Fix kvm teardown for systems using the extended idmap arm64: kaslr: increase randomization granularity arm64: kconfig: drop CONFIG_RTC_LIB dependency arm64: make ARCH_SUPPORTS_DEBUG_PAGEALLOC depend on !HIBERNATION arm64: hibernate: Refuse to hibernate if the boot cpu is offline arm64: kernel: Add support for hibernate/suspend-to-disk PM / Hibernate: Call flush_icache_range() on pages restored in-place arm64: Add new asm macro copy_page arm64: Promote KERNEL_START/KERNEL_END definitions to a header file arm64: kernel: Include _AC definition in page.h ...
2016-04-28arm64: kvm: allows kvm cpu hotplugAKASHI Takahiro
The current kvm implementation on arm64 does cpu-specific initialization at system boot, and has no way to gracefully shutdown a core in terms of kvm. This prevents kexec from rebooting the system at EL2. This patch adds a cpu tear-down function and also puts an existing cpu-init code into a separate function, kvm_arch_hardware_disable() and kvm_arch_hardware_enable() respectively. We don't need the arm64 specific cpu hotplug hook any more. Since this patch modifies common code between arm and arm64, one stub definition, __cpu_reset_hyp_mode(), is added on arm side to avoid compilation errors. Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> [Rebase, added separate VHE init/exit path, changed resets use of kvm_call_hyp() to the __version, en/disabled hardware in init_subsystems(), added icache maintenance to __kvm_hyp_reset() and removed lr restore, removed guest-enter after teardown handling] 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 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>
2016-04-06arm64: KVM: Warn when PARange is less than 40 bitsMarc Zyngier
We always thought that 40bits of PA range would be the minimum people would actually build. Anything less is terrifyingly small. Turns out that we were both right and wrong. Nobody has ever built such a system, but the ARM Foundation Model has a PARange set to 36bits. Just because we can. Oh well. Now, the KVM API explicitely says that we offer a 40bit PA space to the VM, so we shouldn't run KVM on the Foundation Model at all. That being said, this patch offers a less agressive alternative, and loudly warns about the configuration being unsupported. You'll still be able to run VMs (at your own risks, though). This is just a workaround until we have a proper userspace API where we report the PARange to userspace. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-03-21arm64: KVM: Turn kvm_ksym_ref into a NOP on VHEMarc Zyngier
When running with VHE, there is no need to translate kernel pointers to the EL2 memory space, since we're already there (and we have a much saner memory map to start with). Unfortunately, kvm_ksym_ref is getting in the way, and the first call into the "hypervisor" section is going to end up in fireworks, since we're now branching into nowhereland. Meh. A potential solution is to test if VHE is engaged or not, and only perform the translation in the negative case. With this in place, VHE is able to run again. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-03-17Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: "Here are the main arm64 updates for 4.6. There are some relatively intrusive changes to support KASLR, the reworking of the kernel virtual memory layout and initial page table creation. Summary: - Initial page table creation reworked to avoid breaking large block mappings (huge pages) into smaller ones. The ARM architecture requires break-before-make in such cases to avoid TLB conflicts but that's not always possible on live page tables - Kernel virtual memory layout: the kernel image is no longer linked to the bottom of the linear mapping (PAGE_OFFSET) but at the bottom of the vmalloc space, allowing the kernel to be loaded (nearly) anywhere in physical RAM - Kernel ASLR: position independent kernel Image and modules being randomly mapped in the vmalloc space with the randomness is provided by UEFI (efi_get_random_bytes() patches merged via the arm64 tree, acked by Matt Fleming) - Implement relative exception tables for arm64, required by KASLR (initial code for ARCH_HAS_RELATIVE_EXTABLE added to lib/extable.c but actual x86 conversion to deferred to 4.7 because of the merge dependencies) - Support for the User Access Override feature of ARMv8.2: this allows uaccess functions (get_user etc.) to be implemented using LDTR/STTR instructions. Such instructions, when run by the kernel, perform unprivileged accesses adding an extra level of protection. The set_fs() macro is used to "upgrade" such instruction to privileged accesses via the UAO bit - Half-precision floating point support (part of ARMv8.2) - Optimisations for CPUs with or without a hardware prefetcher (using run-time code patching) - copy_page performance improvement to deal with 128 bytes at a time - Sanity checks on the CPU capabilities (via CPUID) to prevent incompatible secondary CPUs from being brought up (e.g. weird big.LITTLE configurations) - valid_user_regs() reworked for better sanity check of the sigcontext information (restored pstate information) - ACPI parking protocol implementation - CONFIG_DEBUG_RODATA enabled by default - VDSO code marked as read-only - DEBUG_PAGEALLOC support - ARCH_HAS_UBSAN_SANITIZE_ALL enabled - Erratum workaround Cavium ThunderX SoC - set_pte_at() fix for PROT_NONE mappings - Code clean-ups" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (99 commits) arm64: kasan: Fix zero shadow mapping overriding kernel image shadow arm64: kasan: Use actual memory node when populating the kernel image shadow arm64: Update PTE_RDONLY in set_pte_at() for PROT_NONE permission arm64: Fix misspellings in comments. arm64: efi: add missing frame pointer assignment arm64: make mrs_s prefixing implicit in read_cpuid arm64: enable CONFIG_DEBUG_RODATA by default arm64: Rework valid_user_regs arm64: mm: check at build time that PAGE_OFFSET divides the VA space evenly arm64: KVM: Move kvm_call_hyp back to its original localtion arm64: mm: treat memstart_addr as a signed quantity arm64: mm: list kernel sections in order arm64: lse: deal with clobbered IP registers after branch via PLT arm64: mm: dump: Use VA_START directly instead of private LOWEST_ADDR arm64: kconfig: add submenu for 8.2 architectural features arm64: kernel: acpi: fix ioremap in ACPI parking protocol cpu_postboot arm64: Add support for Half precision floating point arm64: Remove fixmap include fragility arm64: Add workaround for Cavium erratum 27456 arm64: mm: Mark .rodata as RO ...
2016-03-09arm64: KVM: vgic-v3: Reset LRs at boot timeMarc Zyngier
In order to let the GICv3 code be more lazy in the way it accesses the LRs, it is necessary to start with a clean slate. Let's reset the LRs on each CPU when the vgic is probed (which includes a round trip to EL2...). Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29arm64: KVM: Switch to C-based stage2 initMarc Zyngier
There is no real need to leave the stage2 initialization as part of the early HYP bootstrap, and we can easily postpone it to the point where we can safely run C code. This will help VHE, which doesn't need any of this bootstrap. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29ARM: KVM: Remove __kvm_hyp_code_start/__kvm_hyp_code_endMarc Zyngier
Now that we've unified the way we refer to the HYP text between arm and arm64, drop __kvm_hyp_code_start/end, and just use the __hyp_text_start/end symbols. Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-18arm64: allow kernel Image to be loaded anywhere in physical memoryArd Biesheuvel
This relaxes the kernel Image placement requirements, so that it may be placed at any 2 MB aligned offset in physical memory. This is accomplished by ignoring PHYS_OFFSET when installing memblocks, and accounting for the apparent virtual offset of the kernel Image. As a result, virtual address references below PAGE_OFFSET are correctly mapped onto physical references into the kernel Image regardless of where it sits in memory. Special care needs to be taken for dealing with memory limits passed via mem=, since the generic implementation clips memory top down, which may clip the kernel image itself if it is loaded high up in memory. To deal with this case, we simply add back the memory covering the kernel image, which may result in more memory to be retained than was passed as a mem= parameter. Since mem= should not be considered a production feature, a panic notifier handler is installed that dumps the memory limit at panic time if one was set. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18arm64: kvm: deal with kernel symbols outside of linear mappingArd Biesheuvel
KVM on arm64 uses a fixed offset between the linear mapping at EL1 and the HYP mapping at EL2. Before we can move the kernel virtual mapping out of the linear mapping, we have to make sure that references to kernel symbols that are accessed via the HYP mapping are translated to their linear equivalent. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-12-14arm64: KVM: Turn system register numbers to an enumMarc Zyngier
Having the system register numbers as #defines has been a pain since day one, as the ordering is pretty fragile, and moving things around leads to renumbering and epic conflict resolutions. Now that we're mostly acessing the sysreg file in C, an enum is a much better type to use, and we can clean things up a bit. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-09-17arm64: KVM: Remove all traces of the ThumbEE registersWill Deacon
Although the ThumbEE registers and traps were present in earlier versions of the v8 architecture, it was retrospectively removed and so we can do the same. Whilst this breaks migrating a guest started on a previous version of the kernel, it is much better to kill these (non existent) registers as soon as possible. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> [maz: added commend about migration] Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-07-21KVM: arm64: introduce vcpu->arch.debug_ptrAlex Bennée
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>
2015-07-21KVM: arm: introduce kvm_arm_init/setup/clear_debugAlex Bennée
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>
2015-06-24Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: "Mostly refactoring/clean-up: - CPU ops and PSCI (Power State Coordination Interface) refactoring following the merging of the arm64 ACPI support, together with handling of Trusted (secure) OS instances - Using fixmap for permanent FDT mapping, removing the initial dtb placement requirements (within 512MB from the start of the kernel image). This required moving the FDT self reservation out of the memreserve processing - Idmap (1:1 mapping used for MMU on/off) handling clean-up - Removing flush_cache_all() - not safe on ARM unless the MMU is off. Last stages of CPU power down/up are handled by firmware already - "Alternatives" (run-time code patching) refactoring and support for immediate branch patching, GICv3 CPU interface access - User faults handling clean-up And some fixes: - Fix for VDSO building with broken ELF toolchains - Fix another case of init_mm.pgd usage for user mappings (during ASID roll-over broadcasting) - Fix for FPSIMD reloading after CPU hotplug - Fix for missing syscall trace exit - Workaround for .inst asm bug - Compat fix for switching the user tls tpidr_el0 register" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (42 commits) arm64: use private ratelimit state along with show_unhandled_signals arm64: show unhandled SP/PC alignment faults arm64: vdso: work-around broken ELF toolchains in Makefile arm64: kernel: rename __cpu_suspend to keep it aligned with arm arm64: compat: print compat_sp instead of sp arm64: mm: Fix freeing of the wrong memmap entries with !SPARSEMEM_VMEMMAP arm64: entry: fix context tracking for el0_sp_pc arm64: defconfig: enable memtest arm64: mm: remove reference to tlb.S from comment block arm64: Do not attempt to use init_mm in reset_context() arm64: KVM: Switch vgic save/restore to alternative_insn arm64: alternative: Introduce feature for GICv3 CPU interface arm64: psci: fix !CONFIG_HOTPLUG_CPU build warning arm64: fix bug for reloading FPSIMD state after CPU hotplug. arm64: kernel thread don't need to save fpsimd context. arm64: fix missing syscall trace exit arm64: alternative: Work around .inst assembler bugs arm64: alternative: Merge alternative-asm.h into alternative.h arm64: alternative: Allow immediate branch as alternative instruction arm64: Rework alternate sequence for ARM erratum 845719 ...
2015-06-23Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial tree updates from Jiri Kosina: "As usual, mostly comment, kerneldoc and printk() fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: lpfc: Grammar s/an negative/a negative/ ARM: lib/lib1funcs.S: fix typo s/substractions/subtractions/ cx25821: cx25821-medusa-reg.h: fix 0x0x prefix lib: crc-itu-t.[ch] fix 0x0x prefix in integer constants rapidio: Fix kerneldoc and comment qla4xxx: Fix printk() in qla4_83xx_read_reset_template() and qla4_83xx_pre_loopback_config() treewide: Kconfig: fix wording / spelling usb/serial: fix grammar in Kconfig help text for FTDI_SIO megaraid_sas: fix kerneldoc netfilter: ebtables: fix comment grammar drm/radeon: fix comment isdn: fix grammar in comment ARM: KVM: fix comment
2015-06-12arm64: KVM: Switch vgic save/restore to alternative_insnMarc Zyngier
So far, we configured the world-switch by having a small array of pointers to the save and restore functions, depending on the GIC used on the platform. Loading these values each time is a bit silly (they never change), and it makes sense to rely on the instruction patching instead. This leads to a nice cleanup of the code. Acked-by: Will Deacon <will.deacon@arm.com> 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>
2015-05-26ARM: KVM: fix commentGeert Uytterhoeven
Fix spelling in comment. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-01-16KVM: arm64: ARMv8 header changes for page loggingMario Smarduch
This patch adds arm64 helpers to write protect pmds/ptes and retrieve permissions while logging dirty pages. Also adds prototype to write protect a memory slot and adds a pmd define to check for read-only pmds. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Mario Smarduch <m.smarduch@samsung.com>
2014-07-11arm64: KVM: add trap handlers for AArch32 debug registersMarc Zyngier
Add handlers for all the AArch32 debug registers that are accessible from EL0 or EL1. The code follow the same strategy as the AArch64 counterpart with regards to tracking the dirty state of the debug registers. Reviewed-by: Anup Patel <anup.patel@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2014-07-11arm64: KVM: common infrastructure for handling AArch32 CP14/CP15Marc Zyngier
As we're about to trap a bunch of CP14 registers, let's rework the CP15 handling so it can be generalized and work with multiple tables. Reviewed-by: Anup Patel <anup.patel@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2014-07-11arm64: KVM: add trap handlers for AArch64 debug registersMarc Zyngier
Add handlers for all the AArch64 debug registers that are accessible from EL0 or EL1. The trapping code keeps track of the state of the debug registers, allowing for the switch code to implement a lazy switching strategy. Reviewed-by: Anup Patel <anup.patel@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>