- 23 Dec, 2020 2 commits
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Alexandru Elisei authored
kvm_timer_enable() is called in kvm_vcpu_first_run_init() after kvm_vgic_map_resources() if the VGIC wasn't ready. kvm_vgic_map_resources() is the only place where kvm->arch.vgic.ready is set to true. For a v2 VGIC, kvm_vgic_map_resources() will attempt to initialize the VGIC and set the initialized flag. For a v3 VGIC, kvm_vgic_map_resources() will return an error code if the VGIC isn't already initialized. The end result is that if we've reached kvm_timer_enable(), the VGIC is initialzed and ready and vgic_initialized() will always be true, so remove this check. Signed-off-by:
Alexandru Elisei <alexandru.elisei@arm.com> Reviewed-by:
Eric Auger <eric.auger@redhat.com> [maz: added comment about vgic initialisation, as suggested by Eric] Signed-off-by:
Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201201150157.223625-3-alexandru.elisei@arm.com
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Alexandru Elisei authored
The API documentation states that general error codes are not detailed, but errors with specific meanings are. On arm64, KVM_RUN can return error numbers with a different meaning than what is described by POSIX or the C99 standard (as taken from man 3 errno). Absent from the newly documented error codes is ERANGE which can be returned when making a change to the EL2 stage 1 tables if the address is larger than the largest supported input address. Assuming no bugs in the implementation, that is not possible because the input addresses which are mapped are the result of applying the macro kern_hyp_va() on kernel virtual addresses. CC: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by:
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- 22 Dec, 2020 8 commits
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Marc Zyngier authored
Although there is nothing wrong with the current host PSCI relay implementation, we can clean it up and remove some of the helpers that do not improve the overall readability of the legacy PSCI 0.1 handling. Opportunity is taken to turn the bitmap into a set of booleans, and creative use of preprocessor macros make init and check more concise/readable. Suggested-by:
Mark Rutland <mark.rutland@arm.com> Signed-off-by:
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David Brazdil authored
Move function for skipping host instruction in the host trap handler to a header file containing analogical helpers for guests. Signed-off-by:
David Brazdil <dbrazdil@google.com> Signed-off-by:
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David Brazdil authored
Minor cleanup removing unused includes. Signed-off-by:
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David Brazdil authored
Small cleanup moving declarations of hyp-exported variables to kvm_host.h and using macros to avoid having to refer to them with kvm_nvhe_sym() in host. No functional change intended. Signed-off-by:
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David Brazdil authored
Computing the hyp VA layout is redundant when the kernel runs in EL2 and hyp shares its VA mappings. Make calling kvm_compute_layout() conditional on not just CONFIG_KVM but also !is_kernel_in_hyp_mode(). Signed-off-by:
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David Brazdil authored
init_hyp_physvirt_offset() computes PA from a kernel VA. Conversion to kernel linear-map is required first but the code used kvm_ksym_ref() for this purpose. Under VHE that is a NOP and resulted in a runtime warning. Replace kvm_ksym_ref with lm_alias. Reported-by:
Qian Cai <qcai@redhat.com> Signed-off-by:
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David Brazdil authored
PSCI driver exposes a struct containing the PSCI v0.1 function IDs configured in the DT. However, the struct does not convey the information whether these were set from DT or contain the default value zero. This could be a problem for PSCI proxy in KVM protected mode. Extend config passed to KVM with a bit mask with individual bits set depending on whether the corresponding function pointer in psci_ops is set, eg. set bit for PSCI_CPU_SUSPEND if psci_ops.cpu_suspend != NULL. Previously config was split into multiple global variables. Put everything into a single struct for convenience. Reported-by:
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Marc Zyngier authored
We reset the guest's view of PMCR_EL0 unconditionally, based on the host's view of this register. It is however legal for an implementation not to provide any PMU, resulting in an UNDEF. The obvious fix is to skip the reset of this shadow register when no PMU is available, sidestepping the issue entirely. If no PMU is available, the guest is not able to request a virtual PMU anyway, so not doing nothing is the right thing to do! It is unlikely that this bug can hit any HW implementation though, as they all provide a PMU. It has been found using nested virt with the host KVM not implementing the PMU itself. Fixes: ab946834 ("arm64: KVM: Add access handler for PMCR register") Reviewed-by:
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- 09 Dec, 2020 1 commit
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Marc Zyngier authored
Signed-off-by:
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- 08 Dec, 2020 1 commit
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Marc Zyngier authored
Conflict resolution gone astray results in the kernel not booting on VHE-capable HW when VHE support is disabled. Thankfully spotted by David. Reported-by:
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- 04 Dec, 2020 28 commits
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Marc Zyngier authored
Signed-off-by: -
David Brazdil authored
With protected nVHE hyp code interception host's PSCI SMCs, the host starts seeing new CPUs boot in EL1 instead of EL2. The kernel logic that keeps track of the boot mode needs to be adjusted. Add a static key enabled if KVM protected mode initialization is successful. When the key is enabled, is_hyp_mode_available continues to report `true` because its users either treat it as a check whether KVM will be / was initialized, or whether stub HVCs can be made (eg. hibernate). is_hyp_mode_mismatched is changed to report `false` when the key is enabled. That's because all cores' modes matched at the point of KVM init and KVM will not allow cores not present at init to boot. That said, the function is never used after KVM is initialized. Signed-off-by:
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David Brazdil authored
While protected KVM is installed, start trapping all host SMCs. For now these are simply forwarded to EL3, except PSCI CPU_ON/CPU_SUSPEND/SYSTEM_SUSPEND which are intercepted and the hypervisor installed on newly booted cores. Create new constant HCR_HOST_NVHE_PROTECTED_FLAGS with the new set of HCR flags to use while the nVHE vector is installed when the kernel was booted with the protected flag enabled. Switch back to the default HCR flags when switching back to the stub vector. Signed-off-by:
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David Brazdil authored
KVM by default keeps the stub vector installed and installs the nVHE vector only briefly for init and later on demand. Change this policy to install the vector at init and then never uninstall it if the kernel was given the protected KVM command line parameter. Signed-off-by:
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David Brazdil authored
Add a handler of SYSTEM_SUSPEND host PSCI SMCs. The semantics are equivalent to CPU_SUSPEND, typically called on the last online CPU. Reuse the same entry point and boot args struct as CPU_SUSPEND. Signed-off-by:
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David Brazdil authored
Add a handler of CPU_SUSPEND host PSCI SMCs. The SMC can either enter a sleep state indistinguishable from a WFI or a deeper sleep state that behaves like a CPU_OFF+CPU_ON except that the core is still considered online while asleep. The handler saves r0,pc of the host and makes the same call to EL3 with the hyp CPU entry point. It either returns back to the handler and then back to the host, or wakes up into the entry point and initializes EL2 state before dropping back to EL1. No EL2 state needs to be saved/restored for this purpose. CPU_ON and CPU_SUSPEND are both implemented using struct psci_boot_args to store the state upon powerup, with each CPU having separate structs for CPU_ON and CPU_SUSPEND so that CPU_SUSPEND can operate locklessly and so that a CPU_ON call targeting a CPU cannot interfere with a concurrent CPU_SUSPEND call on that CPU. Signed-off-by:
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David Brazdil authored
Add a handler of the CPU_ON PSCI call from host. When invoked, it looks up the logical CPU ID corresponding to the provided MPIDR and populates the state struct of the target CPU with the provided x0, pc. It then calls CPU_ON itself, with an entry point in hyp that initializes EL2 state before returning ERET to the provided PC in EL1. There is a simple atomic lock around the boot args struct. If it is already locked, CPU_ON will return PENDING_ON error code. Signed-off-by:
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David Brazdil authored
All nVHE hyp code is currently executed as handlers of host's HVCs. This will change as nVHE starts intercepting host's PSCI CPU_ON SMCs. The newly booted CPU will need to initialize EL2 state and then enter the host. Add __host_enter function that branches into the existing host state-restoring code after the trap handler would have returned. Signed-off-by:
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David Brazdil authored
In preparation for adding a CPU entry point in nVHE hyp code, extract most of __do_hyp_init hypervisor initialization code into a common helper function. This will be invoked by the entry point to install KVM on the newly booted CPU. Signed-off-by:
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David Brazdil authored
Forward the following PSCI SMCs issued by host to EL3 as they do not require the hypervisor's intervention. This assumes that EL3 correctly implements the PSCI specification. Only function IDs implemented in Linux are included. Where both 32-bit and 64-bit variants exist, it is assumed that the host will always use the 64-bit variant. * SMCs that only return information about the system * PSCI_VERSION - PSCI version implemented by EL3 * PSCI_FEATURES - optional features supported by EL3 * AFFINITY_INFO - power state of core/cluster * MIGRATE_INFO_TYPE - whether Trusted OS can be migrated * MIGRATE_INFO_UP_CPU - resident core of Trusted OS * operations which do not affect the hypervisor * MIGRATE - migrate Trusted OS to a different core * SET_SUSPEND_MODE - toggle OS-initiated mode * system shutdown/reset * SYSTEM_OFF * SYSTEM_RESET * SYSTEM_RESET2 Signed-off-by:
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David Brazdil authored
Add a host-initialized constant to KVM nVHE hyp code for converting between EL2 linear map virtual addresses and physical addresses. Also add `__hyp_pa` macro that performs the conversion. Signed-off-by:
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David Brazdil authored
Add a handler of PSCI SMCs in nVHE hyp code. The handler is initialized with the version used by the host's PSCI driver and the function IDs it was configured with. If the SMC function ID matches one of the configured PSCI calls (for v0.1) or falls into the PSCI function ID range (for v0.2+), the SMC is handled by the PSCI handler. For now, all SMCs return PSCI_RET_NOT_SUPPORTED. Signed-off-by:
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David Brazdil authored
Add handler of host SMCs in KVM nVHE trap handler. Forward all SMCs to EL3 and propagate the result back to EL1. This is done in preparation for validating host SMCs in KVM protected mode. The implementation assumes that firmware uses SMCCC v1.2 or older. That means x0-x17 can be used both for arguments and results, other GPRs are preserved. Signed-off-by:
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David Brazdil authored
When KVM starts validating host's PSCI requests, it will need to map MPIDR back to the CPU ID. To this end, copy cpu_logical_map into nVHE hyp memory when KVM is initialized. Only copy the information for CPUs that are online at the point of KVM initialization so that KVM rejects CPUs whose features were not checked against the finalized capabilities. Signed-off-by:
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David Brazdil authored
When compiling with __KVM_NVHE_HYPERVISOR__, redefine per_cpu_offset() to __hyp_per_cpu_offset() which looks up the base of the nVHE per-CPU region of the given cpu and computes its offset from the .hyp.data..percpu section. This enables use of per_cpu_ptr() helpers in nVHE hyp code. Until now only this_cpu_ptr() was supported by setting TPIDR_EL2. Signed-off-by:
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David Brazdil authored
Add rules for renaming the .data..ro_after_init ELF section in KVM nVHE object files to .hyp.data..ro_after_init, linking it into the kernel and mapping it in hyp at runtime. The section is RW to the host, then mapped RO in hyp. The expectation is that the host populates the variables in the section and they are never changed by hyp afterwards. Signed-off-by:
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David Brazdil authored
MAIR_EL2 and TCR_EL2 are currently initialized from their _EL1 values. This will not work once KVM starts intercepting PSCI ON/SUSPEND SMCs and initializing EL2 state before EL1 state. Obtain the EL1 values during KVM init and store them in the init params struct. The struct will stay in memory and can be used when booting new cores. Take the opportunity to move copying the T0SZ value from idmap_t0sz in KVM init rather than in .hyp.idmap.text. This avoids the need for the idmap_t0sz symbol alias. Signed-off-by:
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David Brazdil authored
Once we start initializing KVM on newly booted cores before the rest of the kernel, parameters to __do_hyp_init will need to be provided by EL2 rather than EL1. At that point it will not be possible to pass its three arguments directly because PSCI_CPU_ON only supports one context argument. Refactor __do_hyp_init to accept its parameters in a struct. This prepares the code for KVM booting cores as well as removes any limits on the number of __do_hyp_init arguments. Signed-off-by:
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David Brazdil authored
KVM precomputes the hyp VA of __kvm_hyp_host_vector, essentially a constant (minus ASLR), before passing it to __kvm_hyp_init. Now that we have alternatives for converting kimg VA to hyp VA, replace this with computing the constant inside __kvm_hyp_init, thus removing the need for an argument. Signed-off-by:
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David Brazdil authored
When a CPU is booted in EL2, the kernel checks for VHE support and initializes the CPU core accordingly. For nVHE it also installs the stub vectors and drops down to EL1. Once KVM gains the ability to boot cores without going through the kernel entry point, it will need to initialize the CPU the same way. Extract the relevant bits of el2_setup into an init_el2_state macro with an argument specifying whether to initialize for VHE or nVHE. The following ifdefs are removed: * CONFIG_ARM_GIC_V3 - always selected on arm64 * CONFIG_COMPAT - hstr_el2 can be set even without 32-bit support No functional change intended. Size of el2_setup increased by 148 bytes due to duplication. Signed-off-by:
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David Brazdil authored
CPU index should never be negative. Change the signature of (set_)cpu_logical_map to take an unsigned int. This still works even if the users treat the CPU index as an int, and will allow the hypervisor's implementation to check that the index is valid with a single upper-bound check. Signed-off-by:
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David Brazdil authored
Make it possible to retrieve a copy of the psci_0_1_function_ids struct. This is useful for KVM if it is configured to intercept host's PSCI SMCs. Signed-off-by:
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David Brazdil authored
Small refactor that replaces array of v0.1 function IDs indexed by an enum of function-name constants with a struct of function IDs "indexed" by field names. This is done in preparation for exposing the IDs to other parts of the kernel. Exposing a struct avoids the need for bounds checking. Signed-off-by:
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David Brazdil authored
Refactor implementation of v0.1+ functions (CPU_SUSPEND, CPU_OFF, CPU_ON, MIGRATE) to have two functions psci_0_1_foo / psci_0_2_foo that select the function ID and call a common helper __psci_foo. This is a small cleanup so that the function ID array is only used for v0.1 configurations. Signed-off-by:
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David Brazdil authored
KVM's host PSCI SMC filter needs to be aware of the PSCI version of the system but currently it is impossible to distinguish between v0.1 and PSCI disabled because both have get_version == NULL. Populate get_version for v0.1 with a function that returns a constant. psci_opt.get_version is currently unused so this has no effect on existing functionality. Signed-off-by:
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David Brazdil authored
Expose the boolean value whether the system is running with KVM in protected mode (nVHE + kernel param). CPU capability was selected over a global variable to allow use in alternatives. Signed-off-by:
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David Brazdil authored
Add an early parameter that allows users to select the mode of operation for KVM/arm64. For now, the only supported value is "protected". By passing this flag users opt into the hypervisor placing additional restrictions on the host kernel. These allow the hypervisor to spawn guests whose state is kept private from the host. Restrictions will include stage-2 address translation to prevent host from accessing guest memory, filtering its SMC calls, etc. Without this parameter, the default behaviour remains selecting VHE/nVHE based on hardware support and CONFIG_ARM64_VHE. Signed-off-by:
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Marc Zyngier authored
Signed-off-by:
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