kernel.git/arch/arm64/include/asm/virt.h, branch linux-5.12.y

arm64: Provide an 'upgrade to VHE' stub hypercall

2021-02-08T12:51:26Z

As we are about to change the way a VHE system boots, let's provide the core helper, in the form of a stub hypercall that enables VHE and replicates the full EL1 context at EL2, thanks to EL1 and VHE-EL2 being extremely similar. On exception return, the kernel carries on at EL2. Fancy! Nothing calls this new hypercall yet, so no functional change. Signed-off-by: Marc Zyngier Acked-by: David Brazdil Acked-by: Catalin Marinas Link: https://lore.kernel.org/r/20210208095732.3267263-5-maz@kernel.org Signed-off-by: Will Deacon

KVM: arm64: Fix EL2 mode availability checks

2020-12-04T10:08:36Z

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: David Brazdil Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20201202184122.26046-27-dbrazdil@google.com

KVM: arm64: Add ARM64_KVM_PROTECTED_MODE CPU capability

2020-12-04T08:44:19Z

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: David Brazdil Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20201202184122.26046-3-dbrazdil@google.com

arm64: cpufeature: upgrade hyp caps to final

2020-10-30T08:53:10Z

We finalize caps before initializing kvm hyp code, and any use of cpus_have_const_cap() in kvm hyp code generates redundant and potentially unsound code to read the cpu_hwcaps array. A number of helper functions used in both hyp context and regular kernel context use cpus_have_const_cap(), as some regular kernel code runs before the capabilities are finalized. It's tedious and error-prone to write separate copies of these for hyp and non-hyp code. So that we can avoid the redundant code, let's automatically upgrade cpus_have_const_cap() to cpus_have_final_cap() when used in hyp context. With this change, there's never a reason to access to cpu_hwcaps array from hyp code, and we don't need to create an NVHE alias for this. This should have no effect on non-hyp code. Signed-off-by: Mark Rutland Signed-off-by: Marc Zyngier Acked-by: Will Deacon Cc: David Brazdil Cc: Marc Zyngier Cc: Will Deacon Link: https://lore.kernel.org/r/20201026134931.28246-4-mark.rutland@arm.com

KVM: arm64: Factor out is_{vhe,nvhe}_hyp_code()

2020-10-30T08:52:51Z

Currently has_vhe() detects whether it is being compiled for VHE/NVHE hyp code based on preprocessor definitions, and uses this knowledge to avoid redundant runtime checks. There are other cases where we'd like to use this knowledge, so let's factor the preprocessor checks out into separate helpers. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Signed-off-by: Marc Zyngier Acked-by: Will Deacon Cc: David Brazdil Cc: Marc Zyngier Cc: Will Deacon Link: https://lore.kernel.org/r/20201026134931.28246-2-mark.rutland@arm.com

KVM: arm64: Use build-time defines in has_vhe()

2020-07-05T17:38:01Z

Build system compiles hyp code with macros specifying if the code belongs to VHE or nVHE. Use these macros to evaluate has_vhe() at compile time. Signed-off-by: David Brazdil Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20200625131420.71444-5-dbrazdil@google.com

KVM: arm64: Use cpus_have_final_cap for has_vhe()

2020-05-16T14:04:51Z

By the time we start using the has_vhe() helper, we have long discovered whether we are running VHE or not. It thus makes sense to use cpus_have_final_cap() instead of cpus_have_const_cap(), which leads to a small text size reduction. Signed-off-by: Marc Zyngier Acked-by: David Brazdil Link: https://lore.kernel.org/r/20200513103828.74580-1-maz@kernel.org

KVM: arm64: Ask the compiler to __always_inline functions used at HYP

2020-02-22T11:01:47Z

On non VHE CPUs, KVM's __hyp_text contains code run at EL2 while the rest of the kernel runs at EL1. This code lives in its own section with start and end markers so we can map it to EL2. The compiler may decide not to inline static-inline functions from the header file. It may also decide not to put these out-of-line functions in the same section, meaning they aren't mapped when called at EL2. Clang-9 does exactly this with __kern_hyp_va() and a few others when x18 is reserved for the shadow call stack. Add the additional __always_ hint to all the static-inlines that are called from a hyp file. Signed-off-by: James Morse Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20200220165839.256881-2-james.morse@arm.com ---- kvm_get_hyp_vector() pulls in all the regular per-cpu accessors and this_cpu_has_cap(), fortunately its only called for VHE.

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234

2019-06-19T15:09:07Z

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 Reviewed-by: Alexios Zavras Reviewed-by: Allison Randal Reviewed-by: Enrico Weigelt Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de Signed-off-by: Greg Kroah-Hartman

arm64: capabilities: Change scope of VHE to Boot CPU feature

2018-03-26T17:01:41Z

We expect all CPUs to be running at the same EL inside the kernel with or without VHE enabled and we have strict checks to ensure that any mismatch triggers a kernel panic. If VHE is enabled, we use the feature based on the boot CPU and all other CPUs should follow. This makes it a perfect candidate for a capability based on the boot CPU, which should be matched by all the CPUs (both when is ON and OFF). This saves us some not-so-pretty hooks and special code, just for verifying the conflict. The patch also makes the VHE capability entry depend on CONFIG_ARM64_VHE. Cc: Marc Zyngier Cc: Will Deacon Reviewed-by: Dave Martin Signed-off-by: Suzuki K Poulose Signed-off-by: Will Deacon