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2025-05-19arm64: errata: Work around AmpereOne's erratum AC04_CPU_23D Scott Phillips
On AmpereOne AC04, updates to HCR_EL2 can rarely corrupt simultaneous translations for data addresses initiated by load/store instructions. Only instruction initiated translations are vulnerable, not translations from prefetches for example. A DSB before the store to HCR_EL2 is sufficient to prevent older instructions from hitting the window for corruption, and an ISB after is sufficient to prevent younger instructions from hitting the window for corruption. Signed-off-by: D Scott Phillips <scott@os.amperecomputing.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20250513184514.2678288-1-scott@os.amperecomputing.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-03-02KVM: arm64: Initialize SCTLR_EL1 in __kvm_hyp_init_cpu()Ahmed Genidi
When KVM is in protected mode, host calls to PSCI are proxied via EL2, and cold entries from CPU_ON, CPU_SUSPEND, and SYSTEM_SUSPEND bounce through __kvm_hyp_init_cpu() at EL2 before entering the host kernel's entry point at EL1. While __kvm_hyp_init_cpu() initializes SPSR_EL2 for the exception return to EL1, it does not initialize SCTLR_EL1. Due to this, it's possible to enter EL1 with SCTLR_EL1 in an UNKNOWN state. In practice this has been seen to result in kernel crashes after CPU_ON as a result of SCTLR_EL1.M being 1 in violation of the initial core configuration specified by PSCI. Fix this by initializing SCTLR_EL1 for cold entry to the host kernel. As it's necessary to write to SCTLR_EL12 in VHE mode, this initialization is moved into __kvm_host_psci_cpu_entry() where we can use write_sysreg_el1(). The remnants of the '__init_el2_nvhe_prepare_eret' macro are folded into its only caller, as this is clearer than having the macro. Fixes: cdf367192766ad11 ("KVM: arm64: Intercept host's CPU_ON SMCs") Reported-by: Leo Yan <leo.yan@arm.com> Signed-off-by: Ahmed Genidi <ahmed.genidi@arm.com> [ Mark: clarify commit message, handle E2H, move to C, remove macro ] Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Ahmed Genidi <ahmed.genidi@arm.com> Cc: Ben Horgan <ben.horgan@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Leo Yan <leo.yan@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Oliver Upton <oliver.upton@linux.dev> Cc: Will Deacon <will@kernel.org> Reviewed-by: Leo Yan <leo.yan@arm.com> Link: https://lore.kernel.org/r/20250227180526.1204723-3-mark.rutland@arm.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-03-02KVM: arm64: Initialize HCR_EL2.E2H earlyMark Rutland
On CPUs without FEAT_E2H0, HCR_EL2.E2H is RES1, but may reset to an UNKNOWN value out of reset and consequently may not read as 1 unless it has been explicitly initialized. We handled this for the head.S boot code in commits: 3944382fa6f22b54 ("arm64: Treat HCR_EL2.E2H as RES1 when ID_AA64MMFR4_EL1.E2H0 is negative") b3320142f3db9b3f ("arm64: Fix early handling of FEAT_E2H0 not being implemented") Unfortunately, we forgot to apply a similar fix to the KVM PSCI entry points used when relaying CPU_ON, CPU_SUSPEND, and SYSTEM SUSPEND. When KVM is entered via these entry points, the value of HCR_EL2.E2H may be consumed before it has been initialized (e.g. by the 'init_el2_state' macro). Initialize HCR_EL2.E2H early in these paths such that it can be consumed reliably. The existing code in head.S is factored out into a new 'init_el2_hcr' macro, and this is used in the __kvm_hyp_init_cpu() function common to all the relevant PSCI entry points. For clarity, I've tweaked the assembly used to check whether ID_AA64MMFR4_EL1.E2H0 is negative. The bitfield is extracted as a signed value, and this is checked with a signed-greater-or-equal (GE) comparison. As the hyp code will reconfigure HCR_EL2 later in ___kvm_hyp_init(), all bits other than E2H are initialized to zero in __kvm_hyp_init_cpu(). Fixes: 3944382fa6f22b54 ("arm64: Treat HCR_EL2.E2H as RES1 when ID_AA64MMFR4_EL1.E2H0 is negative") Fixes: b3320142f3db9b3f ("arm64: Fix early handling of FEAT_E2H0 not being implemented") Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Ahmed Genidi <ahmed.genidi@arm.com> Cc: Ben Horgan <ben.horgan@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Leo Yan <leo.yan@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Oliver Upton <oliver.upton@linux.dev> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20250227180526.1204723-2-mark.rutland@arm.com [maz: fixed LT->GE thinko] Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-10-17KVM: arm64: Shave a few bytes from the EL2 idmap codeMarc Zyngier
Our idmap is becoming too big, to the point where it doesn't fit in a 4kB page anymore. There are some low-hanging fruits though, such as the el2_init_state horror that is expanded 3 times in the kernel. Let's at least limit ourselves to two copies, which makes the kernel link again. At some point, we'll have to have a better way of doing this. Reported-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20241009204903.GA3353168@thelio-3990X
2024-08-15KVM: arm64: Invalidate EL1&0 TLB entries for all VMIDs in nvhe hyp initWill Deacon
When initialising the nVHE hypervisor, we invalidate potentially stale TLB entries for the EL1&0 regime using a 'vmalls12e1' invalidation. However, this invalidation operation applies only to the active VMID and therefore we could proceed with stale TLB entries for other VMIDs. Replace the operation with an 'alle1' which applies to all entries for the EL1&0 regime, regardless of the VMID. Cc: Marc Zyngier <maz@kernel.org> Cc: Oliver Upton <oliver.upton@linux.dev> Fixes: 1025c8c0c6ac ("KVM: arm64: Wrap the host with a stage 2") Signed-off-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20240814123429.20457-2-will@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-06-20KVM: arm64: nVHE: Support CONFIG_CFI_CLANG at EL2Pierre-Clément Tosi
The compiler implements kCFI by adding type information (u32) above every function that might be indirectly called and, whenever a function pointer is called, injects a read-and-compare of that u32 against the value corresponding to the expected type. In case of a mismatch, a BRK instruction gets executed. When the hypervisor triggers such an exception in nVHE, it panics and triggers and exception return to EL1. Therefore, teach nvhe_hyp_panic_handler() to detect kCFI errors from the ESR and report them. If necessary, remind the user that EL2 kCFI is not affected by CONFIG_CFI_PERMISSIVE. Pass $(CC_FLAGS_CFI) to the compiler when building the nVHE hyp code. Use SYM_TYPED_FUNC_START() for __pkvm_init_switch_pgd, as nVHE can't call it directly and must use a PA function pointer from C (because it is part of the idmap page), which would trigger a kCFI failure if the type ID wasn't present. Signed-off-by: Pierre-Clément Tosi <ptosi@google.com> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20240610063244.2828978-9-ptosi@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-06-20KVM: arm64: Fix __pkvm_init_switch_pgd call ABIPierre-Clément Tosi
Fix the mismatch between the (incorrect) C signature, C call site, and asm implementation by aligning all three on an API passing the parameters (pgd and SP) separately, instead of as a bundled struct. Remove the now unnecessary memory accesses while the MMU is off from the asm, which simplifies the C caller (as it does not need to convert a VA struct pointer to PA) and makes the code slightly more robust by offsetting the struct fields from C and properly expressing the call to the C compiler (e.g. type checker and kCFI). Fixes: f320bc742bc2 ("KVM: arm64: Prepare the creation of s1 mappings at EL2") Signed-off-by: Pierre-Clément Tosi <ptosi@google.com> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20240610063244.2828978-3-ptosi@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-01-04KVM: arm64: Add missing memory barriers when switching to pKVM's hyp pgdWill Deacon
In commit f320bc742bc23 ("KVM: arm64: Prepare the creation of s1 mappings at EL2"), pKVM switches from a temporary host-provided page-table to its own page-table at EL2. Since there is only a single TTBR for the nVHE hypervisor, this involves disabling and re-enabling the MMU in __pkvm_init_switch_pgd(). Unfortunately, the memory barriers here are not quite correct. Specifically: - A DSB is required to complete the TLB invalidation executed while the MMU is disabled. - An ISB is required to make the new TTBR value visible to the page-table walker before the MMU is enabled in the SCTLR. An earlier version of the patch actually got this correct: https://lore.kernel.org/lkml/20210304184717.GB21795@willie-the-truck/ but thanks to some badly worded review comments from yours truly, these were dropped for the version that was eventually merged. Bring back the barriers and fix the potential issue (but note that this was found by code inspection). Cc: Quentin Perret <qperret@google.com> Fixes: f320bc742bc23 ("KVM: arm64: Prepare the creation of s1 mappings at EL2") Signed-off-by: Will Deacon <will@kernel.org> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240104164220.7968-1-will@kernel.org
2023-11-27KVM: arm64: Use LPA2 page-tables for stage2 and hyp stage1Ryan Roberts
Implement a simple policy whereby if the HW supports FEAT_LPA2 for the page size we are using, always use LPA2-style page-tables for stage 2 and hyp stage 1 (assuming an nvhe hyp), regardless of the VMM-requested IPA size or HW-implemented PA size. When in use we can now support up to 52-bit IPA and PA sizes. We use the previously created cpu feature to track whether LPA2 is supported for deciding whether to use the LPA2 or classic pte format. Note that FEAT_LPA2 brings support for bigger block mappings (512GB with 4KB, 64GB with 16KB). We explicitly don't enable these in the library because stage2_apply_range() works on batch sizes of the largest used block mapping, and increasing the size of the batch would lead to soft lockups. See commit 5994bc9e05c2 ("KVM: arm64: Limit stage2_apply_range() batch size to largest block"). With the addition of LPA2 support in the hypervisor, the PA size supported by the HW must be capped with a runtime decision, rather than simply using a compile-time decision based on PA_BITS. For example, on a system that advertises 52 bit PA but does not support FEAT_LPA2, A 4KB or 16KB kernel compiled with LPA2 support must still limit the PA size to 48 bits. Therefore, move the insertion of the PS field into TCR_EL2 out of __kvm_hyp_init assembly code and instead do it in cpu_prepare_hyp_mode() where the rest of TCR_EL2 is prepared. This allows us to figure out PS with kvm_get_parange(), which has the appropriate logic to ensure the above requirement. (and the PS field of VTCR_EL2 is already populated this way). Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231127111737.1897081-8-ryan.roberts@arm.com
2023-09-12KVM: arm64: nvhe: Ignore SVE hint in SMCCC function IDJean-Philippe Brucker
When SVE is enabled, the host may set bit 16 in SMCCC function IDs, a hint that indicates an unused SVE state. At the moment NVHE doesn't account for this bit when inspecting the function ID, and rejects most calls. Clear the hint bit before comparing function IDs. About version compatibility: the host's PSCI driver initially probes the firmware for a SMCCC version number. If the firmware implements a protocol recent enough (1.3), subsequent SMCCC calls have the hint bit set. Since the hint bit was reserved in earlier versions of the protocol, clearing it is fine regardless of the version in use. When a new hint is added to the protocol in the future, it will be added to ARM_SMCCC_CALL_HINTS and NVHE will handle it straight away. This patch only clears known hints and leaves reserved bits as is, because future SMCCC versions could use reserved bits as modifiers for the function ID, rather than hints. Fixes: cfa7ff959a78 ("arm64: smccc: Support SMCCC v1.3 SVE register saving hint") Reported-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230911145254.934414-4-jean-philippe@linaro.org
2023-06-15Merge branch kvm-arm64/misc into kvmarm/nextOliver Upton
* kvm-arm64/misc: : Miscellaneous updates : : - Avoid trapping CTR_EL0 on systems with FEAT_EVT, as the register is : commonly read by userspace : : - Make use of FEAT_BTI at hyp stage-1, setting the Guard Page bit to 1 : for executable mappings : : - Use a separate set of pointer authentication keys for the hypervisor : when running in protected mode (i.e. pKVM) : : - Plug a few holes in timer initialization where KVM fails to free the : timer IRQ(s) KVM: arm64: Use different pointer authentication keys for pKVM KVM: arm64: timers: Fix resource leaks in kvm_timer_hyp_init() KVM: arm64: Use BTI for nvhe KVM: arm64: Relax trapping of CTR_EL0 when FEAT_EVT is available Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-06-15KVM: arm64: Fix hVHE init on CPUs where HCR_EL2.E2H is not RES1Marc Zyngier
On CPUs where E2H is RES1, we very quickly set the scene for running EL2 with a VHE configuration, as we do not have any other choice. However, CPUs that conform to the current writing of the architecture start with E2H=0, and only later upgrade with E2H=1. This is all good, but nothing there is actually reconfiguring EL2 to be able to correctly run the kernel at EL1. Huhuh... The "obvious" solution is not to just reinitialise the timer controls like we do, but to really intitialise *everything* unconditionally. This requires a bit of surgery, and is a good opportunity to remove the macro that messes with SPSR_EL2 in init_el2_state. With that, hVHE now works correctly on my trusted A55 machine! Reported-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230614155129.2697388-1-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-06-12arm64: Allow EL1 physical timer access when running VHEMarc Zyngier
To initialise the timer access from EL2 when HCR_EL2.E2H is set, we must make use the CNTHCTL_EL2 formap used is appropriate. This amounts to shifting the timer/counter enable bits by 10 to the left. Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20230609162200.2024064-7-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-05-30KVM: arm64: Use BTI for nvheMostafa Saleh
CONFIG_ARM64_BTI_KERNEL compiles the kernel to support ARMv8.5-BTI. However, the nvhe code doesn't make use of it as it doesn't map any pages with Guarded Page(GP) bit. kvm pgtable code is modified to map executable pages with GP bit if BTI is enabled for the kernel. At hyp init, SCTLR_EL2.BT is set to 1 to match EL1 configuration (SCTLR_EL1.BT1) set in bti_enable(). One difference between kernel and nvhe code, is that the kernel maps .text with GP while nvhe maps all the executable pages, this makes nvhe code need to deal with special initialization code coming from other executable sections (.idmap.text). For this we need to add bti instruction at the beginning of __kvm_handle_stub_hvc as it can be called by __host_hvc through branch instruction(br) and unlike SYM_FUNC_START, SYM_CODE_START doesn’t add bti instruction at the beginning, and it can’t be modified to add it as it is used with vector tables. Another solution which is more intrusive is to convert __kvm_handle_stub_hvc to a function and inject “bti jc” instead of “bti c” in SYM_FUNC_START Signed-off-by: Mostafa Saleh <smostafa@google.com> Link: https://lore.kernel.org/r/20230530150845.2856828-1-smostafa@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-02-02KVM: arm64: Finalise EL2 state from pKVM PSCI relayQuentin Perret
The EL2 state is not initialised correctly when a CPU comes out of CPU_{SUSPEND,OFF} as the finalise_el2 function is not being called. Let's directly call finalise_el2_state from this path to solve the issue. Fixes: 504ee23611c4 ("arm64: Add the arm64.nosve command line option") Signed-off-by: Quentin Perret <qperret@google.com> Link: https://lore.kernel.org/r/20230201103755.1398086-5-qperret@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2021-04-13Merge branch 'kvm-arm64/nvhe-wxn' into kvmarm-master/nextMarc Zyngier
Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-03-19KVM: arm64: Wrap the host with a stage 2Quentin Perret
When KVM runs in protected nVHE mode, make use of a stage 2 page-table to give the hypervisor some control over the host memory accesses. The host stage 2 is created lazily using large block mappings if possible, and will default to page mappings in absence of a better solution. >From this point on, memory accesses from the host to protected memory regions (e.g. not 'owned' by the host) are fatal and lead to hyp_panic(). Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210319100146.1149909-36-qperret@google.com
2021-03-19KVM: arm64: Set host stage 2 using kvm_nvhe_init_paramsQuentin Perret
Move the registers relevant to host stage 2 enablement to kvm_nvhe_init_params to prepare the ground for enabling it in later patches. Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210319100146.1149909-22-qperret@google.com
2021-03-19KVM: arm64: Prepare the creation of s1 mappings at EL2Quentin Perret
When memory protection is enabled, the EL2 code needs the ability to create and manage its own page-table. To do so, introduce a new set of hypercalls to bootstrap a memory management system at EL2. This leads to the following boot flow in nVHE Protected mode: 1. the host allocates memory for the hypervisor very early on, using the memblock API; 2. the host creates a set of stage 1 page-table for EL2, installs the EL2 vectors, and issues the __pkvm_init hypercall; 3. during __pkvm_init, the hypervisor re-creates its stage 1 page-table and stores it in the memory pool provided by the host; 4. the hypervisor then extends its stage 1 mappings to include a vmemmap in the EL2 VA space, hence allowing to use the buddy allocator introduced in a previous patch; 5. the hypervisor jumps back in the idmap page, switches from the host-provided page-table to the new one, and wraps up its initialization by enabling the new allocator, before returning to the host. 6. the host can free the now unused page-table created for EL2, and will now need to issue hypercalls to make changes to the EL2 stage 1 mappings instead of modifying them directly. Note that for the sake of simplifying the review, this patch focuses on the hypervisor side of things. In other words, this only implements the new hypercalls, but does not make use of them from the host yet. The host-side changes will follow in a subsequent patch. Credits to Will for __pkvm_init_switch_pgd. Acked-by: Will Deacon <will@kernel.org> Co-authored-by: Will Deacon <will@kernel.org> Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210319100146.1149909-18-qperret@google.com
2021-03-18KVM: arm64: Turn SCTLR_ELx_FLAGS into INIT_SCTLR_EL2_MMU_ONMarc Zyngier
Only the nVHE EL2 code is using this define, so let's make it plain that it is EL2 only, and refactor it to contain all the bits we need when configuring the EL2 MMU, and only those. Acked-by: Will Deacon <will@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-03-18KVM: arm64: Use INIT_SCTLR_EL2_MMU_OFF to disable the MMU on KVM teardownMarc Zyngier
Instead of doing a RMW on SCTLR_EL2 to disable the MMU, use the existing define that loads the right set of bits. Acked-by: Will Deacon <will@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-02-21Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Paolo Bonzini: "x86: - Support for userspace to emulate Xen hypercalls - Raise the maximum number of user memslots - Scalability improvements for the new MMU. Instead of the complex "fast page fault" logic that is used in mmu.c, tdp_mmu.c uses an rwlock so that page faults are concurrent, but the code that can run against page faults is limited. Right now only page faults take the lock for reading; in the future this will be extended to some cases of page table destruction. I hope to switch the default MMU around 5.12-rc3 (some testing was delayed due to Chinese New Year). - Cleanups for MAXPHYADDR checks - Use static calls for vendor-specific callbacks - On AMD, use VMLOAD/VMSAVE to save and restore host state - Stop using deprecated jump label APIs - Workaround for AMD erratum that made nested virtualization unreliable - Support for LBR emulation in the guest - Support for communicating bus lock vmexits to userspace - Add support for SEV attestation command - Miscellaneous cleanups PPC: - Support for second data watchpoint on POWER10 - Remove some complex workarounds for buggy early versions of POWER9 - Guest entry/exit fixes ARM64: - Make the nVHE EL2 object relocatable - Cleanups for concurrent translation faults hitting the same page - Support for the standard TRNG hypervisor call - A bunch of small PMU/Debug fixes - Simplification of the early init hypercall handling Non-KVM changes (with acks): - Detection of contended rwlocks (implemented only for qrwlocks, because KVM only needs it for x86) - Allow __DISABLE_EXPORTS from assembly code - Provide a saner follow_pfn replacements for modules" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (192 commits) KVM: x86/xen: Explicitly pad struct compat_vcpu_info to 64 bytes KVM: selftests: Don't bother mapping GVA for Xen shinfo test KVM: selftests: Fix hex vs. decimal snafu in Xen test KVM: selftests: Fix size of memslots created by Xen tests KVM: selftests: Ignore recently added Xen tests' build output KVM: selftests: Add missing header file needed by xAPIC IPI tests KVM: selftests: Add operand to vmsave/vmload/vmrun in svm.c KVM: SVM: Make symbol 'svm_gp_erratum_intercept' static locking/arch: Move qrwlock.h include after qspinlock.h KVM: PPC: Book3S HV: Fix host radix SLB optimisation with hash guests KVM: PPC: Book3S HV: Ensure radix guest has no SLB entries KVM: PPC: Don't always report hash MMU capability for P9 < DD2.2 KVM: PPC: Book3S HV: Save and restore FSCR in the P9 path KVM: PPC: remove unneeded semicolon KVM: PPC: Book3S HV: Use POWER9 SLBIA IH=6 variant to clear SLB KVM: PPC: Book3S HV: No need to clear radix host SLB before loading HPT guest KVM: PPC: Book3S HV: Fix radix guest SLB side channel KVM: PPC: Book3S HV: Remove support for running HPT guest on RPT host without mixed mode support KVM: PPC: Book3S HV: Introduce new capability for 2nd DAWR KVM: PPC: Book3S HV: Add infrastructure to support 2nd DAWR ...
2021-02-21Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: - vDSO build improvements including support for building with BSD. - Cleanup to the AMU support code and initialisation rework to support cpufreq drivers built as modules. - Removal of synthetic frame record from exception stack when entering the kernel from EL0. - Add support for the TRNG firmware call introduced by Arm spec DEN0098. - Cleanup and refactoring across the board. - Avoid calling arch_get_random_seed_long() from add_interrupt_randomness() - Perf and PMU updates including support for Cortex-A78 and the v8.3 SPE extensions. - Significant steps along the road to leaving the MMU enabled during kexec relocation. - Faultaround changes to initialise prefaulted PTEs as 'old' when hardware access-flag updates are supported, which drastically improves vmscan performance. - CPU errata updates for Cortex-A76 (#1463225) and Cortex-A55 (#1024718) - Preparatory work for yielding the vector unit at a finer granularity in the crypto code, which in turn will one day allow us to defer softirq processing when it is in use. - Support for overriding CPU ID register fields on the command-line. * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (85 commits) drivers/perf: Replace spin_lock_irqsave to spin_lock mm: filemap: Fix microblaze build failure with 'mmu_defconfig' arm64: Make CPU_BIG_ENDIAN depend on ld.bfd or ld.lld 13.0.0+ arm64: cpufeatures: Allow disabling of Pointer Auth from the command-line arm64: Defer enabling pointer authentication on boot core arm64: cpufeatures: Allow disabling of BTI from the command-line arm64: Move "nokaslr" over to the early cpufeature infrastructure KVM: arm64: Document HVC_VHE_RESTART stub hypercall arm64: Make kvm-arm.mode={nvhe, protected} an alias of id_aa64mmfr1.vh=0 arm64: Add an aliasing facility for the idreg override arm64: Honor VHE being disabled from the command-line arm64: Allow ID_AA64MMFR1_EL1.VH to be overridden from the command line arm64: cpufeature: Add an early command-line cpufeature override facility arm64: Extract early FDT mapping from kaslr_early_init() arm64: cpufeature: Use IDreg override in __read_sysreg_by_encoding() arm64: cpufeature: Add global feature override facility arm64: Move SCTLR_EL1 initialisation to EL-agnostic code arm64: Simplify init_el2_state to be non-VHE only arm64: Move VHE-specific SPE setup to mutate_to_vhe() arm64: Drop early setting of MDSCR_EL2.TPMS ...
2021-02-12Merge tag 'kvmarm-5.12' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for Linux 5.12 - Make the nVHE EL2 object relocatable, resulting in much more maintainable code - Handle concurrent translation faults hitting the same page in a more elegant way - Support for the standard TRNG hypervisor call - A bunch of small PMU/Debug fixes - Allow the disabling of symbol export from assembly code - Simplification of the early init hypercall handling
2021-02-12Merge branch 'kvm-arm64/hyp-reloc' into kvmarm-master/nextMarc Zyngier
Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-02-09arm64: Simplify init_el2_state to be non-VHE onlyMarc Zyngier
As init_el2_state is now nVHE only, let's simplify it and drop the VHE setup. Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: David Brazdil <dbrazdil@google.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20210208095732.3267263-9-maz@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-01-25KVM: arm64: Simplify __kvm_hyp_init HVC detectionAndrew Scull
The arguments for __do_hyp_init are now passed with a pointer to a struct which means there are scratch registers available for use. Thanks to this, we no longer need to use clever, but hard to read, tricks that avoid the need for scratch registers when checking for the __kvm_hyp_init HVC. Tested-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Andrew Scull <ascull@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210125145415.122439-2-ascull@google.com
2021-01-25KVM: arm64: Don't clobber x4 in __do_hyp_initAndrew Scull
arm_smccc_1_1_hvc() only adds write contraints for x0-3 in the inline assembly for the HVC instruction so make sure those are the only registers that change when __do_hyp_init is called. Tested-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Andrew Scull <ascull@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210125145415.122439-3-ascull@google.com
2021-01-23KVM: arm64: Fix constant-pool users in hypDavid Brazdil
Hyp code uses absolute addressing to obtain a kimg VA of a small number of kernel symbols. Since the kernel now converts constant pool addresses to hyp VAs, this trick does not work anymore. Change the helpers to convert from hyp VA back to kimg VA or PA, as needed and rework the callers accordingly. Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210105180541.65031-7-dbrazdil@google.com
2021-01-23KVM: arm64: Rename .idmap.text in hyp linker scriptDavid Brazdil
So far hyp-init.S created a .hyp.idmap.text section directly, without relying on the hyp linker script to prefix its name. Change it to create .idmap.text and add a HYP_SECTION entry to hyp.lds.S. This way all .hyp* sections go through the linker script and can be instrumented there. Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210105180541.65031-2-dbrazdil@google.com
2020-12-04KVM: arm64: Trap host SMCs in protected modeDavid Brazdil
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: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201202184122.26046-26-dbrazdil@google.com
2020-12-04KVM: arm64: Intercept host's SYSTEM_SUSPEND PSCI SMCsDavid Brazdil
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: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201202184122.26046-24-dbrazdil@google.com
2020-12-04KVM: arm64: Intercept host's CPU_SUSPEND PSCI SMCsDavid Brazdil
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: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201202184122.26046-23-dbrazdil@google.com
2020-12-04KVM: arm64: Intercept host's CPU_ON SMCsDavid Brazdil
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: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201202184122.26046-22-dbrazdil@google.com
2020-12-04KVM: arm64: Extract __do_hyp_init into a helper functionDavid Brazdil
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: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201202184122.26046-20-dbrazdil@google.com
2020-12-04KVM: arm64: Init MAIR/TCR_EL2 from params structDavid Brazdil
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: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201202184122.26046-12-dbrazdil@google.com
2020-12-04KVM: arm64: Move hyp-init params to a per-CPU structDavid Brazdil
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: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201202184122.26046-11-dbrazdil@google.com
2020-12-04KVM: arm64: Remove vector_ptr param of hyp-initDavid Brazdil
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: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201202184122.26046-10-dbrazdil@google.com
2020-10-29KVM: arm64: Don't corrupt tpidr_el2 on failed HVC callMarc Zyngier
The hyp-init code starts by stashing a register in TPIDR_EL2 in in order to free a register. This happens no matter if the HVC call is legal or not. Although nothing wrong seems to come out of it, it feels odd to alter the EL2 state for something that eventually returns an error. Instead, use the fact that we know exactly which bits of the __kvm_hyp_init call are non-zero to perform the check with a series of EOR/ROR instructions, combined with a build-time check that the value is the one we expect. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201026095116.72051-2-maz@kernel.org
2020-09-15KVM: arm64: nVHE: Migrate hyp-init to SMCCCAndrew Scull
To complete the transition to SMCCC, the hyp initialization is given a function ID. This looks neater than comparing the hyp stub function IDs to the page table physical address. Some care is taken to only clobber x0-3 before the host context is saved as only those registers can be clobbered accoring to SMCCC. Fortunately, only a few acrobatics are needed. The possible new tpidr_el2 is moved to the argument in x2 so that it can be stashed in tpidr_el2 early to free up a scratch register. The page table configuration then makes use of x0-2. Signed-off-by: Andrew Scull <ascull@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200915104643.2543892-19-ascull@google.com
2020-09-15KVM: arm64: nVHE: Pass pointers consistently to hyp-initAndrew Scull
Rather than some being kernel pointer and others being hyp pointers, standardize on all pointers being hyp pointers. Signed-off-by: Andrew Scull <ascull@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200915104643.2543892-15-ascull@google.com
2020-08-09Merge tag 'kvmarm-5.9' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-next-5.6 KVM/arm64 updates for Linux 5.9: - Split the VHE and nVHE hypervisor code bases, build the EL2 code separately, allowing for the VHE code to now be built with instrumentation - Level-based TLB invalidation support - Restructure of the vcpu register storage to accomodate the NV code - Pointer Authentication available for guests on nVHE hosts - Simplification of the system register table parsing - MMU cleanups and fixes - A number of post-32bit cleanups and other fixes
2020-07-28Merge branch 'kvm-arm64/ptrauth-nvhe' into kvmarm-master/next-WIPMarc Zyngier
Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-07-05KVM: arm64: Move hyp-init.S to nVHEAndrew Scull
hyp-init.S contains the identity mapped initialisation code for the non-VHE code that runs at EL2. It is only used for non-VHE. Adjust code that calls into this to use the prefixed symbol name. Signed-off-by: Andrew Scull <ascull@google.com> Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200625131420.71444-8-dbrazdil@google.com