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2025-10-13KVM: arm64: Compute per-vCPU FGTs at vcpu_load()Oliver Upton1-0/+1
To date KVM has used the fine-grained traps for the sake of UNDEF enforcement (so-called FGUs), meaning the constituent parts could be computed on a per-VM basis and folded into the effective value when programmed. Prepare for traps changing based on the vCPU context by computing the whole mess of them at vcpu_load(). Aggressively inline all the helpers to preserve the build-time checks that were there before. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Reviewed-by: Joey Gouly <joey.gouly@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-30Merge tag 'kvmarm-6.18' of ↵Paolo Bonzini6-121/+309
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for 6.18 - Add support for FF-A 1.2 as the secure memory conduit for pKVM, allowing more registers to be used as part of the message payload. - Change the way pKVM allocates its VM handles, making sure that the privileged hypervisor is never tricked into using uninitialised data. - Speed up MMIO range registration by avoiding unnecessary RCU synchronisation, which results in VMs starting much quicker. - Add the dump of the instruction stream when panic-ing in the EL2 payload, just like the rest of the kernel has always done. This will hopefully help debugging non-VHE setups. - Add 52bit PA support to the stage-1 page-table walker, and make use of it to populate the fault level reported to the guest on failing to translate a stage-1 walk. - Add NV support to the GICv3-on-GICv5 emulation code, ensuring feature parity for guests, irrespective of the host platform. - Fix some really ugly architecture problems when dealing with debug in a nested VM. This has some bad performance impacts, but is at least correct. - Add enough infrastructure to be able to disable EL2 features and give effective values to the EL2 control registers. This then allows a bunch of features to be turned off, which helps cross-host migration. - Large rework of the selftest infrastructure to allow most tests to transparently run at EL2. This is the first step towards enabling NV testing. - Various fixes and improvements all over the map, including one BE fix, just in time for the removal of the feature.
2025-09-20Merge branch kvm-arm64/misc-6.18 into kvmarm-master/nextMarc Zyngier1-3/+6
* kvm-arm64/misc-6.18: : . : . : Misc improvements and bug fixes: : : - Fix XN handling in the S2 page table dumper : (20250809135356.1003520-1-r09922117@csie.ntu.edu.tw) : : - Fix sanitity checks for huge mapping with pKVM running np guests : (20250815162655.121108-1-ben.horgan@arm.com) : : - Fix use of TRBE when KVM is disabled, and Linux running under : a lesser hypervisor (20250902-etm_crash-v2-1-aa9713a7306b@oss.qualcomm.com) : : - Fix out of date MTE-related comments (20250915155234.196288-1-alexandru.elisei@arm.com) : : - Fix PSCI BE support when running a NV guest (20250916161103.1040727-1-maz@kernel.org) : : - Fix page reference leak when refusing to map a page due to mismatched attributes : (20250917130737.2139403-1-tabba@google.com) : : - Add trap handling for PMSDSFR_EL1 : (20250901-james-perf-feat_spe_eft-v8-7-2e2738f24559@linaro.org) : : - Add advertisement from FEAT_LSFE (Large System Float Extension) : (20250918-arm64-lsfe-v4-1-0abc712101c7@kernel.org) : . KVM: arm64: Expose FEAT_LSFE to guests KVM: arm64: Add trap configs for PMSDSFR_EL1 KVM: arm64: Fix page leak in user_mem_abort() KVM: arm64: Fix kvm_vcpu_{set,is}_be() to deal with EL2 state KVM: arm64: Update stale comment for sanitise_mte_tags() KVM: arm64: Return early from trace helpers when KVM isn't available KVM: arm64: Fix debug checking for np-guests using huge mappings KVM: arm64: ptdump: Don't test PTE_VALID alongside other attributes Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-17Merge branch kvm-arm64/dump-instr into kvmarm-master/nextMarc Zyngier1-2/+10
* kvm-arm64/dump-instr: : . : Dump the isntruction stream on panic, just like the rest of the kernel : already does. : : Patches courtesy of Mostafa Saleh (20250909133631.3844423-1-smostafa@google.com) : . KVM: arm64: Map hyp text as RO and dump instr on panic KVM: arm64: Dump instruction on hyp panic Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-15KVM: arm64: Map hyp text as RO and dump instr on panicMostafa Saleh1-2/+10
Map the hyp text section as RO, there are no secrets there and that allows the kernel extract info for debugging. As in case of panic we can now dump the faulting instructions similar to the kernel. Signed-off-by: Mostafa Saleh <smostafa@google.com> Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-15Merge branch kvm-arm64/pkvm_vm_handle into kvmarm-master/nextMarc Zyngier2-43/+148
* kvm-arm64/pkvm_vm_handle: : pKVM VM handle allocation fixes, courtesy of Fuad Tabba. : : From the cover letter (20250909072437.4110547-1-tabba@google.com): : : "In pKVM, this handle is allocated when the VM is initialized at the : hypervisor, which is on the first vCPU run. However, the host starts : initializing the VM and setting up its data structures earlier. MMU : notifiers for the VMs are also registered before VM initialization at : the hypervisor, and rely on the handle to identify the VM. : : Therefore, there is a potential gap between when the VM is (partially) : setup at the host, but still without a valid pKVM handle to identify it : when communicating with the hypervisor." KVM: arm64: Reserve pKVM handle during pkvm_init_host_vm() KVM: arm64: Introduce separate hypercalls for pKVM VM reservation and initialization KVM: arm64: Consolidate pKVM hypervisor VM initialization logic KVM: arm64: Separate allocation and insertion of pKVM VM table entries KVM: arm64: Decouple hyp VM creation state from its handle KVM: arm64: Clarify comments to distinguish pKVM mode from protected VMs KVM: arm64: Rename 'host_kvm' to 'kvm' in pKVM host code KVM: arm64: Rename pkvm.enabled to pkvm.is_protected KVM: arm64: Add build-time check for duplicate DECLARE_REG use Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-15KVM: arm64: Introduce separate hypercalls for pKVM VM reservation and ↵Fuad Tabba2-22/+94
initialization The existing __pkvm_init_vm hypercall performs both the reservation of a VM table entry and the initialization of the hypervisor VM state in a single operation. This design prevents the host from obtaining a VM handle from the hypervisor until all preparation for the creation and the initialization of the VM is done, which is on the first vCPU run operation. To support more flexible VM lifecycle management, the host needs the ability to reserve a handle early, before the first vCPU run. Refactor the hypercall interface to enable this, splitting the single hypercall into a two-stage process: - __pkvm_reserve_vm: A new hypercall that allocates a slot in the hypervisor's vm_table, marks it as reserved, and returns a unique handle to the host. - __pkvm_unreserve_vm: A corresponding cleanup hypercall to safely release the reservation if the host fails to proceed with full initialization. - __pkvm_init_vm: The existing hypercall is modified to no longer allocate a slot. It now expects a pre-reserved handle and commits the donated VM memory to that slot. For now, the host-side code in __pkvm_create_hyp_vm calls the new reserve and init hypercalls back-to-back to maintain existing behavior. This paves the way for subsequent patches to separate the reservation and initialization steps in the VM's lifecycle. Signed-off-by: Fuad Tabba <tabba@google.com> Tested-by: Mark Brown <broonie@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-15KVM: arm64: Consolidate pKVM hypervisor VM initialization logicFuad Tabba1-23/+24
The insert_vm_table_entry() function was performing tasks beyond its primary responsibility. In addition to inserting a VM pointer into the vm_table, it was also initializing several fields within 'struct pkvm_hyp_vm', such as the VMID and stage-2 MMU pointers. This mixing of concerns made the code harder to follow. As another preparatory step towards allowing a VM table entry to be reserved before the VM is fully created, this logic must be cleaned up. By separating table insertion from state initialization, we can control the timing of the initialization step more precisely in subsequent patches. Refactor the code to consolidate all initialization logic into init_pkvm_hyp_vm(): - Move the initialization of the handle, VMID, and MMU fields from insert_vm_table_entry() to init_pkvm_hyp_vm(). - Simplify insert_vm_table_entry() to perform only one action: placing the provided pkvm_hyp_vm pointer into the vm_table. - Update the calling sequence in __pkvm_init_vm() to first allocate an entry in the VM table, initialize the VM, and then insert the VM into the VM table. This is all protected by the vm_table_lock for now. Subsequent patches will adjust the sequence and not hold the vm_table_lock while initializing the VM at the hypervisor (init_pkvm_hyp_vm()). Signed-off-by: Fuad Tabba <tabba@google.com> Tested-by: Mark Brown <broonie@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-15KVM: arm64: Separate allocation and insertion of pKVM VM table entriesFuad Tabba1-9/+43
The current insert_vm_table_entry() function performs two actions at once: it finds a free slot in the pKVM VM table and populates it with the pkvm_hyp_vm pointer. Refactor this function as a preparatory step for future work that will require reserving a VM slot and its corresponding handle earlier in the VM lifecycle, before the pkvm_hyp_vm structure is initialized and ready to be inserted. Split the function into a two-phase process: - A new allocate_vm_table_entry() function finds an empty slot, marks it as reserved with a RESERVED_ENTRY placeholder, and returns a handle derived from the slot's index. - The insert_vm_table_entry() function is repurposed to take the handle, validate that the corresponding slot is in the reserved state, and then populate it with the pkvm_hyp_vm pointer. Signed-off-by: Fuad Tabba <tabba@google.com> Tested-by: Mark Brown <broonie@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-15KVM: arm64: Decouple hyp VM creation state from its handleFuad Tabba1-0/+1
Currently, the presence of a pKVM handle (pkvm.handle != 0) is used to determine if the corresponding hypervisor (EL2) VM has been created and initialized. This couples the handle's lifecycle with the VM's creation state. This coupling will become problematic with upcoming changes that will allocate the pKVM handle earlier in the VM's life, before the VM is instantiated at the hypervisor. To prepare for this and make the state tracking explicit, decouple the two concepts. Introduce a new boolean flag, 'pkvm.is_created', to track whether the hypervisor-side VM has been created and initialized. A new helper, pkvm_hyp_vm_is_created(), is added to check this flag. All call sites that previously checked for the handle's existence are converted to use the new, explicit check. The 'is_created' flag is set to true upon successful creation in the hypervisor (EL2) and cleared upon destruction. Signed-off-by: Fuad Tabba <tabba@google.com> Tested-by: Mark Brown <broonie@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-15KVM: arm64: Clarify comments to distinguish pKVM mode from protected VMsFuad Tabba1-14/+11
The hypervisor code for protected KVM contains comments that are imprecise and at times flat-out wrong. They often refer to a "protected VM" in contexts where the code or data structure applies to _any_ VM managed by the hypervisor when pKVM is enabled. For instance, the 'vm_table' holds handles for all VMs known to the hypervisor, not exclusively for those that are configured as protected. This inaccurate terminology can make the code scope harder to understand for future (and current) developers. Clarify the comments throughout the pKVM hypervisor code to make a clear distinction between the pKVM feature itself (i.e., "protected mode") and the VMs that are specifically configured to be protected. This involves replacing ambiguous uses of "protected VM" with more accurate phrasing. No functional change intended. Signed-off-by: Fuad Tabba <tabba@google.com> Tested-by: Mark Brown <broonie@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-15KVM: arm64: Rename pkvm.enabled to pkvm.is_protectedFuad Tabba1-1/+1
The 'pkvm.enabled' field in struct kvm_protected_vm is confusingly named. Its purpose is to indicate whether a VM is a _protected_ VM under pKVM, and not whether the VM itself is enabled or running. For a non-protected VM, the VM can be fully active and running, yet this field would be false. This ambiguity can lead to incorrect assumptions about the VM's operational state and makes the code harder to reason about. Rename the field to 'is_protected' to make it unambiguous that the flag tracks the protected status of the VM. No functional change intended. Reviewed-by: Kunwu Chan <kunwu.chan@linux.dev> Signed-off-by: Fuad Tabba <tabba@google.com> Reviewed-by: Kunwu Chan <chentao@kylinos.cn> Tested-by: Mark Brown <broonie@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-15KVM: arm64: Fix debug checking for np-guests using huge mappingsBen Horgan1-3/+6
When running with transparent huge pages and CONFIG_NVHE_EL2_DEBUG then the debug checking in assert_host_shared_guest() fails on the launch of an np-guest. This WARN_ON() causes a panic and generates the stack below. In __pkvm_host_relax_perms_guest() the debug checking assumes the mapping is a single page but it may be a block map. Update the checking so that the size is not checked and just assumes the correct size. While we're here make the same fix in __pkvm_host_mkyoung_guest(). Info: # lkvm run -k /share/arch/arm64/boot/Image -m 704 -c 8 --name guest-128 Info: Removed ghost socket file "/.lkvm//guest-128.sock". [ 1406.521757] kvm [141]: nVHE hyp BUG at: arch/arm64/kvm/hyp/nvhe/mem_protect.c:1088! [ 1406.521804] kvm [141]: nVHE call trace: [ 1406.521828] kvm [141]: [<ffff8000811676b4>] __kvm_nvhe_hyp_panic+0xb4/0xe8 [ 1406.521946] kvm [141]: [<ffff80008116d12c>] __kvm_nvhe_assert_host_shared_guest+0xb0/0x10c [ 1406.522049] kvm [141]: [<ffff80008116f068>] __kvm_nvhe___pkvm_host_relax_perms_guest+0x48/0x104 [ 1406.522157] kvm [141]: [<ffff800081169df8>] __kvm_nvhe_handle___pkvm_host_relax_perms_guest+0x64/0x7c [ 1406.522250] kvm [141]: [<ffff800081169f0c>] __kvm_nvhe_handle_trap+0x8c/0x1a8 [ 1406.522333] kvm [141]: [<ffff8000811680fc>] __kvm_nvhe___skip_pauth_save+0x4/0x4 [ 1406.522454] kvm [141]: ---[ end nVHE call trace ]--- [ 1406.522477] kvm [141]: Hyp Offset: 0xfffece8013600000 [ 1406.522554] Kernel panic - not syncing: HYP panic: [ 1406.522554] PS:834003c9 PC:0000b1806db6d170 ESR:00000000f2000800 [ 1406.522554] FAR:ffff8000804be420 HPFAR:0000000000804be0 PAR:0000000000000000 [ 1406.522554] VCPU:0000000000000000 [ 1406.523337] CPU: 3 UID: 0 PID: 141 Comm: kvm-vcpu-0 Not tainted 6.16.0-rc7 #97 PREEMPT [ 1406.523485] Hardware name: FVP Base RevC (DT) [ 1406.523566] Call trace: [ 1406.523629] show_stack+0x18/0x24 (C) [ 1406.523753] dump_stack_lvl+0xd4/0x108 [ 1406.523899] dump_stack+0x18/0x24 [ 1406.524040] panic+0x3d8/0x448 [ 1406.524184] nvhe_hyp_panic_handler+0x10c/0x23c [ 1406.524325] kvm_handle_guest_abort+0x68c/0x109c [ 1406.524500] handle_exit+0x60/0x17c [ 1406.524630] kvm_arch_vcpu_ioctl_run+0x2e0/0x8c0 [ 1406.524794] kvm_vcpu_ioctl+0x1a8/0x9cc [ 1406.524919] __arm64_sys_ioctl+0xac/0x104 [ 1406.525067] invoke_syscall+0x48/0x10c [ 1406.525189] el0_svc_common.constprop.0+0x40/0xe0 [ 1406.525322] do_el0_svc+0x1c/0x28 [ 1406.525441] el0_svc+0x38/0x120 [ 1406.525588] el0t_64_sync_handler+0x10c/0x138 [ 1406.525750] el0t_64_sync+0x1ac/0x1b0 [ 1406.525876] SMP: stopping secondary CPUs [ 1406.525965] Kernel Offset: disabled [ 1406.526032] CPU features: 0x0000,00000080,8e134ca1,9446773f [ 1406.526130] Memory Limit: none [ 1406.959099] ---[ end Kernel panic - not syncing: HYP panic: [ 1406.959099] PS:834003c9 PC:0000b1806db6d170 ESR:00000000f2000800 [ 1406.959099] FAR:ffff8000804be420 HPFAR:0000000000804be0 PAR:0000000000000000 [ 1406.959099] VCPU:0000000000000000 ] Signed-off-by: Ben Horgan <ben.horgan@arm.com> Fixes: f28f1d02f4eaa ("KVM: arm64: Add a range to __pkvm_host_unshare_guest()") Cc: Vincent Donnefort <vdonnefort@google.com> Cc: Quentin Perret <qperret@google.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: stable@vger.kernel.org Reviewed-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-15Merge branch kvm-arm64/ffa-1.2 into kvmarm-master/nextMarc Zyngier2-73/+145
* kvm-arm64/ffa-1.2: : . : FFA 1.2 support for pKVM, courtesy of Per Larsen. : : From the cover letter at [1]: : : "The FF-A 1.2 specification introduces a new SEND_DIRECT2 ABI which : allows registers x4-x17 to be used for the message payload. This patch : set prevents the host from using a lower FF-A version than what has : already been negotiated with the hypervisor. This is necessary because : the hypervisor does not have the necessary compatibility paths to : translate from the hypervisor FF-A version to a previous version." : : [1] https://lore.kernel.org/r/20250820-virtio-msg-ffa-v11-0-497ef43550a3@google.com : . KVM: arm64: Bump the supported version of FF-A to 1.2 KVM: arm64: Mask response to FFA_FEATURE call KVM: arm64: Mark optional FF-A 1.2 interfaces as unsupported KVM: arm64: Mark FFA_NOTIFICATION_* calls as unsupported KVM: arm64: Use SMCCC 1.2 for FF-A initialization and in host handler KVM: arm64: Correct return value on host version downgrade attempt Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-10KVM: arm64: Fix parameter ordering for VBAR_EL1 assignmentFuad Tabba1-1/+1
The __vcpu_assign_sys_reg() helper expects the register ID as the second argument and the value to be assigned as the third. However, the existing code was passing these parameters in the incorrect order. Fix the function call to properly read the live value of VBAR_EL1 from the guest and update the vCPU value immediately before pending the exception. This ensures the vCPU's value is the same as the guest's and that the exception will be handled at the correct address upon resuming the guest. Fixes: 798eb5978700 ("KVM: arm64: Sync protected guest VBAR_EL1 on injecting an undef exception") Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20250908163557.2419780-1-tabba@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-09-10KVM: arm64: VHE: Save and restore host MDCR_EL2 value correctlyAlexandru Elisei1-0/+6
Prior to commit 75a5fbaf6623 ("KVM: arm64: Compute MDCR_EL2 at vcpu_load()"), host MDCR_EL2 was saved correctly: kvm_arch_vcpu_load() kvm_vcpu_load_debug() /* Doesn't touch hardware MDCR_EL2. */ kvm_vcpu_load_vhe() __activate_traps_common() /* Saves host MDCR_EL2. */ *host_data_ptr(host_debug_state.mdcr_el2) = read_sysreg(mdcr_el2) /* Writes VCPU MDCR_EL2. */ write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2) The MDCR_EL2 value saved previously was restored in kvm_arch_vcpu_put() -> kvm_vcpu_put_vhe(). After the aforementioned commit, host MDCR_EL2 is never saved: kvm_arch_vcpu_load() kvm_vcpu_load_debug() /* Writes VCPU MDCR_EL2 */ kvm_vcpu_load_vhe() __activate_traps_common() /* Saves **VCPU** MDCR_EL2. */ *host_data_ptr(host_debug_state.mdcr_el2) = read_sysreg(mdcr_el2) /* Writes VCPU MDCR_EL2 a second time. */ write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2) kvm_arch_vcpu_put() -> kvm_vcpu_put_vhe() then restores the VCPU MDCR_EL2 value. Also VCPU's MDCR_EL2 value gets written to hardware twice now. Fix this by saving the host MDCR_EL2 in kvm_arch_vcpu_load() before it gets overwritten by the VCPU's MDCR_EL2 value, and restore it on VCPU put. Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20250902130833.338216-3-alexandru.elisei@arm.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-09-08KVM: arm64: Bump the supported version of FF-A to 1.2Per Larsen1-3/+3
FF-A version 1.2 introduces the DIRECT_REQ2 ABI. Bump the FF-A version preferred by the hypervisor to enable implementation of the 1.2-only FFA_MSG_SEND_DIRECT_REQ2 and FFA_MSG_SEND_RESP2 messaging interfaces. Co-developed-by: Ayrton Munoz <ayrton@google.com> Signed-off-by: Ayrton Munoz <ayrton@google.com> Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Per Larsen <perlarsen@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-08KVM: arm64: Mask response to FFA_FEATURE callPer Larsen1-1/+1
The minimum size and alignment boundary for FFA_RXTX_MAP is returned in bit[1:0]. Mask off any other bits in w2 when reading the minimum buffer size in hyp_ffa_post_init. Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Per Larsen <perlarsen@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-08KVM: arm64: Mark optional FF-A 1.2 interfaces as unsupportedPer Larsen1-0/+5
Mark FF-A 1.2 interfaces as unsupported lest they get proxied. Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Per Larsen <perlarsen@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-08KVM: arm64: Mark FFA_NOTIFICATION_* calls as unsupportedPer Larsen1-0/+8
Prevent FFA_NOTIFICATION_* interfaces from being passed through to TZ. Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Per Larsen <perlarsen@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-08KVM: arm64: Use SMCCC 1.2 for FF-A initialization and in host handlerPer Larsen2-69/+125
SMCCC 1.1 and prior allows four registers to be sent back as a result of an FF-A interface. SMCCC 1.2 increases the number of results that can be sent back to 8 and 16 for 32-bit and 64-bit SMC/HVCs respectively. FF-A 1.0 references SMCCC 1.2 (reference [4] on page xi) and FF-A 1.2 explicitly requires SMCCC 1.2 so it should be safe to use this version unconditionally. Moreover, it is simpler to implement FF-A features without having to worry about compatibility with SMCCC 1.1 and older. SMCCC 1.2 requires that SMC32/HVC32 from aarch64 mode preserves x8-x30 but given that there is no reliable way to distinguish 32-bit/64-bit calls, we assume SMC64 unconditionally. This has the benefit of being consistent with the handling of calls that are passed through, i.e., not proxied. (A cleaner solution will become available in FF-A 1.3.) Update the FF-A initialization and host handler code to use SMCCC 1.2. Signed-off-by: Per Larsen <perlarsen@google.com> Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-08KVM: arm64: Correct return value on host version downgrade attemptPer Larsen1-1/+4
Once the hypervisor negotiates the FF-A version with the host, it should remain locked-in. However, it is possible to load FF-A as a module first supporting version 1.1 and then 1.0. Without this patch, the FF-A 1.0 driver will use 1.0 data structures to make calls which the hypervisor will incorrectly interpret as 1.1 data structures. With this patch, negotiation will fail. This patch does not change existing functionality in the case where a FF-A 1.2 driver is loaded after a 1.1 driver; the 1.2 driver will need to use 1.1 in order to proceed. Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Per Larsen <perlarsen@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-08-29Merge tag 'kvmarm-fixes-6.17-1' of ↵Paolo Bonzini2-1/+6
https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 changes for 6.17, take #2 - Correctly handle 'invariant' system registers for protected VMs - Improved handling of VNCR data aborts, including external aborts - Fixes for handling of FEAT_RAS for NV guests, providing a sane fault context during SEA injection and preventing the use of RASv1p1 fault injection hardware - Ensure that page table destruction when a VM is destroyed gives an opportunity to reschedule - Large fix to KVM's infrastructure for managing guest context loaded on the CPU, addressing issues where the output of AT emulation doesn't get reflected to the guest - Fix AT S12 emulation to actually perform stage-2 translation when necessary - Avoid attempting vLPI irqbypass when GICv4 has been explicitly disabled for a VM - Minor KVM + selftest fixes
2025-08-08KVM: arm64: Sync protected guest VBAR_EL1 on injecting an undef exceptionFuad Tabba1-0/+1
In pKVM, a race condition can occur if a guest updates its VBAR_EL1 register and, before a vCPU exit synchronizes this change, the hypervisor needs to inject an undefined exception into a protected guest. In this scenario, the vCPU still holds the stale VBAR_EL1 value from before the guest's update. When pKVM injects the exception, it ends up using the stale value. Explicitly read the live value of VBAR_EL1 from the guest and update the vCPU value immediately before pending the exception. This ensures the vCPU's value is the same as the guest's and that the exception will be handled at the correct address upon resuming the guest. Reported-by: Keir Fraser <keirf@google.com> Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20250807120133.871892-3-tabba@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-08-08KVM: arm64: Handle AIDR_EL1 and REVIDR_EL1 in host for protected VMsFuad Tabba1-0/+4
Since commit 17efc1acee62 ("arm64: Expose AIDR_EL1 via sysfs"), AIDR_EL1 is read early during boot. Therefore, a guest running as a protected VM will fail to boot because when it attempts to access AIDR_EL1, access to that register is restricted in pKVM for protected guests. Similar to how MIDR_EL1 is handled by the host for protected VMs, let the host handle accesses to AIDR_EL1 as well as REVIDR_EL1. However note that, unlike MIDR_EL1, AIDR_EL1 and REVIDR_EL1 are trapped by HCR_EL2.TID1. Therefore, explicitly mark them as handled by the host for protected VMs. TID1 is always set in pKVM, because it needs to restrict access to SMIDR_EL1, which is also trapped by that bit. Reported-by: Will Deacon <will@kernel.org> Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://lore.kernel.org/r/20250807120133.871892-2-tabba@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-08-08kvm: arm64: use BUG() instead of BUG_ON(1)Arnd Bergmann1-1/+1
The BUG_ON() macro adds a little bit of complexity over BUG(), and in some cases this ends up confusing the compiler's control flow analysis in a way that results in a warning. This one now shows up with clang-21: arch/arm64/kvm/vgic/vgic-mmio.c:1094:3: error: variable 'len' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized] 1094 | BUG_ON(1); Change both instances of BUG_ON(1) to a plain BUG() in the arm64 kvm code, to avoid the false-positive warning. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20250807072132.4170088-1-arnd@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-29Merge tag 'arm64-upstream' of ↵Linus Torvalds2-1/+33
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: "A quick summary: perf support for Branch Record Buffer Extensions (BRBE), typical PMU hardware updates, small additions to MTE for store-only tag checking and exposing non-address bits to signal handlers, HAVE_LIVEPATCH enabled on arm64, VMAP_STACK forced on. There is also a TLBI optimisation on hardware that does not require break-before-make when changing the user PTEs between contiguous and non-contiguous. More details: Perf and PMU updates: - Add support for new (v3) Hisilicon SLLC and DDRC PMUs - Add support for Arm-NI PMU integrations that share interrupts between clock domains within a given instance - Allow SPE to be configured with a lower sample period than the minimum recommendation advertised by PMSIDR_EL1.Interval - Add suppport for Arm's "Branch Record Buffer Extension" (BRBE) - Adjust the perf watchdog period according to cpu frequency changes - Minor driver fixes and cleanups Hardware features: - Support for MTE store-only checking (FEAT_MTE_STORE_ONLY) - Support for reporting the non-address bits during a synchronous MTE tag check fault (FEAT_MTE_TAGGED_FAR) - Optimise the TLBI when folding/unfolding contiguous PTEs on hardware with FEAT_BBM (break-before-make) level 2 and no TLB conflict aborts Software features: - Enable HAVE_LIVEPATCH after implementing arch_stack_walk_reliable() and using the text-poke API for late module relocations - Force VMAP_STACK always on and change arm64_efi_rt_init() to use arch_alloc_vmap_stack() in order to avoid KASAN false positives ACPI: - Improve SPCR handling and messaging on systems lacking an SPCR table Debug: - Simplify the debug exception entry path - Drop redundant DBG_MDSCR_* macros Kselftests: - Cleanups and improvements for SME, SVE and FPSIMD tests Miscellaneous: - Optimise loop to reduce redundant operations in contpte_ptep_get() - Remove ISB when resetting POR_EL0 during signal handling - Mark the kernel as tainted on SEA and SError panic - Remove redundant gcs_free() call" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (93 commits) arm64/gcs: task_gcs_el0_enable() should use passed task arm64: Kconfig: Keep selects somewhat alphabetically ordered arm64: signal: Remove ISB when resetting POR_EL0 kselftest/arm64: Handle attempts to disable SM on SME only systems kselftest/arm64: Fix SVE write data generation for SME only systems kselftest/arm64: Test SME on SME only systems in fp-ptrace kselftest/arm64: Test FPSIMD format data writes via NT_ARM_SVE in fp-ptrace kselftest/arm64: Allow sve-ptrace to run on SME only systems arm64/mm: Drop redundant addr increment in set_huge_pte_at() kselftest/arm4: Provide local defines for AT_HWCAP3 arm64: Mark kernel as tainted on SAE and SError panic arm64/gcs: Don't call gcs_free() when releasing task_struct drivers/perf: hisi: Support PMUs with no interrupt drivers/perf: hisi: Relax the event number check of v2 PMUs drivers/perf: hisi: Add support for HiSilicon SLLC v3 PMU driver drivers/perf: hisi: Use ACPI driver_data to retrieve SLLC PMU information drivers/perf: hisi: Add support for HiSilicon DDRC v3 PMU driver drivers/perf: hisi: Simplify the probe process for each DDRC version perf/arm-ni: Support sharing IRQs within an NI instance perf/arm-ni: Consolidate CPU affinity handling ...
2025-07-28Merge tag 'hardening-v6.17-rc1' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardening updates from Kees Cook: - Introduce and start using TRAILING_OVERLAP() helper for fixing embedded flex array instances (Gustavo A. R. Silva) - mux: Convert mux_control_ops to a flex array member in mux_chip (Thorsten Blum) - string: Group str_has_prefix() and strstarts() (Andy Shevchenko) - Remove KCOV instrumentation from __init and __head (Ritesh Harjani, Kees Cook) - Refactor and rename stackleak feature to support Clang - Add KUnit test for seq_buf API - Fix KUnit fortify test under LTO * tag 'hardening-v6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (22 commits) sched/task_stack: Add missing const qualifier to end_of_stack() kstack_erase: Support Clang stack depth tracking kstack_erase: Add -mgeneral-regs-only to silence Clang warnings init.h: Disable sanitizer coverage for __init and __head kstack_erase: Disable kstack_erase for all of arm compressed boot code x86: Handle KCOV __init vs inline mismatches arm64: Handle KCOV __init vs inline mismatches s390: Handle KCOV __init vs inline mismatches arm: Handle KCOV __init vs inline mismatches mips: Handle KCOV __init vs inline mismatch powerpc/mm/book3s64: Move kfence and debug_pagealloc related calls to __init section configs/hardening: Enable CONFIG_INIT_ON_FREE_DEFAULT_ON configs/hardening: Enable CONFIG_KSTACK_ERASE stackleak: Split KSTACK_ERASE_CFLAGS from GCC_PLUGINS_CFLAGS stackleak: Rename stackleak_track_stack to __sanitizer_cov_stack_depth stackleak: Rename STACKLEAK to KSTACK_ERASE seq_buf: Introduce KUnit tests string: Group str_has_prefix() and strstarts() kunit/fortify: Add back "volatile" for sizeof() constants acpi: nfit: intel: avoid multiple -Wflex-array-member-not-at-end warnings ...
2025-07-21stackleak: Rename STACKLEAK to KSTACK_ERASEKees Cook1-1/+1
In preparation for adding Clang sanitizer coverage stack depth tracking that can support stack depth callbacks: - Add the new top-level CONFIG_KSTACK_ERASE option which will be implemented either with the stackleak GCC plugin, or with the Clang stack depth callback support. - Rename CONFIG_GCC_PLUGIN_STACKLEAK as needed to CONFIG_KSTACK_ERASE, but keep it for anything specific to the GCC plugin itself. - Rename all exposed "STACKLEAK" names and files to "KSTACK_ERASE" (named for what it does rather than what it protects against), but leave as many of the internals alone as possible to avoid even more churn. While here, also split "prev_lowest_stack" into CONFIG_KSTACK_ERASE_METRICS, since that's the only place it is referenced from. Suggested-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20250717232519.2984886-1-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-08KVM: arm64: nvhe: Disable branch generation in nVHE guestsAnshuman Khandual2-1/+33
While BRBE can record branches within guests, the host recording branches in guests is not supported by perf (though events are). Support for BRBE in guests will supported by providing direct access to BRBE within the guests. That is how x86 LBR works for guests. Therefore, BRBE needs to be disabled on guest entry and restored on exit. For nVHE, this requires explicit handling for guests. Before entering a guest, save the BRBE state and disable the it. When returning to the host, restore the state. For VHE, it is not necessary. We initialize BRBCR_EL1.{E1BRE,E0BRE}=={0,0} at boot time, and HCR_EL2.TGE==1 while running in the host. We configure BRBCR_EL2.{E2BRE,E0HBRE} to enable branch recording in the host. When entering the guest, we set HCR_EL2.TGE==0 which means BRBCR_EL1 is used instead of BRBCR_EL2. Consequently for VHE, BRBE recording is disabled at EL1 and EL0 when running a guest. Should recording in guests (by the host) ever be desired, the perf ABI will need to be extended to distinguish guest addresses (struct perf_branch_entry.priv) for starters. BRBE records would also need to be invalidated on guest entry/exit as guest/host EL1 and EL0 records can't be distinguished. Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Co-developed-by: Rob Herring (Arm) <robh@kernel.org> Signed-off-by: Rob Herring (Arm) <robh@kernel.org> Tested-by: James Clark <james.clark@linaro.org> Reviewed-by: Leo Yan <leo.yan@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Acked-by: Marc Zyngier <maz@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20250611-arm-brbe-v19-v23-3-e7775563036e@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2025-06-26KVM: arm64: Adjust range correctly during host stage-2 faultsQuentin Perret1-8/+12
host_stage2_adjust_range() tries to find the largest block mapping that fits within a memory or mmio region (represented by a kvm_mem_range in this function) during host stage-2 faults under pKVM. To do so, it walks the host stage-2 page-table, finds the faulting PTE and its level, and then progressively increments the level until it finds a granule of the appropriate size. However, the condition in the loop implementing the above is broken as it checks kvm_level_supports_block_mapping() for the next level instead of the current, so pKVM may attempt to map a region larger than can be covered with a single block. This is not a security problem and is quite rare in practice (the kvm_mem_range check usually forces host_stage2_adjust_range() to choose a smaller granule), but this is clearly not the expected behaviour. Refactor the loop to fix the bug and improve readability. Fixes: c4f0935e4d95 ("KVM: arm64: Optimize host memory aborts") Signed-off-by: Quentin Perret <qperret@google.com> Link: https://lore.kernel.org/r/20250625105548.984572-1-qperret@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-06-19KVM: arm64: Remove ad-hoc CPTR manipulation from fpsimd_sve_sync()Mark Rutland1-1/+4
There's no need for fpsimd_sve_sync() to write to CPTR/CPACR. All relevant traps are always disabled earlier within __kvm_vcpu_run(), when __deactivate_cptr_traps() configures CPTR/CPACR. With irrelevant details elided, the flow is: handle___kvm_vcpu_run(...) { flush_hyp_vcpu(...) { fpsimd_sve_flush(...); } __kvm_vcpu_run(...) { __activate_traps(...) { __activate_cptr_traps(...); } do { __guest_enter(...); } while (...); __deactivate_traps(....) { __deactivate_cptr_traps(...); } } sync_hyp_vcpu(...) { fpsimd_sve_sync(...); } } Remove the unnecessary write to CPTR/CPACR. An ISB is still necessary, so a comment is added to describe this requirement. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Fuad Tabba <tabba@google.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Oliver Upton <oliver.upton@linux.dev> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20250617133718.4014181-5-mark.rutland@arm.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-06-19KVM: arm64: Reorganise CPTR trap manipulationMark Rutland1-59/+0
The NVHE/HVHE and VHE modes have separate implementations of __activate_cptr_traps() and __deactivate_cptr_traps() in their respective switch.c files. There's some duplication of logic, and it's not currently possible to reuse this logic elsewhere. Move the logic into the common switch.h header so that it can be reused, and de-duplicate the common logic. This rework changes the way SVE traps are deactivated in VHE mode, aligning it with NVHE/HVHE modes: * Before this patch, VHE's __deactivate_cptr_traps() would unconditionally enable SVE for host EL2 (but not EL0), regardless of whether the ARM64_SVE cpucap was set. * After this patch, VHE's __deactivate_cptr_traps() will take the ARM64_SVE cpucap into account. When ARM64_SVE is not set, SVE will be trapped from EL2 and below. The old and new behaviour are both benign: * When ARM64_SVE is not set, the host will not touch SVE state, and will not reconfigure SVE traps. Host EL0 access to SVE will be trapped as expected. * When ARM64_SVE is set, the host will configure EL0 SVE traps before returning to EL0 as part of reloading the EL0 FPSIMD/SVE/SME state. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Fuad Tabba <tabba@google.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Oliver Upton <oliver.upton@linux.dev> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20250617133718.4014181-4-mark.rutland@arm.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-06-11Merge tag 'kvmarm-fixes-6.16-2' of ↵Paolo Bonzini1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for 6.16, take #2 - Rework of system register accessors for system registers that are directly writen to memory, so that sanitisation of the in-memory value happens at the correct time (after the read, or before the write). For convenience, RMW-style accessors are also provided. - Multiple fixes for the so-called "arch-timer-edge-cases' selftest, which was always broken.
2025-06-05KVM: arm64: Add assignment-specific sysreg accessorMarc Zyngier1-2/+2
Assigning a value to a system register doesn't do what it is supposed to be doing if that register is one that has RESx bits. The main problem is that we use __vcpu_sys_reg(), which can be used both as a lvalue and rvalue. When used as a lvalue, the bit masking occurs *before* the new value is assigned, meaning that we (1) do pointless work on the old cvalue, and (2) potentially assign an invalid value as we fail to apply the masks to it. Fix this by providing a new __vcpu_assign_sys_reg() that does what it says on the tin, and sanitises the *new* value instead of the old one. This comes with a significant amount of churn. Reviewed-by: Miguel Luis <miguel.luis@oracle.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20250603070824.1192795-2-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-26Merge tag 'kvmarm-6.16' of ↵Paolo Bonzini10-150/+579
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for 6.16 * New features: - Add large stage-2 mapping support for non-protected pKVM guests, clawing back some performance. - Add UBSAN support to the standalone EL2 object used in nVHE/hVHE and protected modes. - Enable nested virtualisation support on systems that support it (yes, it has been a long time coming), though it is disabled by default. * Improvements, fixes and cleanups: - Large rework of the way KVM tracks architecture features and links them with the effects of control bits. This ensures correctness of emulation (the data is automatically extracted from the published JSON files), and helps dealing with the evolution of the architecture. - Significant changes to the way pKVM tracks ownership of pages, avoiding page table walks by storing the state in the hypervisor's vmemmap. This in turn enables the THP support described above. - New selftest checking the pKVM ownership transition rules - Fixes for FEAT_MTE_ASYNC being accidentally advertised to guests even if the host didn't have it. - Fixes for the address translation emulation, which happened to be rather buggy in some specific contexts. - Fixes for the PMU emulation in NV contexts, decoupling PMCR_EL0.N from the number of counters exposed to a guest and addressing a number of issues in the process. - Add a new selftest for the SVE host state being corrupted by a guest. - Keep HCR_EL2.xMO set at all times for systems running with the kernel at EL2, ensuring that the window for interrupts is slightly bigger, and avoiding a pretty bad erratum on the AmpereOne HW. - Add workaround for AmpereOne's erratum AC04_CPU_23, which suffers from a pretty bad case of TLB corruption unless accesses to HCR_EL2 are heavily synchronised. - Add a per-VM, per-ITS debugfs entry to dump the state of the ITS tables in a human-friendly fashion. - and the usual random cleanups.
2025-05-23Merge branch kvm-arm64/misc-6.16 into kvmarm-master/nextMarc Zyngier4-5/+5
* kvm-arm64/misc-6.16: : . : Misc changes and improvements for 6.16: : : - Add a new selftest for the SVE host state being corrupted by a guest : : - Keep HCR_EL2.xMO set at all times for systems running with the kernel at EL2, : ensuring that the window for interrupts is slightly bigger, and avoiding : a pretty bad erratum on the AmpereOne HW : : - Replace a couple of open-coded on/off strings with str_on_off() : : - Get rid of the pKVM memblock sorting, which now appears to be superflous : : - Drop superflous clearing of ICH_LR_EOI in the LR when nesting : : - Add workaround for AmpereOne's erratum AC04_CPU_23, which suffers from : a pretty bad case of TLB corruption unless accesses to HCR_EL2 are : heavily synchronised : : - Add a per-VM, per-ITS debugfs entry to dump the state of the ITS tables : in a human-friendly fashion : . KVM: arm64: Fix documentation for vgic_its_iter_next() KVM: arm64: vgic-its: Add debugfs interface to expose ITS tables arm64: errata: Work around AmpereOne's erratum AC04_CPU_23 KVM: arm64: nv: Remove clearing of ICH_LR<n>.EOI if ICH_LR<n>.HW == 1 KVM: arm64: Drop sort_memblock_regions() KVM: arm64: selftests: Add test for SVE host corruption KVM: arm64: Force HCR_EL2.xMO to 1 at all times in VHE mode KVM: arm64: Replace ternary flags with str_on_off() helper Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-23Merge branch kvm-arm64/fgt-masks into kvmarm-master/nextMarc Zyngier1-0/+12
* kvm-arm64/fgt-masks: (43 commits) : . : Large rework of the way KVM deals with trap bits in conjunction with : the CPU feature registers. It now draws a direct link between which : the feature set, the system registers that need to UNDEF to match : the configuration and bits that need to behave as RES0 or RES1 in : the trap registers that are visible to the guest. : : Best of all, these definitions are mostly automatically generated : from the JSON description published by ARM under a permissive : license. : . KVM: arm64: Handle TSB CSYNC traps KVM: arm64: Add FGT descriptors for FEAT_FGT2 KVM: arm64: Allow sysreg ranges for FGT descriptors KVM: arm64: Add context-switch for FEAT_FGT2 registers KVM: arm64: Add trap routing for FEAT_FGT2 registers KVM: arm64: Add sanitisation for FEAT_FGT2 registers KVM: arm64: Add FEAT_FGT2 registers to the VNCR page KVM: arm64: Use HCR_EL2 feature map to drive fixed-value bits KVM: arm64: Use HCRX_EL2 feature map to drive fixed-value bits KVM: arm64: Allow kvm_has_feat() to take variable arguments KVM: arm64: Use FGT feature maps to drive RES0 bits KVM: arm64: Validate FGT register descriptions against RES0 masks KVM: arm64: Switch to table-driven FGU configuration KVM: arm64: Handle PSB CSYNC traps KVM: arm64: Use KVM-specific HCRX_EL2 RES0 mask KVM: arm64: Remove hand-crafted masks for FGT registers KVM: arm64: Use computed FGT masks to setup FGT registers KVM: arm64: Propagate FGT masks to the nVHE hypervisor KVM: arm64: Unconditionally configure fine-grain traps KVM: arm64: Use computed masks as sanitisers for FGT registers ... Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-23Merge branch kvm-arm64/ubsan-el2 into kvmarm-master/nextMarc Zyngier1-0/+6
* kvm-arm64/ubsan-el2: : . : Add UBSAN support to the EL2 portion of KVM, reusing most of the : existing logic provided by CONFIG_IBSAN_TRAP. : : Patches courtesy of Mostafa Saleh. : . KVM: arm64: Handle UBSAN faults KVM: arm64: Introduce CONFIG_UBSAN_KVM_EL2 ubsan: Remove regs from report_ubsan_failure() arm64: Introduce esr_is_ubsan_brk() Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-21KVM: arm64: np-guest CMOs with PMD_SIZE fixmapVincent Donnefort3-26/+115
With the introduction of stage-2 huge mappings in the pKVM hypervisor, guest pages CMO is needed for PMD_SIZE size. Fixmap only supports PAGE_SIZE and iterating over the huge-page is time consuming (mostly due to TLBI on hyp_fixmap_unmap) which is a problem for EL2 latency. Introduce a shared PMD_SIZE fixmap (hyp_fixblock_map/hyp_fixblock_unmap) to improve guest page CMOs when stage-2 huge mappings are installed. On a Pixel6, the iterative solution resulted in a latency of ~700us, while the PMD_SIZE fixmap reduces it to ~100us. Because of the horrendous private range allocation that would be necessary, this is disabled for 64KiB pages systems. Suggested-by: Quentin Perret <qperret@google.com> Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Quentin Perret <qperret@google.com> Link: https://lore.kernel.org/r/20250521124834.1070650-11-vdonnefort@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-21KVM: arm64: Stage-2 huge mappings for np-guestsVincent Donnefort1-9/+14
Now np-guests hypercalls with range are supported, we can let the hypervisor to install block mappings whenever the Stage-1 allows it, that is when backed by either Hugetlbfs or THPs. The size of those block mappings is limited to PMD_SIZE. Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Link: https://lore.kernel.org/r/20250521124834.1070650-10-vdonnefort@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-21KVM: arm64: Add a range to __pkvm_host_test_clear_young_guest()Vincent Donnefort2-6/+11
In preparation for supporting stage-2 huge mappings for np-guest. Add a nr_pages argument to the __pkvm_host_test_clear_young_guest hypercall. This range supports only two values: 1 or PMD_SIZE / PAGE_SIZE (that is 512 on a 4K-pages system). Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Link: https://lore.kernel.org/r/20250521124834.1070650-7-vdonnefort@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-21KVM: arm64: Add a range to __pkvm_host_wrprotect_guest()Vincent Donnefort2-10/+15
In preparation for supporting stage-2 huge mappings for np-guest. Add a nr_pages argument to the __pkvm_host_wrprotect_guest hypercall. This range supports only two values: 1 or PMD_SIZE / PAGE_SIZE (that is 512 on a 4K-pages system). Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Link: https://lore.kernel.org/r/20250521124834.1070650-6-vdonnefort@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-21KVM: arm64: Add a range to __pkvm_host_unshare_guest()Vincent Donnefort2-27/+33
In preparation for supporting stage-2 huge mappings for np-guest. Add a nr_pages argument to the __pkvm_host_unshare_guest hypercall. This range supports only two values: 1 or PMD_SIZE / PAGE_SIZE (that is 512 on a 4K-pages system). Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Link: https://lore.kernel.org/r/20250521124834.1070650-5-vdonnefort@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-21KVM: arm64: Add a range to __pkvm_host_share_guest()Vincent Donnefort2-32/+59
In preparation for supporting stage-2 huge mappings for np-guest. Add a nr_pages argument to the __pkvm_host_share_guest hypercall. This range supports only two values: 1 or PMD_SIZE / PAGE_SIZE (that is 512 on a 4K-pages system). Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Link: https://lore.kernel.org/r/20250521124834.1070650-4-vdonnefort@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-21KVM: arm64: Introduce for_each_hyp_pageVincent Donnefort2-26/+29
Add a helper to iterate over the hypervisor vmemmap. This will be particularly handy with the introduction of huge mapping support for the np-guest stage-2. Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Link: https://lore.kernel.org/r/20250521124834.1070650-3-vdonnefort@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-21KVM: arm64: Handle huge mappings for np-guest CMOsVincent Donnefort1-4/+22
clean_dcache_guest_page() and invalidate_icache_guest_page() accept a size as an argument. But they also rely on fixmap, which can only map a single PAGE_SIZE page. With the upcoming stage-2 huge mappings for pKVM np-guests, those callbacks will get size > PAGE_SIZE. Loop the CMOs on a PAGE_SIZE basis until the whole range is done. Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Link: https://lore.kernel.org/r/20250521124834.1070650-2-vdonnefort@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-21Merge branch kvm-arm64/pkvm-selftest-6.16 into kvm-arm64/pkvm-np-thp-6.16Marc Zyngier3-1/+211
* kvm-arm64/pkvm-selftest-6.16: : . : pKVM selftests covering the memory ownership transitions by : Quentin Perret. From the initial cover letter: : : "We have recently found a bug [1] in the pKVM memory ownership : transitions by code inspection, but it could have been caught with a : test. : : Introduce a boot-time selftest exercising all the known pKVM memory : transitions and importantly checks the rejection of illegal transitions. : : The new test is hidden behind a new Kconfig option separate from : CONFIG_EL2_NVHE_DEBUG on purpose as that has side effects on the : transition checks ([1] doesn't reproduce with EL2 debug enabled). : : [1] https://lore.kernel.org/kvmarm/20241128154406.602875-1-qperret@google.com/" : . KVM: arm64: Extend pKVM selftest for np-guests KVM: arm64: Selftest for pKVM transitions KVM: arm64: Don't WARN from __pkvm_host_share_guest() KVM: arm64: Add .hyp.data section Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-19arm64: errata: Work around AmpereOne's erratum AC04_CPU_23D Scott Phillips4-5/+5
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>
2025-05-19KVM: arm64: Add sanitisation for FEAT_FGT2 registersMarc Zyngier1-0/+5
Just like the FEAT_FGT registers, treat the FGT2 variant the same way. THis is a large update, but a fairly mechanical one. The config dependencies are extracted from the 2025-03 JSON drop. Reviewed-by: Joey Gouly <joey.gouly@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>