kernel.git/arch/arm64/kvm/hyp/include, branch master

Merge branch kvm-arm64/misc-6.20 into kvmarm-master/next

2026-02-05T09:17:58Z

* kvm-arm64/misc-6.20: : . : Misc KVM/arm64 changes for 6.20 : : - Trivial FPSIMD cleanups : : - Calculate hyp VA size only once, avoiding potential mapping issues when : VA bits is smaller than expected : : - Silence sparse warning for the HYP stack base : : - Fix error checking when handling FFA_VERSION : : - Add missing trap configuration for DBGWCR15_EL1 : : - Don't try to deal with nested S2 when NV isn't enabled for a guest : : - Various spelling fixes : . KVM: arm64: nv: Avoid NV stage-2 code when NV is not supported KVM: arm64: Fix various comments KVM: arm64: nv: Add trap config for DBGWCR<15>_EL1 KVM: arm64: Fix error checking for FFA_VERSION KVM: arm64: Fix missing include KVM: arm64: Calculate hyp VA size only once KVM: arm64: Remove ISB after writing FPEXC32_EL2 KVM: arm64: Shuffle KVM_HOST_DATA_FLAG_* indices KVM: arm64: Fix comment in fpsimd_lazy_switch_to_host() Signed-off-by: Marc Zyngier

KVM: arm64: Remove unused parameter in synchronize_vcpu_pstate()

2026-01-08T20:56:17Z

synchronize_vcpu_pstate() doesn't make use of the reference to exit_code, remove the parameter. Reviewed-by: Fuad Tabba Signed-off-by: Alexandru Elisei Reviewed-by: Marc Zyngier Tested-by: Fuad Tabba Link: https://msgid.link/20251216103053.47224-5-alexandru.elisei@arm.com Signed-off-by: Oliver Upton

KVM: arm64: Remove ISB after writing FPEXC32_EL2

2026-01-07T11:56:30Z

The value of FPEX32_EL2 has no effect on execution in AArch64 state, and consequently there's no need for an ISB after writing to it in the hyp code (which executes in AArch64 state). When performing an exception return to AArch32 state, the exception return will provide the necessary context synchronization event. Remove the redundant ISB. Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Fuad Tabba Cc: Marc Zyngier Cc: Mark Brown Cc: Oliver Upton Cc: Will Deacon Tested-by: Fuad Tabba Reviewed-by: Fuad Tabba Link: https://patch.msgid.link/20260106173707.3292074-4-mark.rutland@arm.com Signed-off-by: Marc Zyngier

KVM: arm64: Fix comment in fpsimd_lazy_switch_to_host()

2026-01-07T11:56:30Z

The comment in fpsimd_lazy_switch_to_host() erroneously says guest traps for FPSIMD/SVE/SME are disabled by fpsimd_lazy_switch_to_guest(). In reality, the traps are disabled by __activate_cptr_traps(), and fpsimd_lazy_switch_to_guest() only manipulates the SVE vector length. This was mistake; I accidentally copy+pasted the wrong function name in commit: 59419f10045b ("KVM: arm64: Eagerly switch ZCR_EL{1,2}") Fix the comment. Fixes: 59419f10045b ("KVM: arm64: Eagerly switch ZCR_EL{1,2}") Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Fuad Tabba Cc: Marc Zyngier Cc: Mark Brown Cc: Oliver Upton Cc: Will Deacon Tested-by: Fuad Tabba Reviewed-by: Fuad Tabba Link: https://patch.msgid.link/20260106173707.3292074-2-mark.rutland@arm.com Signed-off-by: Marc Zyngier

KVM: arm64: Compute per-vCPU FGTs at vcpu_load()

2025-10-13T13:44:37Z

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 Reviewed-by: Joey Gouly Signed-off-by: Marc Zyngier

Merge tag 'kvmarm-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

2025-09-30T17:23:28Z

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.

KVM: arm64: Introduce separate hypercalls for pKVM VM reservation and initialization

2025-09-15T09:46:55Z

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 Tested-by: Mark Brown Signed-off-by: Marc Zyngier

KVM: arm64: Clarify comments to distinguish pKVM mode from protected VMs

2025-09-15T09:46:55Z

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 Tested-by: Mark Brown Signed-off-by: Marc Zyngier

KVM: arm64: Add build-time check for duplicate DECLARE_REG use

2025-09-15T09:46:55Z

The DECLARE_REG() macro provides a convenient way to create a local variable initialized from a cpu context in the hyp trap handlers. However, a common error is to use the macro multiple times in the same scope with the same register index, but for different logical purposes. This results in valid C code that compiles without error, but introduces subtle bugs where a developer expects two different variables to hold values from two different registers, when in fact they are both sourced from the same one. To prevent this entire class of bugs, modify the DECLARE_REG() macro to declare a dummy variable whose name is derived from the register index. If the macro is used again with the same index in the same scope, the compiler will fail with a "redeclaration of variable" error, turning a subtle runtime bug into an obvious build-time failure. Signed-off-by: Fuad Tabba Tested-by: Mark Brown Signed-off-by: Marc Zyngier

KVM: arm64: VHE: Save and restore host MDCR_EL2 value correctly

2025-09-10T09:56:19Z

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 Reviewed-by: Oliver Upton Link: https://lore.kernel.org/r/20250902130833.338216-3-alexandru.elisei@arm.com Signed-off-by: Oliver Upton