kernel.git/arch/arm64/include/asm/kvm_nested.h, branch linux-6.15.y

KVM: arm64: Move NV-specific capping to idreg sanitisation

2025-02-24T19:28:43Z

Instead of applying the NV idreg limits at run time, switch to doing it at the same time as the reset of the VM initialisation. This will make things much simpler once we introduce vcpu-driven variants of NV. Signed-off-by: Marc Zyngier Reviewed-by: Joey Gouly Link: https://lore.kernel.org/r/20250220134907.554085-10-maz@kernel.org Signed-off-by: Oliver Upton

Merge branch kvm-arm64/nv-resx-fixes-6.14 into kvmarm-master/next

2025-01-17T11:06:33Z

* kvm-arm64/nv-resx-fixes-6.14: : . : Fixes for NV sysreg accessors. From the cover letter: : : "Joey recently reported that some rather basic tests were failing on : NV, and managed to track it down to critical register fields (such as : HCR_EL2.E2H) not having their expect value. : : Further investigation has outlined a couple of critical issues: : : - Evaluating HCR_EL2.E2H must always be done with a sanitising : accessor, no ifs, no buts. Given that KVM assumes a fixed value for : this bit, we cannot leave it to the guest to mess with. : : - Resetting the sysreg file must result in the RESx bits taking : effect. Otherwise, we may end-up making the wrong decision (see : above), and we definitely expose invalid values to the guest. Note : that because we compute the RESx masks very late in the VM setup, we : need to apply these masks at that particular point as well. : [...]" : . KVM: arm64: nv: Apply RESx settings to sysreg reset values KVM: arm64: nv: Always evaluate HCR_EL2 using sanitising accessors Signed-off-by: Marc Zyngier # Conflicts: # arch/arm64/kvm/nested.c

KVM: arm64: nv: Apply RESx settings to sysreg reset values

2025-01-14T11:33:09Z

While we have sanitisation in place for the guest sysregs, we lack that sanitisation out of reset. So some of the fields could be evaluated and not reflect their RESx status, which sounds like a very bad idea. Apply the RESx masks to the the sysreg file in two situations: - when going via a reset of the sysregs - after having computed the RESx masks Having this separate reset phase from the actual reset handling is a bit grotty, but we need to apply this after the ID registers are final. Tested-by: Joey Gouly Reviewed-by: Joey Gouly Link: https://lore.kernel.org/r/20250112165029.1181056-3-maz@kernel.org Signed-off-by: Marc Zyngier

Merge branch kvm-arm64/pkvm-fixed-features-6.14 into kvmarm-master/next

2025-01-12T10:40:10Z

* kvm-arm64/pkvm-fixed-features-6.14: (24 commits) : . : Complete rework of the pKVM handling of features, catching up : with the rest of the code deals with it these days. : Patches courtesy of Fuad Tabba. From the cover letter: : : "This patch series uses the vm's feature id registers to track the : supported features, a framework similar to nested virt to set the : trap values, and removes the need to store cptr_el2 per vcpu in : favor of setting its value when traps are activated, as VHE mode : does." : : This branch drags the arm64/for-next/cpufeature branch to solve : ugly conflicts in -next. : . KVM: arm64: Fix FEAT_MTE in pKVM KVM: arm64: Use kvm_vcpu_has_feature() directly for struct kvm KVM: arm64: Convert the SVE guest vcpu flag to a vm flag KVM: arm64: Remove PtrAuth guest vcpu flag KVM: arm64: Fix the value of the CPTR_EL2 RES1 bitmask for nVHE KVM: arm64: Refactor kvm_reset_cptr_el2() KVM: arm64: Calculate cptr_el2 traps on activating traps KVM: arm64: Remove redundant setting of HCR_EL2 trap bit KVM: arm64: Remove fixed_config.h header KVM: arm64: Rework specifying restricted features for protected VMs KVM: arm64: Set protected VM traps based on its view of feature registers KVM: arm64: Fix RAS trapping in pKVM for protected VMs KVM: arm64: Initialize feature id registers for protected VMs KVM: arm64: Use KVM extension checks for allowed protected VM capabilities KVM: arm64: Remove KVM_ARM_VCPU_POWER_OFF from protected VMs allowed features in pKVM KVM: arm64: Move checking protected vcpu features to a separate function KVM: arm64: Group setting traps for protected VMs by control register KVM: arm64: Consolidate allowed and restricted VM feature checks arm64/sysreg: Get rid of CPACR_ELx SysregFields arm64/sysreg: Convert *_EL12 accessors to Mapping ... Signed-off-by: Marc Zyngier # Conflicts: # arch/arm64/kvm/fpsimd.c # arch/arm64/kvm/hyp/nvhe/pkvm.c

KVM: arm64: nv: Honor MDCR_EL2.TDE routing for debug exceptions

2024-12-20T09:04:11Z

Inject debug exceptions into vEL2 if MDCR_EL2.TDE is set. Tested-by: James Clark Signed-off-by: Oliver Upton Link: https://lore.kernel.org/r/20241219224116.3941496-17-oliver.upton@linux.dev Signed-off-by: Marc Zyngier

arm64/sysreg: Get rid of CPACR_ELx SysregFields

2024-12-19T18:00:58Z

There is no such thing as CPACR_ELx in the architecture. What we have is CPACR_EL1, for which CPTR_EL12 is an accessor. Rename CPACR_ELx_* to CPACR_EL1_*, and fix the bit of code using these names. Reviewed-by: Mark Brown Acked-by: Mark Rutland Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20241219173351.1123087-5-maz@kernel.org Signed-off-by: Will Deacon

KVM: arm64: nv: Punt stage-2 recycling to a vCPU request

2024-10-08T09:40:27Z

Currently, when a nested MMU is repurposed for some other MMU context, KVM unmaps everything during vcpu_load() while holding the MMU lock for write. This is quite a performance bottleneck for large nested VMs, as all vCPU scheduling will spin until the unmap completes. Start punting the MMU cleanup to a vCPU request, where it is then possible to periodically release the MMU lock and CPU in the presence of contention. Ensure that no vCPU winds up using a stale MMU by tracking the pending unmap on the S2 MMU itself and requesting an unmap on every vCPU that finds it. Signed-off-by: Oliver Upton Link: https://lore.kernel.org/r/20241007233028.2236133-4-oliver.upton@linux.dev Signed-off-by: Marc Zyngier

KVM: arm64: nv: Do not block when unmapping stage-2 if disallowed

2024-10-08T09:40:27Z

Right now the nested code allows unmap operations on a shadow stage-2 to block unconditionally. This is wrong in a couple places, such as a non-blocking MMU notifier or on the back of a sched_in() notifier as part of shadow MMU recycling. Carry through whether or not blocking is allowed to kvm_pgtable_stage2_unmap(). This 'fixes' an issue where stage-2 MMU reclaim would precipitate a stack overflow from a pile of kvm_sched_in() callbacks, all trying to recycle a stage-2 MMU. Signed-off-by: Oliver Upton Link: https://lore.kernel.org/r/20241007233028.2236133-3-oliver.upton@linux.dev Signed-off-by: Marc Zyngier

KVM: arm64: nv: Make ps_to_output_size() generally available

2024-08-30T11:04:20Z

Make this helper visible to at.c, we are going to need it. Signed-off-by: Marc Zyngier

KVM: arm64: nv: Turn upper_attr for S2 walk into the full descriptor

2024-08-30T11:04:20Z

The upper_attr attribute has been badly named, as it most of the time carries the full "last walked descriptor". Rename it to "desc" and make ti contain the full 64bit descriptor. This will be used by the S1 PTW. Signed-off-by: Marc Zyngier