kernel/linux.git/arch/arm64/include/asm/kvm_host.h, branch linux-7.0.y

KVM: arm64: Fix kvm_vcpu_initialized() macro parameter

2026-05-14T13:31:07+00:00

commit d89fdda7dd8a488f922e1175e6782f781ba8a23b upstream. The macro is defined with parameter 'v' but the body references the literal token 'vcpu' instead, causing it to silently operate on whatever 'vcpu' resolves to in the caller's scope rather than the value passed by the caller. All current call sites happen to use a variable named 'vcpu', so the bug is latent. Fixes: e016333745c7 ("KVM: arm64: Only reset vCPU-scoped feature ID regs once") Signed-off-by: Fuad Tabba Link: https://patch.msgid.link/20260424084908.370776-5-tabba@google.com Signed-off-by: Marc Zyngier Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

KVM: arm64: vgic: Pick EOIcount deactivations from AP-list tail

2026-03-07T21:45:58+00:00

Valentine reports that their guests fail to boot correctly, losing interrupts, and indicates that the wrong interrupt gets deactivated. What happens here is that if the maintenance interrupt is slow enough to kick us out of the guest, extra interrupts can be activated from the LRs. We then exit and proceed to handle EOIcount deactivations, picking active interrupts from the AP list. But we start from the top of the list, potentially deactivating interrupts that were in the LRs, while EOIcount only denotes deactivation of interrupts that are not present in an LR. Solve this by tracking the last interrupt that made it in the LRs, and start the EOIcount deactivation walk *after* that interrupt. Since this only makes sense while the vcpu is loaded, stash this in the per-CPU host state. Huge thanks to Valentine for doing all the detective work and providing an initial patch. Fixes: 3cfd59f81e0f3 ("KVM: arm64: GICv3: Handle LR overflow when EOImode==0") Fixes: 281c6c06e2a7b ("KVM: arm64: GICv2: Handle LR overflow when EOImode==0") Reported-by: Valentine Burley Tested-by: Valentine Burley Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20260307115955.369455-1-valentine.burley@collabora.com Link: https://patch.msgid.link/20260307191151.3781182-1-maz@kernel.org Cc: stable@vger.kernel.org

KVM: arm64: Optimise away S1POE handling when not supported by host

2026-02-13T14:54:48+00:00

Although ID register sanitisation prevents guests from seeing the feature, adding this check to the helper allows the compiler to entirely eliminate S1POE-specific code paths (such as context switching POR_EL1) when the host kernel is compiled without support (CONFIG_ARM64_POE is disabled). This aligns with the pattern used for other optional features like SVE (kvm_has_sve()) and FPMR (kvm_has_fpmr()), ensuring no POE logic if the host lacks support, regardless of the guest configuration state. Signed-off-by: Fuad Tabba Link: https://patch.msgid.link/20260213143815.1732675-3-tabba@google.com Signed-off-by: Marc Zyngier

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

2026-02-05T09:17:58+00:00

* 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

Merge branch kvm-arm64/resx into kvmarm-master/next

2026-02-05T09:17:48+00:00

* kvm-arm64/resx: : . : Add infrastructure to deal with the full gamut of RESx bits : for NV. As a result, it is now possible to have the expected : semantics for some bits such as SCTLR_EL2.SPAN. : . KVM: arm64: Add debugfs file dumping computed RESx values KVM: arm64: Add sanitisation to SCTLR_EL2 KVM: arm64: Remove all traces of HCR_EL2.MIOCNCE KVM: arm64: Remove all traces of FEAT_TME KVM: arm64: Simplify handling of full register invalid constraint KVM: arm64: Get rid of FIXED_VALUE altogether KVM: arm64: Simplify handling of HCR_EL2.E2H RESx KVM: arm64: Move RESx into individual register descriptors KVM: arm64: Add RES1_WHEN_E2Hx constraints as configuration flags KVM: arm64: Add REQUIRES_E2H1 constraint as configuration flags KVM: arm64: Simplify FIXED_VALUE handling KVM: arm64: Convert HCR_EL2.RW to AS_RES1 KVM: arm64: Correctly handle SCTLR_EL1 RES1 bits for unsupported features KVM: arm64: Allow RES1 bits to be inferred from configuration KVM: arm64: Inherit RESx bits from FGT register descriptors KVM: arm64: Extend unified RESx handling to runtime sanitisation KVM: arm64: Introduce data structure tracking both RES0 and RES1 bits KVM: arm64: Introduce standalone FGU computing primitive KVM: arm64: Remove duplicate configuration for SCTLR_EL1.{EE,E0E} arm64: Convert SCTLR_EL2 to sysreg infrastructure Signed-off-by: Marc Zyngier

Merge branch kvm-arm64/debugfs-fixes into kvmarm-master/next

2026-02-05T09:17:44+00:00

* kvm-arm64/debugfs-fixes: : . : Cleanup of the debugfs iterator, which are way more complicated : than they ought to be, courtesy of Fuad Tabba. From the cover letter: : : "This series refactors the debugfs implementations for `idregs` and : `vgic-state` to use standard `seq_file` iterator patterns. : : The existing implementations relied on storing iterator state within : global VM structures (`kvm_arch` and `vgic_dist`). This approach : prevented concurrent reads of the debugfs files (returning -EBUSY) and : created improper dependencies between transient file operations and : long-lived VM state." : . KVM: arm64: Use standard seq_file iterator for vgic-debug debugfs KVM: arm64: Reimplement vgic-debug XArray iteration KVM: arm64: Use standard seq_file iterator for idregs debugfs Signed-off-by: Marc Zyngier

KVM: arm64: Add sanitisation to SCTLR_EL2

2026-02-05T09:02:13+00:00

Sanitise SCTLR_EL2 the usual way. The most important aspect of this is that we benefit from SCTLR_EL2.SPAN being RES1 when HCR_EL2.E2H==0. Reviewed-by: Fuad Tabba Tested-by: Fuad Tabba Link: https://patch.msgid.link/20260202184329.2724080-20-maz@kernel.org Signed-off-by: Marc Zyngier

KVM: arm64: Extend unified RESx handling to runtime sanitisation

2026-02-05T08:59:28+00:00

Add a new helper to retrieve the RESx values for a given system register, and use it for the runtime sanitisation. This results in slightly better code generation for a fairly hot path in the hypervisor, and additionally covers all sanitised registers in all conditions, not just the VNCR-based ones. Reviewed-by: Fuad Tabba Tested-by: Fuad Tabba Link: https://patch.msgid.link/20260202184329.2724080-6-maz@kernel.org Signed-off-by: Marc Zyngier

KVM: arm64: Introduce data structure tracking both RES0 and RES1 bits

2026-02-05T08:59:28+00:00

We have so far mostly tracked RES0 bits, but only made a few attempts at being just as strict for RES1 bits (probably because they are both rarer and harder to handle). Start scratching the surface by introducing a data structure tracking RES0 and RES1 bits at the same time. Note that contrary to the usual idiom, this structure is mostly passed around by value -- the ABI handles it nicely, and the resulting code is much nicer. Reviewed-by: Fuad Tabba Tested-by: Fuad Tabba Link: https://patch.msgid.link/20260202184329.2724080-5-maz@kernel.org Signed-off-by: Marc Zyngier

KVM: arm64: Use standard seq_file iterator for idregs debugfs

2026-02-02T10:59:25+00:00

The current implementation uses `idreg_debugfs_iter` in `struct kvm_arch` to track the sequence position. This effectively makes the iterator shared across all open file descriptors for the VM. This approach has significant drawbacks: - It enforces mutual exclusion, preventing concurrent reads of the debugfs file (returning -EBUSY). - It relies on storing transient iterator state in the long-lived VM structure (`kvm_arch`). - The use of `u8` for the iterator index imposes an implicit limit of 255 registers. While not currently exceeded, this is fragile against future architectural growth. Switching to `loff_t` eliminates this overflow risk. Refactor the implementation to use the standard `seq_file` iterator. Instead of storing state in `kvm_arch`, rely on the `pos` argument passed to the `start` and `next` callbacks, which tracks the logical index specific to the file descriptor. This change enables concurrent access and eliminates the `idreg_debugfs_iter` field from `struct kvm_arch`. Signed-off-by: Fuad Tabba Link: https://patch.msgid.link/20260202085721.3954942-2-tabba@google.com Signed-off-by: Marc Zyngier