[PATCH 0/3] arm64/sysreg: Introduce Feat descriptor and generated ICH_VMCR_EL2 support

[Sascha Bischoff <Sascha.Bischoff@arm.com>]

This series introduces support for feature-specific field encodings in
the sysreg description framework and migrates the vGIC-v3 code to use
generated definitions for ICH_VMCR_EL2, in part as an example of how
the Feat descriptor can be used.

The first patch adds the Feat descriptor, allowing sysreg definitions
to vary based on architectural features (e.g., GICv3 vs GICv5). The
Feat/ElseFeat/EndFeat construct enables generation of feature-prefixed
field encodings without affecting legacy definitions. This forms the
basis for supporting feature-dependent register layouts.

The second patch adds the generated description for ICH_VMCR_EL2,
including both its GICv3 and GICv5 variants. This register was
previously defined manually in the KVM GICv3 code; moving it into the
sysreg framework ensures consistency and reduces duplication.

Finally, the third patch updates the KVM vGIC-v3 implementation to use
the generated ICH_VMCR_EL2 definitions. This replaces and removes the
hand-written definitions, with no functional change to behaviour.

Together, these patches complete the migration of ICH_VMCR_EL2 to the
sysreg framework and establish the infrastructure needed to describe
registers whose field layouts depend on architectural features.

Thanks,
Sascha

Sascha Bischoff (3):
  arm64/sysreg: Support feature-specific fields with 'Feat' descriptor
  arm64/sysreg: Add ICH_VMCR_EL2
  KVM: arm64: gic-v3: Switch vGIC-v3 to use generated ICH_VMCR_EL2

 arch/arm64/include/asm/sysreg.h      |  21 ----
 arch/arm64/kvm/hyp/vgic-v3-sr.c      |  64 +++++-------
 arch/arm64/kvm/vgic/vgic-v3-nested.c |   8 +-
 arch/arm64/kvm/vgic/vgic-v3.c        |  42 ++++----
 arch/arm64/tools/gen-sysreg.awk      | 148 +++++++++++++++++++--------
 arch/arm64/tools/sysreg              |  22 ++++
 6 files changed, 177 insertions(+), 128 deletions(-)

-- 
2.34.1