[PATCH 0/1] KVM: arm64: Affinity level 3 support

[Wei-Lin Chang]

Hi everyone,

By supporting Aff3, we not only allow broader usage, but also get the
chance to fix the issue pointed out by Saurav [1]. The current code
returns 0s for GICR_TYPER[63:56], causing guests to fail when its VCPUs
tries to find a matching redistributor, when the VMM programs non-zero
values for VCPUs' MPIDR_EL1.Aff3.

For testing, both 64-bit (with ICH_VTR_EL2.A3V == 1) and 32-bit guests
are ran using QEMU, Aff3 usage is emulated by modifying reset_mpidr to
write non-zero test values to MPIDR_EL1.Aff3 when Aff3 is valid, and
populating the Aff3 field of kvm_sys_reg_set_user's user given value
if r->reg == MPIDR_EL1.
The 64-bit case is checked to have MPIDR_EL1.Aff3 populated and both
64-bit and 32-bit guests seem to work with interrupts being delivered
properly.

Note: I checked with Saurav to make sure he isn't planning on working on
this as well. Also thanks for the maintainers for giving directions for
improvements in [1].

[1]: https://lore.kernel.org/kvmarm/20240205184326.78814-1-sauravsc@amazon.com/

Wei-Lin Chang (1):
  KVM: arm64: Affinity level 3 support

 arch/arm64/kvm/sys_regs.c          | 24 +++++++++++++++++++++---
 arch/arm64/kvm/vgic/vgic-debug.c   |  2 +-
 arch/arm64/kvm/vgic/vgic-mmio-v3.c | 18 +++++++++++-------
 include/kvm/arm_vgic.h             |  7 ++++++-
 4 files changed, 39 insertions(+), 12 deletions(-)

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2.34.1