KVM: arm64: Classify CPTR_EL2 as a SR_LOC_SPECIAL register

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It may not be obvious unless you look at it closely, but CPTR_EL2
is treated very differently from other registers. It is one the
registers that, despite looking very similar between EL1 and EL2
when E2H==1, have RES0 bits that get in the way.

Make it clear that CPTR_EL2 is odd by classifying it as SR_LOC_SPECIAL,
just like CNTHCTL_EL2 (and for the same reasons). This makes it
possible to use vcpu_read_sys_reg() with it, and will be necessary
once we support FEAT_NV2P1.

Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Reviewed-by: Yuan Yao <yaoyuan@linux.alibaba.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://patch.msgid.link/20260730071022.296811-7-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>

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Marc Zyngier 2026-07-30 08:09:59 +01:00 • committed by Oliver Upton

parent fed0a1e87c

commit 0b72c40600

2 changed files with 19 additions and 3 deletions

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arch/arm64/include/asm/kvm_emulate.h

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20

arch/arm64/kvm/sys_regs.c

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