arm64: KVM: Add UAPI notes for swapped registers

Two UAPI system register IDs do not derive their values from the
ARM system register encodings. This is because their values were
accidentally swapped. As the IDs are API, they cannot be changed.
Add WARNING notes to point them out.

Suggested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Andrew Jones <drjones@redhat.com>
[maz: turned XXX into WARNING]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200120130825.28838-1-drjones@redhat.com
This commit is contained in:
Andrew Jones 2020-01-20 14:08:25 +01:00 committed by Marc Zyngier
parent 0e20f5e255
commit 290a6bb06d
2 changed files with 19 additions and 2 deletions

View file

@ -220,10 +220,18 @@ struct kvm_vcpu_events {
#define KVM_REG_ARM_PTIMER_CVAL ARM64_SYS_REG(3, 3, 14, 2, 2)
#define KVM_REG_ARM_PTIMER_CNT ARM64_SYS_REG(3, 3, 14, 0, 1)
/* EL0 Virtual Timer Registers */
/*
* EL0 Virtual Timer Registers
*
* WARNING:
* KVM_REG_ARM_TIMER_CVAL and KVM_REG_ARM_TIMER_CNT are not defined
* with the appropriate register encodings. Their values have been
* accidentally swapped. As this is set API, the definitions here
* must be used, rather than ones derived from the encodings.
*/
#define KVM_REG_ARM_TIMER_CTL ARM64_SYS_REG(3, 3, 14, 3, 1)
#define KVM_REG_ARM_TIMER_CNT ARM64_SYS_REG(3, 3, 14, 3, 2)
#define KVM_REG_ARM_TIMER_CVAL ARM64_SYS_REG(3, 3, 14, 0, 2)
#define KVM_REG_ARM_TIMER_CNT ARM64_SYS_REG(3, 3, 14, 3, 2)
/* KVM-as-firmware specific pseudo-registers */
#define KVM_REG_ARM_FW (0x0014 << KVM_REG_ARM_COPROC_SHIFT)