CONFIG_AMPERE_ERRATUM_AC03_CPU_38: AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics

General informations

The Linux kernel configuration item CONFIG_AMPERE_ERRATUM_AC03_CPU_38:

• prompt: AmpereOne: AC03_CPU_38: Certain bits in the Virtualization Translation Control Register and Translation Control Registers do not follow RES0 semantics
• type: bool
• depends on: (none)
• defined in arch/arm64/Kconfig
• found in Linux kernels: 6.5–6.12, 6.13-rc+HEAD

Help text

This option adds an alternative code sequence to work around Ampere errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne.

The affected design reports FEAT_HAFDBS as not implemented in ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0 as required by the architecture. The unadvertised HAFDBS implementation suffers from an additional erratum where hardware A/D updates can occur after a PTE has been marked invalid.

The workaround forces KVM to explicitly set VTCR_EL2.HA to 0, which avoids enabling unadvertised hardware Access Flag management at stage-2.

If unsure, say Y.

Hardware

LKDDb

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• (none)

Sources

This page is automaticly generated with free (libre, open) software lkddb(see lkddb-sources).

The data is retrived from:

• Linux kernel
• Linux Kernel Driver DataBase (LKDDb)

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