Commit c21df6e4 authored by Marc Zyngier's avatar Marc Zyngier Committed by Oliver Upton
Browse files

KVM: arm64: Expose ID_AA64MMFR4_EL1 to guests 



We can now expose ID_AA64MMFR4_EL1 to guests, and let NV guests
understand that they cannot really switch HCR_EL2.E2H to 0 on
some platforms.

Reviewed-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240122181344.258974-9-maz@kernel.org


Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
parent 3944382f

arch/arm64/kvm/nested.c

+7 −0
Original line number Diff line number Diff line
@@ -133,6 +133,13 @@ static u64 limit_nv_id_reg(u32 id, u64 val) 
		val |= FIELD_PREP(NV_FTR(MMFR2, TTL), 0b0001);

		break;



	case SYS_ID_AA64MMFR4_EL1:

		val = 0;

		if (!cpus_have_final_cap(ARM64_HAS_HCR_NV1))

			val |= FIELD_PREP(NV_FTR(MMFR4, E2H0),

					  ID_AA64MMFR4_EL1_E2H0_NI_NV1);

		break;



	case SYS_ID_AA64DFR0_EL1:

		/* Only limited support for PMU, Debug, BPs and WPs */

		val &= (NV_FTR(DFR0, PMUVer)	|

arch/arm64/kvm/sys_regs.c

+1 −1
Original line number Diff line number Diff line
@@ -2350,7 +2350,7 @@ static const struct sys_reg_desc sys_reg_descs[] = { 
					ID_AA64MMFR2_EL1_NV |

					ID_AA64MMFR2_EL1_CCIDX)),

	ID_SANITISED(ID_AA64MMFR3_EL1),

	ID_UNALLOCATED(7,4),

	ID_SANITISED(ID_AA64MMFR4_EL1),

	ID_UNALLOCATED(7,5),

	ID_UNALLOCATED(7,6),

	ID_UNALLOCATED(7,7),