[PATCH v3 6/7] KVM: arm64: Mask FEAT_CCIDX

From: Akihiko Odaki
Date: Sun Dec 18 2022 - 00:16:33 EST


The CCSIDR access handler masks the associativity bits according to the
bit layout for processors without FEAT_CCIDX. KVM also assumes CCSIDR is
32-bit where it will be 64-bit if FEAT_CCIDX is enabled. Mask FEAT_CCIDX
so that these assumptions hold.

Suggested-by: Marc Zyngier <maz@xxxxxxxxxx>
Signed-off-by: Akihiko Odaki <akihiko.odaki@xxxxxxxxxx>
---
arch/arm64/kvm/sys_regs.c | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index f48a3cc38d24..a7199f34e321 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1195,6 +1195,12 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu, struct sys_reg_desc const *r
ID_DFR0_PERFMON_SHIFT,
kvm_vcpu_has_pmu(vcpu) ? ID_DFR0_PERFMON_8_4 : 0);
break;
+ case SYS_ID_AA64MMFR2_EL1:
+ val &= ~ID_AA64MMFR2_EL1_CCIDX_MASK;
+ break;
+ case SYS_ID_MMFR4_EL1:
+ val &= ~ARM64_FEATURE_MASK(ID_MMFR4_CCIDX);
+ break;
}

return val;
@@ -1676,6 +1682,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {

{ SYS_DESC(SYS_CCSIDR_EL1), access_ccsidr },
{ SYS_DESC(SYS_CLIDR_EL1), access_clidr },
+ { SYS_DESC(SYS_CCSIDR2_EL1), undef_access },
{ SYS_DESC(SYS_SMIDR_EL1), undef_access },
{ SYS_DESC(SYS_CSSELR_EL1), access_csselr, reset_unknown, CSSELR_EL1 },
{ SYS_DESC(SYS_CTR_EL0), access_ctr },
@@ -2177,6 +2184,10 @@ static const struct sys_reg_desc cp15_regs[] = {

{ Op1(1), CRn( 0), CRm( 0), Op2(0), access_ccsidr },
{ Op1(1), CRn( 0), CRm( 0), Op2(1), access_clidr },
+
+ /* CCSIDR2 */
+ { Op1(1), CRn( 0), CRm( 0), Op2(2), undef_access },
+
{ Op1(2), CRn( 0), CRm( 0), Op2(0), access_csselr, NULL, CSSELR_EL1 },
};

--
2.38.1