[PATCH v7 6/7] KVM: arm64: Mask FEAT_CCIDX

From: Akihiko Odaki
Date: Wed Jan 11 2023 - 21:39:54 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 d5ee52d6bf73..5617de916c80 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1155,6 +1155,12 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu, struct sys_reg_desc const *r
val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_DFR0_EL1_PerfMon),
pmuver_to_perfmon(vcpu_pmuver(vcpu)));
break;
+ case SYS_ID_AA64MMFR2_EL1:
+ val &= ~ID_AA64MMFR2_EL1_CCIDX_MASK;
+ break;
+ case SYS_ID_MMFR4_EL1:
+ val &= ~ARM64_FEATURE_MASK(ID_MMFR4_EL1_CCIDX);
+ break;
}

return val;
@@ -1718,6 +1724,7 @@ 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 },
@@ -2219,6 +2226,10 @@ 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 },
};

--
2.39.0