[PATCH v5 6/7] KVM: arm64: Mask FEAT_CCIDX

Akihiko Odaki akihiko.odaki at daynix.com
Fri Dec 30 01:54:51 PST 2022


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 at kernel.org>
Signed-off-by: Akihiko Odaki <akihiko.odaki at daynix.com>
---
 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 f4a7c5abcbca..aeabf1f3370b 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1124,6 +1124,12 @@ 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;
@@ -1605,6 +1611,7 @@ 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 },
@@ -2106,6 +2113,10 @@ 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




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