[PATCH v3 4/4] KVM: arm64: Enable writable for ID_AA64MMFR{0, 1, 2}_EL1
Jing Zhang
jingzhangos at google.com
Wed Apr 5 10:21:46 PDT 2023
Enable writable from userspace for ID_AA64MMFR{0, 1, 2}_EL1.
Added a macro for defining general writable idregs.
Signed-off-by: Jing Zhang <jingzhangos at google.com>
---
arch/arm64/kvm/id_regs.c | 36 ++++++++++++++++++++++++++++++------
1 file changed, 30 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/kvm/id_regs.c b/arch/arm64/kvm/id_regs.c
index 20d1a2d2a0cc..29e344d3c8be 100644
--- a/arch/arm64/kvm/id_regs.c
+++ b/arch/arm64/kvm/id_regs.c
@@ -164,9 +164,6 @@ u64 kvm_arm_read_id_reg(const struct kvm_vcpu *vcpu, u32 id)
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;
@@ -488,6 +485,18 @@ static int set_id_dfr0_el1(struct kvm_vcpu *vcpu,
return 0;
}
+static u64 read_sanitised_id_aa64mmfr2_el1(struct kvm_vcpu *vcpu,
+ const struct sys_reg_desc *rd)
+{
+ u64 val;
+ u32 id = reg_to_encoding(rd);
+
+ val = read_sanitised_ftr_reg(id);
+ val &= ~ID_AA64MMFR2_EL1_CCIDX_MASK;
+
+ return val;
+}
+
/*
* Since reset() callback and field val are not used for idregs, they will be
* used for specific purposes for idregs.
@@ -510,6 +519,16 @@ static int set_id_dfr0_el1(struct kvm_vcpu *vcpu,
.val = 0, \
}
+#define ID_SANITISED_WRITABLE(name) { \
+ SYS_DESC(SYS_##name), \
+ .access = access_id_reg, \
+ .get_user = get_id_reg, \
+ .set_user = set_id_reg, \
+ .visibility = id_visibility, \
+ .reset = general_read_kvm_sanitised_reg,\
+ .val = GENMASK(63, 0), \
+}
+
/* sys_reg_desc initialiser for known cpufeature ID registers */
#define AA32_ID_SANITISED(name) { \
SYS_DESC(SYS_##name), \
@@ -636,9 +655,14 @@ const struct sys_reg_desc id_reg_descs[KVM_ARM_ID_REG_NUM] = {
ID_UNALLOCATED(6, 7),
/* CRm=7 */
- ID_SANITISED(ID_AA64MMFR0_EL1),
- ID_SANITISED(ID_AA64MMFR1_EL1),
- ID_SANITISED(ID_AA64MMFR2_EL1),
+ ID_SANITISED_WRITABLE(ID_AA64MMFR0_EL1),
+ ID_SANITISED_WRITABLE(ID_AA64MMFR1_EL1),
+ { SYS_DESC(SYS_ID_AA64MMFR2_EL1),
+ .access = access_id_reg,
+ .get_user = get_id_reg,
+ .set_user = set_id_reg,
+ .reset = read_sanitised_id_aa64mmfr2_el1,
+ .val = GENMASK(63, 0), },
ID_UNALLOCATED(7, 3),
ID_UNALLOCATED(7, 4),
ID_UNALLOCATED(7, 5),
--
2.40.0.348.gf938b09366-goog
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