With per guest ID registers, ID_AA64PFR0_EL1.[CSV2|CSV3] settings from
userspace can be stored in its corresponding ID register.
No functional change intended.
Signed-off-by: Jing Zhang <jingzhangos@xxxxxxxxxx>
---
arch/arm64/include/asm/kvm_host.h | 3 +--
arch/arm64/kvm/arm.c | 19 +------------------
arch/arm64/kvm/hyp/nvhe/sys_regs.c | 7 +++----
arch/arm64/kvm/id_regs.c | 30 ++++++++++++++++++++++--------
4 files changed, 27 insertions(+), 32 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 5c1cec4efa37..f64347eb77c2 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -230,8 +230,6 @@ struct kvm_arch {
cpumask_var_t supported_cpus;
- u8 pfr0_csv2;
- u8 pfr0_csv3;
struct {
u8 imp:4;
u8 unimp:4;
@@ -254,6 +252,7 @@ struct kvm_arch {
#define KVM_ARM_ID_REG_NUM 56
#define IDREG_IDX(id) (((sys_reg_CRm(id) - 1) << 3) | sys_reg_Op2(id))
#define IDREG(kvm, id) kvm->arch.id_regs[IDREG_IDX(id)]
+#define IDREG_RD(kvm, rd) IDREG(kvm, reg_to_encoding(rd))
u64 id_regs[KVM_ARM_ID_REG_NUM];
};
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 4579c878ab30..c78d68d011cb 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -104,22 +104,6 @@ static int kvm_arm_default_max_vcpus(void)
return vgic_present ? kvm_vgic_get_max_vcpus() : KVM_MAX_VCPUS;
}
-static void set_default_spectre(struct kvm *kvm)
-{
- /*
- * The default is to expose CSV2 == 1 if the HW isn't affected.
- * Although this is a per-CPU feature, we make it global because
- * asymmetric systems are just a nuisance.
- *
- * Userspace can override this as long as it doesn't promise
- * the impossible.
- */
- if (arm64_get_spectre_v2_state() == SPECTRE_UNAFFECTED)
- kvm->arch.pfr0_csv2 = 1;
- if (arm64_get_meltdown_state() == SPECTRE_UNAFFECTED)
- kvm->arch.pfr0_csv3 = 1;
-}
-
/**
* kvm_arch_init_vm - initializes a VM data structure
* @kvm: pointer to the KVM struct
@@ -151,9 +135,8 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
/* The maximum number of VCPUs is limited by the host's GIC model */
kvm->max_vcpus = kvm_arm_default_max_vcpus();
- set_default_spectre(kvm);
- kvm_arm_init_hypercalls(kvm);
kvm_arm_set_default_id_regs(kvm);
+ kvm_arm_init_hypercalls(kvm);
/*
* Initialise the default PMUver before there is a chance to
diff --git a/arch/arm64/kvm/hyp/nvhe/sys_regs.c b/arch/arm64/kvm/hyp/nvhe/sys_regs.c
index 08d2b004f4b7..ff486e78b32b 100644
--- a/arch/arm64/kvm/hyp/nvhe/sys_regs.c
+++ b/arch/arm64/kvm/hyp/nvhe/sys_regs.c
@@ -93,10 +93,9 @@ static u64 get_pvm_id_aa64pfr0(const struct kvm_vcpu *vcpu)
PVM_ID_AA64PFR0_RESTRICT_UNSIGNED);
/* Spectre and Meltdown mitigation in KVM */
- set_mask |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV2),
- (u64)kvm->arch.pfr0_csv2);
- set_mask |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV3),
- (u64)kvm->arch.pfr0_csv3);
+ set_mask |= IDREG(kvm, SYS_ID_AA64PFR0_EL1) &
+ (ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV2) |
+ ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV3));
return (id_aa64pfr0_el1_sys_val & allow_mask) | set_mask;
}
diff --git a/arch/arm64/kvm/id_regs.c b/arch/arm64/kvm/id_regs.c
index 0302507abbce..bc4c408a43eb 100644
--- a/arch/arm64/kvm/id_regs.c
+++ b/arch/arm64/kvm/id_regs.c
@@ -72,12 +72,6 @@ u64 kvm_arm_read_id_reg_with_encoding(const struct kvm_vcpu *vcpu, u32 id)
if (!vcpu_has_sve(vcpu))
val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_SVE);
val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_AMU);
- val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV2);
- val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV2),
- (u64)vcpu->kvm->arch.pfr0_csv2);
- val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV3);
- val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV3),
- (u64)vcpu->kvm->arch.pfr0_csv3);
if (kvm_vgic_global_state.type == VGIC_V3) {
val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_GIC);
val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_GIC), 1);
@@ -212,6 +206,7 @@ static int set_id_aa64pfr0_el1(struct kvm_vcpu *vcpu,
u64 val)
{
u8 csv2, csv3;
+ u64 sval = val;
/*
* Allow AA64PFR0_EL1.CSV2 to be set from userspace as long as
@@ -236,8 +231,7 @@ static int set_id_aa64pfr0_el1(struct kvm_vcpu *vcpu,
if (val)
return -EINVAL;
- vcpu->kvm->arch.pfr0_csv2 = csv2;
- vcpu->kvm->arch.pfr0_csv3 = csv3;
+ IDREG_RD(vcpu->kvm, rd) = sval;
return 0;
}
@@ -520,4 +514,24 @@ void kvm_arm_set_default_id_regs(struct kvm *kvm)
val = read_sanitised_ftr_reg(id);
IDREG(kvm, id) = val;
}
+ /*
+ * The default is to expose CSV2 == 1 if the HW isn't affected.
+ * Although this is a per-CPU feature, we make it global because
+ * asymmetric systems are just a nuisance.
+ *
+ * Userspace can override this as long as it doesn't promise
+ * the impossible.
+ */
+ val = IDREG(kvm, SYS_ID_AA64PFR0_EL1);
+
+ if (arm64_get_spectre_v2_state() == SPECTRE_UNAFFECTED) {
+ val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV2);
+ val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV2), 1);
+ }
+ if (arm64_get_meltdown_state() == SPECTRE_UNAFFECTED) {
+ val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV3);
+ val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV3), 1);
+ }
+
+ IDREG(kvm, SYS_ID_AA64PFR0_EL1) = val;
}
--
2.39.1.581.gbfd45094c4-goog
