KVM: arm64: Advertise ID_AA64PFR0_EL1.CSV3=1 if the CPUs are Meltdown-safe

[mirror_ubuntu-hirsute-kernel.git] / arch / arm64 / kvm / sys_regs.c

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index c1fac9836af1af88723a2f4432096ee88c36e7c8..6f653c0f60eca9b89d1b11044942643463801f69 100644 (file)
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1122,6 +1122,8 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu,
                val &= ~(0xfUL << ID_AA64PFR0_AMU_SHIFT);
                val &= ~(0xfUL << ID_AA64PFR0_CSV2_SHIFT);
                val |= ((u64)vcpu->kvm->arch.pfr0_csv2 << ID_AA64PFR0_CSV2_SHIFT);
+               val &= ~(0xfUL << ID_AA64PFR0_CSV3_SHIFT);
+               val |= ((u64)vcpu->kvm->arch.pfr0_csv3 << ID_AA64PFR0_CSV3_SHIFT);
        } else if (id == SYS_ID_AA64PFR1_EL1) {
                val &= ~(0xfUL << ID_AA64PFR1_MTE_SHIFT);
        } else if (id == SYS_ID_AA64ISAR1_EL1 && !vcpu_has_ptrauth(vcpu)) {
@@ -1209,9 +1211,9 @@ static int set_id_aa64pfr0_el1(struct kvm_vcpu *vcpu,
                               const struct kvm_one_reg *reg, void __user *uaddr)
 {
        const u64 id = sys_reg_to_index(rd);
+       u8 csv2, csv3;
        int err;
        u64 val;
-       u8 csv2;
 
        err = reg_from_user(&val, uaddr, id);
        if (err)
@@ -1227,13 +1229,21 @@ static int set_id_aa64pfr0_el1(struct kvm_vcpu *vcpu,
            (csv2 && arm64_get_spectre_v2_state() != SPECTRE_UNAFFECTED))
                return -EINVAL;
 
-       /* We can only differ with CSV2, and anything else is an error */
+       /* Same thing for CSV3 */
+       csv3 = cpuid_feature_extract_unsigned_field(val, ID_AA64PFR0_CSV3_SHIFT);
+       if (csv3 > 1 ||
+           (csv3 && arm64_get_meltdown_state() != SPECTRE_UNAFFECTED))
+               return -EINVAL;
+
+       /* We can only differ with CSV[23], and anything else is an error */
        val ^= read_id_reg(vcpu, rd, false);
-       val &= ~(0xFUL << ID_AA64PFR0_CSV2_SHIFT);
+       val &= ~((0xFUL << ID_AA64PFR0_CSV2_SHIFT) |
+                (0xFUL << ID_AA64PFR0_CSV3_SHIFT));
        if (val)
                return -EINVAL;
 
        vcpu->kvm->arch.pfr0_csv2 = csv2;
+       vcpu->kvm->arch.pfr0_csv3 = csv3 ;
 
        return 0;
 }