KVM: arm64: Remove AA64ZFR0_EL1 accessors

The AA64ZFR0_EL1 accessors are just the general accessors with
its visibility function open-coded. It also skips the if-else
chain in read_id_reg, but there's no reason not to go there.
Indeed consolidating ID register accessors and removing lines
of code make it worthwhile.

Remove the AA64ZFR0_EL1 accessors, replacing them with the
general accessors for sanitized ID registers.

No functional change intended.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201105091022.15373-5-drjones@redhat.com

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 4ee098abd87c0b61b3f98c45c3ad67fc111a5eef..436043cd327e0d24c20468649a3fb1f4c8116f66 100644 (file)
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1154,6 +1154,16 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu,
 static unsigned int id_visibility(const struct kvm_vcpu *vcpu,
                                  const struct sys_reg_desc *r)
 {
+       u32 id = sys_reg((u32)r->Op0, (u32)r->Op1,
+                        (u32)r->CRn, (u32)r->CRm, (u32)r->Op2);
+
+       switch (id) {
+       case SYS_ID_AA64ZFR0_EL1:
+               if (!vcpu_has_sve(vcpu))
+                       return REG_RAZ;
+               break;
+       }
+
        return 0;
 }
 
@@ -1201,55 +1211,6 @@ static unsigned int sve_visibility(const struct kvm_vcpu *vcpu,
        return REG_HIDDEN;
 }
 
-/* Generate the emulated ID_AA64ZFR0_EL1 value exposed to the guest */
-static u64 guest_id_aa64zfr0_el1(const struct kvm_vcpu *vcpu)
-{
-       if (!vcpu_has_sve(vcpu))
-               return 0;
-
-       return read_sanitised_ftr_reg(SYS_ID_AA64ZFR0_EL1);
-}
-
-static bool access_id_aa64zfr0_el1(struct kvm_vcpu *vcpu,
-                                  struct sys_reg_params *p,
-                                  const struct sys_reg_desc *rd)
-{
-       if (p->is_write)
-               return write_to_read_only(vcpu, p, rd);
-
-       p->regval = guest_id_aa64zfr0_el1(vcpu);
-       return true;
-}
-
-static int get_id_aa64zfr0_el1(struct kvm_vcpu *vcpu,
-               const struct sys_reg_desc *rd,
-               const struct kvm_one_reg *reg, void __user *uaddr)
-{
-       u64 val;
-
-       val = guest_id_aa64zfr0_el1(vcpu);
-       return reg_to_user(uaddr, &val, reg->id);
-}
-
-static int set_id_aa64zfr0_el1(struct kvm_vcpu *vcpu,
-               const struct sys_reg_desc *rd,
-               const struct kvm_one_reg *reg, void __user *uaddr)
-{
-       const u64 id = sys_reg_to_index(rd);
-       int err;
-       u64 val;
-
-       err = reg_from_user(&val, uaddr, id);
-       if (err)
-               return err;
-
-       /* This is what we mean by invariant: you can't change it. */
-       if (val != guest_id_aa64zfr0_el1(vcpu))
-               return -EINVAL;
-
-       return 0;
-}
-
 /*
  * cpufeature ID register user accessors
  *
@@ -1506,7 +1467,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
        ID_SANITISED(ID_AA64PFR1_EL1),
        ID_UNALLOCATED(4,2),
        ID_UNALLOCATED(4,3),
-       { SYS_DESC(SYS_ID_AA64ZFR0_EL1), access_id_aa64zfr0_el1, .get_user = get_id_aa64zfr0_el1, .set_user = set_id_aa64zfr0_el1, },
+       ID_SANITISED(ID_AA64ZFR0_EL1),
        ID_UNALLOCATED(4,5),
        ID_UNALLOCATED(4,6),
        ID_UNALLOCATED(4,7),