Commit c512298e authored by Andrew Jones's avatar Andrew Jones Committed by Marc Zyngier
Browse files

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: default avatarAndrew Jones <drjones@redhat.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201105091022.15373-5-drjones@redhat.com
parent 912dee57

arch/arm64/kvm/sys_regs.c

+11 −50
Original line number Diff line number Diff line
@@ -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),