[PATCH 2/7] KVM: arm64: Reset VM feature ID regs from kvm_reset_sys_regs()

Oliver Upton
2024-05-02T23:35:43Z

A subsequent change to KVM will expand the range of feature ID registers
that get special treatment at reset. Fold the existing ones back in to
kvm_reset_sys_regs() to avoid the need for an additional table walk.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---
arch/arm64/kvm/sys_regs.c | 27 ++++++++++-----------------
1 file changed, 10 insertions(+), 17 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 51a6f91607e5..bb09ce4bce45 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -3510,26 +3510,16 @@ void kvm_sys_regs_create_debugfs(struct kvm *kvm)
&idregs_debug_fops);
}

-static void kvm_reset_id_regs(struct kvm_vcpu *vcpu)
+static void reset_vm_ftr_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *reg)
{
- const struct sys_reg_desc *idreg = first_idreg;
- u32 id = reg_to_encoding(idreg);
+ u32 id = reg_to_encoding(reg);
struct kvm *kvm = vcpu->kvm;

if (test_bit(KVM_ARCH_FLAG_ID_REGS_INITIALIZED, &kvm->arch.flags))
return;

lockdep_assert_held(&kvm->arch.config_lock);
-
- /* Initialize all idregs */
- while (is_vm_ftr_id_reg(id)) {
- IDREG(kvm, id) = idreg->reset(vcpu, idreg);
-
- idreg++;
- id = reg_to_encoding(idreg);
- }
-
- set_bit(KVM_ARCH_FLAG_ID_REGS_INITIALIZED, &kvm->arch.flags);
+ IDREG(kvm, id) = reg->reset(vcpu, reg);
}

/**
@@ -3541,19 +3531,22 @@ static void kvm_reset_id_regs(struct kvm_vcpu *vcpu)
*/
void kvm_reset_sys_regs(struct kvm_vcpu *vcpu)
{
+ struct kvm *kvm = vcpu->kvm;
unsigned long i;

- kvm_reset_id_regs(vcpu);
-
for (i = 0; i < ARRAY_SIZE(sys_reg_descs); i++) {
const struct sys_reg_desc *r = &sys_reg_descs[i];

- if (is_vm_ftr_id_reg(reg_to_encoding(r)))
+ if (!r->reset)
continue;

- if (r->reset)
+ if (is_vm_ftr_id_reg(reg_to_encoding(r)))
+ reset_vm_ftr_id_reg(vcpu, r);
+ else
r->reset(vcpu, r);
}
+
+ set_bit(KVM_ARCH_FLAG_ID_REGS_INITIALIZED, &kvm->arch.flags);
}

/**