[PULL 7/8] KVM: arm/arm64: Extract GICv3 max APRn index calculation

Christoffer Dall
2017-09-05T14:52:06Z

As we are about to access the APRs from the GICv2 uaccess interface,
make this logic generally available.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
---
arch/arm64/kvm/vgic-sys-reg-v3.c | 23 +++--------------------
virt/kvm/arm/vgic/vgic.h | 16 ++++++++++++++++
2 files changed, 19 insertions(+), 20 deletions(-)

diff --git a/arch/arm64/kvm/vgic-sys-reg-v3.c b/arch/arm64/kvm/vgic-sys-reg-v3.c
index 116786d..c77d508 100644
--- a/arch/arm64/kvm/vgic-sys-reg-v3.c
+++ b/arch/arm64/kvm/vgic-sys-reg-v3.c
@@ -208,29 +208,12 @@ static void vgic_v3_access_apr_reg(struct kvm_vcpu *vcpu,
static bool access_gic_aprn(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
const struct sys_reg_desc *r, u8 apr)
{
- struct vgic_cpu *vgic_v3_cpu = &vcpu->arch.vgic_cpu;
u8 idx = r->Op2 & 3;

- /*
- * num_pri_bits are initialized with HW supported values.
- * We can rely safely on num_pri_bits even if VM has not
- * restored ICC_CTLR_EL1 before restoring APnR registers.
- */
- switch (vgic_v3_cpu->num_pri_bits) {
- case 7:
- vgic_v3_access_apr_reg(vcpu, p, apr, idx);
- break;
- case 6:
- if (idx > 1)
- goto err;
- vgic_v3_access_apr_reg(vcpu, p, apr, idx);
- break;
- default:
- if (idx > 0)
- goto err;
- vgic_v3_access_apr_reg(vcpu, p, apr, idx);
- }
+ if (idx > vgic_v3_max_apr_idx(vcpu))
+ goto err;

+ vgic_v3_access_apr_reg(vcpu, p, apr, idx);
return true;
err:
if (!p->is_write)
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index bba7fa2..bf9ceab 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -220,4 +220,20 @@ int vgic_debug_destroy(struct kvm *kvm);
bool lock_all_vcpus(struct kvm *kvm);
void unlock_all_vcpus(struct kvm *kvm);

+static inline int vgic_v3_max_apr_idx(struct kvm_vcpu *vcpu)
+{
+ struct vgic_cpu *cpu_if = &vcpu->arch.vgic_cpu;
+
+ /*
+ * num_pri_bits are initialized with HW supported values.
+ * We can rely safely on num_pri_bits even if VM has not
+ * restored ICC_CTLR_EL1 before restoring APnR registers.
+ */
+ switch (cpu_if->num_pri_bits) {
+ case 7: return 3;
+ case 6: return 1;
+ default: return 0;
+ }
+}
+
#endif
--
2.9.0