[PATCH v2 05/15] KVM: arm64: nv: Load guest hyp's ZCR into EL1 state

Oliver Upton
2024-06-13T20:18:40Z

Load the guest hypervisor's ZCR_EL2 into the corresponding EL1 register
when restoring SVE state, as ZCR_EL2 affects the VL in the hypervisor
context.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---
arch/arm64/include/asm/kvm_host.h | 4 ++++
arch/arm64/kvm/hyp/include/hyp/switch.h | 3 ++-
2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 8170c04fde91..e01e6de414f1 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -844,6 +844,10 @@ struct kvm_vcpu_arch {

#define vcpu_sve_max_vq(vcpu) sve_vq_from_vl((vcpu)->arch.sve_max_vl)

+#define vcpu_sve_zcr_el1(vcpu) \
+ (unlikely(is_hyp_ctxt(vcpu)) ? __vcpu_sys_reg(vcpu, ZCR_EL2) : \
+ __vcpu_sys_reg(vcpu, ZCR_EL1))
+
#define vcpu_sve_state_size(vcpu) ({ \
size_t __size_ret; \
unsigned int __vcpu_vq; \
diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
index 5ecd2600d9df..71a93e336a0c 100644
--- a/arch/arm64/kvm/hyp/include/hyp/switch.h
+++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
@@ -317,7 +317,8 @@ static inline void __hyp_sve_restore_guest(struct kvm_vcpu *vcpu)
sve_cond_update_zcr_vq(vcpu_sve_max_vq(vcpu) - 1, SYS_ZCR_EL2);
__sve_restore_state(vcpu_sve_pffr(vcpu),
&vcpu->arch.ctxt.fp_regs.fpsr);
- write_sysreg_el1(__vcpu_sys_reg(vcpu, ZCR_EL1), SYS_ZCR);
+
+ write_sysreg_el1(vcpu_sve_zcr_el1(vcpu), SYS_ZCR);
}

/*
--
2.45.2.627.g7a2c4fd464-goog