From 5b08709313718e95ba06ef49aa82f964a605bd9c Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Thu, 18 Mar 2021 18:30:26 +0000 Subject: [PATCH] KVM: arm64: Fix host's ZCR_EL2 restore on nVHE We re-enter the EL1 host with CPTR_EL2.TZ set in order to be able to lazily restore ZCR_EL2 when required. However, the same CPTR_EL2 configuration also leads to trapping when ZCR_EL2 is accessed from EL2. Duh! Clear CPTR_EL2.TZ *before* writing to ZCR_EL2. Fixes: beed09067b42 ("KVM: arm64: Trap host SVE accesses when the FPSIMD state is dirty") Reported-by: Will Deacon Signed-off-by: Marc Zyngier --- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index 8d04d69..84a702d 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -178,8 +178,9 @@ void handle_trap(struct kvm_cpu_context *host_ctxt) handle_host_smc(host_ctxt); break; case ESR_ELx_EC_SVE: - sve_cond_update_zcr_vq(ZCR_ELx_LEN_MASK, SYS_ZCR_EL2); sysreg_clear_set(cptr_el2, CPTR_EL2_TZ, 0); + isb(); + sve_cond_update_zcr_vq(ZCR_ELx_LEN_MASK, SYS_ZCR_EL2); break; default: hyp_panic(); -- 2.7.4