From patchwork Fri Feb 17 21:41:40 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Mackerras X-Patchwork-Id: 729371 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3vQ61Q3Lrwz9s7x for ; Sat, 18 Feb 2017 08:42:02 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934926AbdBQVl4 (ORCPT ); Fri, 17 Feb 2017 16:41:56 -0500 Received: from ozlabs.org ([103.22.144.67]:49181 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934415AbdBQVlz (ORCPT ); Fri, 17 Feb 2017 16:41:55 -0500 Received: by ozlabs.org (Postfix, from userid 1003) id 3vQ61F55jNz9s8c; Sat, 18 Feb 2017 08:41:53 +1100 (AEDT) Date: Sat, 18 Feb 2017 08:41:40 +1100 From: Paul Mackerras To: kvm@vger.kernel.org, kvm-ppc@vger.kernel.org Cc: David Gibson Subject: [PATCH] KVM: PPC: Book3S HV: Disable HPT resizing on POWER9 for now Message-ID: <20170217214140.GA8844@fergus.ozlabs.ibm.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) Sender: kvm-ppc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org The new HPT resizing code added in commit b5baa6877315 ("KVM: PPC: Book3S HV: KVM-HV HPT resizing implementation", 2016-12-20) doesn't have code to handle the new HPTE format which POWER9 uses. Thus it would be best not to advertise it to userspace on POWER9 systems until it works properly. Also, since resize_hpt_rehash_hpte() contains BUG_ON() calls that could be hit on POWER9, let's prevent it from being called on POWER9 for now. Signed-off-by: Paul Mackerras Acked-by: David Gibson --- arch/powerpc/kvm/book3s_64_mmu_hv.c | 6 ++++++ arch/powerpc/kvm/powerpc.c | 3 ++- 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c index b68b342..f3158fb 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c @@ -1370,6 +1370,12 @@ static int resize_hpt_rehash(struct kvm_resize_hpt *resize) unsigned long i; int rc; + /* + * resize_hpt_rehash_hpte() doesn't handle the new-format HPTEs + * that POWER9 uses, and could well hit a BUG_ON on POWER9. + */ + if (cpu_has_feature(CPU_FTR_ARCH_300)) + return -EIO; for (i = 0; i < kvmppc_hpt_npte(&kvm->arch.hpt); i++) { rc = resize_hpt_rehash_hpte(resize, i); if (rc != 0) diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 2b3e4e6..fcb253b 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -613,7 +613,8 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) r = 1; break; case KVM_CAP_SPAPR_RESIZE_HPT: - r = !!hv_enabled; + /* Disable this on POWER9 until code handles new HPTE format */ + r = !!hv_enabled && !cpu_has_feature(CPU_FTR_ARCH_300); break; #endif case KVM_CAP_PPC_HTM: