From patchwork Wed May 16 13:05:16 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Graf X-Patchwork-Id: 159630 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 AB0B4B6FFA for ; Wed, 16 May 2012 23:05:58 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967110Ab2EPNFq (ORCPT ); Wed, 16 May 2012 09:05:46 -0400 Received: from cantor2.suse.de ([195.135.220.15]:39315 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965982Ab2EPNF3 (ORCPT ); Wed, 16 May 2012 09:05:29 -0400 Received: from relay1.suse.de (unknown [195.135.220.254]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx2.suse.de (Postfix) with ESMTP id 744488FA97; Wed, 16 May 2012 15:05:28 +0200 (CEST) From: Alexander Graf To: "kvm@vger.kernel.org list" Cc: Avi Kivity , kvm-ppc@vger.kernel.org, mtosatti@redhat.com Subject: [PATCH 2/5] KVM: PPC: Fix PR KVM on POWER7 bare metal Date: Wed, 16 May 2012 15:05:16 +0200 Message-Id: <1337173519-6780-3-git-send-email-agraf@suse.de> X-Mailer: git-send-email 1.6.0.2 In-Reply-To: <1337173519-6780-1-git-send-email-agraf@suse.de> References: <1337173519-6780-1-git-send-email-agraf@suse.de> Sender: kvm-ppc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org When running on a system that is HV capable, some interrupts use HSRR SPRs instead of the normal SRR SPRs. These are also used in the Linux handlers to jump back to code after an interrupt got processed. Unfortunately, in our "jump back to the real host handler after we've done the context switch" code, we were only setting the SRR SPRs, rendering Linux to jump back to some invalid IP after it's processed the interrupt. This fixes random crashes on p7 opal mode with PR KVM for me. Signed-off-by: Alexander Graf --- arch/powerpc/kvm/book3s_segment.S | 35 ++++++++++++++++++++++------------- 1 files changed, 22 insertions(+), 13 deletions(-) diff --git a/arch/powerpc/kvm/book3s_segment.S b/arch/powerpc/kvm/book3s_segment.S index 012fc92..87cfc1d 100644 --- a/arch/powerpc/kvm/book3s_segment.S +++ b/arch/powerpc/kvm/book3s_segment.S @@ -197,6 +197,7 @@ kvmppc_interrupt: /* Save guest PC and MSR */ #ifdef CONFIG_PPC64 BEGIN_FTR_SECTION + mr r10, r12 andi. r0,r12,0x2 beq 1f mfspr r3,SPRN_HSRR0 @@ -322,23 +323,17 @@ no_dcbz32_off: * Having set up SRR0/1 with the address where we want * to continue with relocation on (potentially in module * space), we either just go straight there with rfi[d], - * or we jump to an interrupt handler with bctr if there - * is an interrupt to be handled first. In the latter - * case, the rfi[d] at the end of the interrupt handler - * will get us back to where we want to continue. + * or we jump to an interrupt handler if there is an + * interrupt to be handled first. In the latter case, + * the rfi[d] at the end of the interrupt handler will + * get us back to where we want to continue. */ - cmpwi r12, BOOK3S_INTERRUPT_EXTERNAL - beq 1f - cmpwi r12, BOOK3S_INTERRUPT_DECREMENTER - beq 1f - cmpwi r12, BOOK3S_INTERRUPT_PERFMON -1: mtctr r12 - /* Register usage at this point: * * R1 = host R1 * R2 = host R2 + * R10 = raw exit handler id * R12 = exit handler id * R13 = shadow vcpu (32-bit) or PACA (64-bit) * SVCPU.* = guest * @@ -348,12 +343,26 @@ no_dcbz32_off: PPC_LL r6, HSTATE_HOST_MSR(r13) PPC_LL r8, HSTATE_VMHANDLER(r13) - /* Restore host msr -> SRR1 */ +#ifdef CONFIG_PPC64 +BEGIN_FTR_SECTION + andi. r0,r10,0x2 + beq 1f + mtspr SPRN_HSRR1, r6 + mtspr SPRN_HSRR0, r8 +END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) +#endif +1: /* Restore host msr -> SRR1 */ mtsrr1 r6 /* Load highmem handler address */ mtsrr0 r8 /* RFI into the highmem handler, or jump to interrupt handler */ - beqctr + cmpwi r12, BOOK3S_INTERRUPT_EXTERNAL + beqa BOOK3S_INTERRUPT_EXTERNAL + cmpwi r12, BOOK3S_INTERRUPT_DECREMENTER + beqa BOOK3S_INTERRUPT_DECREMENTER + cmpwi r12, BOOK3S_INTERRUPT_PERFMON + beqa BOOK3S_INTERRUPT_PERFMON + RFI kvmppc_handler_trampoline_exit_end: