From patchwork Tue Jul 7 15:49:34 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Graf X-Patchwork-Id: 492350 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 7B7CF1402AB for ; Wed, 8 Jul 2015 01:53:08 +1000 (AEST) Received: from localhost ([::1]:59021 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZCVBC-0001lW-OI for incoming@patchwork.ozlabs.org; Tue, 07 Jul 2015 11:53:06 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52260) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZCV82-0004st-6q for qemu-devel@nongnu.org; Tue, 07 Jul 2015 11:49:56 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZCV7z-0003o5-54 for qemu-devel@nongnu.org; Tue, 07 Jul 2015 11:49:50 -0400 Received: from cantor2.suse.de ([195.135.220.15]:44469 helo=mx2.suse.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZCV7y-0003m9-U4; Tue, 07 Jul 2015 11:49:47 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 31941ADE7; Tue, 7 Jul 2015 15:49:45 +0000 (UTC) From: Alexander Graf To: qemu-ppc@nongnu.org Date: Tue, 7 Jul 2015 17:49:34 +0200 Message-Id: <1436284182-5063-23-git-send-email-agraf@suse.de> X-Mailer: git-send-email 1.7.12.4 In-Reply-To: <1436284182-5063-1-git-send-email-agraf@suse.de> References: <1436284182-5063-1-git-send-email-agraf@suse.de> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x (no timestamps) [generic] X-Received-From: 195.135.220.15 Cc: peter.maydell@linaro.org, David Gibson , qemu-devel@nongnu.org, Bharata B Rao Subject: [Qemu-devel] [PULL 22/30] xics_kvm: Don't enable KVM_CAP_IRQ_XICS if already enabled X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Bharata B Rao When supporting CPU hot removal by parking the vCPU fd and reusing it during hotplug again, there can be cases where we try to reenable KVM_CAP_IRQ_XICS CAP for the vCPU for which it was already enabled. Introduce a boolean member in ICPState to track this and don't reenable the CAP if it was already enabled earlier. Re-enabling this CAP should ideally work, but currently it results in kernel trying to create and associate ICP with this vCPU and that fails since there is already an ICP associated with it. Hence this patch is needed to work around this problem in the kernel. This change allows CPU hot removal to work for sPAPR. Signed-off-by: Bharata B Rao Reviewed-by: David Gibson Signed-off-by: David Gibson Signed-off-by: Alexander Graf --- hw/intc/xics_kvm.c | 10 ++++++++++ include/hw/ppc/xics.h | 1 + 2 files changed, 11 insertions(+) diff --git a/hw/intc/xics_kvm.c b/hw/intc/xics_kvm.c index ea886da..d58729c 100644 --- a/hw/intc/xics_kvm.c +++ b/hw/intc/xics_kvm.c @@ -331,6 +331,15 @@ static void xics_kvm_cpu_setup(XICSState *icp, PowerPCCPU *cpu) abort(); } + /* + * If we are reusing a parked vCPU fd corresponding to the CPU + * which was hot-removed earlier we don't have to renable + * KVM_CAP_IRQ_XICS capability again. + */ + if (ss->cap_irq_xics_enabled) { + return; + } + if (icpkvm->kernel_xics_fd != -1) { int ret; @@ -343,6 +352,7 @@ static void xics_kvm_cpu_setup(XICSState *icp, PowerPCCPU *cpu) kvm_arch_vcpu_id(cs), strerror(errno)); exit(1); } + ss->cap_irq_xics_enabled = true; } } diff --git a/include/hw/ppc/xics.h b/include/hw/ppc/xics.h index a214dd7..355a966 100644 --- a/include/hw/ppc/xics.h +++ b/include/hw/ppc/xics.h @@ -109,6 +109,7 @@ struct ICPState { uint8_t pending_priority; uint8_t mfrr; qemu_irq output; + bool cap_irq_xics_enabled; }; #define TYPE_ICS "ics"