From patchwork Thu Sep 12 05:28:27 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: pingfan liu X-Patchwork-Id: 274435 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)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 4BC0D2C03A1 for ; Thu, 12 Sep 2013 15:29:13 +1000 (EST) Received: from localhost ([::1]:39368 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VJzSp-0004su-EM for incoming@patchwork.ozlabs.org; Thu, 12 Sep 2013 01:29:11 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53632) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VJzST-0004os-0O for qemu-devel@nongnu.org; Thu, 12 Sep 2013 01:28:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VJzSK-0000KP-92 for qemu-devel@nongnu.org; Thu, 12 Sep 2013 01:28:48 -0400 Received: from mail-ob0-x22e.google.com ([2607:f8b0:4003:c01::22e]:54791) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VJzSK-0000KF-32 for qemu-devel@nongnu.org; Thu, 12 Sep 2013 01:28:40 -0400 Received: by mail-ob0-f174.google.com with SMTP id uz6so84149obc.33 for ; Wed, 11 Sep 2013 22:28:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id; bh=4xqtLXc05obsoEcXvcj1V1sC1kwk8S2KPHZ6hbIkO8U=; b=00zt17UrtiTiVCCJYjR+hICkpIZIKbJB0rcFYB8lAyJGpgpnlv3UNJw5C8AZuAjerj MNfq1L4b0A5Wjj9Ba1Hg+v03g2bvi+fY8j5TB6/Vd8jGdwNCb5cvyBnaf7nsCXakUW/V M2RZ7RbBPdILg47ZhUCHeA0fmgh5aT44j49v3UZuP8c2Izrbon3HyU7KTRoJT67PXeqb qP9oLnYDekjjmHJHCFQ/62tHoSGNrczA4eT/rUX0tXxe8jPfdYSgfLTnueYbJmOOn9J/ WdvB+v1s4uJBRrxi6LVfTX8BNTywZxwh68ouRJlA+KoypqhOXRv6ccUR5mXAsVMvBQ4P +Ktw== X-Received: by 10.60.93.67 with SMTP id cs3mr5006390oeb.12.1378963719573; Wed, 11 Sep 2013 22:28:39 -0700 (PDT) Received: from localhost ([111.192.251.249]) by mx.google.com with ESMTPSA id y1sm3146153oek.4.1969.12.31.16.00.00 (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Wed, 11 Sep 2013 22:28:38 -0700 (PDT) From: Liu Ping Fan To: kvm@vger.kernel.org Date: Thu, 12 Sep 2013 13:28:27 +0800 Message-Id: <1378963707-1259-1-git-send-email-pingfank@linux.vnet.ibm.com> X-Mailer: git-send-email 1.8.1.4 X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-Received-From: 2607:f8b0:4003:c01::22e Cc: Paolo Bonzini , qemu-devel@nongnu.org, Gleb Natapov Subject: [Qemu-devel] [PATCH] KVM: IRQFD: equip irqfd and resamplefd with polarity 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 Nowadays, irqfd can emulate trigger mode, but it can not emulate trigger polarity. While in some cases, ioapic ioredtbl[x] expects _low_ active. So equipping irqfd with the ability. Correspondingly, resamplefd will have the same polarity as irqfd. Signed-off-by: Liu Ping Fan --- This helps to step around making the interrupt component re-entrance in qemu --- include/linux/kvm_host.h | 1 + include/uapi/linux/kvm.h | 2 ++ virt/kvm/eventfd.c | 32 ++++++++++++++++++++++---------- 3 files changed, 25 insertions(+), 10 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index a63d83e..0b8c3b1 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -678,6 +678,7 @@ bool kvm_is_mmio_pfn(pfn_t pfn); struct kvm_irq_ack_notifier { struct hlist_node link; unsigned gsi; + int polarity; /* 0 high active */ void (*irq_acked)(struct kvm_irq_ack_notifier *kian); }; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index acccd08..bba3a1b 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -740,6 +740,8 @@ struct kvm_xen_hvm_config { * emlation. See Documentation/virtual/kvm/api.txt. */ #define KVM_IRQFD_FLAG_RESAMPLE (1 << 1) +/* 0: high-active */ +#define KVM_IRQFD_FLAG_POLARITY (1<<2) struct kvm_irqfd { __u32 fd; diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c index 1550637..865c656 100644 --- a/virt/kvm/eventfd.c +++ b/virt/kvm/eventfd.c @@ -77,6 +77,7 @@ struct _irqfd { struct kvm_kernel_irq_routing_entry __rcu *irq_entry; /* Used for level IRQ fast-path */ int gsi; + int polarity; /* 0 high active */ struct work_struct inject; /* The resampler used by this irqfd (resampler-only) */ struct _irqfd_resampler *resampler; @@ -100,13 +101,13 @@ irqfd_inject(struct work_struct *work) struct kvm *kvm = irqfd->kvm; if (!irqfd->resampler) { - kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID, irqfd->gsi, 1, - false); - kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID, irqfd->gsi, 0, - false); + kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID, irqfd->gsi, + !irqfd->polarity, false); + kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID, irqfd->gsi, + !!irqfd->polarity, false); } else kvm_set_irq(kvm, KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID, - irqfd->gsi, 1, false); + irqfd->gsi, !irqfd->polarity, false); } /* @@ -123,7 +124,8 @@ irqfd_resampler_ack(struct kvm_irq_ack_notifier *kian) resampler = container_of(kian, struct _irqfd_resampler, notifier); kvm_set_irq(resampler->kvm, KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID, - resampler->notifier.gsi, 0, false); + resampler->notifier.gsi, + !!resampler->notifier.polarity, false); rcu_read_lock(); @@ -148,7 +150,7 @@ irqfd_resampler_shutdown(struct _irqfd *irqfd) list_del(&resampler->link); kvm_unregister_irq_ack_notifier(kvm, &resampler->notifier); kvm_set_irq(kvm, KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID, - resampler->notifier.gsi, 0, false); + resampler->notifier.gsi, !!irqfd->polarity, false); kfree(resampler); } @@ -302,6 +304,7 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args) irqfd->kvm = kvm; irqfd->gsi = args->gsi; + irqfd->polarity = !!(args->flags & KVM_IRQFD_FLAG_POLARITY); INIT_LIST_HEAD(&irqfd->list); INIT_WORK(&irqfd->inject, irqfd_inject); INIT_WORK(&irqfd->shutdown, irqfd_shutdown); @@ -337,8 +340,15 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args) list_for_each_entry(resampler, &kvm->irqfds.resampler_list, link) { if (resampler->notifier.gsi == irqfd->gsi) { - irqfd->resampler = resampler; - break; + if (likely(resampler->notifier.polarity == + irqfd->polarity)) { + irqfd->resampler = resampler; + break; + } else { + ret = -EBUSY; + mutex_unlock(&kvm->irqfds.resampler_lock); + goto fail; + } } } @@ -353,6 +363,7 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args) resampler->kvm = kvm; INIT_LIST_HEAD(&resampler->list); resampler->notifier.gsi = irqfd->gsi; + resampler->notifier.polarity = irqfd->polarity; resampler->notifier.irq_acked = irqfd_resampler_ack; INIT_LIST_HEAD(&resampler->link); @@ -489,7 +500,8 @@ kvm_irqfd_deassign(struct kvm *kvm, struct kvm_irqfd *args) int kvm_irqfd(struct kvm *kvm, struct kvm_irqfd *args) { - if (args->flags & ~(KVM_IRQFD_FLAG_DEASSIGN | KVM_IRQFD_FLAG_RESAMPLE)) + if (args->flags & ~(KVM_IRQFD_FLAG_DEASSIGN | KVM_IRQFD_FLAG_RESAMPLE + | KVM_IRQFD_FLAG_POLARITY)) return -EINVAL; if (args->flags & KVM_IRQFD_FLAG_DEASSIGN)