From patchwork Tue Jul 26 08:50:53 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Wang X-Patchwork-Id: 12929049 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4643FC43334 for ; Tue, 26 Jul 2022 08:54:09 +0000 (UTC) Received: from localhost ([::1]:38578 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oGGKO-0001EY-Av for qemu-devel@archiver.kernel.org; Tue, 26 Jul 2022 04:54:08 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:53910) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oGGHU-0007Ie-88 for qemu-devel@nongnu.org; Tue, 26 Jul 2022 04:51:09 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:39819) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oGGHQ-0000ux-Ij for qemu-devel@nongnu.org; Tue, 26 Jul 2022 04:51:05 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1658825463; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=l8aSav+29oJzxnp6tOaz2V0cLdh7Tr2uiOGMFX0cq84=; b=JqD3Rgdun/J6rhYC5FMl/gE6ZWGzxUD75gwniJ58Z/wF4kdSeCAPzYxgTa0rTPnPH3hu8O eUdyPs7ntWt9MrC49eCF+e2u7BfmbC31YE6tZFWyvjsXAfsGp2YEY4+MTCJCZPa32AKrSu sma6xHgmXlva0sjvyRn4kVJPFK0Hq9E= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-178-lkymBlu9NhmFYIXa74so4g-1; Tue, 26 Jul 2022 04:51:02 -0400 X-MC-Unique: lkymBlu9NhmFYIXa74so4g-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 42466801755; Tue, 26 Jul 2022 08:51:02 +0000 (UTC) Received: from localhost.localdomain (ovpn-12-201.pek2.redhat.com [10.72.12.201]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1DB46492CA2; Tue, 26 Jul 2022 08:50:59 +0000 (UTC) From: Jason Wang To: qemu-devel@nongnu.org, peter.maydell@linaro.org Cc: Ake Koomsin , Jason Wang Subject: [PULL 1/3] e1000e: Fix possible interrupt loss when using MSI Date: Tue, 26 Jul 2022 16:50:53 +0800 Message-Id: <20220726085055.17239-2-jasowang@redhat.com> In-Reply-To: <20220726085055.17239-1-jasowang@redhat.com> References: <20220726085055.17239-1-jasowang@redhat.com> MIME-Version: 1.0 Content-type: text/plain X-Scanned-By: MIMEDefang 2.85 on 10.11.54.9 Received-SPF: pass client-ip=170.10.133.124; envelope-from=jasowang@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Ake Koomsin Commit "e1000e: Prevent MSI/MSI-X storms" introduced msi_causes_pending to prevent interrupt storms problem. It was tested with MSI-X. In case of MSI, the guest can rely solely on interrupts to clear ICR. Upon clearing all pending interrupts, msi_causes_pending gets cleared. However, when e1000e_itr_should_postpone() in e1000e_send_msi() returns true, MSI never gets fired by e1000e_intrmgr_on_throttling_timer() because msi_causes_pending is still set. This results in interrupt loss. To prevent this, we need to clear msi_causes_pending when MSI is going to get fired by the throttling timer. The guest can then receive interrupts eventually. Signed-off-by: Ake Koomsin Signed-off-by: Jason Wang --- hw/net/e1000e_core.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/hw/net/e1000e_core.c b/hw/net/e1000e_core.c index 2c51089..208e3e0 100644 --- a/hw/net/e1000e_core.c +++ b/hw/net/e1000e_core.c @@ -159,6 +159,8 @@ e1000e_intrmgr_on_throttling_timer(void *opaque) if (msi_enabled(timer->core->owner)) { trace_e1000e_irq_msi_notify_postponed(); + /* Clear msi_causes_pending to fire MSI eventually */ + timer->core->msi_causes_pending = 0; e1000e_set_interrupt_cause(timer->core, 0); } else { trace_e1000e_irq_legacy_notify_postponed();