From patchwork Tue Jan 15 20:04:00 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Michael S. Tsirkin" X-Patchwork-Id: 1025413 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 43fLsb1jq5z9sBQ for ; Wed, 16 Jan 2019 07:04:49 +1100 (AEDT) Received: from localhost ([127.0.0.1]:40209 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gjUx4-0005m3-1y for incoming@patchwork.ozlabs.org; Tue, 15 Jan 2019 15:04:46 -0500 Received: from eggs.gnu.org ([209.51.188.92]:32872) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gjUwO-0005ll-Oz for qemu-devel@nongnu.org; Tue, 15 Jan 2019 15:04:05 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gjUwN-0001xx-La for qemu-devel@nongnu.org; Tue, 15 Jan 2019 15:04:04 -0500 Received: from mx1.redhat.com ([209.132.183.28]:43830) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gjUwN-0001uE-Ae for qemu-devel@nongnu.org; Tue, 15 Jan 2019 15:04:03 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id ECAABC0528B9; Tue, 15 Jan 2019 20:04:01 +0000 (UTC) Received: from redhat.com (ovpn-125-113.rdu2.redhat.com [10.10.125.113]) by smtp.corp.redhat.com (Postfix) with SMTP id EFDB0601A4; Tue, 15 Jan 2019 20:04:00 +0000 (UTC) Date: Tue, 15 Jan 2019 15:04:00 -0500 From: "Michael S. Tsirkin" To: qemu-devel@nongnu.org Message-ID: <20190115200252.25911-3-mst@redhat.com> References: <20190115200252.25911-1-mst@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190115200252.25911-1-mst@redhat.com> X-Mutt-Fcc: =sent X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Tue, 15 Jan 2019 20:04:02 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL v2 02/49] msix: make pba size math more uniform X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , Dongli Zhang Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Dongli Zhang In msix_exclusive_bar the bar_pba_size is more than what the pba is expected to have, although this never affects the bar size. Specifically, the math in msix_init_exclusive_bar allocates too much memory in some cases. For example consider nentries = 8. msix_exclusive_bar will give us bar_pba_size = 16. So 16 bytes. However 8 bytes would be enough - this is all that the spec requires. So in practice bar_pba_size sometimes allocates an extra 8 bytes but never more. Since each MSIX entry size is 16 bytes, and since we make sure that table+pba is a power of two, this always leaves a multiple of 16 bytes for the PBA, so extra 8 bytes have no effect. However, its ugly to have pba size temporary variable have an incorrect value. For consistency switch to the formula used in msix_init. Signed-off-by: Dongli Zhang Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/pci/msix.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/pci/msix.c b/hw/pci/msix.c index c7bdbeda9e..4e336416a7 100644 --- a/hw/pci/msix.c +++ b/hw/pci/msix.c @@ -345,7 +345,7 @@ int msix_init_exclusive_bar(PCIDevice *dev, unsigned short nentries, char *name; uint32_t bar_size = 4096; uint32_t bar_pba_offset = bar_size / 2; - uint32_t bar_pba_size = (nentries / 8 + 1) * 8; + uint32_t bar_pba_size = QEMU_ALIGN_UP(nentries, 64) / 8; /* * Migration compatibility dictates that this remains a 4k