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: 10765069 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9A2FA1580 for ; Tue, 15 Jan 2019 20:05:34 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 87B072B8CB for ; Tue, 15 Jan 2019 20:05:34 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7BE542BD6E; Tue, 15 Jan 2019 20:05:34 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id F2EEA2B8CB for ; Tue, 15 Jan 2019 20:05:33 +0000 (UTC) Received: from localhost ([127.0.0.1]:40526 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gjUxo-0006rg-Fi for patchwork-qemu-devel@patchwork.kernel.org; Tue, 15 Jan 2019 15:05:32 -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+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP 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