From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 43992C32771 for ; Thu, 9 Jan 2020 12:09:57 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 0F35B2067D for ; Thu, 9 Jan 2020 12:09:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="IBOjwW9/" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0F35B2067D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:59176 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ipWdQ-00039T-2K for qemu-devel@archiver.kernel.org; Thu, 09 Jan 2020 07:09:56 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:50639) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ipWc4-00025E-P8 for qemu-devel@nongnu.org; Thu, 09 Jan 2020 07:08:33 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ipWc2-0004hS-74 for qemu-devel@nongnu.org; Thu, 09 Jan 2020 07:08:31 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:43394 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ipWc2-0004dG-23 for qemu-devel@nongnu.org; Thu, 09 Jan 2020 07:08:30 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1578571709; 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=ED7XSBQ45eTsIGI8SCbNh0PxXfKdZEEwXOD4GbBljmg=; b=IBOjwW9/pX+liWQEuz947j3X4OO7pQJ+U1o8Mceus+/VYp3auRK3Q0lwmJtc5ApKZqUUaq jBRwbdDuRwMPoTnOrRQwiSAxUUDQ0b23ZcNyu1ZhVIANCkUiVVVTxgZFUtvheLtrsQK04o PrvAltB56Gf1CRhnj/G5bK1dncyyjUQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-5-yFJaVQM8Np6Q3aNDPGRa7w-1; Thu, 09 Jan 2020 07:08:27 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B273581E62F for ; Thu, 9 Jan 2020 12:08:26 +0000 (UTC) Received: from work-vm (unknown [10.36.118.29]) by smtp.corp.redhat.com (Postfix) with ESMTPS id ABC875DA66; Thu, 9 Jan 2020 12:08:23 +0000 (UTC) Date: Thu, 9 Jan 2020 12:08:20 +0000 From: "Dr. David Alan Gilbert" To: "Michael S. Tsirkin" Subject: Re: [PATCH 2/2] hyperv/synic: Allocate as ram_device Message-ID: <20200109120820.GB6795@work-vm> References: <20200108135353.75471-1-dgilbert@redhat.com> <20200108135353.75471-3-dgilbert@redhat.com> <20200109064527-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 In-Reply-To: <20200109064527-mutt-send-email-mst@kernel.org> User-Agent: Mutt/1.13.0 (2019-11-30) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-MC-Unique: yFJaVQM8Np6Q3aNDPGRa7w-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.120 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: jasowang@redhat.com, vkuznets@redhat.com, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Michael S. Tsirkin (mst@redhat.com) wrote: > On Wed, Jan 08, 2020 at 01:53:53PM +0000, Dr. David Alan Gilbert (git) wr= ote: > > From: "Dr. David Alan Gilbert" > >=20 > > Mark the synic pages as ram_device so that they won't be visible > > to vhost. > >=20 > > Signed-off-by: Dr. David Alan Gilbert >=20 >=20 > I think I disagree with this one. > * A RAM device represents a mapping to a physical device, such as to a P= CI > * MMIO BAR of an vfio-pci assigned device. The memory region may be map= ped > * into the VM address space and access to the region will modify memory > * directly. However, the memory region should not be included in a memo= ry > * dump (device may not be enabled/mapped at the time of the dump), and > * operations incompatible with manipulating MMIO should be avoided. Rep= laces > * skip_dump flag. >=20 > Looks like an abuse of notation. OK, it did feel a bit like that - any suggestions of another way to do it? This clearly isn't normal RAM. Dave >=20 >=20 > > --- > > hw/hyperv/hyperv.c | 14 ++++++++------ > > 1 file changed, 8 insertions(+), 6 deletions(-) > >=20 > > diff --git a/hw/hyperv/hyperv.c b/hw/hyperv/hyperv.c > > index da8ce82725..4de3ec411d 100644 > > --- a/hw/hyperv/hyperv.c > > +++ b/hw/hyperv/hyperv.c > > @@ -95,12 +95,14 @@ static void synic_realize(DeviceState *dev, Error *= *errp) > > msgp_name =3D g_strdup_printf("synic-%u-msg-page", vp_index); > > eventp_name =3D g_strdup_printf("synic-%u-event-page", vp_index); > > =20 > > - memory_region_init_ram(&synic->msg_page_mr, obj, msgp_name, > > - sizeof(*synic->msg_page), &error_abort); > > - memory_region_init_ram(&synic->event_page_mr, obj, eventp_name, > > - sizeof(*synic->event_page), &error_abort); > > - synic->msg_page =3D memory_region_get_ram_ptr(&synic->msg_page_mr)= ; > > - synic->event_page =3D memory_region_get_ram_ptr(&synic->event_page= _mr); > > + synic->msg_page =3D qemu_memalign(qemu_real_host_page_size, > > + sizeof(*synic->msg_page)); > > + synic->event_page =3D qemu_memalign(qemu_real_host_page_size, > > + sizeof(*synic->event_page)); > > + memory_region_init_ram_device_ptr(&synic->msg_page_mr, obj, msgp_n= ame, > > + sizeof(*synic->msg_page), synic->msg_page); > > + memory_region_init_ram_device_ptr(&synic->event_page_mr, obj, even= tp_name, > > + sizeof(*synic->event_page), synic->event_pa= ge); > > =20 > > g_free(msgp_name); > > g_free(eventp_name); > > --=20 > > 2.24.1 >=20 -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK