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 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 44414CEBF73 for ; Mon, 30 Sep 2024 20:24:42 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1svMvo-00045J-DJ; Mon, 30 Sep 2024 16:23:44 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1svMvn-00044a-3X for qemu-devel@nongnu.org; Mon, 30 Sep 2024 16:23:43 -0400 Received: from mx.treblig.org ([2a00:1098:5b::1]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1svMvk-0006vm-A2 for qemu-devel@nongnu.org; Mon, 30 Sep 2024 16:23:42 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=treblig.org ; s=bytemarkmx; h=Content-Type:MIME-Version:Message-ID:Subject:From:Date:From :Subject; bh=p+NISuZrpNFaCkcIlqbVPEw1U9loKEq4pr26KoOj0EQ=; b=TnBCo6IBp/op66PZ gKpkVZ8Jenq58qg/fhAPgdjNyh73qji0zmYTdotF2gnM3z5Kl5O9KaVcr+0L+CgHRpI2rDV+54E1F +gef/lEQGcMF/7En0CsWDVNl5/IIH5zH7lSSeeQzHpKDf7qr774ffJDSoTpuNyYpbpCe8PkqhkAio 0K13VV5+lY7zlA87Qo9MPR7pSQ/tqKSZLYtPJcrRCiCKhUdmwu00P0ItWw9GQ2hNAqXhQGxqXGOc/ lOYCe5R+UCMchlCFbz0KsnLTghDzapNjmr1jxvo1DnCzXwv9SYW3VfxWW8IlFLOPYwPr30L3jEpqC aTkP/kcsvAheAbKMcw==; Received: from dg by mx.treblig.org with local (Exim 4.96) (envelope-from ) id 1svMve-0084Zx-1e; Mon, 30 Sep 2024 20:23:34 +0000 Date: Mon, 30 Sep 2024 20:23:34 +0000 From: "Dr. David Alan Gilbert" To: Peter Xu Cc: farosas@suse.de, eblake@redhat.com, armbru@redhat.com, qemu-devel@nongnu.org Subject: Re: [PATCH v2 6/7] migration/postcopy: Use uffd helpers Message-ID: References: <20240919134626.166183-1-dave@treblig.org> <20240919134626.166183-7-dave@treblig.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Chocolate: 70 percent or better cocoa solids preferably X-Operating-System: Linux/6.1.0-21-amd64 (x86_64) X-Uptime: 20:22:52 up 145 days, 7:36, 1 user, load average: 0.05, 0.01, 0.00 User-Agent: Mutt/2.2.12 (2023-09-09) Received-SPF: pass client-ip=2a00:1098:5b::1; envelope-from=dg@treblig.org; helo=mx.treblig.org X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 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-bounces+qemu-devel=archiver.kernel.org@nongnu.org * Peter Xu (peterx@redhat.com) wrote: > On Thu, Sep 19, 2024 at 02:46:25PM +0100, dave@treblig.org wrote: > > From: "Dr. David Alan Gilbert" > > > > Use the uffd_copy_page, uffd_zero_page and uffd_wakeup helpers > > rather than calling ioctl ourselves. > > > > They return -errno on error, and print an error_report themselves. > > I think this actually makes postcopy_place_page actually more > > consistent in it's callers. > > > > Signed-off-by: Dr. David Alan Gilbert > > --- > > migration/postcopy-ram.c | 47 +++++++++++----------------------------- > > 1 file changed, 13 insertions(+), 34 deletions(-) > > > > diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c > > index 1c374b7ea1..e2b318d3da 100644 > > --- a/migration/postcopy-ram.c > > +++ b/migration/postcopy-ram.c > > @@ -746,18 +746,9 @@ int postcopy_wake_shared(struct PostCopyFD *pcfd, > > RAMBlock *rb) > > { > > size_t pagesize = qemu_ram_pagesize(rb); > > - struct uffdio_range range; > > - int ret; > > trace_postcopy_wake_shared(client_addr, qemu_ram_get_idstr(rb)); > > - range.start = ROUND_DOWN(client_addr, pagesize); > > - range.len = pagesize; > > - ret = ioctl(pcfd->fd, UFFDIO_WAKE, &range); > > - if (ret) { > > - error_report("%s: Failed to wake: %zx in %s (%s)", > > - __func__, (size_t)client_addr, qemu_ram_get_idstr(rb), > > - strerror(errno)); > > - } > > - return ret; > > + return uffd_wakeup(pcfd->fd, (void *)ROUND_DOWN(client_addr, pagesize), > > + pagesize); > > } > > There's a build issue on i386: > > ../migration/postcopy-ram.c: In function ‘postcopy_wake_shared’: > ../migration/postcopy-ram.c:750:34: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast] > 750 | return uffd_wakeup(pcfd->fd, (void *)ROUND_DOWN(client_addr, pagesize), > | ^ > > The plan is to squash below fix: Thanks! Dave > =========8<=========== > diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c > index 03a63ef5cd..83f6160a36 100644 > --- a/migration/postcopy-ram.c > +++ b/migration/postcopy-ram.c > -@@ -747,7 +747,8 @@ int postcopy_wake_shared(struct PostCopyFD *pcfd, > { > size_t pagesize = qemu_ram_pagesize(rb); > trace_postcopy_wake_shared(client_addr, qemu_ram_get_idstr(rb)); > - return uffd_wakeup(pcfd->fd, (void *)ROUND_DOWN(client_addr, pagesize), > + return uffd_wakeup(pcfd->fd, > + (void *)(uintptr_t)ROUND_DOWN(client_addr, pagesize), > pagesize); > } > =========8<=========== > > Thanks, > > -- > Peter Xu > -- -----Open up your eyes, open up your mind, open up your code ------- / Dr. David Alan Gilbert | Running GNU/Linux | Happy \ \ dave @ treblig.org | | In Hex / \ _________________________|_____ http://www.treblig.org |_______/