From patchwork Thu Sep 19 13:46:24 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Dr. David Alan Gilbert" X-Patchwork-Id: 13807768 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 CABA2CF3942 for ; Thu, 19 Sep 2024 13:48:04 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1srHUf-0007kN-0H; Thu, 19 Sep 2024 09:46:49 -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 1srHUU-00078J-TI for qemu-devel@nongnu.org; Thu, 19 Sep 2024 09:46:39 -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 1srHUQ-000609-UN for qemu-devel@nongnu.org; Thu, 19 Sep 2024 09:46:38 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=treblig.org ; s=bytemarkmx; h=MIME-Version:Message-ID:Date:Subject:From:Content-Type:From :Subject; bh=+ITeZviAUjdU79Lh7KnozJBelk/8symZBSM8bBXNmh8=; b=hTDDoJfmTCNi14vv 2lkRR0W9oAS61ad+vNLQYnVT/ZBeE7aOct/u4ZB1qvUNirQ1FGSSPXgl85gnGse/y6vetv0u6SDEi zcTkWb0AegkR44sjgko7In5ZEKj9RqpYwY0tPyFhKbMxLbI/xkE8I/3xkvK4lXUf9SfaoaV/iN/DJ bDalJNs+YVSlBfj7HPPvUTUOBR1VPa+prD5i2OqjPqKuNQsRqQ837y5+9IB91B0HG5ag1Ci7bZ7On 7K/4q/9wQTHpozhv+zhZYtTNq9YYXbjhdS/2RJARnFqPxi8JflDU3ZDeezUkMWFaJZ4yUTdk8kLtq kC5JhoYLQ8s+c4bs3Q==; Received: from localhost ([127.0.0.1] helo=dalek.home.treblig.org) by mx.treblig.org with esmtp (Exim 4.96) (envelope-from ) id 1srHUN-006QOJ-0s; Thu, 19 Sep 2024 13:46:31 +0000 From: dave@treblig.org To: peterx@redhat.com, farosas@suse.de, eblake@redhat.com, armbru@redhat.com Cc: qemu-devel@nongnu.org, "Dr. David Alan Gilbert" Subject: [PATCH v2 5/7] util/userfaultfd: Return -errno on error Date: Thu, 19 Sep 2024 14:46:24 +0100 Message-ID: <20240919134626.166183-6-dave@treblig.org> X-Mailer: git-send-email 2.46.1 In-Reply-To: <20240919134626.166183-1-dave@treblig.org> References: <20240919134626.166183-1-dave@treblig.org> MIME-Version: 1.0 Received-SPF: pass client-ip=2a00:1098:5b::1; envelope-from=dave@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 From: "Dr. David Alan Gilbert" Convert (the currently unused) uffd_wakeup, uffd_copy_page and uffd_zero_page to return -errno on error rather than -1. That will make it easier to reuse in postcopy. Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Peter Xu --- util/userfaultfd.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/util/userfaultfd.c b/util/userfaultfd.c index 1b2fa949d4..518d5c3586 100644 --- a/util/userfaultfd.c +++ b/util/userfaultfd.c @@ -240,7 +240,7 @@ int uffd_change_protection(int uffd_fd, void *addr, uint64_t length, * Copy range of source pages to the destination to resolve * missing page fault somewhere in the destination range. * - * Returns 0 on success, negative value in case of an error + * Returns 0 on success, -errno in case of an error * * @uffd_fd: UFFD file descriptor * @dst_addr: destination base address @@ -259,10 +259,11 @@ int uffd_copy_page(int uffd_fd, void *dst_addr, void *src_addr, uffd_copy.mode = dont_wake ? UFFDIO_COPY_MODE_DONTWAKE : 0; if (ioctl(uffd_fd, UFFDIO_COPY, &uffd_copy)) { + int e = errno; error_report("uffd_copy_page() failed: dst_addr=%p src_addr=%p length=%" PRIu64 " mode=%" PRIx64 " errno=%i", dst_addr, src_addr, - length, (uint64_t) uffd_copy.mode, errno); - return -1; + length, (uint64_t) uffd_copy.mode, e); + return -e; } return 0; @@ -273,7 +274,7 @@ int uffd_copy_page(int uffd_fd, void *dst_addr, void *src_addr, * * Fill range pages with zeroes to resolve missing page fault within the range. * - * Returns 0 on success, negative value in case of an error + * Returns 0 on success, -errno in case of an error * * @uffd_fd: UFFD file descriptor * @addr: base address @@ -289,10 +290,11 @@ int uffd_zero_page(int uffd_fd, void *addr, uint64_t length, bool dont_wake) uffd_zeropage.mode = dont_wake ? UFFDIO_ZEROPAGE_MODE_DONTWAKE : 0; if (ioctl(uffd_fd, UFFDIO_ZEROPAGE, &uffd_zeropage)) { + int e = errno; error_report("uffd_zero_page() failed: addr=%p length=%" PRIu64 " mode=%" PRIx64 " errno=%i", addr, length, - (uint64_t) uffd_zeropage.mode, errno); - return -1; + (uint64_t) uffd_zeropage.mode, e); + return -e; } return 0; @@ -306,7 +308,7 @@ int uffd_zero_page(int uffd_fd, void *addr, uint64_t length, bool dont_wake) * via UFFD-IO IOCTLs with MODE_DONTWAKE flag set, then after that all waits * for the whole memory range are satisfied in a single call to uffd_wakeup(). * - * Returns 0 on success, negative value in case of an error + * Returns 0 on success, -errno in case of an error * * @uffd_fd: UFFD file descriptor * @addr: base address @@ -320,9 +322,10 @@ int uffd_wakeup(int uffd_fd, void *addr, uint64_t length) uffd_range.len = length; if (ioctl(uffd_fd, UFFDIO_WAKE, &uffd_range)) { + int e = errno; error_report("uffd_wakeup() failed: addr=%p length=%" PRIu64 " errno=%i", - addr, length, errno); - return -1; + addr, length, e); + return -e; } return 0;