From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60165) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eGsFC-0003nb-OY for qemu-devel@nongnu.org; Mon, 20 Nov 2017 15:00:43 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eGsF8-0002GQ-Ly for qemu-devel@nongnu.org; Mon, 20 Nov 2017 15:00:38 -0500 Received: from mx1.redhat.com ([209.132.183.28]:37548) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eGsF8-0002Ft-Cy for qemu-devel@nongnu.org; Mon, 20 Nov 2017 15:00:34 -0500 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 573A980B29 for ; Mon, 20 Nov 2017 20:00:33 +0000 (UTC) References: <1510834622-28800-1-git-send-email-thuth@redhat.com> <20171120175522.76bf71c3@redhat.com> From: Thomas Huth Message-ID: <30190107-f070-8846-fda5-09258d5ee246@redhat.com> Date: Mon, 20 Nov 2017 21:00:28 +0100 MIME-Version: 1.0 In-Reply-To: <20171120175522.76bf71c3@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2] tests/bios-tables-test: Fix endianess problems when passing data to iasl List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Igor Mammedov Cc: qemu-devel@nongnu.org, "Michael S. Tsirkin" On 20.11.2017 17:55, Igor Mammedov wrote: > On Thu, 16 Nov 2017 13:17:02 +0100 > Thomas Huth wrote: > >> The bios-tables-test was writing out files that we pass to iasl in >> with the wrong endianness in the header when running on a big endian >> host. So instead of storing mixed endian information in our structures, >> let's keep everything in little endian and byte-swap it only when we >> need a value in the code. >> >> Reported-by: Daniel P. Berrange >> Buglink: https://bugs.launchpad.net/qemu/+bug/1724570 >> Suggested-by: Michael S. Tsirkin >> Signed-off-by: Thomas Huth >> --- >> v2: Fixed vmgenid-test which was accidentially broken in v1 >> >> tests/acpi-utils.h | 27 +++++---------------------- >> tests/bios-tables-test.c | 42 ++++++++++++++++++++++-------------------- >> tests/vmgenid-test.c | 22 ++++++++++++---------- >> 3 files changed, 39 insertions(+), 52 deletions(-) >> >> diff --git a/tests/acpi-utils.h b/tests/acpi-utils.h >> index f8d8723..d5ca5b6 100644 >> --- a/tests/acpi-utils.h >> +++ b/tests/acpi-utils.h >> @@ -28,24 +28,9 @@ typedef struct { >> bool tmp_files_retain; /* do not delete the temp asl/aml */ >> } AcpiSdtTable; >> >> -#define ACPI_READ_FIELD(field, addr) \ >> - do { \ >> - switch (sizeof(field)) { \ >> - case 1: \ >> - field = readb(addr); \ >> - break; \ >> - case 2: \ >> - field = readw(addr); \ >> - break; \ >> - case 4: \ >> - field = readl(addr); \ >> - break; \ >> - case 8: \ >> - field = readq(addr); \ >> - break; \ >> - default: \ >> - g_assert(false); \ >> - } \ > probably it's been discussed but, why not do > leXX_to_cpu() > here, instead of making each place that access read field > to do leXX_to_cpu() manually.? > > Beside of keeping access to structure in natural host order, > it should also be less error-prone as field users don't > have to worry about endianness. Actually, the readw/l/q functions already do byte-swapping, so the data was stored in host endian order. But Michael said that he'd prefer to store all data from the ACPI tables in little endian mode instead - that's why I've done the patch that way. Thomas