From patchwork Fri Nov 11 18:49:47 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: John Snow X-Patchwork-Id: 693898 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3tFq1Z0QrNz9t1h for ; Sat, 12 Nov 2016 05:58:10 +1100 (AEDT) Received: from localhost ([::1]:54792 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1c5H1b-0002TQ-JJ for incoming@patchwork.ozlabs.org; Fri, 11 Nov 2016 13:58:07 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39158) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1c5Gtm-0004C2-Ul for qemu-devel@nongnu.org; Fri, 11 Nov 2016 13:50:04 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1c5Gtj-0003Fh-HP for qemu-devel@nongnu.org; Fri, 11 Nov 2016 13:50:03 -0500 Received: from mx1.redhat.com ([209.132.183.28]:57564) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1c5Gtj-0003FS-9Z for qemu-devel@nongnu.org; Fri, 11 Nov 2016 13:49:59 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7EA9D5455F; Fri, 11 Nov 2016 18:49:58 +0000 (UTC) Received: from scv.usersys.redhat.com (dhcp-17-171.bos.redhat.com [10.18.17.171]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id uABInv7s030215; Fri, 11 Nov 2016 13:49:58 -0500 From: John Snow To: qemu-devel@nongnu.org Date: Fri, 11 Nov 2016 13:49:47 -0500 Message-Id: <1478890195-30841-2-git-send-email-jsnow@redhat.com> In-Reply-To: <1478890195-30841-1-git-send-email-jsnow@redhat.com> References: <1478890195-30841-1-git-send-email-jsnow@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Fri, 11 Nov 2016 18:49:58 +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 1/9] atapi: classify read_cd as conditionally returning data 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@linaro.org, jsnow@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" For the purposes of byte_count_limit verification, add a new flag that identifies read_cd as sometimes returning data, then check the BCL in its command handler after we know that it will indeed return data. Reported-by: Hervé Poussineau Signed-off-by: John Snow Reviewed-by: Kevin Wolf Message-id: 1477970211-25754-2-git-send-email-jsnow@redhat.com Signed-off-by: John Snow --- hw/ide/atapi.c | 51 ++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 40 insertions(+), 11 deletions(-) diff --git a/hw/ide/atapi.c b/hw/ide/atapi.c index 6189675..fc1d19c 100644 --- a/hw/ide/atapi.c +++ b/hw/ide/atapi.c @@ -637,6 +637,23 @@ static unsigned int event_status_media(IDEState *s, return 8; /* We wrote to 4 extra bytes from the header */ } +/* + * Before transferring data or otherwise signalling acceptance of a command + * marked CONDDATA, we must check the validity of the byte_count_limit. + */ +static bool validate_bcl(IDEState *s) +{ + /* TODO: Check IDENTIFY data word 125 for defacult BCL (currently 0) */ + if (s->atapi_dma || atapi_byte_count_limit(s)) { + return true; + } + + /* TODO: Move abort back into core.c and introduce proper error flow between + * ATAPI layer and IDE core layer */ + ide_abort_command(s); + return false; +} + static void cmd_get_event_status_notification(IDEState *s, uint8_t *buf) { @@ -1028,12 +1045,19 @@ static void cmd_read_cd(IDEState *s, uint8_t* buf) return; } - transfer_request = buf[9]; - switch(transfer_request & 0xf8) { - case 0x00: + transfer_request = buf[9] & 0xf8; + if (transfer_request == 0x00) { /* nothing */ ide_atapi_cmd_ok(s); - break; + return; + } + + /* Check validity of BCL before transferring data */ + if (!validate_bcl(s)) { + return; + } + + switch (transfer_request) { case 0x10: /* normal read */ ide_atapi_cmd_read(s, lba, nb_sectors, 2048); @@ -1266,6 +1290,14 @@ enum { * See ATA8-ACS3 "7.21.5 Byte Count Limit" */ NONDATA = 0x04, + + /* + * CONDDATA implies a command that transfers data only conditionally based + * on the presence of suboptions. It should be exempt from the BCL check at + * command validation time, but it needs to be checked at the command + * handler level instead. + */ + CONDDATA = 0x08, }; static const struct AtapiCmd { @@ -1289,7 +1321,7 @@ static const struct AtapiCmd { [ 0xad ] = { cmd_read_dvd_structure, CHECK_READY }, [ 0xbb ] = { cmd_set_speed, NONDATA }, [ 0xbd ] = { cmd_mechanism_status, 0 }, - [ 0xbe ] = { cmd_read_cd, CHECK_READY }, + [ 0xbe ] = { cmd_read_cd, CHECK_READY | CONDDATA }, /* [1] handler detects and reports not ready condition itself */ }; @@ -1348,15 +1380,12 @@ void ide_atapi_cmd(IDEState *s) return; } - /* Nondata commands permit the byte_count_limit to be 0. + /* Commands that don't transfer DATA permit the byte_count_limit to be 0. * If this is a data-transferring PIO command and BCL is 0, * we abort at the /ATA/ level, not the ATAPI level. * See ATA8 ACS3 section 7.17.6.49 and 7.21.5 */ - if (cmd->handler && !(cmd->flags & NONDATA)) { - /* TODO: Check IDENTIFY data word 125 for default BCL (currently 0) */ - if (!(atapi_byte_count_limit(s) || s->atapi_dma)) { - /* TODO: Move abort back into core.c and make static inline again */ - ide_abort_command(s); + if (cmd->handler && !(cmd->flags & (NONDATA | CONDDATA))) { + if (!validate_bcl(s)) { return; } }