From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:36858) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Q9fDD-0002ay-11 for qemu-devel@nongnu.org; Tue, 12 Apr 2011 11:09:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Q9fDA-0005fP-Vh for qemu-devel@nongnu.org; Tue, 12 Apr 2011 11:09:02 -0400 Received: from mx1.redhat.com ([209.132.183.28]:12798) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Q9fDA-0005ez-Ky for qemu-devel@nongnu.org; Tue, 12 Apr 2011 11:09:00 -0400 Message-ID: <4DA46B9A.9020601@redhat.com> Date: Tue, 12 Apr 2011 17:11:22 +0200 From: Kevin Wolf MIME-Version: 1.0 References: <1632463ee09a9df5690475f0b507757c0876fce9.1302617257.git.amit.shah@redhat.com> <4DA467BD.3010705@redhat.com> <20110412150339.GE13631@amit-x200.redhat.com> In-Reply-To: <20110412150339.GE13631@amit-x200.redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v4 5/5] atapi: GESN: implement 'media' subcommand List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Amit Shah Cc: Juan Quintela , Stefan Hajnoczi , Markus Armbruster , qemu list , Paolo Bonzini Am 12.04.2011 17:03, schrieb Amit Shah: > On (Tue) 12 Apr 2011 [16:54:53], Kevin Wolf wrote: >> Am 12.04.2011 16:09, schrieb Amit Shah: >>> Implement the 'media' sub-command of the GET_EVENT_STATUS_NOTIFICATION >>> command. This helps us report tray open, tray closed, no media, media >>> present states to the guest. >>> >>> Newer Linux kernels (2.6.38+) rely on this command to revalidate discs >>> after media change. >>> >>> This patch also sends out tray open/closed status to the guest driver >>> when requested e.g. via the CDROM_DRIVE_STATUS ioctl (thanks Markus). >>> Without such notification, the guest and qemu's tray open/close status >>> was frequently out of sync, causing installers like Anaconda detecting >>> no disc instead of tray open, confusing them terribly. >>> >>> Signed-off-by: Amit Shah >>> --- >>> hw/ide/core.c | 109 ++++++++++++++++++++++++++++++++++++++++++++++++++-- >>> hw/ide/internal.h | 6 +++ >>> 2 files changed, 110 insertions(+), 5 deletions(-) >>> >>> diff --git a/hw/ide/core.c b/hw/ide/core.c >>> index dafc049..209d8e6 100644 >>> --- a/hw/ide/core.c >>> +++ b/hw/ide/core.c >>> @@ -1084,6 +1084,49 @@ static int ide_dvd_read_structure(IDEState *s, int format, >>> } >>> } >>> >>> +static unsigned int event_status_media(IDEState *s, >>> + uint8_t *buf, >>> + unsigned int max_len) >>> +{ >>> + enum media_event_code { >>> + no_change = 0, /* Status unchanged */ >>> + eject_requested, /* received a request from user to eject */ >>> + new_media, /* new media inserted and ready for access */ >>> + media_removal, /* only for media changers */ >>> + media_changed, /* only for media changers */ >>> + bg_format_completed, /* MRW or DVD+RW b/g format completed */ >>> + bg_format_restarted, /* MRW or DVD+RW b/g format restarted */ >>> + }; >>> + enum media_status { >>> + tray_open = 1, >>> + media_present = 2, >>> + }; >>> + uint8_t event_code, media_status; >>> + >>> + media_status = 0; >>> + if (s->bs->tray_open) { >>> + media_status = tray_open; >>> + } else if (bdrv_is_inserted(s->bs)) { >>> + media_status = media_present; >>> + } >>> + >>> + /* Event notification descriptor */ >>> + event_code = no_change; >>> + if (media_status != tray_open && s->events.new_media) { >>> + event_code = new_media; >>> + s->events.new_media = false; >>> + } >>> + >>> + buf[4] = event_code; >>> + buf[5] = media_status; >>> + >>> + /* These fields are reserved, just clear them. */ >>> + buf[6] = 0; >>> + buf[7] = 0; >>> + >>> + return 8; /* We wrote to 4 extra bytes from the header */ >>> +} >>> + >>> static void handle_get_event_status_notification(IDEState *s, >>> uint8_t *buf, >>> const uint8_t *packet) >>> @@ -1104,6 +1147,26 @@ static void handle_get_event_status_notification(IDEState *s, >>> uint8_t supported_events; >>> } __attribute((packed)) *gesn_event_header; >>> >>> + enum notification_class_request_type { >>> + reserved1 = 1 << 0, >>> + operational_change = 1 << 1, >>> + power_management = 1 << 2, >>> + external_request = 1 << 3, >>> + media = 1 << 4, >>> + multi_host = 1 << 5, >>> + device_busy = 1 << 6, >>> + reserved2 = 1 << 7, >>> + }; >>> + enum event_notification_class_field { >>> + enc_no_events = 0, >>> + enc_operational_change, >>> + enc_power_management, >>> + enc_external_request, >>> + enc_media, >>> + enc_multiple_hosts, >>> + enc_device_busy, >>> + enc_reserved, >>> + }; >>> unsigned int max_len, used_len; >>> >>> gesn_cdb = (void *)packet; >>> @@ -1121,12 +1184,25 @@ static void handle_get_event_status_notification(IDEState *s, >>> >>> /* polling mode operation */ >>> >>> - /* We don't support any event class (yet). */ >>> - gesn_event_header->supported_events = 0; >>> - >>> - gesn_event_header->notification_class = 0x80; /* No event available */ >>> - used_len = sizeof(*gesn_event_header); >>> + /* >>> + * These are the supported events. >>> + * >>> + * We currently only support requests of the 'media' type. >>> + */ >>> + gesn_event_header->supported_events = media; >>> >>> + /* >>> + * Responses to requests are to be based on request priority. The >>> + * notification_class_request_type enum above specifies the >>> + * priority: upper elements are higher prio than lower ones. >>> + */ >>> + if (gesn_cdb->class & media) { >>> + gesn_event_header->notification_class |= enc_media; >> >> Am I missing where this field is initialized or should it be = instead >> of |= ? > > I considered both: if the 'reserved' bits become available and if we > should write to them, |= makes more sense. Currently, = will > suffice. Strong preference? |= is fine if the field is initialized to 0 and you add flags to it. But this patch seems to remove the zero initialization. Maybe it's still there somewhere, I just don't see it right now. Kevin