atapi: Implement 'media' subcommand for GESN

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 <[email protected]>

---
 hw/ide/core.c     |  109 ++++++++++++++++++++++++++++++++++++++++++++++++++--
 hw/ide/internal.h |    6 +++
 2 files changed, 110 insertions(+), 5 deletions(-)

hw/ide/core.c +67 -5

index dafc049..209d8e6 100644
@@ -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.

Am 12.04.2011 16:09, schrieb Amit Shah:

Quoted 116 lines

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 <[email protected]>

---
 hw/ide/core.c     |  109 ++++++++++++++++++++++++++++++++++++++++++++++++++--
 hw/ide/internal.h |    6 +++
 2 files changed, 110 insertions(+), 5 deletions(-)

hw/ide/core.c +69 -5

index dafc049..209d8e6 100644
@@ -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;
 

hw/ide/core.c static void handle_get_event_status_notification(IDEState *s, · line 1200

Quoted 7 lines

hw/ide/core.c +7 -0

+    /*
+     * 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 |= ?

Quoted 117 lines · Kevin Wolf

Am 12.04.2011 16:09, schrieb Amit Shah:

Quoted 116 lines

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 <[email protected]>

---
 hw/ide/core.c     |  109 ++++++++++++++++++++++++++++++++++++++++++++++++++--
 hw/ide/internal.h |    6 +++
 2 files changed, 110 insertions(+), 5 deletions(-)

hw/ide/core.c +69 -5

index dafc049..209d8e6 100644
@@ -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;
 

Quoted 10 lines

hw/ide/core.c static void handle_get_event_status_notification(IDEState *s, · line 1200

Quoted 7 lines

hw/ide/core.c +7 -0

+    /*
+     * 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.

Quoted 117 lines

Am 12.04.2011 16:09, schrieb Amit Shah:

Quoted 116 lines

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 <[email protected]>

---
 hw/ide/core.c     |  109 ++++++++++++++++++++++++++++++++++++++++++++++++++--
 hw/ide/internal.h |    6 +++
 2 files changed, 110 insertions(+), 5 deletions(-)

hw/ide/core.c +69 -5

index dafc049..209d8e6 100644
@@ -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;
 

Quoted 10 lines

hw/ide/core.c static void handle_get_event_status_notification(IDEState *s, · line 1200

Quoted 7 lines

hw/ide/core.c +7 -0

+    /*
+     * 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?

Am 12.04.2011 17:03, schrieb Amit Shah:

Quoted 129 lines · Kevin Wolf

Quoted 127 lines

Am 12.04.2011 16:09, schrieb Amit Shah:

Quoted 113 lines

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 <[email protected]>

---
 hw/ide/core.c     |  109 ++++++++++++++++++++++++++++++++++++++++++++++++++--
 hw/ide/internal.h |    6 +++
 2 files changed, 110 insertions(+), 5 deletions(-)

hw/ide/core.c +67 -5

index dafc049..209d8e6 100644
@@ -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.

hw/ide/core.c static void handle_get_event_status_notification(IDEState *s, · line 1200

Quoted 10 lines

hw/ide/core.c +9 -0

+     */
+    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 |= ?

Quoted 3 lines

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.

hw/ide/core.c +7 -0

index dafc049..209d8e6 100644
@@ -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 */

hw/ide/core.c +14 -0

+    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;

hw/ide/core.c +10 -0

@@ -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,
+    };

Quoted 15 lines

hw/ide/core.c +7 -0

index dafc049..209d8e6 100644
@@ -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 */

hw/ide/core.c static int ide_dvd_read_structure(IDEState *s, int format, · line 1103

Quoted 10 lines

hw/ide/core.c +10 -0

+        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,
+    };

Would be nice if you used upper-case with the enums since they are effectively just defines, to avoid confusing them with variables.

Quoted 18 lines

hw/ide/core.c +18 -0

+    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;

hw/ide/core.c static int ide_dvd_read_structure(IDEState *s, int format, · line 1127

Quoted 6 lines

hw/ide/core.c +6 -0

+
+    /* These fields are reserved, just clear them. */
+    buf[6] = 0;
+    buf[7] = 0;
+
+    return 8; /* We wrote to 4 extra bytes from the header */

Shouldn't you verify that you don't exceed max_len in this?

Am 12.04.2011 17:03, schrieb Jes Sorensen:

Quoted 1 line

Shouldn't you verify that you don't exceed max_len in this?

Not necessary (the buffer is always 2048 bytes), but it looks like the max_len parameter is unused now, so it could be removed.

Kevin