From 66d5fd223afbf662589611f3d6a22ff7bcc38bb0 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Wed, 6 Feb 2019 15:58:28 +0100 Subject: [PATCH 08/33] scsi-disk: Don't use empty string as device id MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Kevin Wolf Message-id: <20190206155829.14641-2-kwolf@redhat.com> Patchwork-id: 84253 O-Subject: [RHEL-7.7/8.0-AV qemu-kvm-rhev PATCH 1/2] scsi-disk: Don't use empty string as device id Bugzilla: 1673080 RH-Acked-by: Max Reitz RH-Acked-by: Thomas Huth RH-Acked-by: Paolo Bonzini scsi-disk includes in the Device Identification VPD page, depending on configuration amongst others, a vendor specific designator that consists either of the serial number if given or the BlockBackend name (which is a host detail that better shouldn't have been leaked to the guest, but now we have to maintain it for compatibility). With anonymous BlockBackends, i.e. scsi-disk devices constructed with drive=, and no serial number explicitly specified, this ends up as an empty string. If this happens to more than one disk, we have accidentally signalled to the OS that this is a multipath setup, which is obviously not what was intended. Instead of using an empty string for the vendor specific designator, simply leave out that designator, which makes Linux detect such setups as separate disks again. Signed-off-by: Kevin Wolf Reviewed-by: Eric Blake Reviewed-by: Philippe Mathieu-Daudé (cherry picked from commit a8f58afcdb86e266e06c9dc41a71605e570244c3) Signed-off-by: Kevin Wolf Signed-off-by: Miroslav Rezanina --- hw/scsi/scsi-disk.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c index a20ef91..de6c7bc 100644 --- a/hw/scsi/scsi-disk.c +++ b/hw/scsi/scsi-disk.c @@ -648,12 +648,14 @@ static int scsi_disk_emulate_vpd_page(SCSIRequest *req, uint8_t *outbuf) DPRINTF("Inquiry EVPD[Device identification] " "buffer size %zd\n", req->cmd.xfer); - outbuf[buflen++] = 0x2; /* ASCII */ - outbuf[buflen++] = 0; /* not officially assigned */ - outbuf[buflen++] = 0; /* reserved */ - outbuf[buflen++] = id_len; /* length of data following */ - memcpy(outbuf + buflen, str, id_len); - buflen += id_len; + if (id_len) { + outbuf[buflen++] = 0x2; /* ASCII */ + outbuf[buflen++] = 0; /* not officially assigned */ + outbuf[buflen++] = 0; /* reserved */ + outbuf[buflen++] = id_len; /* length of data following */ + memcpy(outbuf + buflen, str, id_len); + buflen += id_len; + } if (s->qdev.wwn) { outbuf[buflen++] = 0x1; /* Binary */ -- 1.8.3.1