From dfc8270c27d1eaad36b85d6eab8f912b5bd7e334 Mon Sep 17 00:00:00 2001
Message-Id: <dfc8270c27d1eaad36b85d6eab8f912b5bd7e334@dist-git>
From: Michal Privoznik <mprivozn@redhat.com>
Date: Thu, 24 Oct 2019 08:45:50 +0200
Subject: [PATCH] domain_conf: Relax SCSI addr used check
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In domain_conf.c we have virDomainSCSIDriveAddressIsUsed()
function which returns true or false if given drive address is
already in use for given domain config or not. However, it also
takes a shortcut and returns true (meaning address in use) if the
unit number equals 7. This is because for some controllers this
is reserved address. The limitation comes mostly from vmware and
applies to lsilogic, buslogic, spapr-vscsi and vmpvscsi models.
On the other hand, we were not checking for the maximum unit
number (aka LUN number) which is also relevant and differs from
model to model.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
(cherry picked from commit c8007fdc5d2ce43fec2753cda60fb4963f55abd5)

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1741782

I had to drop
VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VIRTIO_TRANSITIONAL and
VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VIRTIO_NON_TRANSITIONAL from
virDomainSCSIDriveAddressIsUsed() because those don't exist in
RHEL-7.8 branch.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Message-Id: <9e70aa28937fa3ea1bbeb792f848b2be2a6ae2e7.1571899509.git.mprivozn@redhat.com>
Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
---
 src/conf/domain_conf.c | 49 +++++++++++++++++++++++++++++++++++++-----
 1 file changed, 44 insertions(+), 5 deletions(-)

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 333d9836c1..8bd527cfa1 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -4407,11 +4407,50 @@ bool
 virDomainSCSIDriveAddressIsUsed(const virDomainDef *def,
                                 const virDomainDeviceDriveAddress *addr)
 {
-    /* In current implementation, the maximum unit number of a controller
-     * is either 16 or 7 (narrow SCSI bus), and if the maximum unit number
-     * is 16, the controller itself is on unit 7 */
-    if (addr->unit == 7)
-        return true;
+    const virDomainControllerDef *cont;
+
+    cont = virDomainDeviceFindSCSIController(def, addr);
+    if (cont) {
+        int max = -1;
+        int reserved = -1;
+
+        /* Different controllers have different limits. These limits here are
+         * taken from QEMU source code, but nevertheless they should apply to
+         * other hypervisors too. */
+        switch ((virDomainControllerModelSCSI) cont->model) {
+        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VIRTIO_SCSI:
+            max = 16383;
+            break;
+        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_IBMVSCSI:
+            max = 31;
+            reserved = 7;
+            break;
+        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_LSISAS1068:
+            max = 1;
+            break;
+        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_LSISAS1078:
+            max = 255;
+            break;
+        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_LSILOGIC:
+            reserved = 7;
+            break;
+        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VMPVSCSI:
+            reserved = 7;
+            break;
+        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_BUSLOGIC:
+            reserved = 7;
+            break;
+        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_DEFAULT:
+        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_AUTO:
+        case VIR_DOMAIN_CONTROLLER_MODEL_SCSI_LAST:
+            break;
+        }
+
+        if (max != -1 && addr->unit >= max)
+            return true;
+        if (reserved != -1 && addr->unit == reserved)
+            return true;
+    }
 
     if (virDomainDriveAddressIsUsedByDisk(def, VIR_DOMAIN_DISK_BUS_SCSI,
                                           addr) ||
-- 
2.23.0