From 5fb7ab2c9e326f79a1776c930d8f78ea53054500 Mon Sep 17 00:00:00 2001
From: Peter Krempa <pkrempa@redhat.com>
Date: Wed, 1 Nov 2017 11:17:20 +0100
Subject: [PATCH] qemu: command: Refactor qemuBuildDriveStrValidate to make
 qemuCaps optional

To allow merging this with other disk type checks we need to check
qemuCaps only when available, since some of the checks are executed on
disk cold-plug and thus capabilities should not be checked.

Make the checks optional by making them conditional on qemuCaps not
being NULL.
---
 src/qemu/qemu_command.c | 98 +++++++++++++++++++++--------------------
 1 file changed, 50 insertions(+), 48 deletions(-)

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 16de7be4cf..07b79b3bcd 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -1553,31 +1553,6 @@ qemuBuildDriveStrValidate(virDomainDiskDefPtr disk,
         return -1;
     }
 
-    if (disk->serial &&
-        virQEMUCapsGet(qemuCaps, QEMU_CAPS_DRIVE_SERIAL)) {
-        if (disk->bus == VIR_DOMAIN_DISK_BUS_SCSI &&
-            disk->device == VIR_DOMAIN_DISK_DEVICE_LUN) {
-            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
-                           _("scsi-block 'lun' devices do not support the "
-                             "serial property"));
-            return -1;
-        }
-    }
-
-    if (disk->cachemode == VIR_DOMAIN_DISK_CACHE_DIRECTSYNC &&
-        !virQEMUCapsGet(qemuCaps, QEMU_CAPS_DRIVE_CACHE_DIRECTSYNC)) {
-        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
-                       _("disk cache mode 'directsync' is not supported by this QEMU"));
-        return -1;
-    }
-
-    if (disk->cachemode == VIR_DOMAIN_DISK_CACHE_UNSAFE &&
-        !virQEMUCapsGet(qemuCaps, QEMU_CAPS_DRIVE_CACHE_UNSAFE)) {
-        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
-                       _("disk cache mode 'unsafe' is not supported by this QEMU"));
-        return -1;
-    }
-
     if (disk->iomode == VIR_DOMAIN_DISK_IO_NATIVE &&
         disk->cachemode != VIR_DOMAIN_DISK_CACHE_DIRECTSYNC &&
         disk->cachemode != VIR_DOMAIN_DISK_CACHE_DISABLE) {
@@ -1588,32 +1563,59 @@ qemuBuildDriveStrValidate(virDomainDiskDefPtr disk,
         return -1;
     }
 
-    if (disk->copy_on_read &&
-        !virQEMUCapsGet(qemuCaps, QEMU_CAPS_DRIVE_COPY_ON_READ)) {
-        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
-                       _("copy_on_read is not supported by this QEMU binary"));
-        return -1;
-    }
+    if (qemuCaps) {
+        if (disk->serial &&
+            virQEMUCapsGet(qemuCaps, QEMU_CAPS_DRIVE_SERIAL)) {
+            if (disk->bus == VIR_DOMAIN_DISK_BUS_SCSI &&
+                disk->device == VIR_DOMAIN_DISK_DEVICE_LUN) {
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                               _("scsi-block 'lun' devices do not support the "
+                                 "serial property"));
+                return -1;
+            }
+        }
 
-    if (disk->discard &&
-        !virQEMUCapsGet(qemuCaps, QEMU_CAPS_DRIVE_DISCARD)) {
-        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
-                       _("discard is not supported by this QEMU binary"));
-        return -1;
-    }
+        if (disk->cachemode == VIR_DOMAIN_DISK_CACHE_DIRECTSYNC &&
+            !virQEMUCapsGet(qemuCaps, QEMU_CAPS_DRIVE_CACHE_DIRECTSYNC)) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("disk cache mode 'directsync' is not supported by this QEMU"));
+            return -1;
+        }
 
-    if (disk->detect_zeroes &&
-        !virQEMUCapsGet(qemuCaps, QEMU_CAPS_DRIVE_DETECT_ZEROES)) {
-        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
-                       _("detect_zeroes is not supported by this QEMU binary"));
-        return -1;
-    }
+        if (disk->cachemode == VIR_DOMAIN_DISK_CACHE_UNSAFE &&
+            !virQEMUCapsGet(qemuCaps, QEMU_CAPS_DRIVE_CACHE_UNSAFE)) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("disk cache mode 'unsafe' is not supported by this QEMU"));
+            return -1;
+        }
 
-    if (disk->iomode &&
-        !virQEMUCapsGet(qemuCaps, QEMU_CAPS_DRIVE_AIO)) {
-        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
-                       _("disk aio mode not supported with this QEMU binary"));
-        return -1;
+        if (disk->copy_on_read &&
+            !virQEMUCapsGet(qemuCaps, QEMU_CAPS_DRIVE_COPY_ON_READ)) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("copy_on_read is not supported by this QEMU binary"));
+            return -1;
+        }
+
+        if (disk->discard &&
+            !virQEMUCapsGet(qemuCaps, QEMU_CAPS_DRIVE_DISCARD)) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("discard is not supported by this QEMU binary"));
+            return -1;
+        }
+
+        if (disk->detect_zeroes &&
+            !virQEMUCapsGet(qemuCaps, QEMU_CAPS_DRIVE_DETECT_ZEROES)) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("detect_zeroes is not supported by this QEMU binary"));
+            return -1;
+        }
+
+        if (disk->iomode &&
+            !virQEMUCapsGet(qemuCaps, QEMU_CAPS_DRIVE_AIO)) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("disk aio mode not supported with this QEMU binary"));
+            return -1;
+        }
     }
 
     return 0;