libvirt/libvirt-RHEL-Enable-usage-of-x-blockdev-reopen.patch

From 44a70fb199212fcfa762979d1dfa0a7b6f6eaa34 Mon Sep 17 00:00:00 2001
Message-Id: <44a70fb199212fcfa762979d1dfa0a7b6f6eaa34@dist-git>
From: Peter Krempa <pkrempa@redhat.com>
Date: Mon, 16 Mar 2020 22:12:34 +0100
Subject: [PATCH] RHEL: Enable usage of x-blockdev-reopen
MIME-Version: 1.0
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Content-Transfer-Encoding: 8bit

RHEL-only

Introduce a new capability QEMU_CAPS_BLOCKDEV_REOPEN_COM_REDHAT_AV_8_2_0_API
based on the presence of '__com.redhat_rhel-av-8_2_0-api' feature for
'x-blockdev-reopen' which states that reopen works for what libvirt
is going to use it and wire up code to call the x- prefixed command.

This implementation will become dormant once qemu starts supporting
upstream-stable blockdev-reopen.

https://bugzilla.redhat.com/show_bug.cgi?id=1953939

Message-Id: <098dc0e73e1b561af991f2a9ecf13436dde3b33d.1584391727.git.pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
---
 src/qemu/qemu_block.c        |  3 ++-
 src/qemu/qemu_capabilities.c | 11 +++++++++++
 src/qemu/qemu_capabilities.h |  1 +
 src/qemu/qemu_monitor.c      |  5 +++--
 src/qemu/qemu_monitor.h      |  3 ++-
 src/qemu/qemu_monitor_json.c | 12 +++++++++---
 src/qemu/qemu_monitor_json.h |  3 ++-
 7 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/src/qemu/qemu_block.c b/src/qemu/qemu_block.c
index 6627d044cd..a531bdd704 100644
--- a/src/qemu/qemu_block.c
+++ b/src/qemu/qemu_block.c
@@ -3317,6 +3317,7 @@ qemuBlockReopenFormat(virDomainObj *vm,
     qemuDomainObjPrivate *priv = vm->privateData;
     virQEMUDriver *driver = priv->driver;
     g_autoptr(virJSONValue) reopenprops = NULL;
+    bool downstream = virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_BLOCKDEV_REOPEN_COM_REDHAT_AV_8_2_0_API);
     int rc;
 
     /* If we are lacking the object here, qemu might have opened an image with
@@ -3333,7 +3334,7 @@ qemuBlockReopenFormat(virDomainObj *vm,
     if (qemuDomainObjEnterMonitorAsync(driver, vm, asyncJob) < 0)
         return -1;
 
-    rc = qemuMonitorBlockdevReopen(priv->mon, &reopenprops);
+    rc = qemuMonitorBlockdevReopen(priv->mon, &reopenprops, downstream);
 
     if (qemuDomainObjExitMonitor(driver, vm) < 0 || rc < 0)
         return -1;
diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index 75dd01f06e..9f33e57d8e 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -630,6 +630,7 @@ VIR_ENUM_IMPL(virQEMUCaps,
               "compat-deprecated",
               "acpi-index",
               "input-linux",
+              "blockdev-reopen.__com.redhat_rhel-av-8_2_0-api",
     );
 
 
@@ -1544,6 +1545,7 @@ static struct virQEMUCapsDevicePropsFlags virQEMUCapsDevicePropsVhostUserFS[] =
 
 /* see documentation for virQEMUQAPISchemaPathGet for the query format */
 static struct virQEMUCapsStringFlags virQEMUCapsQMPSchemaQueries[] = {
+    { "x-blockdev-reopen/$__com.redhat_rhel-av-8_2_0-api", QEMU_CAPS_BLOCKDEV_REOPEN_COM_REDHAT_AV_8_2_0_API },
     { "blockdev-add/arg-type/options/+gluster/debug-level", QEMU_CAPS_GLUSTER_DEBUG_LEVEL},
     { "blockdev-add/arg-type/+gluster/debug", QEMU_CAPS_GLUSTER_DEBUG_LEVEL},
     { "blockdev-add/arg-type/+vxhs", QEMU_CAPS_VXHS},
@@ -5192,6 +5194,15 @@ virQEMUCapsInitProcessCaps(virQEMUCaps *qemuCaps)
         qemuCaps->arch == VIR_ARCH_MIPS)
         virQEMUCapsSet(qemuCaps, QEMU_CAPS_SCSI_NCR53C90);
 
+    /* RHEL-only:
+     * - if upstream blockdev-reopen is enabled, clear the downstream flag
+     * - if the downstream flag is present but not the upstream, assert the upstream flag too
+     */
+    if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_BLOCKDEV_REOPEN))
+        virQEMUCapsClear(qemuCaps, QEMU_CAPS_BLOCKDEV_REOPEN_COM_REDHAT_AV_8_2_0_API);
+    if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_BLOCKDEV_REOPEN_COM_REDHAT_AV_8_2_0_API))
+        virQEMUCapsSet(qemuCaps, QEMU_CAPS_BLOCKDEV_REOPEN);
+
     virQEMUCapsInitProcessCapsInterlock(qemuCaps);
 }
 
diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h
index 94f2fad05a..97448e54e3 100644
--- a/src/qemu/qemu_capabilities.h
+++ b/src/qemu/qemu_capabilities.h
@@ -610,6 +610,7 @@ typedef enum { /* virQEMUCapsFlags grouping marker for syntax-check */
     QEMU_CAPS_COMPAT_DEPRECATED, /* -compat deprecated-(input|output) is supported */
     QEMU_CAPS_ACPI_INDEX, /* PCI device 'acpi-index' property */
     QEMU_CAPS_INPUT_LINUX, /* -object input-linux */
+    QEMU_CAPS_BLOCKDEV_REOPEN_COM_REDHAT_AV_8_2_0_API, /* downstream support for blockdev reopen in rhel-av-8.2.0 */
 
     QEMU_CAPS_LAST /* this must always be the last item */
 } virQEMUCapsFlags;
diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c
index 8f35b4240f..14e38a2abc 100644
--- a/src/qemu/qemu_monitor.c
+++ b/src/qemu/qemu_monitor.c
@@ -4458,14 +4458,15 @@ qemuMonitorBlockdevAdd(qemuMonitor *mon,
 
 int
 qemuMonitorBlockdevReopen(qemuMonitor *mon,
-                          virJSONValue **props)
+                          virJSONValue **props,
+                          bool downstream)
 {
     VIR_DEBUG("props=%p (node-name=%s)", *props,
               NULLSTR(virJSONValueObjectGetString(*props, "node-name")));
 
     QEMU_CHECK_MONITOR(mon);
 
-    return qemuMonitorJSONBlockdevReopen(mon, props);
+    return qemuMonitorJSONBlockdevReopen(mon, props, downstream);
 }
 
 
diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h
index 6a25def78b..14bfbb600e 100644
--- a/src/qemu/qemu_monitor.h
+++ b/src/qemu/qemu_monitor.h
@@ -1371,7 +1371,8 @@ int qemuMonitorBlockdevAdd(qemuMonitor *mon,
                            virJSONValue **props);
 
 int qemuMonitorBlockdevReopen(qemuMonitor *mon,
-                              virJSONValue **props);
+                              virJSONValue **props,
+                              bool downstream);
 
 int qemuMonitorBlockdevDel(qemuMonitor *mon,
                            const char *nodename);
diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
index 46aa3330a8..1a5c3a6f4d 100644
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -8746,13 +8746,19 @@ qemuMonitorJSONBlockdevAdd(qemuMonitor *mon,
 
 int
 qemuMonitorJSONBlockdevReopen(qemuMonitor *mon,
-                              virJSONValue **props)
+                              virJSONValue **props,
+                              bool downstream)
 {
     g_autoptr(virJSONValue) cmd = NULL;
     g_autoptr(virJSONValue) reply = NULL;
 
-    if (!(cmd = qemuMonitorJSONMakeCommandInternal("blockdev-reopen", props)))
-        return -1;
+    if (downstream) {
+        if (!(cmd = qemuMonitorJSONMakeCommandInternal("x-blockdev-reopen", props)))
+            return -1;
+    } else {
+        if (!(cmd = qemuMonitorJSONMakeCommandInternal("blockdev-reopen", props)))
+            return -1;
+    }
 
     if (qemuMonitorJSONCommand(mon, cmd, &reply) < 0)
         return -1;
diff --git a/src/qemu/qemu_monitor_json.h b/src/qemu/qemu_monitor_json.h
index 01a3ba25f1..90792c9939 100644
--- a/src/qemu/qemu_monitor_json.h
+++ b/src/qemu/qemu_monitor_json.h
@@ -601,7 +601,8 @@ int qemuMonitorJSONBlockdevAdd(qemuMonitor *mon,
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
 
 int qemuMonitorJSONBlockdevReopen(qemuMonitor *mon,
-                                  virJSONValue **props)
+                                  virJSONValue **props,
+                                  bool downstream)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
 
 int qemuMonitorJSONBlockdevDel(qemuMonitor *mon,
-- 
2.31.1