From b0e155481dd03971fe3d24b9abbe3cdf0e2373c4 Mon Sep 17 00:00:00 2001
Message-Id: <b0e155481dd03971fe3d24b9abbe3cdf0e2373c4@dist-git>
From: Jiri Denemark <jdenemar@redhat.com>
Date: Fri, 16 Aug 2019 14:52:29 +0200
Subject: [PATCH] qemu: Pass qemuCaps to qemuDomainSaveImageOpen
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Since qemuDomainDefPostParse callback requires qemuCaps, we need to make
sure it gets the capabilities stored in the domain's private data if the
domain is running. Passing NULL may cause QEMU capabilities probing to
be triggered in case QEMU binary changed in the meantime. When this
happens while a running domain object is locked, QMP event delivered to
the domain before QEMU capabilities probing finishes will deadlock the
event loop.

This patch fixes all paths leading to qemuDomainSaveImageOpen.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
(cherry picked from commit fd60aefec7f49d1053efdd5119db494bb474aeec)

https://bugzilla.redhat.com/show_bug.cgi?id=1731783
https://bugzilla.redhat.com/show_bug.cgi?id=1742023

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Message-Id: <6206f14c127037e0822fb6c1e04e8f2d8e6069ce.1565959866.git.jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
---
 src/qemu/qemu_driver.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 7d87215904..04915798ab 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -6368,6 +6368,7 @@ qemuDomainSaveImageUpdateDef(virQEMUDriverPtr driver,
 /**
  * qemuDomainSaveImageOpen:
  * @driver: qemu driver data
+ * @qemuCaps: pointer to qemuCaps if the domain is running or NULL
  * @path: path of the save image
  * @ret_def: returns domain definition created from the XML stored in the image
  * @ret_data: returns structure filled with data from the image header
@@ -6382,6 +6383,7 @@ qemuDomainSaveImageUpdateDef(virQEMUDriverPtr driver,
  */
 static int ATTRIBUTE_NONNULL(3) ATTRIBUTE_NONNULL(4)
 qemuDomainSaveImageOpen(virQEMUDriverPtr driver,
+                        virQEMUCapsPtr qemuCaps,
                         const char *path,
                         virDomainDefPtr *ret_def,
                         virQEMUSaveDataPtr *ret_data,
@@ -6506,7 +6508,7 @@ qemuDomainSaveImageOpen(virQEMUDriverPtr driver,
     }
 
     /* Create a domain from this XML */
-    if (!(def = virDomainDefParseString(data->xml, caps, driver->xmlopt, NULL,
+    if (!(def = virDomainDefParseString(data->xml, caps, driver->xmlopt, qemuCaps,
                                         VIR_DOMAIN_DEF_PARSE_INACTIVE |
                                         VIR_DOMAIN_DEF_PARSE_SKIP_VALIDATE)))
         goto error;
@@ -6681,7 +6683,7 @@ qemuDomainRestoreFlags(virConnectPtr conn,
 
     virNWFilterReadLockFilterUpdates();
 
-    fd = qemuDomainSaveImageOpen(driver, path, &def, &data,
+    fd = qemuDomainSaveImageOpen(driver, NULL, path, &def, &data,
                                  (flags & VIR_DOMAIN_SAVE_BYPASS_CACHE) != 0,
                                  &wrapperFd, false, false);
     if (fd < 0)
@@ -6779,7 +6781,7 @@ qemuDomainSaveImageGetXMLDesc(virConnectPtr conn, const char *path,
     /* We only take subset of virDomainDefFormat flags.  */
     virCheckFlags(VIR_DOMAIN_XML_SECURE, NULL);
 
-    fd = qemuDomainSaveImageOpen(driver, path, &def, &data,
+    fd = qemuDomainSaveImageOpen(driver, NULL, path, &def, &data,
                                  false, NULL, false, false);
 
     if (fd < 0)
@@ -6817,7 +6819,7 @@ qemuDomainSaveImageDefineXML(virConnectPtr conn, const char *path,
     else if (flags & VIR_DOMAIN_SAVE_PAUSED)
         state = 0;
 
-    fd = qemuDomainSaveImageOpen(driver, path, &def, &data,
+    fd = qemuDomainSaveImageOpen(driver, NULL, path, &def, &data,
                                  false, NULL, true, false);
 
     if (fd < 0)
@@ -6902,7 +6904,7 @@ qemuDomainManagedSaveGetXMLDesc(virDomainPtr dom, unsigned int flags)
         goto cleanup;
     }
 
-    if ((fd = qemuDomainSaveImageOpen(driver, path, &def, &data,
+    if ((fd = qemuDomainSaveImageOpen(driver, priv->qemuCaps, path, &def, &data,
                                       false, NULL, false, false)) < 0)
         goto cleanup;
 
@@ -6969,7 +6971,7 @@ qemuDomainObjRestore(virConnectPtr conn,
     virQEMUSaveDataPtr data = NULL;
     virFileWrapperFdPtr wrapperFd = NULL;
 
-    fd = qemuDomainSaveImageOpen(driver, path, &def, &data,
+    fd = qemuDomainSaveImageOpen(driver, NULL, path, &def, &data,
                                  bypass_cache, &wrapperFd, false, true);
     if (fd < 0) {
         if (fd == -3)
-- 
2.22.1