From b7638da5f8a4ad19fc45f530063044d0b5020422 Mon Sep 17 00:00:00 2001

Message-Id: <b7638da5f8a4ad19fc45f530063044d0b5020422@dist-git>

From: Jiri Denemark <jdenemar@redhat.com>

Date: Thu, 25 May 2017 10:20:57 +0200

Subject: [PATCH] qemu: Store save cookie in save images and snapshots

The following patches will add an actual content in the cookie and use

the data when restoring a domain.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>

(cherry picked from commit 5c2f01abcb43810e7617f9a6544ce0d0b6caed34)

https://bugzilla.redhat.com/show_bug.cgi?id=1441662

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>

---

 docs/formatsnapshot.html.in     |  6 +++

 docs/schemas/domainsnapshot.rng |  7 +++

 src/qemu/qemu_driver.c          | 96 ++++++++++++++++++++++++++++++++++++-----

 3 files changed, 99 insertions(+), 10 deletions(-)

diff --git a/docs/formatsnapshot.html.in b/docs/formatsnapshot.html.in

index c3ab516fa4..5e8e21c8a7 100644

--- a/docs/formatsnapshot.html.in

+++ b/docs/formatsnapshot.html.in

@@ -235,6 +235,12 @@

         at the time of the snapshot (since

         0.9.5).  Readonly.

+      
cookie

+      
Save image cookie containing additional data libvirt may need to

+        properly restore a domain from an active snapshot when such data

+        cannot be stored directly in the domain to maintain

+        compatibility with older libvirt or hypervisor. Readonly.

+      

     
Examples

diff --git a/docs/schemas/domainsnapshot.rng b/docs/schemas/domainsnapshot.rng

index 4ab1b828f2..2680887095 100644

--- a/docs/schemas/domainsnapshot.rng

+++ b/docs/schemas/domainsnapshot.rng

@@ -90,6 +90,13 @@

             </element>

           </element>

         </optional>

+        <optional>

+          <element name='cookie'>

+            <zeroOrMore>

+              <ref name='customElement'/>

+            </zeroOrMore>

+          </element>

+        </optional>

       </interleave>

     </element>

   </define>

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c

index 7ce0f01f70..dbb1ea9475 100644

--- a/src/qemu/qemu_driver.c

+++ b/src/qemu/qemu_driver.c

@@ -2813,7 +2813,8 @@ struct _virQEMUSaveHeader {

     uint32_t data_len;

     uint32_t was_running;

     uint32_t compressed;

-    uint32_t unused[15];

+    uint32_t cookieOffset;

+    uint32_t unused[14];

 };

 typedef struct _virQEMUSaveData virQEMUSaveData;

@@ -2821,6 +2822,7 @@ typedef virQEMUSaveData *virQEMUSaveDataPtr;

 struct _virQEMUSaveData {

     virQEMUSaveHeader header;

     char *xml;

+    char *cookie;

 };

@@ -2831,6 +2833,7 @@ bswap_header(virQEMUSaveHeaderPtr hdr)

     hdr->data_len = bswap_32(hdr->data_len);

     hdr->was_running = bswap_32(hdr->was_running);

     hdr->compressed = bswap_32(hdr->compressed);

+    hdr->cookieOffset = bswap_32(hdr->cookieOffset);

 }

@@ -2841,6 +2844,7 @@ virQEMUSaveDataFree(virQEMUSaveDataPtr data)

         return;

     VIR_FREE(data->xml);

+    VIR_FREE(data->cookie);

     VIR_FREE(data);

 }

@@ -2850,8 +2854,10 @@ virQEMUSaveDataFree(virQEMUSaveDataPtr data)

  */

 static virQEMUSaveDataPtr

 virQEMUSaveDataNew(char *domXML,

+                   qemuDomainSaveCookiePtr cookieObj,

                    bool running,

-                   int compressed)

+                   int compressed,

+                   virDomainXMLOptionPtr xmlopt)

 {

     virQEMUSaveDataPtr data = NULL;

     virQEMUSaveHeaderPtr header;

@@ -2861,6 +2867,11 @@ virQEMUSaveDataNew(char *domXML,

     VIR_STEAL_PTR(data->xml, domXML);

+    if (cookieObj &&

+        !(data->cookie = virSaveCookieFormat((virObjectPtr) cookieObj,

+                                             virDomainXMLOptionGetSaveCookie(xmlopt))))

+        goto error;

+

     header = &data->header;

     memcpy(header->magic, QEMU_SAVE_PARTIAL, sizeof(header->magic));

     header->version = QEMU_SAVE_VERSION;

@@ -2868,6 +2879,10 @@ virQEMUSaveDataNew(char *domXML,

     header->compressed = compressed;

     return data;

+

+ error:

+    virQEMUSaveDataFree(data);

+    return NULL;

 }

@@ -2887,11 +2902,17 @@ virQEMUSaveDataWrite(virQEMUSaveDataPtr data,

 {

     virQEMUSaveHeaderPtr header = &data->header;

     size_t len;

+    size_t xml_len;

+    size_t cookie_len = 0;

     int ret = -1;

     size_t zerosLen = 0;

     char *zeros = NULL;

-    len = strlen(data->xml) + 1;

+    xml_len = strlen(data->xml) + 1;

+    if (data->cookie)

+        cookie_len = strlen(data->cookie) + 1;

+

+    len = xml_len + cookie_len;

     if (header->data_len > 0) {

         if (len > header->data_len) {

@@ -2907,6 +2928,9 @@ virQEMUSaveDataWrite(virQEMUSaveDataPtr data,

         header->data_len = len;

     }

+    if (data->cookie)

+        header->cookieOffset = xml_len;

+

     if (safewrite(fd, header, sizeof(*header)) != sizeof(*header)) {

         virReportSystemError(errno,

                              _("failed to write header to domain save file '%s'"),

@@ -2914,14 +2938,28 @@ virQEMUSaveDataWrite(virQEMUSaveDataPtr data,

         goto cleanup;

     }

-    if (safewrite(fd, data->xml, header->data_len) != header->data_len ||

-        safewrite(fd, zeros, zerosLen) != zerosLen) {

+    if (safewrite(fd, data->xml, xml_len) != xml_len) {

         virReportSystemError(errno,

                              _("failed to write domain xml to '%s'"),

                              path);

         goto cleanup;

     }

+    if (data->cookie &&

+        safewrite(fd, data->cookie, cookie_len) != cookie_len) {

+        virReportSystemError(errno,

+                             _("failed to write cookie to '%s'"),

+                             path);

+        goto cleanup;

+    }

+

+    if (safewrite(fd, zeros, zerosLen) != zerosLen) {

+        virReportSystemError(errno,

+                             _("failed to write padding to '%s'"),

+                             path);

+        goto cleanup;

+    }

+

     ret = 0;

  cleanup:

@@ -3236,6 +3274,7 @@ qemuDomainSaveInternal(virQEMUDriverPtr driver, virDomainPtr dom,

     qemuDomainObjPrivatePtr priv = vm->privateData;

     virCapsPtr caps;

     virQEMUSaveDataPtr data = NULL;

+    qemuDomainSaveCookiePtr cookie = NULL;

     if (!(caps = virQEMUDriverGetCapabilities(driver, false)))

         goto cleanup;

@@ -3301,7 +3340,11 @@ qemuDomainSaveInternal(virQEMUDriverPtr driver, virDomainPtr dom,

         goto endjob;

     }

-    if (!(data = virQEMUSaveDataNew(xml, was_running, compressed)))

+    if (!(cookie = qemuDomainSaveCookieNew(vm)))

+        goto endjob;

+

+    if (!(data = virQEMUSaveDataNew(xml, cookie, was_running, compressed,

+                                    driver->xmlopt)))

         goto endjob;

     xml = NULL;

@@ -3338,6 +3381,7 @@ qemuDomainSaveInternal(virQEMUDriverPtr driver, virDomainPtr dom,

         qemuDomainRemoveInactive(driver, vm);

  cleanup:

+    virObjectUnref(cookie);

     VIR_FREE(xml);

     virQEMUSaveDataFree(data);

     qemuDomainEventQueue(driver, event);

@@ -6282,6 +6326,8 @@ qemuDomainSaveImageOpen(virQEMUDriverPtr driver,

     virDomainDefPtr def = NULL;

     int oflags = open_write ? O_RDWR : O_RDONLY;

     virCapsPtr caps = NULL;

+    size_t xml_len;

+    size_t cookie_len;

     if (bypass_cache) {

         int directFlag = virFileDirectFdFlag();

@@ -6362,15 +6408,33 @@ qemuDomainSaveImageOpen(virQEMUDriverPtr driver,

         goto error;

     }

-    if (VIR_ALLOC_N(data->xml, header->data_len) < 0)

+    if (header->cookieOffset)

+        xml_len = header->cookieOffset;

+    else

+        xml_len = header->data_len;

+

+    cookie_len = header->data_len - xml_len;

+

+    if (VIR_ALLOC_N(data->xml, xml_len) < 0)

         goto error;

-    if (saferead(fd, data->xml, header->data_len) != header->data_len) {

+    if (saferead(fd, data->xml, xml_len) != xml_len) {

         virReportError(VIR_ERR_OPERATION_FAILED,

                        "%s", _("failed to read domain XML"));

         goto error;

     }

+    if (cookie_len > 0) {

+        if (VIR_ALLOC_N(data->cookie, cookie_len) < 0)

+            goto error;

+

+        if (saferead(fd, data->cookie, cookie_len) != cookie_len) {

+            virReportError(VIR_ERR_OPERATION_FAILED, "%s",

+                           _("failed to read cookie"));

+            goto error;

+        }

+    }

+

     /* Create a domain from this XML */

     if (!(def = virDomainDefParseString(data->xml, caps, driver->xmlopt, NULL,

                                         VIR_DOMAIN_DEF_PARSE_INACTIVE |

@@ -6411,6 +6475,11 @@ qemuDomainSaveImageStartVM(virConnectPtr conn,

     char *errbuf = NULL;

     virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver);

     virQEMUSaveHeaderPtr header = &data->header;

+    qemuDomainSaveCookiePtr cookie = NULL;

+

+    if (virSaveCookieParseString(data->cookie, (virObjectPtr *) &cookie,

+                                 virDomainXMLOptionGetSaveCookie(driver->xmlopt)) < 0)

+        goto cleanup;

     if ((header->version == 2) &&

         (header->compressed != QEMU_SAVE_FORMAT_RAW)) {

@@ -6501,6 +6570,7 @@ qemuDomainSaveImageStartVM(virConnectPtr conn,

     ret = 0;

  cleanup:

+    virObjectUnref(cookie);

     virCommandFree(cmd);

     VIR_FREE(errbuf);

     if (qemuSecurityRestoreSavedStateLabel(driver->securityManager,

@@ -13561,6 +13631,9 @@ qemuDomainSnapshotCreateActiveInternal(virConnectPtr conn,

     if (ret < 0)

         goto cleanup;

+    if (!(snap->def->cookie = (virObjectPtr) qemuDomainSaveCookieNew(vm)))

+        goto cleanup;

+

     if (flags & VIR_DOMAIN_SNAPSHOT_CREATE_HALT) {

         event = virDomainEventLifecycleNewFromObj(vm, VIR_DOMAIN_EVENT_STOPPED,

                                          VIR_DOMAIN_EVENT_STOPPED_FROM_SNAPSHOT);

@@ -14439,10 +14512,13 @@ qemuDomainSnapshotCreateActiveExternal(virConnectPtr conn,

                                                     "snapshot", false)) < 0)

             goto cleanup;

-        if (!(xml = qemuDomainDefFormatLive(driver, vm->def, true, true)))

+        if (!(xml = qemuDomainDefFormatLive(driver, vm->def, true, true)) ||

+            !(snap->def->cookie = (virObjectPtr) qemuDomainSaveCookieNew(vm)))

             goto cleanup;

-        if (!(data = virQEMUSaveDataNew(xml, resume, compressed)))

+        if (!(data = virQEMUSaveDataNew(xml,

+                                        (qemuDomainSaveCookiePtr) snap->def->cookie,

+                                        resume, compressed, driver->xmlopt)))

             goto cleanup;

         xml = NULL;

-- 

2.13.1