From e2354416fdccb9649f080cdf912c5dc16d0eb578 Mon Sep 17 00:00:00 2001

From: Michal Privoznik <mprivozn@redhat.com>

Date: Thu, 7 Aug 2014 16:59:21 +0200

Subject: [PATCH] qemu: Automatically create NVRAM store

When using split UEFI image, it may come handy if libvirt manages per

domain _VARS file automatically. While the _CODE file is RO and can be

shared among multiple domains, you certainly don't want to do that on

the _VARS file. This latter one needs to be per domain. So at the

domain startup process, if it's determined that domain needs _VARS

file it's copied from this master _VARS file. The location of the

master file is configurable in qemu.conf.

Temporary, on per domain basis the location of master NVRAM file can

be overridden by this @template attribute I'm inventing to the

<nvram/> element. All it does is holding path to the master NVRAM file

from which local copy is created. If that's the case, the map in

qemu.conf is not consulted.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>

Acked-by: Laszlo Ersek <lersek@redhat.com>

(cherry picked from commit 742b08e30fd503bc992e864828cbabd7e6a099ec)

---

 docs/formatdomain.html.in                          |  11 +-

 docs/schemas/domaincommon.rng                      |   9 +-

 libvirt.spec.in                                    |   2 +

 src/Makefile.am                                    |   1 +

 src/conf/domain_conf.c                             |  11 +-

 src/conf/domain_conf.h                             |   1 +

 src/qemu/libvirtd_qemu.aug                         |   3 +

 src/qemu/qemu.conf                                 |  14 +++

 src/qemu/qemu_conf.c                               |  94 ++++++++++++++

 src/qemu/qemu_conf.h                               |   5 +

 src/qemu/qemu_process.c                            | 137 +++++++++++++++++++++

 src/qemu/test_libvirtd_qemu.aug.in                 |   3 +

 tests/domainschemadata/domain-bios-nvram-empty.xml |  40 ++++++

 13 files changed, 325 insertions(+), 6 deletions(-)

 create mode 100644 tests/domainschemadata/domain-bios-nvram-empty.xml

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

index 757035a..a2ea758 100644

--- a/docs/formatdomain.html.in

+++ b/docs/formatdomain.html.in

@@ -103,7 +103,7 @@

   <os>

     <type>hvm</type>

     <loader readonly='on' type='rom'>/usr/lib/xen/boot/hvmloader</loader>

-    <nvram>/var/lib/libvirt/nvram/guest_VARS.fd</nvram>

+    <nvram template='/usr/share/OVMF/OVMF_VARS.fd'>/var/lib/libvirt/nvram/guest_VARS.fd</nvram>

     <boot dev='hd'/>

     <boot dev='cdrom'/>

     <bootmenu enable='yes' timeout='3000'/>

@@ -142,9 +142,12 @@

         pflash.

       
nvram

       
Some UEFI firmwares may want to use a non-volatile memory to store

-        some variables. In the host, this is represented as a file and the

-        path to the file is stored in this element. Since

-        1.2.8

+        some variables. In the host, this is represented as a file and the path

+        to the file is stored in this element. Moreover, when the domain is

+        started up libvirt copies so called master NVRAM store file defined

+        in qemu.conf. If needed, the template

+        attribute can be used to per domain override map of master NVRAM stores

+        from the config file. Since 1.2.8

       
boot

       
The dev attribute takes one of the values "fd", "hd",

         "cdrom" or "network" and is used to specify the next boot device

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

index 5d9c21c..6ae940a 100644

--- a/docs/schemas/domaincommon.rng

+++ b/docs/schemas/domaincommon.rng

@@ -263,7 +263,14 @@

         </optional>

         <optional>

           <element name="nvram">

-            <ref name="absFilePath"/>

+            <optional>

+              <attribute name="template">

+                <ref name="absFilePath"/>

+              </attribute>

+            </optional>

+            <optional>

+              <ref name="absFilePath"/>

+            </optional>

           </element>

         </optional>

         <optional>

diff --git a/libvirt.spec.in b/libvirt.spec.in

index 6129f00..935b8c8 100644

--- a/libvirt.spec.in

+++ b/libvirt.spec.in

@@ -1970,6 +1970,7 @@ exit 0

 %dir %attr(0750, %{qemu_user}, %{qemu_group}) %{_localstatedir}/lib/libvirt/qemu/

 %dir %attr(0750, %{qemu_user}, %{qemu_group}) %{_localstatedir}/lib/libvirt/qemu/channel/

 %dir %attr(0750, %{qemu_user}, %{qemu_group}) %{_localstatedir}/lib/libvirt/qemu/channel/target/

+%dir %attr(0750, %{qemu_user}, %{qemu_group}) %{_localstatedir}/lib/libvirt/qemu/nvram/

 %dir %attr(0750, %{qemu_user}, %{qemu_group}) %{_localstatedir}/cache/libvirt/qemu/

 %{_datadir}/augeas/lenses/libvirtd_qemu.aug

 %{_datadir}/augeas/lenses/tests/test_libvirtd_qemu.aug

@@ -2072,6 +2073,7 @@ exit 0

 %dir %attr(0750, %{qemu_user}, %{qemu_group}) %{_localstatedir}/lib/libvirt/qemu/

 %dir %attr(0750, %{qemu_user}, %{qemu_group}) %{_localstatedir}/lib/libvirt/qemu/channel/

 %dir %attr(0750, %{qemu_user}, %{qemu_group}) %{_localstatedir}/lib/libvirt/qemu/channel/target/

+%dir %attr(0750, %{qemu_user}, %{qemu_group}) %{_localstatedir}/lib/libvirt/qemu/nvram/

 %dir %attr(0750, %{qemu_user}, %{qemu_group}) %{_localstatedir}/cache/libvirt/qemu/

 %{_datadir}/augeas/lenses/libvirtd_qemu.aug

 %{_datadir}/augeas/lenses/tests/test_libvirtd_qemu.aug

diff --git a/src/Makefile.am b/src/Makefile.am

index 46e411e..fa741a8 100644

--- a/src/Makefile.am

+++ b/src/Makefile.am

@@ -2679,6 +2679,7 @@ endif WITH_SANLOCK

 if WITH_QEMU

 	$(MKDIR_P) "$(DESTDIR)$(localstatedir)/lib/libvirt/qemu"

 	$(MKDIR_P) "$(DESTDIR)$(localstatedir)/lib/libvirt/qemu/channel/target"

+	$(MKDIR_P) "$(DESTDIR)$(localstatedir)/lib/libvirt/qemu/nvram"

 	$(MKDIR_P) "$(DESTDIR)$(localstatedir)/run/libvirt/qemu"

 	$(MKDIR_P) "$(DESTDIR)$(localstatedir)/cache/libvirt/qemu"

 	$(MKDIR_P) "$(DESTDIR)$(localstatedir)/log/libvirt/qemu"

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c

index 6ee5c17..84f5f1d 100644

--- a/src/conf/domain_conf.c

+++ b/src/conf/domain_conf.c

@@ -2023,6 +2023,7 @@ virDomainLoaderDefFree(virDomainLoaderDefPtr loader)

     VIR_FREE(loader->path);

     VIR_FREE(loader->nvram);

+    VIR_FREE(loader->templt);

     VIR_FREE(loader);

 }

@@ -12768,6 +12769,7 @@ virDomainDefParseXML(xmlDocPtr xml,

                 goto error;

             def->os.loader->nvram = virXPathString("string(./os/nvram[1])", ctxt);

+            def->os.loader->templt = virXPathString("string(./os/nvram[1]/@template)", ctxt);

         }

     }

@@ -17866,7 +17868,14 @@ virDomainLoaderDefFormat(virBufferPtr buf,

     virBufferAsprintf(buf, " type='%s'>", type);

     virBufferEscapeString(buf, "%s</loader>\n", loader->path);

-    virBufferEscapeString(buf, "<nvram>%s</nvram>\n", loader->nvram);

+    if (loader->nvram || loader->templt) {

+        virBufferAddLit(buf, "

+        virBufferEscapeString(buf, " template='%s'", loader->templt);

+        if (loader->nvram)

+            virBufferEscapeString(buf, ">%s</nvram>\n", loader->nvram);

+        else

+            virBufferAddLit(buf, "/>\n");

+    }

 }

 static bool

diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h

index c97a10c..3316fb6 100644

--- a/src/conf/domain_conf.h

+++ b/src/conf/domain_conf.h

@@ -1644,6 +1644,7 @@ struct _virDomainLoaderDef {

     int readonly;   /* enum virTristateBool */

     virDomainLoader type;

     char *nvram;    /* path to non-volatile RAM */

+    char *templt;   /* user override of path to master nvram */

 };

 void virDomainLoaderDefFree(virDomainLoaderDefPtr loader);

diff --git a/src/qemu/libvirtd_qemu.aug b/src/qemu/libvirtd_qemu.aug

index e7db7fe..62951da 100644

--- a/src/qemu/libvirtd_qemu.aug

+++ b/src/qemu/libvirtd_qemu.aug

@@ -88,6 +88,8 @@ module Libvirtd_qemu =

    let log_entry = bool_entry "log_timestamp"

+   let nvram_entry = str_array_entry "nvram"

+

    (* Each entry in the config is one of the following ... *)

    let entry = vnc_entry

              | spice_entry

@@ -100,6 +102,7 @@ module Libvirtd_qemu =

              | rpc_entry

              | network_entry

              | log_entry

+             | nvram_entry

    let comment = [ label "#comment" . del /#[ \t]*/ "# " .  store /([^ \t\n][^\n]*)?/ . del /\n/ "\n" ]

    let empty = [ label "#empty" . eol ]

diff --git a/src/qemu/qemu.conf b/src/qemu/qemu.conf

index 7bbbe09..79bba36 100644

--- a/src/qemu/qemu.conf

+++ b/src/qemu/qemu.conf

@@ -487,3 +487,17 @@

 # Defaults to 1.

 #

 #log_timestamp = 0

+

+

+# Location of master nvram file

+#

+# When a domain is configured to use UEFI instead of standard

+# BIOS it may use a separate storage for UEFI variables. If

+# that's the case libvirt creates the variable store per domain

+# using this master file as image. Each UEFI firmware can,

+# however, have different variables store. Therefore the nvram is

+# a list of strings when a single item is in form of:

+#   ${PATH_TO_UEFI_FW}:${PATH_TO_UEFI_VARS}.

+# Later, when libvirt creates per domain variable store, this

+# list is searched for the master image.

+#nvram = [ "/usr/share/OVMF/OVMF_CODE.fd:/usr/share/OVMF/OVMF_VARS.fd" ]

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

index e2ec54f..ac10b64 100644

--- a/src/qemu/qemu_conf.c

+++ b/src/qemu/qemu_conf.c

@@ -107,6 +107,9 @@ void qemuDomainCmdlineDefFree(qemuDomainCmdlineDefPtr def)

     VIR_FREE(def);

 }

+#define VIR_QEMU_LOADER_FILE_PATH "/usr/share/OVMF/OVMF_CODE.fd"

+#define VIR_QEMU_NVRAM_FILE_PATH "/usr/share/OVMF/OVMF_VARS.fd"

+

 virQEMUDriverConfigPtr virQEMUDriverConfigNew(bool privileged)

 {

     virQEMUDriverConfigPtr cfg;

@@ -255,6 +258,15 @@ virQEMUDriverConfigPtr virQEMUDriverConfigNew(bool privileged)

     cfg->logTimestamp = true;

+    if (VIR_ALLOC_N(cfg->loader, 1) < 0 ||

+        VIR_ALLOC_N(cfg->nvram, 1) < 0)

+        goto error;

+    cfg->nloader = 1;

+

+    if (VIR_STRDUP(cfg->loader[0], VIR_QEMU_LOADER_FILE_PATH) < 0 ||

+        VIR_STRDUP(cfg->nvram[0], VIR_QEMU_NVRAM_FILE_PATH) < 0)

+        goto error;

+

     return cfg;

  error:

@@ -305,6 +317,14 @@ static void virQEMUDriverConfigDispose(void *obj)

     virStringFreeList(cfg->securityDriverNames);

     VIR_FREE(cfg->lockManagerName);

+

+    while (cfg->nloader) {

+        VIR_FREE(cfg->loader[cfg->nloader - 1]);

+        VIR_FREE(cfg->nvram[cfg->nloader - 1]);

+        cfg->nloader--;

+    }

+    VIR_FREE(cfg->loader);

+    VIR_FREE(cfg->nvram);

 }

@@ -328,6 +348,43 @@ virQEMUDriverConfigHugeTLBFSInit(virHugeTLBFSPtr hugetlbfs,

 }

+static int

+virQEMUDriverConfigNVRAMParse(const char *str,

+                              char **loader,

+                              char **nvram)

+{

+    int ret = -1;

+    char **token;

+

+    if (!(token = virStringSplit(str, ":", 0)))

+        goto cleanup;

+

+    if (token[0]) {

+        virSkipSpaces((const char **) &token[0]);

+        if (token[1])

+            virSkipSpaces((const char **) &token[1]);

+    }

+

+    /* Exactly two tokens are expected */

+    if (!token[0] || !token[1] || token[2] ||

+        STREQ(token[0], "") || STREQ(token[1], "")) {

+        virReportError(VIR_ERR_CONF_SYNTAX,

+                       _("Invalid nvram format: '%s'"),

+                       str);

+        goto cleanup;

+    }

+

+    if (VIR_STRDUP(*loader, token[0]) < 0 ||

+        VIR_STRDUP(*nvram, token[1]) < 0)

+        goto cleanup;

+

+    ret = 0;

+ cleanup:

+    virStringFreeList(token);

+    return ret;

+}

+

+

 int virQEMUDriverConfigLoadFile(virQEMUDriverConfigPtr cfg,

                                 const char *filename)

 {

@@ -654,6 +711,43 @@ int virQEMUDriverConfigLoadFile(virQEMUDriverConfigPtr cfg,

     GET_VALUE_BOOL("log_timestamp", cfg->logTimestamp);

+    if ((p = virConfGetValue(conf, "nvram"))) {

+        size_t len;

+        virConfValuePtr pp;

+

+        CHECK_TYPE("nvram", VIR_CONF_LIST);

+

+        while (cfg->nloader) {

+            VIR_FREE(cfg->loader[cfg->nloader - 1]);

+            VIR_FREE(cfg->nvram[cfg->nloader - 1]);

+            cfg->nloader--;

+        }

+        VIR_FREE(cfg->loader);

+        VIR_FREE(cfg->nvram);

+

+        /* Calc length and check items */

+        for (len = 0, pp = p->list; pp; len++, pp = pp->next) {

+            if (pp->type != VIR_CONF_STRING) {

+                virReportError(VIR_ERR_CONF_SYNTAX, "%s",

+                               _("nvram must be a list of strings"));

+                goto cleanup;

+            }

+        }

+

+        if (len &&

+            (VIR_ALLOC_N(cfg->loader, len) < 0 ||

+             VIR_ALLOC_N(cfg->nvram, len) < 0))

+            goto cleanup;

+        cfg->nloader = len;

+

+        for (i = 0, pp = p->list; pp; i++, pp = pp->next) {

+            if (virQEMUDriverConfigNVRAMParse(pp->str,

+                                              &cfg->loader[i],

+                                              &cfg->nvram[i]) < 0)

+                goto cleanup;

+        }

+    }

+

     ret = 0;

  cleanup:

diff --git a/src/qemu/qemu_conf.h b/src/qemu/qemu_conf.h

index ae7ac56..1f521e5 100644

--- a/src/qemu/qemu_conf.h

+++ b/src/qemu/qemu_conf.h

@@ -172,6 +172,11 @@ struct _virQEMUDriverConfig {

     int migrationPortMax;

     bool logTimestamp;

+

+    /* Pairs of loader:nvram paths. The list is @nloader items long */

+    char **loader;

+    char **nvram;

+    size_t nloader;

 };

 /* Main driver state */

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

index f68dfbe..5b120d4 100644

--- a/src/qemu/qemu_process.c

+++ b/src/qemu/qemu_process.c

@@ -67,6 +67,7 @@

 #include "virstring.h"

 #include "virhostdev.h"

 #include "storage/storage_driver.h"

+#include "configmake.h"

 #define VIR_FROM_THIS VIR_FROM_QEMU

@@ -3734,6 +3735,135 @@ qemuProcessVerifyGuestCPU(virQEMUDriverPtr driver,

 }

+static int

+qemuPrepareNVRAM(virQEMUDriverConfigPtr cfg,

+                 virDomainDefPtr def,

+                 bool migrated)

+{

+    int ret = -1;

+    int srcFD = -1;

+    int dstFD = -1;

+    virDomainLoaderDefPtr loader = def->os.loader;

+    bool generated = false;

+    bool created = false;

+

+    /* Unless domain has RO loader of pflash type, we have

+     * nothing to do here.  If the loader is RW then it's not

+     * using split code and vars feature, so no nvram file needs

+     * to be created. */

+    if (!loader || loader->type != VIR_DOMAIN_LOADER_TYPE_PFLASH ||

+        loader->readonly != VIR_TRISTATE_SWITCH_ON)

+        return 0;

+

+    /* If the nvram path is configured already, there's nothing

+     * we need to do. Unless we are starting the destination side

+     * of migration in which case nvram is configured in the

+     * domain XML but the file doesn't exist yet. Moreover, after

+     * the migration is completed, qemu will invoke a

+     * synchronization write into the nvram file so we don't have

+     * to take care about transmitting the real data on the other

+     * side. */

+    if (loader->nvram && !migrated)

+        return 0;

+

+    /* Autogenerate nvram path if needed.*/

+    if (!loader->nvram) {

+        if (virAsprintf(&loader->nvram,

+                        "%s/lib/libvirt/qemu/nvram/%s_VARS.fd",

+                        LOCALSTATEDIR, def->name) < 0)

+            goto cleanup;

+

+        generated = true;

+    }

+

+    if (!virFileExists(loader->nvram)) {

+        const char *master_nvram_path = loader->templt;

+        ssize_t r;

+

+        if (!loader->templt) {

+            size_t i;

+            for (i = 0; i < cfg->nloader; i++) {

+                if (STREQ(cfg->loader[i], loader->path)) {

+                    master_nvram_path = cfg->nvram[i];

+                    break;

+                }

+            }

+        }

+

+        if (!master_nvram_path) {

+            virReportError(VIR_ERR_OPERATION_FAILED,

+                           _("unable to find any master var store for "

+                             "loader: %s"), loader->path);

+            goto cleanup;

+        }

+

+        if ((srcFD = virFileOpenAs(master_nvram_path, O_RDONLY,

+                                   0, -1, -1, 0)) < 0) {

+            virReportSystemError(-srcFD,

+                                 _("Failed to open file '%s'"),

+                                 master_nvram_path);

+            goto cleanup;

+        }

+        if ((dstFD = virFileOpenAs(loader->nvram,

+                                   O_WRONLY | O_CREAT | O_EXCL,

+                                   S_IRUSR | S_IWUSR,

+                                   cfg->user, cfg->group, 0)) < 0) {

+            virReportSystemError(-dstFD,

+                                 _("Failed to create file '%s'"),

+                                 loader->nvram);

+            goto cleanup;

+        }

+        created = true;

+

+        do {

+            char buf[1024];

+

+            if ((r = saferead(srcFD, buf, sizeof(buf))) < 0) {

+                virReportSystemError(errno,

+                                     _("Unable to read from file '%s'"),

+                                     master_nvram_path);

+                goto cleanup;

+            }

+

+            if (safewrite(dstFD, buf, r) < 0) {

+                virReportSystemError(errno,

+                                     _("Unable to write to file '%s'"),

+                                     loader->nvram);

+                goto cleanup;

+            }

+        } while (r);

+

+        if (VIR_CLOSE(srcFD) < 0) {

+            virReportSystemError(errno,

+                                 _("Unable to close file '%s'"),

+                                 master_nvram_path);

+            goto cleanup;

+        }

+        if (VIR_CLOSE(dstFD) < 0) {

+            virReportSystemError(errno,

+                                 _("Unable to close file '%s'"),

+                                 loader->nvram);

+            goto cleanup;

+        }

+    }

+

+    ret = 0;

+ cleanup:

+    /* We successfully generated the nvram path, but failed to

+     * copy the file content. Roll back. */

+    if (ret < 0) {

+        if (created)

+            unlink(loader->nvram);

+        if (generated)

+            VIR_FREE(loader->nvram);

+    }

+

+    VIR_FORCE_CLOSE(srcFD);

+    VIR_FORCE_CLOSE(dstFD);

+    return ret;

+}

+

+

 int qemuProcessStart(virConnectPtr conn,

                      virQEMUDriverPtr driver,

                      virDomainObjPtr vm,

@@ -3802,6 +3932,13 @@ int qemuProcessStart(virConnectPtr conn,

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

         goto cleanup;

+    /* Some things, paths, ... are generated here and we want them to persist.

+     * Fill them in prior to setting the domain def as transient. */

+    VIR_DEBUG("Generating paths");

+

+    if (qemuPrepareNVRAM(cfg, vm->def, migrateFrom) < 0)

+        goto cleanup;

+

     /* Do this upfront, so any part of the startup process can add

      * runtime state to vm->def that won't be persisted. This let's us

      * report implicit runtime defaults in the XML, like vnc listen/socket

diff --git a/src/qemu/test_libvirtd_qemu.aug.in b/src/qemu/test_libvirtd_qemu.aug.in

index 7796acc..d2bc2c0 100644

--- a/src/qemu/test_libvirtd_qemu.aug.in

+++ b/src/qemu/test_libvirtd_qemu.aug.in

@@ -74,3 +74,6 @@ module Test_libvirtd_qemu =

 { "migration_port_min" = "49152" }

 { "migration_port_max" = "49215" }

 { "log_timestamp" = "0" }

+{ "nvram"

+    { "1" = "/usr/share/OVMF/OVMF_CODE.fd:/usr/share/OVMF/OVMF_VARS.fd" }

+}

diff --git a/tests/domainschemadata/domain-bios-nvram-empty.xml b/tests/domainschemadata/domain-bios-nvram-empty.xml

new file mode 100644

index 0000000..e7643f3

--- /dev/null

+++ b/tests/domainschemadata/domain-bios-nvram-empty.xml

@@ -0,0 +1,40 @@

+<domain type='qemu'>

+  <name>test-bios</name>

+  <uuid>362d1fc1-df7d-193e-5c18-49a71bd1da66</uuid>

+  <memory unit='KiB'>1048576</memory>

+  <currentMemory unit='KiB'>1048576</currentMemory>

+  <vcpu placement='static'>1</vcpu>

+  <os>

+    <type arch='x86_64' machine='pc'>hvm</type>

+    <loader readonly='yes' type='pflash'>/usr/share/OVMF/OVMF_CODE.fd</loader>

+    <nvram template='/usr/share/OVMF/OVMF_VARS.fd'/>

+    <boot dev='hd'/>

+    <bootmenu enable='yes'/>

+  </os>

+  <features>

+    <acpi/>

+  </features>

+  <clock offset='utc'/>

+  <on_poweroff>destroy</on_poweroff>

+  <on_reboot>restart</on_reboot>

+  <on_crash>restart</on_crash>

+  <devices>

+    <emulator>/usr/bin/qemu</emulator>

+    <disk type='block' device='disk'>

+      <source dev='/dev/HostVG/QEMUGuest1'/>

+      <target dev='hda' bus='ide'/>

+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>

+    </disk>

+    <controller type='usb' index='0'/>

+    <controller type='ide' index='0'/>

+    <controller type='pci' index='0' model='pci-root'/>

+    <serial type='pty'>

+      <target port='0'/>

+    </serial>

+    <console type='pty'>

+      <target type='serial' port='0'/>

+    </console>

+    <input type='tablet' bus='usb'/>

+    <memballoon model='virtio'/>

+  </devices>

+</domain>