qemu: Implement extended loader and nvram

QEMU now supports UEFI with the following command line:

  -drive file=/usr/share/OVMF/OVMF_CODE.fd,if=pflash,format=raw,unit=0,readonly=on \
  -drive file=/usr/share/OVMF/OVMF_VARS.fd,if=pflash,format=raw,unit=1 \

where the first line reflects <loader> and the second one <nvram>.
Moreover, these two lines obsolete the -bios argument.

Note that UEFI is unusable without ACPI. This is handled properly now.
Among with this extension, the variable file is expected to be
writable and hence we need security drivers to label it.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>

src/qemu/qemu_command.c

@@ -7371,6 +7371,94 @@ qemuBuildChrDeviceCommandLine(virCommandPtr cmd,
     return 0;
 }
 
+static int
+qemuBuildDomainLoaderCommandLine(virCommandPtr cmd,
+                                 virDomainDefPtr def,
+                                 virQEMUCapsPtr qemuCaps)
+{
+    int ret = -1;
+    virDomainLoaderDefPtr loader = def->os.loader;
+    virBuffer buf = VIR_BUFFER_INITIALIZER;
+    int unit = 0;
+
+    if (!loader)
+        return 0;
+
+    switch ((virDomainLoader) loader->type) {
+    case VIR_DOMAIN_LOADER_TYPE_ROM:
+        virCommandAddArg(cmd, "-bios");
+        virCommandAddArg(cmd, loader->path);
+        break;
+
+    case VIR_DOMAIN_LOADER_TYPE_PFLASH:
+        /* UEFI is supported only for x86_64 currently */
+        if (def->os.arch != VIR_ARCH_X86_64) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                           _("pflash is not supported for %s guest architecture"),
+                           virArchToString(def->os.arch));
+            goto cleanup;
+        }
+
+        if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_DRIVE)) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("this QEMU binary doesn't support -drive"));
+            goto cleanup;
+        }
+        if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_DRIVE_FORMAT)) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("this QEMU binary doesn't support passing "
+                             "drive format"));
+            goto cleanup;
+        }
+        if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_NO_ACPI) &&
+            def->features[VIR_DOMAIN_FEATURE_ACPI] != VIR_TRISTATE_SWITCH_ON) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("ACPI must be enabled in order to use UEFI"));
+            goto cleanup;
+        }
+
+        virBufferAsprintf(&buf,
+                          "file=%s,if=pflash,format=raw,unit=%d",
+                          loader->path, unit);
+        unit++;
+
+        if (loader->readonly) {
+            if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_DRIVE_READONLY)) {
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                               _("this qemu doesn't support passing "
+                                 "readonly attribute"));
+                goto cleanup;
+            }
+
+            virBufferAsprintf(&buf, ",readonly=%s",
+                              virTristateSwitchTypeToString(loader->readonly));
+        }
+
+        virCommandAddArg(cmd, "-drive");
+        virCommandAddArgBuffer(cmd, &buf);
+
+        if (loader->nvram) {
+            virBufferFreeAndReset(&buf);
+            virBufferAsprintf(&buf,
+                              "file=%s,if=pflash,format=raw,unit=%d",
+                              loader->nvram, unit);
+
+            virCommandAddArg(cmd, "-drive");
+            virCommandAddArgBuffer(cmd, &buf);
+        }
+        break;
+
+    case VIR_DOMAIN_LOADER_TYPE_LAST:
+        /* nada */
+        break;
+    }
+
+    ret = 0;
+ cleanup:
+    virBufferFreeAndReset(&buf);
+    return ret;
+}
+
 qemuBuildCommandLineCallbacks buildCommandLineCallbacks = {
     .qemuGetSCSIDeviceSgName = virSCSIDeviceGetSgName,
 };
@@ -7526,10 +7614,8 @@ qemuBuildCommandLine(virConnectPtr conn,
             virCommandAddArg(cmd, "-enable-nesting");
     }
 
-    if (def->os.loader) {
-        virCommandAddArg(cmd, "-bios");
-        virCommandAddArg(cmd, def->os.loader->path);
-    }
+    if (qemuBuildDomainLoaderCommandLine(cmd, def, qemuCaps) < 0)
+        goto error;
 
     /* Set '-m MB' based on maxmem, because the lower 'memory' limit
      * is set post-startup using the balloon driver. If balloon driver

src/security/security_dac.c

@@ -960,6 +960,10 @@ virSecurityDACRestoreSecurityAllLabel(virSecurityManagerPtr mgr,
             rc = -1;
     }
 
+    if (def->os.loader && def->os.loader->nvram &&
+        virSecurityDACRestoreSecurityFileLabel(def->os.loader->nvram) < 0)
+        rc = -1;
+
     if (def->os.kernel &&
         virSecurityDACRestoreSecurityFileLabel(def->os.kernel) < 0)
         rc = -1;
@@ -1036,6 +1040,10 @@ virSecurityDACSetSecurityAllLabel(virSecurityManagerPtr mgr,
     if (virSecurityDACGetImageIds(secdef, priv, &user, &group))
         return -1;
 
+    if (def->os.loader && def->os.loader->nvram &&
+        virSecurityDACSetOwnership(def->os.loader->nvram, user, group) < 0)
+        return -1;
+
     if (def->os.kernel &&
         virSecurityDACSetOwnership(def->os.kernel, user, group) < 0)
         return -1;

src/security/security_selinux.c

@@ -1913,6 +1913,10 @@ virSecuritySELinuxRestoreSecurityAllLabel(virSecurityManagerPtr mgr,
                                      mgr) < 0)
         rc = -1;
 
+    if (def->os.loader && def->os.loader->nvram &&
+        virSecuritySELinuxRestoreSecurityFileLabel(mgr, def->os.loader->nvram) < 0)
+        rc = -1;
+
     if (def->os.kernel &&
         virSecuritySELinuxRestoreSecurityFileLabel(mgr, def->os.kernel) < 0)
         rc = -1;
@@ -2296,6 +2300,10 @@ virSecuritySELinuxSetSecurityAllLabel(virSecurityManagerPtr mgr,
                                      mgr) < 0)
         return -1;
 
+    if (def->os.loader && def->os.loader->nvram &&
+        virSecuritySELinuxSetFilecon(def->os.loader->nvram, data->content_context) < 0)
+        return -1;
+
     if (def->os.kernel &&
         virSecuritySELinuxSetFilecon(def->os.kernel, data->content_context) < 0)
         return -1;

tests/qemuxml2argvdata/qemuxml2argv-bios-nvram.args

@@ -0,0 +1,10 @@
+LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test QEMU_AUDIO_DRV=none \
+/usr/bin/qemu -S -M pc \
+-drive file=/usr/share/OVMF/OVMF_CODE.fd,if=pflash,format=raw,unit=0,readonly=on \
+-drive file=/usr/share/OVMF/OVMF_VARS.fd,if=pflash,format=raw,unit=1 \
+-m 1024 -smp 1 -nographic -nodefaults \
+-monitor unix:/tmp/test-monitor,server,nowait -boot c -usb \
+-drive file=/dev/HostVG/QEMUGuest1,if=none,id=drive-ide0-0-0,format=raw \
+-device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0 \
+-serial pty -device usb-tablet,id=input0 \
+-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3

tests/qemuxml2argvtest.c

@@ -642,6 +642,8 @@ mymain(void)
     DO_TEST_FAILURE("reboot-timeout-enabled", NONE);
 
     DO_TEST("bios", QEMU_CAPS_DEVICE, QEMU_CAPS_SGA);
+    DO_TEST("bios-nvram", QEMU_CAPS_DEVICE, QEMU_CAPS_DRIVE,
+            QEMU_CAPS_DRIVE_FORMAT, QEMU_CAPS_DRIVE_READONLY);
     DO_TEST("clock-utc", QEMU_CAPS_NODEFCONFIG, QEMU_CAPS_DEVICE);
     DO_TEST("clock-localtime", NONE);
     DO_TEST("clock-localtime-basis-localtime", QEMU_CAPS_RTC);