drop libxml2 checks since libxml is not actually used (for parallels)

For a long time, we assumed that libxml2 is necessary for parallels
block format support (block/parallels*). However, this format actually
does not use libxml [*]. Since this is the only user of libxml2 in
whole QEMU tree, we can drop all libxml2 checks and dependencies too.

It is even more: --enable-parallels configure option was the only
option which was silently ignored when it's (fake) dependency
(libxml2) isn't installed.

Drop all mentions of libxml2.

[*] Actually the basis for libxml use were introduced in commit
    ed279a06c53 ("configure: add dependency") but the implementation
    was never merged:
    https://lore.kernel.org/qemu-devel/70227bbd-a517-70e9-714f-e6e0ec431be9@openvz.org/

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20220119090423.149315-1-mjt@msgid.tls.msk.ru>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
[PMD: Updated description and adapted to use lcitool]
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220121154134.315047-5-f4bug@amsat.org>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20220204204335.1689602-9-alex.bennee@linaro.org>

5 files changed, 1 insertions, 7 deletions

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 5caa739db4..5e50111060 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -307,7 +307,6 @@ our @typeList = (
 	qr{target_(?:u)?long},
 	qr{hwaddr},
         # external libraries
-	qr{xml${Ident}},
 	qr{xen\w+_handle},
 	# Glib definitions
 	qr{gchar},
diff --git a/scripts/ci/org.centos/stream/8/x86_64/configure b/scripts/ci/org.centos/stream/8/x86_64/configure
index e05f2fddcc..9850dd4444 100755
--- a/scripts/ci/org.centos/stream/8/x86_64/configure
+++ b/scripts/ci/org.centos/stream/8/x86_64/configure
@@ -81,7 +81,6 @@
 --disable-libssh \
 --disable-libudev \
 --disable-libusb \
---disable-libxml2 \
 --disable-linux-aio \
 --disable-linux-io-uring \
 --disable-linux-user \
diff --git a/scripts/coverity-scan/coverity-scan.docker b/scripts/coverity-scan/coverity-scan.docker
index ecff6ac5b4..6f60a52d23 100644
--- a/scripts/coverity-scan/coverity-scan.docker
+++ b/scripts/coverity-scan/coverity-scan.docker
@@ -59,7 +59,6 @@ ENV PACKAGES \
     libubsan \
     libudev-devel \
     libusbx-devel \
-    libxml2-devel \
     libzstd-devel \
     llvm \
     lzo-devel \
diff --git a/scripts/coverity-scan/run-coverity-scan b/scripts/coverity-scan/run-coverity-scan
index 6d443250a9..181bdcb263 100755
--- a/scripts/coverity-scan/run-coverity-scan
+++ b/scripts/coverity-scan/run-coverity-scan
@@ -402,7 +402,7 @@ echo "Configuring..."
     --enable-libiscsi --enable-libnfs --enable-seccomp \
     --enable-tpm --enable-libssh --enable-lzo --enable-snappy --enable-bzip2 \
     --enable-numa --enable-rdma --enable-smartcard --enable-virglrenderer \
-    --enable-mpath --enable-libxml2 --enable-glusterfs \
+    --enable-mpath --enable-glusterfs \
     --enable-virtfs --enable-zstd
 
 echo "Running cov-build..."
diff --git a/scripts/meson-buildoptions.sh b/scripts/meson-buildoptions.sh
index a4af02c527..48a454cece 100644
--- a/scripts/meson-buildoptions.sh
+++ b/scripts/meson-buildoptions.sh
@@ -58,7 +58,6 @@ meson_options_help() {
   printf "%s\n" '  libssh          ssh block device support'
   printf "%s\n" '  libudev         Use libudev to enumerate host devices'
   printf "%s\n" '  libusb          libusb support for USB passthrough'
-  printf "%s\n" '  libxml2         libxml2 support for Parallels image format'
   printf "%s\n" '  linux-aio       Linux AIO support'
   printf "%s\n" '  linux-io-uring  Linux io_uring support'
   printf "%s\n" '  lzfse           lzfse support for DMG images'
@@ -188,8 +187,6 @@ _meson_option_parse() {
     --disable-libudev) printf "%s" -Dlibudev=disabled ;;
     --enable-libusb) printf "%s" -Dlibusb=enabled ;;
     --disable-libusb) printf "%s" -Dlibusb=disabled ;;
-    --enable-libxml2) printf "%s" -Dlibxml2=enabled ;;
-    --disable-libxml2) printf "%s" -Dlibxml2=disabled ;;
     --enable-linux-aio) printf "%s" -Dlinux_aio=enabled ;;
     --disable-linux-aio) printf "%s" -Dlinux_aio=disabled ;;
     --enable-linux-io-uring) printf "%s" -Dlinux_io_uring=enabled ;;