Split modules into separate sub-package

Move modules to kernel-modules package, build modules.img in %post of
kernel-qubes-vm package, using qubes-prepare-vm-kernel.

Fixes QubesOS/qubes-issues#7969

kernel.spec.in

@@ -107,6 +107,7 @@ Provides:       kernel-drm-nouveau = 16
 Provides:       kernel-modules-extra = %kernelrelease
 Provides:       kernel-modeset = 1
 
+Requires:       %name-modules = %kernelrelease
 Requires(pre):  coreutils gawk
 Requires(post): dracut binutils
 Requires:       qubes-core-dom0-linux-kernel-install
@@ -151,6 +152,20 @@ Patch26: 0001-sound-Disable-SG-buffer.patch
 %description
 Qubes Dom0 kernel.
 
+%package modules
+Summary:        Kernel modules
+License:        GPL v2 only
+Provides:       multiversion(kernel)
+Provides:       %name-modules = %kernelrelease
+%if "%{?name_suffix}" != ""
+Provides:       kernel-modules = %kernelrelease
+%endif
+Provides:       kernel-modules-uname-r = %kernelrelease
+AutoReqProv:    on
+
+%description modules
+This package provides kernel modules.
+
 %prep
 SYMBOLS="xen-dom0 pvops"
 
@@ -499,48 +514,20 @@ if [ -e /usr/lib/dracut/modules.d/90qubes-vm-simple/xen-scrub-pages-supported ];
 fi
 echo "$def_kernelopts " > %buildroot/%vm_install_dir/default-kernelopts-common.txt
 
-# Modules for Qubes VM
-mkdir -p %buildroot%vm_install_dir/modules
-cp -a %buildroot/lib/modules/%kernelrelease %buildroot%vm_install_dir/modules/
-mkdir -p %buildroot%vm_install_dir/modules/firmware
-cp -a %buildroot/lib/firmware/%kernelrelease %buildroot%vm_install_dir/modules/firmware/
-
-# Include kernel headers for Qubes VM in "/lib/modules" - so kernel-devel
-# package will be unnecessary there, regardless of distribution
-rm -f %buildroot%vm_install_dir/modules/%kernelrelease/build
-cp -a %buildroot/%src_install_dir %buildroot%vm_install_dir/modules/%kernelrelease/build
-
-# include kernel+initramfs also inside modules.img, for direct kernel boot with
-# stubdomain
-cp %buildroot%vm_install_dir/vmlinuz %buildroot%vm_install_dir/modules/
-cp %buildroot%vm_install_dir/initramfs %buildroot%vm_install_dir/modules/
-
-%if 0%{?fedora} >= 32
-flags=,no_copy_xattrs,hash_seed=dcee2318-92bd-47a5-a15d-e79d1412cdce
-%else
-flags=
-%endif
-
-PATH=/usr/sbin:/sbin:$PATH mkfs.ext3 -F "-Enum_backup_sb=0,root_owner=0:0$flags" \
-    -d %buildroot%vm_install_dir/modules %buildroot%vm_install_dir/modules.img 768M
-
-%if 0%{?fedora} >= 32
-SOURCE_DATE_EPOCH=$SOURCE_DATE_EPOCH %{_builddir}/genfs %buildroot%vm_install_dir/modules.img %kernelrelease immutable=yes
-e2fsck -pDfE optimize_extents -- %buildroot%vm_install_dir/modules.img
-resize2fs -M -- %buildroot%vm_install_dir/modules.img
-e2fsck -pDfE optimize_extents -- %buildroot%vm_install_dir/modules.img
-SOURCE_DATE_EPOCH=$SOURCE_DATE_EPOCH %{_builddir}/genfs %buildroot%vm_install_dir/modules.img
-%endif
+# Create a dummy modules.img with roughly the size the real one will have.
+# That way, rpm will know that this package requires some additional
+# space in /boot.
+dd if=/dev/zero of=%buildroot/%vm_install_dir/modules.img \
+        bs=1M count=500
 
-rm -rf %buildroot%vm_install_dir/modules
 
 # remove files that will be auto generated by depmod at rpm -i time
 for i in alias alias.bin ccwmap dep dep.bin ieee1394map inputmap isapnpmap ofmap pcimap seriomap symbols symbols.bin usbmap
 do
   rm -f %buildroot/lib/modules/%kernelrelease/modules.$i
 done
 
-%post
+%post modules
 /sbin/depmod -a %{kernelrelease}
 
 %posttrans
@@ -571,6 +558,8 @@ fi
 /boot/symvers-%kernelrelease.gz
 %attr(0644, root, root) /boot/vmlinuz-%{kernelrelease}
 /lib/firmware/%{kernelrelease}
+
+%files modules
 /lib/modules/%{kernelrelease}
 
 %package devel
@@ -624,8 +613,10 @@ Provides:       kernel-xen-domU
 Provides:       kernel-qubes-domU
 
 Requires(pre):  coreutils gawk
-Requires(post): dracut
 Requires(post): qubes-core-dom0
+Requires(post): qubes-prepare-vm-kernel >= 2
+Requires(post): kernel-devel = %kernelrelease
+Requires(post): kernel-modules = %kernelrelease
 
 Conflicts:      sysfsutils < 2.0
 # root-lvm only works with newer udevs
@@ -649,8 +640,9 @@ if [ "$current_default_package" = "%{name}-qubes-vm" ]; then
 type qubes-prefs &>/dev/null && qubes-prefs --set default-kernel %upstream_version-%plainrel
 fi
 
-# make modules.img sparse (again)
-fallocate --dig-holes %vm_install_dir/modules.img
+SOURCE_DATE_EPOCH=$(stat -c %%Y %vm_install_dir/initramfs)
+export SOURCE_DATE_EPOCH
+qubes-prepare-vm-kernel --modules-only --include-devel %kernelrelease "%upstream_version-%{plainrel}"
 
 exit 0
 
@@ -670,7 +662,7 @@ exit 0
 %files qubes-vm
 %defattr(-, root, root)
 %dir %vm_install_dir
-%attr(0644, root, root) %vm_install_dir/modules.img
+%ghost %attr(0644, root, root) %vm_install_dir/modules.img
 %attr(0644, root, root) %vm_install_dir/initramfs
 %attr(0644, root, root) %vm_install_dir/vmlinuz
 %attr(0644, root, root) %vm_install_dir/default-kernelopts-common.txt