virtiofs support for kexec-tools
    
    upstream: fedora
    resolves: bz2085347
    conflict: yes, small conflict due to patch
              "kdumpctl: drop DUMP_TARGET variable" not
              backported to rhel9.
    
    commit c743881ae691c4e2bcf049cbf28abd2850b816e8
    Author: Tao Liu <ltao@redhat.com>
    Date:   Fri Sep 23 18:13:11 2022 +0800
    
        virtiofs support for kexec-tools
    
        This patch add virtiofs support for kexec-tools by introducing a new option
        for /etc/kdump.conf:
    
        virtiofs myfs
    
        Where myfs is a variable tag name specified in qemu cmdline
        "-device vhost-user-fs-pci,tag=myfs".
    
        The patch covers the following cases:
        1) Dumping VM's vmcore to a virtiofs shared directory;
        2) When the VM's rootfs is a virtiofs shared directory and dumping the
           VM's vmcore to its subdirectory, such as /var/crash;
        3) The combination of case 1 & 2: The VM's rootfs is a virtiofs shared
           directory and dumping the VM's vmcore to another virtiofs shared
           directory.
    
        Case 2 & 3 need dracut >= 057, otherwise VM cannot boot from virtiofs
        shared rootfs. But it is not the issue of kexec-tools.
    
        Reviewed-by: Philipp Rudo <prudo@redhat.com>
        Signed-off-by: Tao Liu <ltao@redhat.com>
    
    Signed-off-by: Tao Liu <ltao@redhat.com>