then in the windows vm just type \10.0.2.4 into file explorer. Does that not work?
man qemu says:
<span style="color:#323232;"> smb=dir[,smbserver=addr]
</span><span style="color:#323232;"> When using the user mode network stack, activate a
</span><span style="color:#323232;"> built-in SMB server so that Windows OSes can access to
</span><span style="color:#323232;"> the host files in dir transparently. The IP address of
</span><span style="color:#323232;"> the SMB server can be set to addr. By default the 4th IP
</span><span style="color:#323232;"> in the guest network is used, i.e. x.x.x.4.
</span><span style="color:#323232;">
</span><span style="color:#323232;"> In the guest Windows OS, the line:
</span><span style="color:#323232;">
</span><span style="color:#323232;"> 10.0.2.4 smbserver
</span><span style="color:#323232;">
</span><span style="color:#323232;"> must be added in the file C:WINDOWSLMHOSTS (for windows
</span><span style="color:#323232;"> 9x/Me) or C:WINNTSYSTEM32DRIVERSETCLMHOSTS (Windows
</span><span style="color:#323232;"> NT/2000).
</span><span style="color:#323232;">
</span><span style="color:#323232;"> Then dir can be accessed in \smbserverqemu.
</span><span style="color:#323232;">
</span><span style="color:#323232;"> Note that a SAMBA server must be installed on the host
</span><span style="color:#323232;"> OS.
</span><span style="color:#323232;">
</span>
Another way is to setup Spice and use a webdav daemon in Windows to transfer files over Spice folder sharing.
You could also just RDP to the machine which is probably the easiest.
The simplest would just be to scp files to and from Windows. Like in powershell do scp -R yourusername@10.0.2.2:~/path/stuff output_dir to get files from Linux.