Description of problem:
Boot RHEL8.1 guest with 2 disks. one is system disk. another is data disk. Then disk format data disk and mount it to /mnt. Sent guest-fsfreeze-freeze to freeze guest file system. But return a error"{"error": {"class": "GenericError", "desc": "failed to open /mnt: Permission denied"}}"

If disable selinux inside guest. It works well.

Version-Release number of selected component (if applicable):
4.18.0-120.el8.x86_64
qemu-guest-agent-4.0.0-5.module+el8.1.0+3622+5812d9bf.x86_64

How reproducible:
100%

Steps to Reproduce:
1.Boot a RHEL8.1 guest with 2 disks

/usr/libexec/qemu-kvm -name avocado-vt-vm1 -machine pc -nodefaults -device VGA,bus=pci.0,addr=0x2 -device virtio-serial-pci,id=virtio-serial1,max_ports=31 -chardev socket,id=channel2,path=/tmp/helloworld2,server,nowait -device virtserialport,bus=virtio-serial1.0,chardev=channel2,name=org.qemu.guest_agent.0 -device virtio-scsi-pci,id=virtio_scsi_pci0,bus=pci.0,addr=0x5 -drive id=drive_image1,if=none,snapshot=off,aio=threads,cache=none,format=qcow2,file=/home/kvm_autotest_root/images/rhel810-64-virtio-scsi.qcow2 -device scsi-hd,id=image1,drive=drive_image1 -drive file=/home/data-disk.qcow2,id=data-disk,if=none,snapshot=off,aio=threads,cache=none,format=qcow2 -device virtio-blk-pci,drive=data-disk,id=data-disk1 -m 14336 -smp 12,maxcpus=12,cores=6,threads=1,sockets=2 -cpu Haswell-noTSX,+kvm_pv_unhalt -vnc :0 -rtc base=utc,clock=host,driftfix=slew -boot order=cdn,once=c,menu=off,strict=off -enable-kvm -monitor stdio

2. format data disk and mount it to /mnt
#mkfs /dev/vda
#mount /dev/vda /mnt

3.# nc -U /tmp/helloworld2
{"execute": "guest-fsfreeze-status"}
{"return": "thawed"}
{"execute": "guest-fsfreeze-freeze"}

Actual results:
{"error": {"class": "GenericError", "desc": "failed to open /mnt: Permission denied"}}

Expected results:
works

Additional info:
disable selinux inside guest, it works.

# ausearch -m avc -m user_avc -m selinux_err -m user_selinux_err -i -ts today
----
type=PROCTITLE msg=audit(08/08/2019 17:16:06.257:111) : proctitle=/usr/bin/qemu-ga --method=virtio-serial --path=/dev/virtio-ports/org.qemu.guest_agent.0 --blacklist=,,,,,,,-status -F/etc/qemu-g 
type=SYSCALL msg=audit(08/08/2019 17:16:06.257:111) : arch=x86_64 syscall=openat success=no exit=EACCES(Permission denied) a0=0xffffff9c a1=0x555d2daa7040 a2=O_RDONLY|O_CLOEXEC a3=0x0 items=0 ppid=1 pid=1610 auid=unset uid=root gid=root euid=root suid=root fsuid=root egid=root sgid=root fsgid=root tty=(none) ses=unset comm=qemu-ga exe=/usr/bin/qemu-ga subj=system_u:system_r:virt_qemu_ga_t:s0 key=(null) 
type=AVC msg=audit(08/08/2019 17:16:06.257:111) : avc:  denied  { read } for  pid=1610 comm=qemu-ga name=/ dev="vda" ino=128 scontext=system_u:system_r:virt_qemu_ga_t:s0 tcontext=system_u:object_r:unlabeled_t:s0 tclass=dir permissive=0 
----
type=PROCTITLE msg=audit(08/08/2019 17:16:06.257:112) : proctitle=/usr/bin/qemu-ga --method=virtio-serial --path=/dev/virtio-ports/org.qemu.guest_agent.0 --blacklist=,,,,,,,-status -F/etc/qemu-g 
type=SYSCALL msg=audit(08/08/2019 17:16:06.257:112) : arch=x86_64 syscall=openat success=no exit=EACCES(Permission denied) a0=0xffffff9c a1=0x555d2daa6d40 a2=O_RDONLY|O_CLOEXEC a3=0x0 items=0 ppid=1 pid=1610 auid=unset uid=root gid=root euid=root suid=root fsuid=root egid=root sgid=root fsgid=root tty=(none) ses=unset comm=qemu-ga exe=/usr/bin/qemu-ga subj=system_u:system_r:virt_qemu_ga_t:s0 key=(null) 
type=AVC msg=audit(08/08/2019 17:16:06.257:112) : avc:  denied  { read } for  pid=1610 comm=qemu-ga name=/ dev="vda" ino=128 scontext=system_u:system_r:virt_qemu_ga_t:s0 tcontext=system_u:object_r:unlabeled_t:s0 tclass=dir permissive=0