I downloaded buildroot-2019.05 source code from the website and executed the following steps:
$ make qemu_x86_64_defconfig
$ make -j8
$ qemu-system-x86_64 -M pc -kernel output/images/bzImage -drive file=output/images/rootfs.ext2,if=virtio,format=raw -append "root=/dev/vda console=ttyS0" -net nic,model=virtio -net user -nographic
I get the kernel logs on the terminal,
Starting network: udhcpc: started, v1.30.1
random: mktemp: uninitialized urandom read (6 bytes read)
udhcpc: sending discover
udhcpc: sending select for 10.0.2.15
udhcpc: lease of 10.0.2.15 obtained, lease time 86400
deleting routers
random: mktemp: uninitialized urandom read (6 bytes read)
adding dns 10.0.2.3
OK
But i don't get buildroot login.
When i run the following command
qemu-system-x86_64 -M pc -kernel output/images/bzImage -drive file=output/images/rootfs.ext2,if=virtio,format=raw -append "root=/dev/vda" -net nic,model=virtio -net user
I get QEMU terminal and also the login screen