On 10/20/2016 01:45 PM, Gonglei wrote: > The front-end linux kernel driver (Experimental at present) is publicly > accessible from: > > https://github.com/gongleiarei/virtio-crypto-linux-driver.git
Hi!
I'm very interested in making sure this work for the s390x architecture
too. So to familiarize with the stuff I wanted to give it a spin on
x86_64 and then transit to s390x and look for possible issues.
Unfortunately I encountered a problem already on x86_64, more precisely
the guest hangs in virtio_crypto_alg_ablkcipher_init_session after the
kick. But before I start explaining in detail let me ask you: what are
your plans for the linux kernel driver? I used the most current version
from your github, but also tried to look for patches on mailing lists
and I have found none. IMHO the problem causing my hang is in the kernel
module. But I do not know here am I supposed to comment on it -- so I'm
commenting here. Furthermore your kernel module currently do not seem to
care about endianness which is bad for s390x.
The hangs basically boils down to the following: after the kick in
virtio_crypto_alg_ablkcipher_init_session we reach the point (in QEMU)
where we want to translate the address for the third descriptor, the one
which designates a buffer for the virtio_crypto_session_input. My
backtrace looks like this:
#0 address_space_translate (as=<optimized out>, as@entry=0x55555607d700
<address_space_memory>, addr=addr@entry=71468256835928,
xlat=xlat@entry=0x7fffef4dc1a0, plen=plen@entry=0x7fffef4dc198,
is_write=is_write@entry=true)
at /home/pasic/devel/qemu/exec.c:481
#1 0x000055555575ef19 in address_space_map (as=0x55555607d700
<address_space_memory>, addr=71468256835928, plen=<optimized out>,
is_write=<optimized out>) at /home/pasic/devel/qemu/exec.c:2927
#2 0x00005555557e5d00 in virtqueue_map_desc (vdev=0x555557d80de0,
p_num_sg=0x7fffef4dc2bc, addr=0x7fffef4dc2f0, iov=0x7fffef4de300,
max_num_sg=1022, is_write=true, pa=71468256835928, sz=16)
at /home/pasic/devel/qemu/hw/virtio/virtio.c:558
#3 0x00005555557e5f86 in virtqueue_pop (vq=0x7fffef4dc2c0, sz=93825003936576)
at /home/pasic/devel/qemu/hw/virtio/virtio.c:717
#4 0x00005555557ed80b in virtio_crypto_handle_ctrl (vdev=<optimized out>,
vq=0x7fffeec3e090) at /home/pasic/devel/qemu/hw/virtio/virtio-crypto.c:218
Now the first suspicious thing I see is that address_space_translate
returns a pointer to the memory region io_mem_unassigned. Next thing
happening is that we take the !memory_access_is_direct(mr, is_write)
branch in address_space_map and return NULL at line 2932 which however
makes virtqueue_map_desc report "qemu-system-x86_64: virtio: bogus
descriptor or out of resources" and return with false. Then pop returns
null too and spins virtio_crypto_alg_ablkcipher_init_session till the
end of time waiting for the answer.
Now if I change the code so that the virtio_crypto_session_input
instance's backing memory is allocated with kzalloc(sizeof(*input),
GFP_DMA|GFP_NOIO) of allocating the on the stack things start working
for me. I'm not too deep into this yet, so please forgive me if
I'm a bit vague.
I was testing with tcrypt mode=500 instead of cryptodev-linux but I
guess that should be irrelevant.
Looking forward to your answer.
Halil
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