Re: [Qemu-devel] [PATCH v6 2/2] crypto: add virtio-crypto driver

[Gonglei (Arei)]

Hi,

>
> Subject: Re: [PATCH v6 2/2] crypto: add virtio-crypto driver
> 
> 
> 
> On 12/12/2016 11:05 PM, Michael S. Tsirkin wrote:
> > On Mon, Dec 12, 2016 at 06:54:07PM +0800, Herbert Xu wrote:
> >> On Mon, Dec 12, 2016 at 06:25:12AM +0000, Gonglei (Arei) wrote:
> >>> Hi, Michael & Herbert
> >>>
> >>> Because the virtio-crypto device emulation had been in QEMU 2.8,
> >>> would you please merge the virtio-crypto driver for 4.10 if no other
> >>> comments? If so, Miachel pls ack and/or review the patch, then
> >>> Herbert will take it (I asked him last week). Thank you!
> >>>
> >>> Ps: Note on 4.10 merge window timing from Linus
> >>>  https://lkml.org/lkml/2016/12/7/506
> >>>
> >>> Dec 23rd is the deadline for 4.10 merge window.
> >>
> >> Sorry but it's too late for 4.10.  It needed to have been in my
> >> tree before the merge window opened to make it for this cycle.
> >>
> >> Cheers,
> >
> >
> > Objections to me merging this? I'm preparing my tree right now.
> 
> Got this when testing the most recent version on s390x
> 
> [   20.391074] test 0 (128 bit key, 16 byte blocks): [   20.391078] BUG: using
> smp_processor_id() in preemptible [00000000] code: insmod/97
> [   20.391082] caller is virtio_crypto_ablkcipher_setkey+0x44/0x198
> [   20.391085] CPU: 0 PID: 97 Comm: insmod Not tainted
> 4.9.0-02683-gb62a1ab #46
> [   20.391088] Hardware name: IBM              2964 NC9
> 704              (KVM)
> [   20.391405] Stack:
> [   20.391407]        000000000c0eb6d0 000000000c0eb760
> 0000000000000003 0000000000000000
> [   20.391414]        000000000c0eb800 000000000c0eb778
> 000000000c0eb778 0000000000000020
> [   20.391420]        0000000000000000 000000000000000a
> 0000000000000020 000003ff0000000a
> [   20.391426]        000003ff0000000c 000000000c0eb7c8
> 0000000000000000 0000000000000000
> [   20.391432]        0700000000c173c8 00000000001126ba
> 000000000c0eb760 000000000c0eb7b8
> [   20.391439] Call Trace:
> [   20.391442] ([<000000000011259e>] show_trace+0x8e/0xe0)
> [   20.391446]  [<0000000000112670>] show_stack+0x80/0xd8
> [   20.391449]  [<0000000000753ab6>] dump_stack+0x96/0xd8
> [   20.391453]  [<00000000007872e6>]
> check_preemption_disabled+0xfe/0x128
> [   20.391456]  [<0000000000839cc4>]
> virtio_crypto_ablkcipher_setkey+0x44/0x198
> [   20.391459]  [<0000000000705a40>]
> skcipher_setkey_ablkcipher+0x50/0x70
> [   20.391476]  [<000003ff80002a48>] test_skcipher_speed+0x328/0xb98
> [tcrypt]
> [   20.391492]  [<000003ff800063dc>] do_test+0x1c24/0x28e0 [tcrypt]
> [   20.391509]  [<000003ff8001006a>] tcrypt_mod_init+0x6a/0x1000
> [tcrypt]
> [   20.391512]  [<00000000001002cc>] do_one_initcall+0xb4/0x148
> [   20.391515]  [<0000000000298632>] do_init_module+0x7a/0x228
> [   20.391519]  [<00000000001fd380>] load_module+0x2428/0x2de0
> [   20.391522]  [<00000000001fde8a>] SyS_init_module+0x152/0x160
> [   20.391526]  [<00000000009f1306>] system_call+0xd6/0x270
> [   20.391528] no locks held by insmod/97.
> 
> Gonglei, any idea? Did not look into it myself yet.
> 
Thanks for report. You must open CONFIG_DEBUG_PREEMPT,
but I didn't do that before. I open some kernel hacking debug switches to test 
it as well today,
and the following patch can fix it.

diff --git a/drivers/crypto/virtio/virtio_crypto_common.h 
b/drivers/crypto/virtio/virtio_crypto_common.h
index 975404b..518dc7ad 100644
--- a/drivers/crypto/virtio/virtio_crypto_common.h
+++ b/drivers/crypto/virtio/virtio_crypto_common.h
@@ -113,7 +113,13 @@ struct virtio_crypto_request {

 static inline int virtio_crypto_get_current_node(void)
 {
-   return topology_physical_package_id(smp_processor_id());
+   int cpu, node;
+
+   cpu = get_cpu();
+   node = topology_physical_package_id(cpu);
+   put_cpu();
+
+   return node;
 }

Meanwhile I find aother problem, will fix it in the following V7.

Regards,
-Gonglei