On 2/2/11 8:42 AM, Julian Elischer wrote:
On 2/2/11 7:06 AM, Monthadar Al Jaberi wrote:Thanx makes more sense, but I have noticed something weired if you can shade some light on.I added printfs one when the module is first loaded (static int event_handler(module_t module, int event, void *arg)): curthread=0xc3f95870 curthread->td_vnet=0xc3170e00 curthread->td_ucred=0xc3185d00 TD_TO_VNET=0 CRED_TO_VNET=0 And same printf in wtap_ioctl which is called from a user space program (I am root): curthread=0xc3f952d0 curthread->td_vnet=0 curthread->td_ucred=0xc3185d00 TD_TO_VNET=0 CRED_TO_VNET=0 In both cases TD_TO_VNET/CRED_TO_VNET return NULL... shouldn't they return a pointer same as curthread->td_vnet? Another thing is that in wtap_ioctl curthread->td_vnet is NUL
that depends on where in your code you did the print.. have you read this file?http://p4db.freebsd.org/fileViewer.cgi?FSPC=//depot/projects/vimage/porting_to_vimage.txt&REV=18use the 'download' button to get a more readable version.it goes into some of the details of this. especially the initialization or vimage modules.
oops sent too early.I think you said you had seen it but read it again now that I have explained some of it to you and maybe
it will give new insights.The VNET_SYSINIT() code will get called once for every vnet, and the current vnet is set up for you before it calls you.
it is also called once when you start a NEW vnet..this is the place where Marko jumps in because my head is currently full of other stuff from work and I
have paged the vimage stuff out to swap.. :-)
I still get a panic... br,On Tue, Feb 1, 2011 at 8:37 PM, Julian Elischer<jul...@freebsd.org> wrote:ok here's how it works..any place you access a V_xxx variable you need to have the current vnet set. so somewhere in your code path to get to that point you have to have doneCURVNET_SET() and after you have finised on the way out you should do CURVNET_RESTORE(). you can get the vnet from several places:1/ as shown below, you can get it from any thread's cred if teh runningthread is part of a process in the jail in question.2/ if you have an ifp pointer, you can use ifp->vnet . I think that'sright, it's been a while... 3/ I believe though I may be wrong (I may be thinking of multi FIBS)that it maybe in the socket structure too but don't trust me on that one..check it. if, like in a timer thread you have access to NONE of those, you have several choices..1/ the caller of the timer may have given you indirect access to it in thearg. 2/ maybe you juaast have to interate through all the vimages.. to do whatever it is that you do (that happens in some protocols) On 2/1/11 11:04 AM, Monthadar Al Jaberi wrote:On Tue, Feb 1, 2011 at 6:25 PM, Julian Elischer<jul...@freebsd.org> wrote:On 2/1/11 8:40 AM, Monthadar Al Jaberi wrote:Hi, I hope I am on the write place, second try... I have written a module that loads fake wifi devices (wtap?) anddistributes packets between them. For now I use route command to routepackets between them from upper layers (TCP,...).I want to take it to next step and create jails with VNET. I started reading Julian Elischer's "Vimage: what is it?" and he says that if Iam writing hardware drivers I dont need to make any changes when Ienable VIMAGE option on the kernel, because each one will have theirown stack.I can give a more detailed explanation on how my module works. But for now I get a panic when calling if_alloc() when using option VIMAGE.Thank you,while this was true to some extent it i snot 100% true now. during allocation we now try to have separate interface indexes per vimagewhich means that the setup routines do need to know the current vnet.so I cant call if_alloc directly?My wtap is based on ath driver code (if_ath.c) which should look likeit looks like wtap_ioctl or wtap_attach should have the following: (copied from the tun driver)this should not be needed from real hardware based drivers as far as Ican tell. CURVNET_SET(CRED_TO_VNET(cred)); /* find any existing device, or allocate new unit number */ i = clone_create(&tunclones,&tun_cdevsw,&u, dev, 0); [blah] if_clone_create(name, namelen, NULL); CURVNET_RESTORE();a real device right? if_ath.c is not using VNET, as far as I can tell.... Currently my module creates a couple of wtaps, which I then create acorresponding wlan. These wtaps are interconnected together, so no outworld yet... so I dont have struct cdev *dev.... Basic idea is my module have a main queue (simulating air) and each wtap have a rx_task which sends packets up to higher layers, plus callout timer for generation beacons... I will try to use CURVET_SET(...) tomoMy setup: FreeBSD Current 201010 guest on VirtualBox on Ubuntu 10.04. Kernel page fault with the following non-sleepable locks held: exclusive rw ifnet_rw (ifnet_rw) r = 0 (0xc0fc8284) locked @ /usr/src/sys/net/if.c:414 KDB: stack backtrace: db_trace_self_wrapper(c0cf3cdb,1,0,0,0,...) at db_trace_self_wrapper+0x26 kdb_backtrace(19e,1,ffffffff,c0f9b194,c2fc9a1c,...) at kdb_backtrace+0x2a_witness_debugger(c0cf6408,c2fc9a30,4,1,0,...) at _witness_debugger+0x25witness_warn(5,0,c0d2c479,3,c4070d48,...) at witness_warn+0x1fe trap(c2fc9abc) at trap+0x195 calltrap() at calltrap+0x6--- trap 0xc, eip = 0xc0970999, esp = 0xc2fc9afc, ebp = 0xc2fc9b1c ---ifindex_alloc_locked(c0d003cf,c2fc9b36,19e,19e,c15ab714,...) at ifindex_alloc_locked+0x19 if_alloc(47,c4085a16,3,c0de9614,c32aa780,...) at if_alloc+0x85 wtap_attach(c31a7800,c40857c0,0,4,0,...) at wtap_attach+0x29new_wtap(c32aa780,0,c2fc9bf0,c083ac9b,c3cbb200,...) at new_wtap+0x9b wtap_ioctl(c3cbb200,80045701,c31edaa0,1,c3f90b40,...) at wtap_ioctl+0x36devfs_ioctl_f(c3cfe3b8,80045701,c31edaa0,c3185d00,c3f90b40,...) at devfs_ioctl_f+0x10bkern_ioctl(c3f90b40,3,80045701,c31edaa0,fc9cec,...) at kern_ioctl+0x20dioctl(c3f90b40,c2fc9cec,c2fc9d28,c0cf5783,0,...) at ioctl+0x134syscallenter(c3f90b40,c2fc9ce4,c2fc9ce4,0,0,...) at syscallenter+0x263syscall(c2fc9d28) at syscall+0x34 Xint0x80_syscall() at Xint0x80_syscall+0x21 --- syscall (54, FreeBSD ELF32, ioctl), eip = 0x28181203, esp = 0xbfbfec3c, ebp = 0xbfbfec58 --- Fatal trap 12: page fault while in kernel mode cpuid = 0; apic id = 00 fault virtual address = 0x18 fault code = supervisor read, page not present instruction pointer = 0x20:0xc0970999 stack pointer = 0x28:0xc2fc9afc frame pointer = 0x28:0xc2fc9b1c code segment = base 0x0, limit 0xfffff, type 0x1b = DPL 0, pres 1, def32 1, gran 1 processor eflags = interrupt enabled, resume, IOPL = 0 current process = 1203 (ioctl) panic: from debugger cpuid = 0 Uptime: 21s Physical memory: 495 MB Dumping 55 MB: 40 24 8_______________________________________________ email@example.com mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-virtualizationTo unsubscribe, send any mail to "freebsd-virtualization-unsubscr...@freebsd.org"
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