Hi Adam,
Did you have any thoughts?

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From: Adam Lackorzynski <adam@l4re.org>
Sent: Saturday, May 31, 2025 6:37:43 PM
To: Moshe Kravchik <mkravchik@hotmail.com>; l4-hackers@os.inf.tu-dresden.de <l4-hackers@os.inf.tu-dresden.de>
Subject: Re: Linux fails on startup looking for SMC
 
Hi Moshe,

I was thinking a bit about this and cannot think of a reason. I'd now
try to issue those calls in bootstrap, just to check whether they work
from a "bare-metal" environment. And then work from there.


Adam

On Mon May 26, 2025 at 08:49:01 +0000, Moshe Kravchik wrote:
> Sorry for a long delay.
> On this board, there is a Uboot which can load and run Ubuntu. I replaced Ubuntu with L4, which starts a Linux VM that I want to pass the Ethernet to as a passthrough device.
>
> I don't explicitly load ATF, if I understand correctly, it should be loaded before Uboot and therefore before L4 is loaded. I switched to using a kernel from the working Ubuntu image, but SMC calls still return -1 and I can't init the ethernet driver inside the VM.
> I added prints into the fiasco part and see:
> vm-1    | [   17.285888] calling  smccc_devices_init+0x0/0xa4 @ 1
> vm-1    | [   17.294574] initcall smccc_devices_init+0x0/0xa4 returned 0 after 0 usecs
> vm-1    | [   17.301414] calling  smccc_soc_init+0x0/0x2ac @ 1
> SMC_USER: kinvoke (1)
> MC_USER: kinvoke (2)
> [SMC_USER: kinvoke (3)
> 3SMC_USER: kinvoke (4) 0x80000001
> SMC_USER: kinvoke (5)
> 7SMC_USER: kinvoke (6) r0 0x1 r1 0x80000002 r2 0x4 r3 0x152b198
> mSMC_USER: kinvoke (7) r0 0xffffffffffffffff r1 0xffff40400000 r2 0xffffffffffffffff r3 0x1
> vm-1    | vm_call 0x80000001
> vm-1    | [   17.340449] SMCCC: SOC_ID: ARCH_SOC_ID not implemented, skipping ....
> vm-1    | [   17.344029] initcall smccc_soc_init+0x0/0x2ac returned 0 after 33538 usecs
> vm-1    | [   17.352198] calling  zynqmp_firmware_driver_init+0x0/0x34 @ 1
> vm-1    | [   17.360828] probe of firmware:zynqmp-firmware returned 0 after 160 usecs
> vm-1    | [   17.368210] initcall zynqmp_firmware_driver_init+0x0/0x34 returned 0 after 7382 usecs
>
> And later:
> vm-1    | [   19.699352] calling  deferred_probe_initcall+0x0/0xc0 @ 1
> vm-1    | [   19.708582] probe of ff0a0000.gpio returned 517 after 55 usecs
> vm-1    | [   19.716071] probe of ff0c0000.ethernet returned -517 after 15 usecs
> vm-1    | [   19.723148] zynq-gpio ff0a0000.gpio: deferred probe timeout, ignoring dependency
> vm-1    | [   19.731093] zynq-gpio: probe of ff0a0000.gpio failed with error -110
> vm-1    | [   19.740075] probe of ff0a0000.gpio returned 110 after 16951 usecs
> vm-1    | [   19.748483] macb ff0c0000.ethernet: deferred probe timeout, ignoring dependency
> vm-1    | [   19.756015] probe of ff0c0000.ethernet returned -517 after 7540 usecs
> vm-1    | [   19.764931] initcall deferred_probe_initcall+0x0/0xc0 returned 0 after 55255 usecs
>
> Any ideas appreciated,
> Moshe
> ________________________________
> From: Adam Lackorzynski <adam@l4re.org>
> Sent: Tuesday, April 29, 2025 10:57 AM
> To: Moshe Kravchik <mkravchik@hotmail.com>; l4-hackers@os.inf.tu-dresden.de <l4-hackers@os.inf.tu-dresden.de>
> Subject: Re: Linux fails on startup looking for SMC
>
> If there is a return that's good as there is someone responding. Are you
> currently running without ATF? Do you just run L4Re instead of Linux or
> is there some bigger difference?
>
>
> Adam
>
> On Tue Apr 29, 2025 at 05:50:37 +0000, Moshe Kravchik wrote:
> > OK, that's great, I just commented out the range check in `fiasco/src/kern/arm/smc_user.cpp`, but even though I see the calls get through, they still return -1.
> > Should I load ATF or some other code first so that someone will respond to these SMC calls?
> > ________________________________
> > From: Adam Lackorzynski <adam@l4re.org>
> > Sent: Tuesday, April 29, 2025 12:04 AM
> > To: Moshe Kravchik <mkravchik@hotmail.com>; l4-hackers@os.inf.tu-dresden.de <l4-hackers@os.inf.tu-dresden.de>
> > Subject: Re: Linux fails on startup looking for SMC
> >
> > Hi,
> >
> > Could you tune ARM_SMC_USER_MIN/ARM_SMC_USER_MAX in the kernel? Seems
> > the SMC functions asked are 0x8200ff03U and 0xC2000xxx and that's not
> > covered by the default range, so increasing ARM_SMC_USER_MAX to
> > 0xcfffffff or so.
> >
> >
> > Adam
> >
> > On Mon Apr 28, 2025 at 15:00:04 +0000, Moshe Kravchik wrote:
> > > Thank you!
> > > This configuration indeed resulted in the capability present.
> > > However, I still get the error:
> > > `zynqmp_firmware firmware:zynqmp-firmware: probe with driver zynqmp_firmware failed with error -22` and when I add prints I see that the SMC calls in the Linux kernel return -1.
> > > Anything else I need to add to the device tree to initialize it or something?
> > > When I boot into Ubuntu without L4 it works.
> > > Moshe
> > > ________________________________
> > > From: Adam Lackorzynski <adam@l4re.org>
> > > Sent: Monday, April 28, 2025 2:53 PM
> > > To: Moshe Kravchik <mkravchik@hotmail.com>; l4-hackers@os.inf.tu-dresden.de <l4-hackers@os.inf.tu-dresden.de>
> > > Subject: Re: Linux fails on startup looking for SMC
> > >
> > >
> > > On Mon Apr 28, 2025 at 05:25:34 +0000, Moshe Kravchik wrote:
> > > > Thanks a lot, Adam!
> > > > I added both and rebuilt the device tree, but now I'm getting:
> > > > ```
> > > > vm-1    | VMM[smccc_proxy]: smccc_proxy
> > > > vm-1    | VMM: smccc_proxy.l4vmm,smccc_cap: capability smc is invalid.
> > > > vm-1    | VMM[vm]: Device creation for virtual device smccc_proxy failed. Disabling device.
> > > > ```
> > >
> > > This tells that the 'smc' cap is not there in uvmm. Is it there in the
> > > 'caps' table with which uvmm is started? There, where "ram = ..." is
> > > as well: caps = { ram = ...., smc = L4.Env.arm_smc, }, ....
> > > Additionally, in the microkernel, the CONFIG_ARM_SMC_USER option must
> > > also be enabled.
> > >
> > >
> > > Adam
> > >
> > > > Moshe
> > > > ________________________________
> > > > From: Adam Lackorzynski <adam@l4re.org>
> > > > Sent: Monday, April 28, 2025 12:07 AM
> > > > To: Moshe Kravchik <mkravchik@hotmail.com>; l4-hackers@os.inf.tu-dresden.de <l4-hackers@os.inf.tu-dresden.de>
> > > > Subject: Re: Linux fails on startup looking for SMC
> > > >
> > > > Hi Moshe,
> > > >
> > > > On Sun Apr 27, 2025 at 15:32:53 +0000, Moshe Kravchik wrote:
> > > > > Hi,
> > > > > I'm trying to set up a Linux running on uvmm with a HW passthrough.
> > > > > I added `zynqmp_firmware` to my DTS (it was required for the device I'm trying to pass).
> > > > > However, Linux fails to add the device and I see:
> > > > > vm-1 | [ 1.772078] ledtrig-cpu: registered to indicate activity on CPUs
> > > > > vm-1 | VMM[guest]: No handler for SMC call: imm=0 a0=c200003f a1=3f ip=ffff800080026884 lr=ffff800080dcdb04
> > > > > vm-1 | VMM[guest]: No handler for SMC call: imm=0 a0=c2000001 a1=0 ip=ffff800080026884 lr=ffff800080dcdb04
> > > > > vm-1 | [ 1.805957] zynqmp_firmware firmware:zynqmp-firmware: probe with driver zynqmp_firmware failed with error -22
> > > > >
> > > > > >From the traces I added, the failure is in `zynqmp_pm_get_api_version`.
> > > > >
> > > > > How do I add SMC handling?
> > > >
> > > > You give uvmm in the Ned script: smc = L4.Env.arm_smc
> > > >
> > > > And put this into you device tree:
> > > >    smccc_proxy {
> > > >        compatible = "l4vmm,smccc_proxy";
> > > >        l4vmm,smccc_cap = "smc";
> > > >        method = "smc";
> > > >    };
> > > >
> > > > Note that L4.Env.arm_smc gives access to the real interface with all the
> > > > power that is behind it (the kernel only filters its range). So in a
> > > > longer run it might be necessary to have proxy for this interface, or
> > > > emulate the SMCs, or modify Linux to not use it, whatever fits best.
> > > >
> > > >
> > > >
> > > > Adam