hello Mathieu,
On 1/31/24 19:52, Mathieu Poirier wrote:
> On Tue, Jan 30, 2024 at 10:13:48AM +0100, Arnaud POULIQUEN wrote:
>>
>>
>> On 1/26/24 18:11, Mathieu Poirier wrote:
>>> On Thu, Jan 18, 2024 at 11:04:33AM +0100, Arnaud Pouliquen wrote:
>>>> The new TEE remoteproc device is used to manage remote firmware in a
>>>> secure, trusted context. The 'st,stm32mp1-m4-tee' compatibility is
>>>> introduced to delegate the loading of the firmware to the trusted
>>>> execution context. In such cases, the firmware should be signed and
>>>> adhere to the image format defined by the TEE.
>>>>
>>>> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxxxxxxx>
>>>> ---
>>>> V1 to V2 update:
>>>> - remove the select "TEE_REMOTEPROC" in STM32_RPROC config as detected by
>>>> the kernel test robot:
>>>> WARNING: unmet direct dependencies detected for TEE_REMOTEPROC
>>>> Depends on [n]: REMOTEPROC [=y] && OPTEE [=n]
>>>> Selected by [y]:
>>>> - STM32_RPROC [=y] && (ARCH_STM32 || COMPILE_TEST [=y]) && REMOTEPROC [=y]
>>>> - Fix initialized trproc variable in stm32_rproc_probe
>>>> ---
>>>> drivers/remoteproc/stm32_rproc.c | 149 +++++++++++++++++++++++++++++--
>>>> 1 file changed, 144 insertions(+), 5 deletions(-)
>>>>
>>>> diff --git a/drivers/remoteproc/stm32_rproc.c b/drivers/remoteproc/stm32_rproc.c
>>>> index fcc0001e2657..cf6a21bac945 100644
>>>> --- a/drivers/remoteproc/stm32_rproc.c
>>>> +++ b/drivers/remoteproc/stm32_rproc.c
>>>> @@ -20,6 +20,7 @@
>>>> #include <linux/remoteproc.h>
>>>> #include <linux/reset.h>
>>>> #include <linux/slab.h>
>>>> +#include <linux/tee_remoteproc.h>
>>>> #include <linux/workqueue.h>
>>>>
>>>> #include "remoteproc_internal.h"
>>>> @@ -49,6 +50,9 @@
>>>> #define M4_STATE_STANDBY 4
>>>> #define M4_STATE_CRASH 5
>>>>
>>>> +/* Remote processor unique identifier aligned with the Trusted Execution Environment definitions */
>>>> +#define STM32_MP1_M4_PROC_ID 0
>>>> +
>>>> struct stm32_syscon {
>>>> struct regmap *map;
>>>> u32 reg;
>>>> @@ -90,6 +94,8 @@ struct stm32_rproc {
>>>> struct stm32_mbox mb[MBOX_NB_MBX];
>>>> struct workqueue_struct *workqueue;
>>>> bool hold_boot_smc;
>>>> + bool fw_loaded;
>>>> + struct tee_rproc *trproc;
>>>> void __iomem *rsc_va;
>>>> };
>>>>
>>>> @@ -257,6 +263,91 @@ static int stm32_rproc_release(struct rproc *rproc)
>>>> return err;
>>>> }
>>>>
>>>> +static int stm32_rproc_tee_elf_sanity_check(struct rproc *rproc,
>>>> + const struct firmware *fw)
>>>> +{
>>>> + struct stm32_rproc *ddata = rproc->priv;
>>>> + unsigned int ret = 0;
>>>> +
>>>> + if (rproc->state == RPROC_DETACHED)
>>>> + return 0;
>>>> +
>>>> + ret = tee_rproc_load_fw(ddata->trproc, fw);
>>>> + if (!ret)
>>>> + ddata->fw_loaded = true;
>>>> +
>>>> + return ret;
>>>> +}
>>>> +
>>>> +static int stm32_rproc_tee_elf_load(struct rproc *rproc,
>>>> + const struct firmware *fw)
>>>> +{
>>>> + struct stm32_rproc *ddata = rproc->priv;
>>>> + unsigned int ret;
>>>> +
>>>> + /*
>>>> + * This function can be called by remote proc for recovery
>>>> + * without the sanity check. In this case we need to load the firmware
>>>> + * else nothing done here as the firmware has been preloaded for the
>>>> + * sanity check to be able to parse it for the resource table.
>>>> + */
>>>
>>> This comment is very confusing - please consider refactoring.
>>>
>>>> + if (ddata->fw_loaded)
>>>> + return 0;
>>>> +
>>>
>>> I'm not sure about keeping a flag to indicate the status of the loaded firmware.
>>> It is not done for the non-secure method, I don't see why it would be needed for
>>> the secure one.
>>>
>>
>> The difference is on the sanity check.
>> - in rproc_elf_sanity_check we parse the elf file to verify that it is
>> valid.
>> - in stm32_rproc_tee_elf_sanity_check we have to do the same, that means to
>> authenticate it. the authentication is done during the load.
>>
>> So this flag is used to avoid to reload it twice time.
>> refactoring the comment should help to understand this flag
>>
>>
>> An alternative would be to bypass the sanity check. But this lead to same
>> limitation.
>> Before loading the firmware in remoteproc_core, we call rproc_parse_fw() that is
>> used to get the resource table address. To get it from tee we need to
>> authenticate the firmware so load it...
>>
>
> I spent a long time thinking about this patchset. Looking at the code as it
> is now, request_firmware() in rproc_boot() is called even when the TEE is
> responsible for loading the firmware. There should be some conditional code
> that calls either request_firmware() or tee_rproc_load_fw(). The latter should
> also be renamed to tee_rproc_request_firmware() to avoid confusion.
The request_firmware() call is needed in both cases to get the image from the
filesystem. The tee_rproc_load_fw() gets, as input, the struct firmware provided
by request_firmware().
If we want to integrate in remoteproc_core the solution could probably have to
create the equivalent of the rproc_fw_boot() to load the firmware with an
external method. Here is an example based on a new rproc_ops ( not tested)
+ static int rproc_fw_ext_boot(struct rproc *rproc, const struct firmware *fw)
+ {
+ struct device *dev = &rproc->dev;
+ const char *name = rproc->firmware;
+ int ret;
+
+
+ dev_info(dev, "Booting fw image %s, size %zd\n", name, fw->size);
+
+ /* ops to load and start the remoteprocessor */
+ ret = rproc->ops->boot(rproc, fw);
+ if (ret)
+ return ret;
+
+ /*
+ * if enabling an IOMMU isn't relevant for this rproc, this is
+ * just a nop
+ */
+ ret = rproc_enable_iommu(rproc);
+ if (ret) {
+ dev_err(dev, "can't enable iommu: %d\n", ret);
+ return ret;
+ }
+
+ /* Prepare rproc for firmware loading if needed */
+ ret = rproc_prepare_device(rproc);
+ if (ret) {
+ dev_err(dev, "can't prepare rproc %s: %d\n", rproc->name, ret);
+ goto disable_iommu;
+ }
+
+ ret = rproc_set_rsc_table(rproc);
+ if (ret) {
+ dev_err(dev, "can't load resource table: %d\n", ret);
+ goto unprepare_device;
+ }
+
+
+ /* reset max_notifyid */
+ rproc->max_notifyid = -1;
+
+ /* reset handled vdev */
+ rproc->nb_vdev = 0;
+
+ /* handle fw resources which are required to boot rproc */
+ ret = rproc_handle_resources(rproc, rproc_loading_handlers);
+ if (ret) {
+ dev_err(dev, "Failed to process resources: %d\n", ret);
+ goto clean_up_resources;
+ }
+
+ /* Allocate carveout resources associated to rproc */
+ ret = rproc_alloc_registered_carveouts(rproc);
+ if (ret) {
+ dev_err(dev, "Failed to allocate associated carveouts: %d\n",
+ ret);
+ goto clean_up_resources;
+ }
+
+ return 0;
+
+ clean_up_resources:
+ rproc_resource_cleanup(rproc);
+ unprepare_rproc:
+ /* release HW resources if needed */
+ rproc_unprepare_device(rproc);
+ disable_iommu:
+ rproc_disable_iommu(rproc);
+ return ret;
+ }
int rproc_boot(struct rproc *rproc)
{
[...]
- ret = rproc_fw_boot(rproc, firmware_p);
+ if(rproc->ops->boot)
+ ret = rproc_fw_ext_boot(rproc, firmware_p);
+ else
+ ret = rproc_fw_boot(rproc, firmware_p);
Another advantage of this solution is that it opens the framework to other
formats. For instance it could be a way to support dtb format requested in [RFC]
Passing device-tree to remoteproc [1].
[1]
https://lore.kernel.org/linux-remoteproc/f67cd822-4e29-71f2-7c42-e11dbaa6cd8c@xxxxxxxxxxxxx/T/#t
Thanks,
Arnaud
>
> I touched on that before but please rename rproc_tee_get_rsc_table() to
> rproc_tee_elf_load_rsc_table(). I also suggest to introduce a new function,
> rproc_tee_get_loaded_rsc_table() that would be called from
> rproc_tee_elf_load_rsc_table(). That way we don't need trproc->rsc_va.
>
> I also think tee_rproc should be renamed to "rproc_tee_interface" and folded
> under struct rproc.
>
> With the above most of the problems with the current implementation should
> naturally go away.
>
> Thanks,
> Mathieu
>
>>
>>>> + ret = tee_rproc_load_fw(ddata->trproc, fw);
>>>> + if (ret)
>>>> + return ret;
>>>> + ddata->fw_loaded = true;
>>>> +
>>>> + /* Update the resource table parameters. */
>>>> + if (rproc_tee_get_rsc_table(ddata->trproc)) {
>>>> + /* No resource table: reset the related fields. */
>>>> + rproc->cached_table = NULL;
>>>> + rproc->table_ptr = NULL;
>>>> + rproc->table_sz = 0;
>>>> + }
>>>> +
>>>> + return 0;
>>>> +}
>>>> +
>>>> +static struct resource_table *
>>>> +stm32_rproc_tee_elf_find_loaded_rsc_table(struct rproc *rproc,
>>>> + const struct firmware *fw)
>>>> +{
>>>> + struct stm32_rproc *ddata = rproc->priv;
>>>> +
>>>> + return tee_rproc_get_loaded_rsc_table(ddata->trproc);
>>>> +}
>>>> +
>>>> +static int stm32_rproc_tee_start(struct rproc *rproc)
>>>> +{
>>>> + struct stm32_rproc *ddata = rproc->priv;
>>>> +
>>>> + return tee_rproc_start(ddata->trproc);
>>>> +}
>>>> +
>>>> +static int stm32_rproc_tee_attach(struct rproc *rproc)
>>>> +{
>>>> + /* Nothing to do, remote proc already started by the secured context. */
>>>> + return 0;
>>>> +}
>>>> +
>>>> +static int stm32_rproc_tee_stop(struct rproc *rproc)
>>>> +{
>>>> + struct stm32_rproc *ddata = rproc->priv;
>>>> + int err;
>>>> +
>>>> + stm32_rproc_request_shutdown(rproc);
>>>> +
>>>> + err = tee_rproc_stop(ddata->trproc);
>>>> + if (err)
>>>> + return err;
>>>> +
>>>> + ddata->fw_loaded = false;
>>>> +
>>>> + return stm32_rproc_release(rproc);
>>>> +}
>>>> +
>>>> static int stm32_rproc_prepare(struct rproc *rproc)
>>>> {
>>>> struct device *dev = rproc->dev.parent;
>>>> @@ -319,7 +410,14 @@ static int stm32_rproc_prepare(struct rproc *rproc)
>>>>
>>>> static int stm32_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw)
>>>> {
>>>> - if (rproc_elf_load_rsc_table(rproc, fw))
>>>> + struct stm32_rproc *ddata = rproc->priv;
>>>> + int ret;
>>>> +
>>>> + if (ddata->trproc)
>>>> + ret = rproc_tee_get_rsc_table(ddata->trproc);
>>>> + else
>>>> + ret = rproc_elf_load_rsc_table(rproc, fw);
>>>> + if (ret)
>>>> dev_warn(&rproc->dev, "no resource table found for this firmware\n");
>>>>
>>>> return 0;
>>>> @@ -693,8 +791,22 @@ static const struct rproc_ops st_rproc_ops = {
>>>> .get_boot_addr = rproc_elf_get_boot_addr,
>>>> };
>>>>
>>>> +static const struct rproc_ops st_rproc_tee_ops = {
>>>> + .prepare = stm32_rproc_prepare,
>>>> + .start = stm32_rproc_tee_start,
>>>> + .stop = stm32_rproc_tee_stop,
>>>> + .attach = stm32_rproc_tee_attach,
>>>> + .kick = stm32_rproc_kick,
>>>> + .parse_fw = stm32_rproc_parse_fw,
>>>> + .find_loaded_rsc_table = stm32_rproc_tee_elf_find_loaded_rsc_table,
>>>> + .get_loaded_rsc_table = stm32_rproc_get_loaded_rsc_table,
>>>> + .sanity_check = stm32_rproc_tee_elf_sanity_check,
>>>> + .load = stm32_rproc_tee_elf_load,
>>>> +};
>>>> +
>>>> static const struct of_device_id stm32_rproc_match[] = {
>>>> - { .compatible = "st,stm32mp1-m4" },
>>>> + {.compatible = "st,stm32mp1-m4",},
>>>> + {.compatible = "st,stm32mp1-m4-tee",},
>>>> {},
>>>> };
>>>> MODULE_DEVICE_TABLE(of, stm32_rproc_match);
>>>> @@ -853,6 +965,7 @@ static int stm32_rproc_probe(struct platform_device *pdev)
>>>> struct device *dev = &pdev->dev;
>>>> struct stm32_rproc *ddata;
>>>> struct device_node *np = dev->of_node;
>>>> + struct tee_rproc *trproc = NULL;
>>>> struct rproc *rproc;
>>>> unsigned int state;
>>>> int ret;
>>>> @@ -861,11 +974,31 @@ static int stm32_rproc_probe(struct platform_device *pdev)
>>>> if (ret)
>>>> return ret;
>>>>
>>>> - rproc = rproc_alloc(dev, np->name, &st_rproc_ops, NULL, sizeof(*ddata));
>>>> - if (!rproc)
>>>> - return -ENOMEM;
>>>> + if (of_device_is_compatible(np, "st,stm32mp1-m4-tee")) {
>>>> + trproc = tee_rproc_register(dev, STM32_MP1_M4_PROC_ID);
>>>> + if (IS_ERR(trproc)) {
>>>> + dev_err_probe(dev, PTR_ERR(trproc),
>>>> + "signed firmware not supported by TEE\n");
>>>> + return PTR_ERR(trproc);
>>>> + }
>>>> + /*
>>>> + * Delegate the firmware management to the secure context.
>>>> + * The firmware loaded has to be signed.
>>>> + */
>>>> + dev_info(dev, "Support of signed firmware only\n");
>>>
>>> Not sure what this adds. Please remove.
>>
>> This is used to inform the user that only a signed firmware can be loaded, not
>> an ELF file.
>> I have a patch in my pipe to provide the supported format in the debugfs. In a
>> first step, I can suppress this message and we can revisit the issue when I push
>> the debugfs proposal.
>>
>> Thanks,
>> Arnaud
>>
>>>
>>>> + }
>>>> + rproc = rproc_alloc(dev, np->name,
>>>> + trproc ? &st_rproc_tee_ops : &st_rproc_ops,
>>>> + NULL, sizeof(*ddata));
>>>> + if (!rproc) {
>>>> + ret = -ENOMEM;
>>>> + goto free_tee;
>>>> + }
>>>>
>>>> ddata = rproc->priv;
>>>> + ddata->trproc = trproc;
>>>> + if (trproc)
>>>> + trproc->rproc = rproc;
>>>>
>>>> rproc_coredump_set_elf_info(rproc, ELFCLASS32, EM_NONE);
>>>>
>>>> @@ -916,6 +1049,10 @@ static int stm32_rproc_probe(struct platform_device *pdev)
>>>> device_init_wakeup(dev, false);
>>>> }
>>>> rproc_free(rproc);
>>>> +free_tee:
>>>> + if (trproc)
>>>> + tee_rproc_unregister(trproc);
>>>> +
>>>> return ret;
>>>> }
>>>>
>>>> @@ -937,6 +1074,8 @@ static void stm32_rproc_remove(struct platform_device *pdev)
>>>> device_init_wakeup(dev, false);
>>>> }
>>>> rproc_free(rproc);
>>>> + if (ddata->trproc)
>>>> + tee_rproc_unregister(ddata->trproc);
>>>> }
>>>>
>>>> static int stm32_rproc_suspend(struct device *dev)
>>>> --
>>>> 2.25.1
>>>>
