diff mbox series

[v4,05/18] nitro_enclaves: Handle PCI device command requests

Message ID 20200622200329.52996-6-andraprs@amazon.com (mailing list archive)
State New, archived
Headers show
Series Add support for Nitro Enclaves | expand

Commit Message

Paraschiv, Andra-Irina June 22, 2020, 8:03 p.m. UTC 
The Nitro Enclaves PCI device exposes a MMIO space that this driver
uses to submit command requests and to receive command replies e.g. for
enclave creation / termination or setting enclave resources.

Add logic for handling PCI device command requests based on the given
command type.

Register an MSI-X interrupt vector for command reply notifications to
handle this type of communication events.

Signed-off-by: Alexandru-Catalin Vasile <lexnv@amazon.com>
Signed-off-by: Andra Paraschiv <andraprs@amazon.com>

Fix issue reported in:
https://lore.kernel.org/lkml/202004231644.xTmN4Z1z%25lkp@intel.com/

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
---
Changelog

v3 -> v4

* Use dev_err instead of custom NE log pattern.
* Return IRQ_NONE when interrupts are not handled.

v2 -> v3

* Remove the WARN_ON calls.
* Update static calls sanity checks.
* Remove "ratelimited" from the logs that are not in the ioctl call
  paths.

v1 -> v2

* Add log pattern for NE.
* Remove the BUG_ON calls.
* Update goto labels to match their purpose.
* Add fix for kbuild report.
---
 drivers/virt/nitro_enclaves/ne_pci_dev.c | 232 +++++++++++++++++++++++
 1 file changed, 232 insertions(+)

Comments

Alexander Graf July 2, 2020, 3:19 p.m. UTC | #1 
On 22.06.20 22:03, Andra Paraschiv wrote:
> The Nitro Enclaves PCI device exposes a MMIO space that this driver
> uses to submit command requests and to receive command replies e.g. for
> enclave creation / termination or setting enclave resources.
> 
> Add logic for handling PCI device command requests based on the given
> command type.
> 
> Register an MSI-X interrupt vector for command reply notifications to
> handle this type of communication events.
> 
> Signed-off-by: Alexandru-Catalin Vasile <lexnv@amazon.com>
> Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
> 
> Fix issue reported in:
> https://lore.kernel.org/lkml/202004231644.xTmN4Z1z%25lkp@intel.com/
> 
> Reported-by: kbuild test robot <lkp@intel.com>
> Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
> ---
> Changelog
> 
> v3 -> v4
> 
> * Use dev_err instead of custom NE log pattern.
> * Return IRQ_NONE when interrupts are not handled.
> 
> v2 -> v3
> 
> * Remove the WARN_ON calls.
> * Update static calls sanity checks.
> * Remove "ratelimited" from the logs that are not in the ioctl call
>    paths.
> 
> v1 -> v2
> 
> * Add log pattern for NE.
> * Remove the BUG_ON calls.
> * Update goto labels to match their purpose.
> * Add fix for kbuild report.
> ---
>   drivers/virt/nitro_enclaves/ne_pci_dev.c | 232 +++++++++++++++++++++++
>   1 file changed, 232 insertions(+)
> 
> diff --git a/drivers/virt/nitro_enclaves/ne_pci_dev.c b/drivers/virt/nitro_enclaves/ne_pci_dev.c
> index 235fa3ecbee2..c24230cfe7c0 100644
> --- a/drivers/virt/nitro_enclaves/ne_pci_dev.c
> +++ b/drivers/virt/nitro_enclaves/ne_pci_dev.c
> @@ -27,6 +27,218 @@ static const struct pci_device_id ne_pci_ids[] = {
>   
>   MODULE_DEVICE_TABLE(pci, ne_pci_ids);
>   
> +/**
> + * ne_submit_request - Submit command request to the PCI device based on the
> + * command type.
> + *
> + * This function gets called with the ne_pci_dev mutex held.
> + *
> + * @pdev: PCI device to send the command to.
> + * @cmd_type: command type of the request sent to the PCI device.
> + * @cmd_request: command request payload.
> + * @cmd_request_size: size of the command request payload.
> + *
> + * @returns: 0 on success, negative return value on failure.
> + */
> +static int ne_submit_request(struct pci_dev *pdev,
> +			     enum ne_pci_dev_cmd_type cmd_type,
> +			     void *cmd_request, size_t cmd_request_size)
> +{
> +	struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
> +
> +	if (!ne_pci_dev || !ne_pci_dev->iomem_base)
> +		return -EINVAL;

How can this ever happen?

> +
> +	memcpy_toio(ne_pci_dev->iomem_base + NE_SEND_DATA, cmd_request,
> +		    cmd_request_size);
> +
> +	iowrite32(cmd_type, ne_pci_dev->iomem_base + NE_COMMAND);
> +
> +	return 0;
> +}
> +
> +/**
> + * ne_retrieve_reply - Retrieve reply from the PCI device.
> + *
> + * This function gets called with the ne_pci_dev mutex held.
> + *
> + * @pdev: PCI device to receive the reply from.
> + * @cmd_reply: command reply payload.
> + * @cmd_reply_size: size of the command reply payload.
> + *
> + * @returns: 0 on success, negative return value on failure.
> + */
> +static int ne_retrieve_reply(struct pci_dev *pdev,
> +			     struct ne_pci_dev_cmd_reply *cmd_reply,
> +			     size_t cmd_reply_size)
> +{
> +	struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
> +
> +	if (!ne_pci_dev || !ne_pci_dev->iomem_base)
> +		return -EINVAL;

Same.

> +
> +	memcpy_fromio(cmd_reply, ne_pci_dev->iomem_base + NE_RECV_DATA,
> +		      cmd_reply_size);
> +
> +	return 0;
> +}
> +
> +/**
> + * ne_wait_for_reply - Wait for a reply of a PCI command.
> + *
> + * This function gets called with the ne_pci_dev mutex held.
> + *
> + * @pdev: PCI device for which a reply is waited.
> + *
> + * @returns: 0 on success, negative return value on failure.
> + */
> +static int ne_wait_for_reply(struct pci_dev *pdev)
> +{
> +	struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
> +	int rc = -EINVAL;

Unused assignment?

> +
> +	if (!ne_pci_dev)
> +		return -EINVAL;

Same.

> +
> +	/*
> +	 * TODO: Update to _interruptible and handle interrupted wait event
> +	 * e.g. -ERESTARTSYS, incoming signals + add / update timeout.
> +	 */
> +	rc = wait_event_timeout(ne_pci_dev->cmd_reply_wait_q,
> +				atomic_read(&ne_pci_dev->cmd_reply_avail) != 0,
> +				msecs_to_jiffies(NE_DEFAULT_TIMEOUT_MSECS));
> +	if (!rc)
> +		return -ETIMEDOUT;
> +
> +	return 0;
> +}
> +
> +int ne_do_request(struct pci_dev *pdev, enum ne_pci_dev_cmd_type cmd_type,
> +		  void *cmd_request, size_t cmd_request_size,
> +		  struct ne_pci_dev_cmd_reply *cmd_reply, size_t cmd_reply_size)
> +{
> +	struct ne_pci_dev *ne_pci_dev = NULL;
> +	int rc = -EINVAL;
> +
> +	if (!pdev)
> +		return -ENODEV;

When can this happen?

> +
> +	ne_pci_dev = pci_get_drvdata(pdev);
> +	if (!ne_pci_dev || !ne_pci_dev->iomem_base)
> +		return -EINVAL;

Same

> +
> +	if (cmd_type <= INVALID_CMD || cmd_type >= MAX_CMD) {
> +		dev_err_ratelimited(&pdev->dev, "Invalid cmd type=%u\n",
> +				    cmd_type);
> +
> +		return -EINVAL;
> +	}
> +
> +	if (!cmd_request) {
> +		dev_err_ratelimited(&pdev->dev, "Null cmd request\n");
> +
> +		return -EINVAL;
> +	}
> +
> +	if (cmd_request_size > NE_SEND_DATA_SIZE) {
> +		dev_err_ratelimited(&pdev->dev,
> +				    "Invalid req size=%zu for cmd type=%u\n",
> +				    cmd_request_size, cmd_type);
> +
> +		return -EINVAL;
> +	}
> +
> +	if (!cmd_reply) {
> +		dev_err_ratelimited(&pdev->dev, "Null cmd reply\n");
> +
> +		return -EINVAL;
> +	}
> +
> +	if (cmd_reply_size > NE_RECV_DATA_SIZE) {
> +		dev_err_ratelimited(&pdev->dev, "Invalid reply size=%zu\n",
> +				    cmd_reply_size);
> +
> +		return -EINVAL;
> +	}
> +
> +	/*
> +	 * Use this mutex so that the PCI device handles one command request at
> +	 * a time.
> +	 */
> +	mutex_lock(&ne_pci_dev->pci_dev_mutex);
> +
> +	atomic_set(&ne_pci_dev->cmd_reply_avail, 0);
> +
> +	rc = ne_submit_request(pdev, cmd_type, cmd_request, cmd_request_size);
> +	if (rc < 0) {
> +		dev_err_ratelimited(&pdev->dev,
> +				    "Error in submit request [rc=%d]\n", rc);
> +
> +		goto unlock_mutex;
> +	}
> +
> +	rc = ne_wait_for_reply(pdev);
> +	if (rc < 0) {
> +		dev_err_ratelimited(&pdev->dev,
> +				    "Error in wait for reply [rc=%d]\n", rc);
> +
> +		goto unlock_mutex;
> +	}
> +
> +	rc = ne_retrieve_reply(pdev, cmd_reply, cmd_reply_size);
> +	if (rc < 0) {
> +		dev_err_ratelimited(&pdev->dev,
> +				    "Error in retrieve reply [rc=%d]\n", rc);
> +
> +		goto unlock_mutex;
> +	}
> +
> +	atomic_set(&ne_pci_dev->cmd_reply_avail, 0);
> +
> +	if (cmd_reply->rc < 0) {
> +		dev_err_ratelimited(&pdev->dev,
> +				    "Error in cmd process logic [rc=%d]\n",
> +				    cmd_reply->rc);
> +
> +		rc = cmd_reply->rc;
> +
> +		goto unlock_mutex;
> +	}
> +
> +	mutex_unlock(&ne_pci_dev->pci_dev_mutex);
> +
> +	return 0;

Can you just set rc to 0 and fall through?

> +
> +unlock_mutex:
> +	mutex_unlock(&ne_pci_dev->pci_dev_mutex);
> +
> +	return rc;
> +}
> +
> +/**
> + * ne_reply_handler - Interrupt handler for retrieving a reply matching
> + * a request sent to the PCI device for enclave lifetime management.
> + *
> + * @irq: received interrupt for a reply sent by the PCI device.
> + * @args: PCI device private data structure.
> + *
> + * @returns: IRQ_HANDLED on handled interrupt, IRQ_NONE otherwise.
> + */
> +static irqreturn_t ne_reply_handler(int irq, void *args)
> +{
> +	struct ne_pci_dev *ne_pci_dev = (struct ne_pci_dev *)args;
> +
> +	if (!ne_pci_dev)
> +		return IRQ_NONE;

How can this ever happen?


Alex

> +
> +	atomic_set(&ne_pci_dev->cmd_reply_avail, 1);
> +
> +	/* TODO: Update to _interruptible. */
> +	wake_up(&ne_pci_dev->cmd_reply_wait_q);
> +
> +	return IRQ_HANDLED;
> +}
> +
>   /**
>    * ne_setup_msix - Setup MSI-X vectors for the PCI device.
>    *
> @@ -59,7 +271,25 @@ static int ne_setup_msix(struct pci_dev *pdev)
>   		return rc;
>   	}
>   
> +	/*
> +	 * This IRQ gets triggered every time the PCI device responds to a
> +	 * command request. The reply is then retrieved, reading from the MMIO
> +	 * space of the PCI device.
> +	 */
> +	rc = request_irq(pci_irq_vector(pdev, NE_VEC_REPLY),
> +			 ne_reply_handler, 0, "enclave_cmd", ne_pci_dev);
> +	if (rc < 0) {
> +		dev_err(&pdev->dev, "Error in request irq reply [rc=%d]\n", rc);
> +
> +		goto free_irq_vectors;
> +	}
> +
>   	return 0;
> +
> +free_irq_vectors:
> +	pci_free_irq_vectors(pdev);
> +
> +	return rc;
>   }
>   
>   /**
> @@ -74,6 +304,8 @@ static void ne_teardown_msix(struct pci_dev *pdev)
>   	if (!ne_pci_dev)
>   		return;
>   
> +	free_irq(pci_irq_vector(pdev, NE_VEC_REPLY), ne_pci_dev);
> +
>   	pci_free_irq_vectors(pdev);
>   }
>   
> 



Amazon Development Center Germany GmbH
Krausenstr. 38
10117 Berlin
Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss
Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B
Sitz: Berlin
Ust-ID: DE 289 237 879
Paraschiv, Andra-Irina July 4, 2020, 3:05 p.m. UTC | #2 
On 02/07/2020 18:19, Alexander Graf wrote:
>
>
> On 22.06.20 22:03, Andra Paraschiv wrote:
>> The Nitro Enclaves PCI device exposes a MMIO space that this driver
>> uses to submit command requests and to receive command replies e.g. for
>> enclave creation / termination or setting enclave resources.
>>
>> Add logic for handling PCI device command requests based on the given
>> command type.
>>
>> Register an MSI-X interrupt vector for command reply notifications to
>> handle this type of communication events.
>>
>> Signed-off-by: Alexandru-Catalin Vasile <lexnv@amazon.com>
>> Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
>>
>> Fix issue reported in:
>> https://lore.kernel.org/lkml/202004231644.xTmN4Z1z%25lkp@intel.com/
>>
>> Reported-by: kbuild test robot <lkp@intel.com>
>> Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
>> ---
>> Changelog
>>
>> v3 -> v4
>>
>> * Use dev_err instead of custom NE log pattern.
>> * Return IRQ_NONE when interrupts are not handled.
>>
>> v2 -> v3
>>
>> * Remove the WARN_ON calls.
>> * Update static calls sanity checks.
>> * Remove "ratelimited" from the logs that are not in the ioctl call
>>    paths.
>>
>> v1 -> v2
>>
>> * Add log pattern for NE.
>> * Remove the BUG_ON calls.
>> * Update goto labels to match their purpose.
>> * Add fix for kbuild report.
>> ---
>>   drivers/virt/nitro_enclaves/ne_pci_dev.c | 232 +++++++++++++++++++++++
>>   1 file changed, 232 insertions(+)
>>
>> diff --git a/drivers/virt/nitro_enclaves/ne_pci_dev.c 
>> b/drivers/virt/nitro_enclaves/ne_pci_dev.c
>> index 235fa3ecbee2..c24230cfe7c0 100644
>> --- a/drivers/virt/nitro_enclaves/ne_pci_dev.c
>> +++ b/drivers/virt/nitro_enclaves/ne_pci_dev.c
>> @@ -27,6 +27,218 @@ static const struct pci_device_id ne_pci_ids[] = {
>>     MODULE_DEVICE_TABLE(pci, ne_pci_ids);
>>   +/**
>> + * ne_submit_request - Submit command request to the PCI device 
>> based on the
>> + * command type.
>> + *
>> + * This function gets called with the ne_pci_dev mutex held.
>> + *
>> + * @pdev: PCI device to send the command to.
>> + * @cmd_type: command type of the request sent to the PCI device.
>> + * @cmd_request: command request payload.
>> + * @cmd_request_size: size of the command request payload.
>> + *
>> + * @returns: 0 on success, negative return value on failure.
>> + */
>> +static int ne_submit_request(struct pci_dev *pdev,
>> +                 enum ne_pci_dev_cmd_type cmd_type,
>> +                 void *cmd_request, size_t cmd_request_size)
>> +{
>> +    struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
>> +
>> +    if (!ne_pci_dev || !ne_pci_dev->iomem_base)
>> +        return -EINVAL;
>
> How can this ever happen?

Removed this one and the next checks in v5 of the patch series.

Thanks,
Andra

>
>> +
>> +    memcpy_toio(ne_pci_dev->iomem_base + NE_SEND_DATA, cmd_request,
>> +            cmd_request_size);
>> +
>> +    iowrite32(cmd_type, ne_pci_dev->iomem_base + NE_COMMAND);
>> +
>> +    return 0;
>> +}
>> +
>> +/**
>> + * ne_retrieve_reply - Retrieve reply from the PCI device.
>> + *
>> + * This function gets called with the ne_pci_dev mutex held.
>> + *
>> + * @pdev: PCI device to receive the reply from.
>> + * @cmd_reply: command reply payload.
>> + * @cmd_reply_size: size of the command reply payload.
>> + *
>> + * @returns: 0 on success, negative return value on failure.
>> + */
>> +static int ne_retrieve_reply(struct pci_dev *pdev,
>> +                 struct ne_pci_dev_cmd_reply *cmd_reply,
>> +                 size_t cmd_reply_size)
>> +{
>> +    struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
>> +
>> +    if (!ne_pci_dev || !ne_pci_dev->iomem_base)
>> +        return -EINVAL;
>
> Same.
>
>> +
>> +    memcpy_fromio(cmd_reply, ne_pci_dev->iomem_base + NE_RECV_DATA,
>> +              cmd_reply_size);
>> +
>> +    return 0;
>> +}
>> +
>> +/**
>> + * ne_wait_for_reply - Wait for a reply of a PCI command.
>> + *
>> + * This function gets called with the ne_pci_dev mutex held.
>> + *
>> + * @pdev: PCI device for which a reply is waited.
>> + *
>> + * @returns: 0 on success, negative return value on failure.
>> + */
>> +static int ne_wait_for_reply(struct pci_dev *pdev)
>> +{
>> +    struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
>> +    int rc = -EINVAL;
>
> Unused assignment?
>
>> +
>> +    if (!ne_pci_dev)
>> +        return -EINVAL;
>
> Same.
>
>> +
>> +    /*
>> +     * TODO: Update to _interruptible and handle interrupted wait event
>> +     * e.g. -ERESTARTSYS, incoming signals + add / update timeout.
>> +     */
>> +    rc = wait_event_timeout(ne_pci_dev->cmd_reply_wait_q,
>> + atomic_read(&ne_pci_dev->cmd_reply_avail) != 0,
>> +                msecs_to_jiffies(NE_DEFAULT_TIMEOUT_MSECS));
>> +    if (!rc)
>> +        return -ETIMEDOUT;
>> +
>> +    return 0;
>> +}
>> +
>> +int ne_do_request(struct pci_dev *pdev, enum ne_pci_dev_cmd_type 
>> cmd_type,
>> +          void *cmd_request, size_t cmd_request_size,
>> +          struct ne_pci_dev_cmd_reply *cmd_reply, size_t 
>> cmd_reply_size)
>> +{
>> +    struct ne_pci_dev *ne_pci_dev = NULL;
>> +    int rc = -EINVAL;
>> +
>> +    if (!pdev)
>> +        return -ENODEV;
>
> When can this happen?
>
>> +
>> +    ne_pci_dev = pci_get_drvdata(pdev);
>> +    if (!ne_pci_dev || !ne_pci_dev->iomem_base)
>> +        return -EINVAL;
>
> Same
>
>> +
>> +    if (cmd_type <= INVALID_CMD || cmd_type >= MAX_CMD) {
>> +        dev_err_ratelimited(&pdev->dev, "Invalid cmd type=%u\n",
>> +                    cmd_type);
>> +
>> +        return -EINVAL;
>> +    }
>> +
>> +    if (!cmd_request) {
>> +        dev_err_ratelimited(&pdev->dev, "Null cmd request\n");
>> +
>> +        return -EINVAL;
>> +    }
>> +
>> +    if (cmd_request_size > NE_SEND_DATA_SIZE) {
>> +        dev_err_ratelimited(&pdev->dev,
>> +                    "Invalid req size=%zu for cmd type=%u\n",
>> +                    cmd_request_size, cmd_type);
>> +
>> +        return -EINVAL;
>> +    }
>> +
>> +    if (!cmd_reply) {
>> +        dev_err_ratelimited(&pdev->dev, "Null cmd reply\n");
>> +
>> +        return -EINVAL;
>> +    }
>> +
>> +    if (cmd_reply_size > NE_RECV_DATA_SIZE) {
>> +        dev_err_ratelimited(&pdev->dev, "Invalid reply size=%zu\n",
>> +                    cmd_reply_size);
>> +
>> +        return -EINVAL;
>> +    }
>> +
>> +    /*
>> +     * Use this mutex so that the PCI device handles one command 
>> request at
>> +     * a time.
>> +     */
>> +    mutex_lock(&ne_pci_dev->pci_dev_mutex);
>> +
>> +    atomic_set(&ne_pci_dev->cmd_reply_avail, 0);
>> +
>> +    rc = ne_submit_request(pdev, cmd_type, cmd_request, 
>> cmd_request_size);
>> +    if (rc < 0) {
>> +        dev_err_ratelimited(&pdev->dev,
>> +                    "Error in submit request [rc=%d]\n", rc);
>> +
>> +        goto unlock_mutex;
>> +    }
>> +
>> +    rc = ne_wait_for_reply(pdev);
>> +    if (rc < 0) {
>> +        dev_err_ratelimited(&pdev->dev,
>> +                    "Error in wait for reply [rc=%d]\n", rc);
>> +
>> +        goto unlock_mutex;
>> +    }
>> +
>> +    rc = ne_retrieve_reply(pdev, cmd_reply, cmd_reply_size);
>> +    if (rc < 0) {
>> +        dev_err_ratelimited(&pdev->dev,
>> +                    "Error in retrieve reply [rc=%d]\n", rc);
>> +
>> +        goto unlock_mutex;
>> +    }
>> +
>> +    atomic_set(&ne_pci_dev->cmd_reply_avail, 0);
>> +
>> +    if (cmd_reply->rc < 0) {
>> +        dev_err_ratelimited(&pdev->dev,
>> +                    "Error in cmd process logic [rc=%d]\n",
>> +                    cmd_reply->rc);
>> +
>> +        rc = cmd_reply->rc;
>> +
>> +        goto unlock_mutex;
>> +    }
>> +
>> +    mutex_unlock(&ne_pci_dev->pci_dev_mutex);
>> +
>> +    return 0;
>
> Can you just set rc to 0 and fall through?

Done.

>
>> +
>> +unlock_mutex:
>> +    mutex_unlock(&ne_pci_dev->pci_dev_mutex);
>> +
>> +    return rc;
>> +}
>> +
>> +/**
>> + * ne_reply_handler - Interrupt handler for retrieving a reply matching
>> + * a request sent to the PCI device for enclave lifetime management.
>> + *
>> + * @irq: received interrupt for a reply sent by the PCI device.
>> + * @args: PCI device private data structure.
>> + *
>> + * @returns: IRQ_HANDLED on handled interrupt, IRQ_NONE otherwise.
>> + */
>> +static irqreturn_t ne_reply_handler(int irq, void *args)
>> +{
>> +    struct ne_pci_dev *ne_pci_dev = (struct ne_pci_dev *)args;
>> +
>> +    if (!ne_pci_dev)
>> +        return IRQ_NONE;
>
> How can this ever happen?
>
>
> Alex
>
>> +
>> +    atomic_set(&ne_pci_dev->cmd_reply_avail, 1);
>> +
>> +    /* TODO: Update to _interruptible. */
>> +    wake_up(&ne_pci_dev->cmd_reply_wait_q);
>> +
>> +    return IRQ_HANDLED;
>> +}
>> +
>>   /**
>>    * ne_setup_msix - Setup MSI-X vectors for the PCI device.
>>    *
>> @@ -59,7 +271,25 @@ static int ne_setup_msix(struct pci_dev *pdev)
>>           return rc;
>>       }
>>   +    /*
>> +     * This IRQ gets triggered every time the PCI device responds to a
>> +     * command request. The reply is then retrieved, reading from 
>> the MMIO
>> +     * space of the PCI device.
>> +     */
>> +    rc = request_irq(pci_irq_vector(pdev, NE_VEC_REPLY),
>> +             ne_reply_handler, 0, "enclave_cmd", ne_pci_dev);
>> +    if (rc < 0) {
>> +        dev_err(&pdev->dev, "Error in request irq reply [rc=%d]\n", 
>> rc);
>> +
>> +        goto free_irq_vectors;
>> +    }
>> +
>>       return 0;
>> +
>> +free_irq_vectors:
>> +    pci_free_irq_vectors(pdev);
>> +
>> +    return rc;
>>   }
>>     /**
>> @@ -74,6 +304,8 @@ static void ne_teardown_msix(struct pci_dev *pdev)
>>       if (!ne_pci_dev)
>>           return;
>>   +    free_irq(pci_irq_vector(pdev, NE_VEC_REPLY), ne_pci_dev);
>> +
>>       pci_free_irq_vectors(pdev);
>>   }
>>




Amazon Development Center (Romania) S.R.L. registered office: 27A Sf. Lazar Street, UBC5, floor 2, Iasi, Iasi County, 700045, Romania. Registered in Romania. Registration number J22/2621/2005.
diff mbox series

Patch

diff --git a/drivers/virt/nitro_enclaves/ne_pci_dev.c b/drivers/virt/nitro_enclaves/ne_pci_dev.c
index 235fa3ecbee2..c24230cfe7c0 100644
--- a/drivers/virt/nitro_enclaves/ne_pci_dev.c
+++ b/drivers/virt/nitro_enclaves/ne_pci_dev.c
@@ -27,6 +27,218 @@  static const struct pci_device_id ne_pci_ids[] = {
 
 MODULE_DEVICE_TABLE(pci, ne_pci_ids);
 
+/**
+ * ne_submit_request - Submit command request to the PCI device based on the
+ * command type.
+ *
+ * This function gets called with the ne_pci_dev mutex held.
+ *
+ * @pdev: PCI device to send the command to.
+ * @cmd_type: command type of the request sent to the PCI device.
+ * @cmd_request: command request payload.
+ * @cmd_request_size: size of the command request payload.
+ *
+ * @returns: 0 on success, negative return value on failure.
+ */
+static int ne_submit_request(struct pci_dev *pdev,
+			     enum ne_pci_dev_cmd_type cmd_type,
+			     void *cmd_request, size_t cmd_request_size)
+{
+	struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
+
+	if (!ne_pci_dev || !ne_pci_dev->iomem_base)
+		return -EINVAL;
+
+	memcpy_toio(ne_pci_dev->iomem_base + NE_SEND_DATA, cmd_request,
+		    cmd_request_size);
+
+	iowrite32(cmd_type, ne_pci_dev->iomem_base + NE_COMMAND);
+
+	return 0;
+}
+
+/**
+ * ne_retrieve_reply - Retrieve reply from the PCI device.
+ *
+ * This function gets called with the ne_pci_dev mutex held.
+ *
+ * @pdev: PCI device to receive the reply from.
+ * @cmd_reply: command reply payload.
+ * @cmd_reply_size: size of the command reply payload.
+ *
+ * @returns: 0 on success, negative return value on failure.
+ */
+static int ne_retrieve_reply(struct pci_dev *pdev,
+			     struct ne_pci_dev_cmd_reply *cmd_reply,
+			     size_t cmd_reply_size)
+{
+	struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
+
+	if (!ne_pci_dev || !ne_pci_dev->iomem_base)
+		return -EINVAL;
+
+	memcpy_fromio(cmd_reply, ne_pci_dev->iomem_base + NE_RECV_DATA,
+		      cmd_reply_size);
+
+	return 0;
+}
+
+/**
+ * ne_wait_for_reply - Wait for a reply of a PCI command.
+ *
+ * This function gets called with the ne_pci_dev mutex held.
+ *
+ * @pdev: PCI device for which a reply is waited.
+ *
+ * @returns: 0 on success, negative return value on failure.
+ */
+static int ne_wait_for_reply(struct pci_dev *pdev)
+{
+	struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
+	int rc = -EINVAL;
+
+	if (!ne_pci_dev)
+		return -EINVAL;
+
+	/*
+	 * TODO: Update to _interruptible and handle interrupted wait event
+	 * e.g. -ERESTARTSYS, incoming signals + add / update timeout.
+	 */
+	rc = wait_event_timeout(ne_pci_dev->cmd_reply_wait_q,
+				atomic_read(&ne_pci_dev->cmd_reply_avail) != 0,
+				msecs_to_jiffies(NE_DEFAULT_TIMEOUT_MSECS));
+	if (!rc)
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
+int ne_do_request(struct pci_dev *pdev, enum ne_pci_dev_cmd_type cmd_type,
+		  void *cmd_request, size_t cmd_request_size,
+		  struct ne_pci_dev_cmd_reply *cmd_reply, size_t cmd_reply_size)
+{
+	struct ne_pci_dev *ne_pci_dev = NULL;
+	int rc = -EINVAL;
+
+	if (!pdev)
+		return -ENODEV;
+
+	ne_pci_dev = pci_get_drvdata(pdev);
+	if (!ne_pci_dev || !ne_pci_dev->iomem_base)
+		return -EINVAL;
+
+	if (cmd_type <= INVALID_CMD || cmd_type >= MAX_CMD) {
+		dev_err_ratelimited(&pdev->dev, "Invalid cmd type=%u\n",
+				    cmd_type);
+
+		return -EINVAL;
+	}
+
+	if (!cmd_request) {
+		dev_err_ratelimited(&pdev->dev, "Null cmd request\n");
+
+		return -EINVAL;
+	}
+
+	if (cmd_request_size > NE_SEND_DATA_SIZE) {
+		dev_err_ratelimited(&pdev->dev,
+				    "Invalid req size=%zu for cmd type=%u\n",
+				    cmd_request_size, cmd_type);
+
+		return -EINVAL;
+	}
+
+	if (!cmd_reply) {
+		dev_err_ratelimited(&pdev->dev, "Null cmd reply\n");
+
+		return -EINVAL;
+	}
+
+	if (cmd_reply_size > NE_RECV_DATA_SIZE) {
+		dev_err_ratelimited(&pdev->dev, "Invalid reply size=%zu\n",
+				    cmd_reply_size);
+
+		return -EINVAL;
+	}
+
+	/*
+	 * Use this mutex so that the PCI device handles one command request at
+	 * a time.
+	 */
+	mutex_lock(&ne_pci_dev->pci_dev_mutex);
+
+	atomic_set(&ne_pci_dev->cmd_reply_avail, 0);
+
+	rc = ne_submit_request(pdev, cmd_type, cmd_request, cmd_request_size);
+	if (rc < 0) {
+		dev_err_ratelimited(&pdev->dev,
+				    "Error in submit request [rc=%d]\n", rc);
+
+		goto unlock_mutex;
+	}
+
+	rc = ne_wait_for_reply(pdev);
+	if (rc < 0) {
+		dev_err_ratelimited(&pdev->dev,
+				    "Error in wait for reply [rc=%d]\n", rc);
+
+		goto unlock_mutex;
+	}
+
+	rc = ne_retrieve_reply(pdev, cmd_reply, cmd_reply_size);
+	if (rc < 0) {
+		dev_err_ratelimited(&pdev->dev,
+				    "Error in retrieve reply [rc=%d]\n", rc);
+
+		goto unlock_mutex;
+	}
+
+	atomic_set(&ne_pci_dev->cmd_reply_avail, 0);
+
+	if (cmd_reply->rc < 0) {
+		dev_err_ratelimited(&pdev->dev,
+				    "Error in cmd process logic [rc=%d]\n",
+				    cmd_reply->rc);
+
+		rc = cmd_reply->rc;
+
+		goto unlock_mutex;
+	}
+
+	mutex_unlock(&ne_pci_dev->pci_dev_mutex);
+
+	return 0;
+
+unlock_mutex:
+	mutex_unlock(&ne_pci_dev->pci_dev_mutex);
+
+	return rc;
+}
+
+/**
+ * ne_reply_handler - Interrupt handler for retrieving a reply matching
+ * a request sent to the PCI device for enclave lifetime management.
+ *
+ * @irq: received interrupt for a reply sent by the PCI device.
+ * @args: PCI device private data structure.
+ *
+ * @returns: IRQ_HANDLED on handled interrupt, IRQ_NONE otherwise.
+ */
+static irqreturn_t ne_reply_handler(int irq, void *args)
+{
+	struct ne_pci_dev *ne_pci_dev = (struct ne_pci_dev *)args;
+
+	if (!ne_pci_dev)
+		return IRQ_NONE;
+
+	atomic_set(&ne_pci_dev->cmd_reply_avail, 1);
+
+	/* TODO: Update to _interruptible. */
+	wake_up(&ne_pci_dev->cmd_reply_wait_q);
+
+	return IRQ_HANDLED;
+}
+
 /**
  * ne_setup_msix - Setup MSI-X vectors for the PCI device.
  *
@@ -59,7 +271,25 @@  static int ne_setup_msix(struct pci_dev *pdev)
 		return rc;
 	}
 
+	/*
+	 * This IRQ gets triggered every time the PCI device responds to a
+	 * command request. The reply is then retrieved, reading from the MMIO
+	 * space of the PCI device.
+	 */
+	rc = request_irq(pci_irq_vector(pdev, NE_VEC_REPLY),
+			 ne_reply_handler, 0, "enclave_cmd", ne_pci_dev);
+	if (rc < 0) {
+		dev_err(&pdev->dev, "Error in request irq reply [rc=%d]\n", rc);
+
+		goto free_irq_vectors;
+	}
+
 	return 0;
+
+free_irq_vectors:
+	pci_free_irq_vectors(pdev);
+
+	return rc;
 }
 
 /**
@@ -74,6 +304,8 @@  static void ne_teardown_msix(struct pci_dev *pdev)
 	if (!ne_pci_dev)
 		return;
 
+	free_irq(pci_irq_vector(pdev, NE_VEC_REPLY), ne_pci_dev);
+
 	pci_free_irq_vectors(pdev);
 }