Re: [PATCH v6 08/18] nitro_enclaves: Add logic for creating an enclave VM

Alexander Graf
2020-08-10T06:11:28Z

On 05.08.20 11:10, Andra Paraschiv wrote:
> Add ioctl command logic for enclave VM creation. It triggers a slot
> allocation. The enclave resources will be associated with this slot and
> it will be used as an identifier for triggering enclave run.
>
> Return a file descriptor, namely enclave fd. This is further used by the
> associated user space enclave process to set enclave resources and
> trigger enclave termination.
>
> The poll function is implemented in order to notify the enclave process
> when an enclave exits without a specific enclave termination command
> trigger e.g. when an enclave crashes.
>
> Signed-off-by: Alexandru Vasile <lexnv@amazon.com>
> Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
> Reviewed-by: Alexander Graf <graf@amazon.com>
> ---
> Changelog
>
> v5 -> v6
>
> * Update the code base to init the ioctl function in this patch.
> * Update documentation to kernel-doc format.
>
> v4 -> v5
>
> * Release the reference to the NE PCI device on create VM error.
> * Close enclave fd on copy_to_user() failure; rename fd to enclave fd
> while at it.
> * Remove sanity checks for situations that shouldn't happen, only if
> buggy system or broken logic at all.
> * Remove log on copy_to_user() failure.
>
> v3 -> v4
>
> * Use dev_err instead of custom NE log pattern.
> * Update the NE ioctl call to match the decoupling from the KVM API.
> * Add metadata for the NUMA node for the enclave memory and CPUs.
>
> v2 -> v3
>
> * Remove the WARN_ON calls.
> * Update static calls sanity checks.
> * Update kzfree() calls to kfree().
> * Remove file ops that do nothing for now - open.
>
> v1 -> v2
>
> * Add log pattern for NE.
> * Update goto labels to match their purpose.
> * Remove the BUG_ON calls.
> ---
> drivers/virt/nitro_enclaves/ne_misc_dev.c | 229 ++++++++++++++++++++++
> 1 file changed, 229 insertions(+)
>
> diff --git a/drivers/virt/nitro_enclaves/ne_misc_dev.c b/drivers/virt/nitro_enclaves/ne_misc_dev.c
> index 472850250220..6c8c12f65666 100644
> --- a/drivers/virt/nitro_enclaves/ne_misc_dev.c
> +++ b/drivers/virt/nitro_enclaves/ne_misc_dev.c

[...]

> +/**
> + * ne_ioctl() - Ioctl function provided by the NE misc device.
> + * @file: File associated with this ioctl function.
> + * @cmd: The command that is set for the ioctl call.
> + * @arg: The argument that is provided for the ioctl call.
> + *
> + * Context: Process context.
> + * Return:
> + * * Ioctl result (e.g. enclave file descriptor) on success.
> + * * Negative return value on failure.
> + */
> +static long ne_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
> +{
> + switch (cmd) {
> + case NE_CREATE_VM: {
> + int enclave_fd = -1;
> + struct file *enclave_file = NULL;
> + struct ne_pci_dev *ne_pci_dev = NULL;
> + /* TODO: Find another way to get the NE PCI device reference. */
> + struct pci_dev *pdev = pci_get_device(PCI_VENDOR_ID_AMAZON,
> + PCI_DEVICE_ID_NE, NULL);

This should go away if you set misc_dev.parent.

> + int rc = -EINVAL;
> + u64 slot_uid = 0;
> +
> + ne_pci_dev = pci_get_drvdata(pdev);
> +
> + mutex_lock(&ne_pci_dev->enclaves_list_mutex);
> +
> + enclave_fd = ne_create_vm_ioctl(pdev, ne_pci_dev, &slot_uid);
> + if (enclave_fd < 0) {
> + rc = enclave_fd;
> +
> + mutex_unlock(&ne_pci_dev->enclaves_list_mutex);
> +
> + pci_dev_put(pdev);

This should also disappear.

Alex

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