From: Liran Alon <liran.alon@oracle.com>
To: Andra Paraschiv <andraprs@amazon.com>, linux-kernel@vger.kernel.org
Cc: Anthony Liguori <aliguori@amazon.com>,
Benjamin Herrenschmidt <benh@amazon.com>,
Colm MacCarthaigh <colmmacc@amazon.com>,
Bjoern Doebel <doebel@amazon.de>,
David Woodhouse <dwmw@amazon.co.uk>,
Frank van der Linden <fllinden@amazon.com>,
Alexander Graf <graf@amazon.de>,
Martin Pohlack <mpohlack@amazon.de>, Matt Wilson <msw@amazon.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Balbir Singh <sblbir@amazon.com>,
Stewart Smith <trawets@amazon.com>,
Uwe Dannowski <uwed@amazon.de>,
kvm@vger.kernel.org, ne-devel-upstream@amazon.com
Subject: Re: [PATCH v1 05/15] nitro_enclaves: Handle PCI device command requests
Date: Sat, 25 Apr 2020 17:52:17 +0300 [thread overview]
Message-ID: <39060271-279b-546b-05a6-c5b2fd7ff5d0@oracle.com> (raw)
In-Reply-To: <20200421184150.68011-6-andraprs@amazon.com>
On 21/04/2020 21:41, 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>
> ---
> .../virt/amazon/nitro_enclaves/ne_pci_dev.c | 264 ++++++++++++++++++
> 1 file changed, 264 insertions(+)
>
> diff --git a/drivers/virt/amazon/nitro_enclaves/ne_pci_dev.c b/drivers/virt/amazon/nitro_enclaves/ne_pci_dev.c
> index 8fbee95ea291..7453d129689a 100644
> --- a/drivers/virt/amazon/nitro_enclaves/ne_pci_dev.c
> +++ b/drivers/virt/amazon/nitro_enclaves/ne_pci_dev.c
> @@ -40,6 +40,251 @@ 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 = NULL;
These local vars are unnecessarily initialized.
> +
> + BUG_ON(!pdev);
> +
> + ne_pci_dev = pci_get_drvdata(pdev);
> + BUG_ON(!ne_pci_dev);
> + BUG_ON(!ne_pci_dev->iomem_base);
You should remove these defensive BUG_ON() calls.
> +
> + if (WARN_ON(cmd_type <= INVALID_CMD || cmd_type >= MAX_CMD)) {
> + dev_err_ratelimited(&pdev->dev, "Invalid cmd type=%d\n",
> + cmd_type);
> +
> + return -EINVAL;
> + }
> +
> + if (WARN_ON(!cmd_request))
> + return -EINVAL;
> +
> + if (WARN_ON(cmd_request_size > NE_SEND_DATA_SIZE)) {
> + dev_err_ratelimited(&pdev->dev,
> + "Invalid req size=%ld for cmd type=%d\n",
> + cmd_request_size, cmd_type);
> +
> + return -EINVAL;
> + }
It doesn't make sense to have WARN_ON() print error to dmesg on every
evaluation to true,
together with using dev_err_ratelimited() which attempts to rate-limit
prints.
Anyway, these conditions were already checked by ne_do_request(). Why
also check them here?
> +
> + 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 = NULL;
These local vars are unnecessarily initialized.
> +
> + BUG_ON(!pdev);
> +
> + ne_pci_dev = pci_get_drvdata(pdev);
> + BUG_ON(!ne_pci_dev);
> + BUG_ON(!ne_pci_dev->iomem_base);
You should remove these defensive BUG_ON() calls.
> +
> + if (WARN_ON(!cmd_reply))
> + return -EINVAL;
> +
> + if (WARN_ON(cmd_reply_size > NE_RECV_DATA_SIZE)) {
> + dev_err_ratelimited(&pdev->dev, "Invalid reply size=%ld\n",
> + cmd_reply_size);
> +
> + return -EINVAL;
> + }
It doesn't make sense to have WARN_ON() print error to dmesg on every
evaluation to true,
together with using dev_err_ratelimited() which attempts to rate-limit
prints.
Anyway, these conditions were already checked by ne_do_request(). Why
also check them here?
> +
> + 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 = NULL;
> + int rc = -EINVAL;
These local vars are unnecessarily initialized.
> +
> + BUG_ON(!pdev);
> +
> + ne_pci_dev = pci_get_drvdata(pdev);
> + BUG_ON(!ne_pci_dev);
You should remove these defensive BUG_ON() calls.
> +
> + /*
> + * 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(DEFAULT_TIMEOUT_MSECS));
> + if (!rc) {
> + pr_err("Wait event timed out when waiting for PCI cmd reply\n");
> +
> + 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)
This function is introduced in this patch but it is not used.
It will cause compiling the kernel on this commit to raise
warnings/errors on unused functions.
You should introduce functions on the patch that they are used.
> +{
> + struct ne_pci_dev *ne_pci_dev = NULL;
> + int rc = -EINVAL;
These local vars are unnecessarily initialized.
> +
> + BUG_ON(!pdev);
> +
> + ne_pci_dev = pci_get_drvdata(pdev);
> + BUG_ON(!ne_pci_dev);
> + BUG_ON(!ne_pci_dev->iomem_base);
You should remove these defensive BUG_ON() calls.
> +
> + if (WARN_ON(cmd_type <= INVALID_CMD || cmd_type >= MAX_CMD)) {
> + dev_err_ratelimited(&pdev->dev, "Invalid cmd type=%d\n",
> + cmd_type);
> +
> + return -EINVAL;
> + }
> +
> + if (WARN_ON(!cmd_request))
> + return -EINVAL;
> +
> + if (WARN_ON(cmd_request_size > NE_SEND_DATA_SIZE)) {
> + dev_err_ratelimited(&pdev->dev,
> + "Invalid req size=%ld for cmd type=%d\n",
> + cmd_request_size, cmd_type);
> +
> + return -EINVAL;
> + }
> +
> + if (WARN_ON(!cmd_reply))
> + return -EINVAL;
> +
> + if (WARN_ON(cmd_reply_size > NE_RECV_DATA_SIZE)) {
> + dev_err_ratelimited(&pdev->dev, "Invalid reply size=%ld\n",
> + cmd_reply_size);
> +
> + return -EINVAL;
> + }
I would consider specifying all these conditions in function
documentation instead of enforcing them at runtime on every function call.
> +
> + /*
> + * 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,
> + "Failure in submit cmd request [rc=%d]\n",
> + rc);
> +
> + mutex_unlock(&ne_pci_dev->pci_dev_mutex);
> +
> + return rc;
Consider leaving function with a goto to a label that unlocks mutex and
then return.
> + }
> +
> + rc = ne_wait_for_reply(pdev);
> + if (rc < 0) {
> + dev_err_ratelimited(&pdev->dev,
> + "Failure in wait cmd reply [rc=%d]\n",
> + rc);
> +
> + mutex_unlock(&ne_pci_dev->pci_dev_mutex);
> +
> + return rc;
> + }
> +
> + rc = ne_retrieve_reply(pdev, cmd_reply, cmd_reply_size);
> + if (rc < 0) {
> + dev_err_ratelimited(&pdev->dev,
> + "Failure in retrieve cmd reply [rc=%d]\n",
> + rc);
> +
> + mutex_unlock(&ne_pci_dev->pci_dev_mutex);
> +
> + return rc;
> + }
> +
> + atomic_set(&ne_pci_dev->cmd_reply_avail, 0);
> +
> + if (cmd_reply->rc < 0) {
> + dev_err_ratelimited(&pdev->dev,
> + "Failure in cmd process logic [rc=%d]\n",
> + cmd_reply->rc);
> +
> + mutex_unlock(&ne_pci_dev->pci_dev_mutex);
> +
> + return cmd_reply->rc;
> + }
> +
> + mutex_unlock(&ne_pci_dev->pci_dev_mutex);
> +
> + return 0;
> +}
> +
> +/**
> + * 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;
> +
> + 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.
> *
> @@ -75,8 +320,25 @@ static int ne_setup_msix(struct pci_dev *pdev, struct ne_pci_dev *ne_pci_dev)
> goto err_alloc_irq_vecs;
> }
>
> + /*
> + * 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_ratelimited(&pdev->dev,
> + "Failure in allocating irq reply [rc=%d]\n",
> + rc);
> +
> + goto err_req_irq_reply;
> + }
> +
> return 0;
>
> +err_req_irq_reply:
> + pci_free_irq_vectors(pdev);
> err_alloc_irq_vecs:
> return rc;
> }
> @@ -232,6 +494,7 @@ static int ne_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>
> err_ne_pci_dev_enable:
> err_ne_pci_dev_disable:
> + free_irq(pci_irq_vector(pdev, NE_VEC_REPLY), ne_pci_dev);
> pci_free_irq_vectors(pdev);
I suggest to introduce a ne_teardown_msix() utility. That is aimed to
cleanup after ne_setup_msix().
> err_setup_msix:
> pci_iounmap(pdev, ne_pci_dev->iomem_base);
> @@ -255,6 +518,7 @@ static void ne_remove(struct pci_dev *pdev)
>
> pci_set_drvdata(pdev, NULL);
>
> + free_irq(pci_irq_vector(pdev, NE_VEC_REPLY), ne_pci_dev);
> pci_free_irq_vectors(pdev);
>
> pci_iounmap(pdev, ne_pci_dev->iomem_base);
next prev parent reply other threads:[~2020-04-25 14:52 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-21 18:41 [PATCH v1 00/15] Add support for Nitro Enclaves Andra Paraschiv
2020-04-21 18:41 ` [PATCH v1 01/15] nitro_enclaves: Add ioctl interface definition Andra Paraschiv
2020-04-21 18:47 ` Randy Dunlap
2020-04-21 21:45 ` Paolo Bonzini
2020-04-22 15:49 ` Paraschiv, Andra-Irina
2020-04-21 18:41 ` [PATCH v1 02/15] nitro_enclaves: Define the PCI device interface Andra Paraschiv
2020-04-21 21:22 ` Paolo Bonzini
2020-04-23 13:37 ` Paraschiv, Andra-Irina
2020-04-24 15:10 ` Paraschiv, Andra-Irina
2020-04-21 18:41 ` [PATCH v1 03/15] nitro_enclaves: Define enclave info for internal bookkeeping Andra Paraschiv
2020-04-21 18:41 ` [PATCH v1 04/15] nitro_enclaves: Init PCI device driver Andra Paraschiv
2020-04-25 14:25 ` Liran Alon
2020-04-29 16:31 ` Paraschiv, Andra-Irina
2020-04-21 18:41 ` [PATCH v1 05/15] nitro_enclaves: Handle PCI device command requests Andra Paraschiv
2020-04-25 14:52 ` Liran Alon [this message]
2020-04-29 17:00 ` Paraschiv, Andra-Irina
2020-04-21 18:41 ` [PATCH v1 06/15] nitro_enclaves: Handle out-of-band PCI device events Andra Paraschiv
2020-04-21 18:41 ` [PATCH v1 07/15] nitro_enclaves: Init misc device providing the ioctl interface Andra Paraschiv
2020-04-21 18:41 ` [PATCH v1 08/15] nitro_enclaves: Add logic for enclave vm creation Andra Paraschiv
2020-04-21 18:41 ` [PATCH v1 09/15] nitro_enclaves: Add logic for enclave vcpu creation Andra Paraschiv
2020-04-21 18:41 ` [PATCH v1 10/15] nitro_enclaves: Add logic for enclave memory region set Andra Paraschiv
2020-04-21 18:41 ` [PATCH v1 11/15] nitro_enclaves: Add logic for enclave start Andra Paraschiv
2020-04-21 18:41 ` [PATCH v1 12/15] nitro_enclaves: Add logic for enclave termination Andra Paraschiv
2020-04-21 18:41 ` [PATCH v1 13/15] nitro_enclaves: Add Kconfig for the Nitro Enclaves driver Andra Paraschiv
2020-04-21 18:50 ` Randy Dunlap
2020-04-22 14:35 ` Paraschiv, Andra-Irina
2020-04-21 18:41 ` [PATCH v1 14/15] nitro_enclaves: Add Makefile " Andra Paraschiv
2020-04-23 8:12 ` kbuild test robot
2020-04-24 17:00 ` Paraschiv, Andra-Irina
2020-04-23 8:43 ` kbuild test robot
2020-04-24 15:27 ` Paraschiv, Andra-Irina
2020-04-21 18:41 ` [PATCH v1 15/15] MAINTAINERS: Add entry " Andra Paraschiv
2020-04-21 21:46 ` [PATCH v1 00/15] Add support for Nitro Enclaves Paolo Bonzini
2020-04-23 13:19 ` Paraschiv, Andra-Irina
2020-04-23 13:42 ` Paolo Bonzini
2020-04-23 17:42 ` Paraschiv, Andra-Irina
2020-04-23 17:51 ` Paolo Bonzini
2020-04-23 20:56 ` Alexander Graf
2020-04-23 21:18 ` Paolo Bonzini
2020-04-24 12:56 ` Alexander Graf
2020-04-24 16:27 ` Paolo Bonzini
2020-04-24 19:11 ` Alexander Graf
2020-04-25 16:05 ` Paolo Bonzini
2020-04-27 9:15 ` Paraschiv, Andra-Irina
2020-04-27 9:22 ` Paraschiv, Andra-Irina
2020-04-27 9:46 ` Paolo Bonzini
2020-04-27 10:00 ` Paraschiv, Andra-Irina
2020-04-28 15:07 ` Alexander Graf
2020-04-29 13:20 ` Paolo Bonzini
2020-04-30 13:59 ` Paraschiv, Andra-Irina
2020-04-30 10:34 ` Paolo Bonzini
2020-04-30 11:21 ` Alexander Graf
2020-04-30 11:38 ` Paolo Bonzini
2020-04-30 11:47 ` Alexander Graf
2020-04-30 11:58 ` Paolo Bonzini
2020-04-30 12:19 ` Alexander Graf
2020-05-07 17:44 ` Pavel Machek
2020-05-08 7:00 ` Paraschiv, Andra-Irina
2020-05-09 19:21 ` Pavel Machek
2020-05-10 11:02 ` Herrenschmidt, Benjamin
2020-05-11 10:49 ` Paraschiv, Andra-Irina
2020-05-11 13:49 ` Stefan Hajnoczi
2020-04-24 3:04 ` Longpeng (Mike, Cloud Infrastructure Service Product Dept.)
2020-04-24 8:19 ` Paraschiv, Andra-Irina
2020-04-24 9:54 ` Paraschiv, Andra-Irina
2020-04-26 1:55 ` Longpeng (Mike, Cloud Infrastructure Service Product Dept.)
2020-04-27 18:39 ` Paraschiv, Andra-Irina
2020-04-24 9:59 ` Tian, Kevin
2020-04-24 13:59 ` Paraschiv, Andra-Irina
2020-04-26 8:16 ` Tian, Kevin
2020-04-27 19:05 ` Paraschiv, Andra-Irina
[not found] ` <CAKXe6SLonLQLAOY9Q_2AzTeg4uJxiknsAWnJpTF0hMcXEG5Tew@mail.gmail.com>
2020-05-11 12:05 ` Paraschiv, Andra-Irina
2020-04-25 15:25 ` Liran Alon
2020-04-27 7:56 ` Paraschiv, Andra-Irina
2020-04-27 11:44 ` Liran Alon
2020-04-28 15:25 ` Alexander Graf
2020-04-28 16:01 ` Liran Alon
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