| Message ID | 20200421184150.68011-6-andraprs@amazon.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add support for Nitro Enclaves | expand |
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);
On 25/04/2020 17:52, Liran Alon wrote: > > 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. I would keep this initialized overall. >> + >> + 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. Done. >> + >> + 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? Updated to not use WARN_ON. Right, they were checked before, but I kept them here just for checking the parameters. > >> + >> + 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. This function is externally available, via the ne_pci_dev header, so it shouldn't raise warnings. >> +{ >> + 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. I think that both PCI dev logic checks and documentation would be helpful in this case. :) >> + >> + /* >> + * 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. Done, I added a goto for mutex unlock and return. In this patch and in a following one, that was having a similar cleanup structure. >> + } >> + >> + 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(). I added this functionality in a new function, then I used it for cleanup in this function and teardown in pci remove function. Thank you. Andra >> 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); 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 --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; + + BUG_ON(!pdev); + + ne_pci_dev = pci_get_drvdata(pdev); + BUG_ON(!ne_pci_dev); + BUG_ON(!ne_pci_dev->iomem_base); + + 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; + } + + 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; + + BUG_ON(!pdev); + + ne_pci_dev = pci_get_drvdata(pdev); + BUG_ON(!ne_pci_dev); + BUG_ON(!ne_pci_dev->iomem_base); + + 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; + } + + 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; + + BUG_ON(!pdev); + + ne_pci_dev = pci_get_drvdata(pdev); + BUG_ON(!ne_pci_dev); + + /* + * 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) +{ + struct ne_pci_dev *ne_pci_dev = NULL; + int rc = -EINVAL; + + BUG_ON(!pdev); + + ne_pci_dev = pci_get_drvdata(pdev); + BUG_ON(!ne_pci_dev); + BUG_ON(!ne_pci_dev->iomem_base); + + 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; + } + + /* + * 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; + } + + 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); 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);