LKML Archive on lore.kernel.org
 help / color / Atom feed
From: Andra Paraschiv <andraprs@amazon.com>
To: <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>,
	Andra Paraschiv <andraprs@amazon.com>
Subject: [PATCH v1 06/15] nitro_enclaves: Handle out-of-band PCI device events
Date: Tue, 21 Apr 2020 21:41:41 +0300
Message-ID: <20200421184150.68011-7-andraprs@amazon.com> (raw)
In-Reply-To: <20200421184150.68011-1-andraprs@amazon.com>

In addition to the replies sent by the Nitro Enclaves PCI device in
response to command requests, out-of-band enclave events can happen e.g.
an enclave crashes. In this case, the Nitro Enclaves driver needs to be
aware of the event and notify the corresponding user space process that
abstracts the enclave.

Register an MSI-X interrupt vector to be used for this kind of
out-of-band events. The interrupt notifies that the state of an enclave
changed and the driver logic scans the state of each running enclave to
identify for which this notification is intended.

Create an workqueue to handle the out-of-band events. Notify user space
enclave process that is using a polling mechanism on the enclave fd. The
enclave fd is returned as a result of KVM_CREATE_VM ioctl call.

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   | 120 ++++++++++++++++++
 1 file changed, 120 insertions(+)

diff --git a/drivers/virt/amazon/nitro_enclaves/ne_pci_dev.c b/drivers/virt/amazon/nitro_enclaves/ne_pci_dev.c
index 7453d129689a..884acbb92305 100644
--- a/drivers/virt/amazon/nitro_enclaves/ne_pci_dev.c
+++ b/drivers/virt/amazon/nitro_enclaves/ne_pci_dev.c
@@ -285,6 +285,85 @@ static irqreturn_t ne_reply_handler(int irq, void *args)
 	return IRQ_HANDLED;
 }
 
+/**
+ * ne_event_work_handler - Work queue handler for notifying enclaves on
+ * a state change received by the event interrupt handler.
+ *
+ * An out-of-band event is being issued by the Nitro Hypervisor when at least
+ * one enclave is changing state without client interaction.
+ *
+ * @work: item containing the Nitro Enclaves PCI device for which a
+ *	  out-of-band event was issued.
+ */
+static void ne_event_work_handler(struct work_struct *work)
+{
+	struct ne_pci_dev_cmd_reply cmd_reply = {};
+	struct ne_enclave *ne_enclave = NULL;
+	struct ne_pci_dev *ne_pci_dev =
+		container_of(work, struct ne_pci_dev, notify_work);
+	int rc = -EINVAL;
+	struct slot_info_req slot_info_req = {};
+
+	mutex_lock(&ne_pci_dev->enclaves_list_mutex);
+
+	/*
+	 * Iterate over all enclaves registered for the Nitro Enclaves
+	 * PCI device and determine for which enclave(s) the out-of-band event
+	 * is corresponding to.
+	 */
+	list_for_each_entry(ne_enclave, &ne_pci_dev->enclaves_list,
+			    enclave_list_entry) {
+		mutex_lock(&ne_enclave->enclave_info_mutex);
+
+		/*
+		 * Enclaves that were never started cannot receive out-of-band
+		 * events.
+		 */
+		if (ne_enclave->state != NE_STATE_RUNNING)
+			goto unlock;
+
+		slot_info_req.slot_uid = ne_enclave->slot_uid;
+
+		rc = ne_do_request(ne_enclave->pdev, SLOT_INFO, &slot_info_req,
+				   sizeof(slot_info_req), &cmd_reply,
+				   sizeof(cmd_reply));
+		WARN_ON(rc < 0);
+
+		/* Notify enclave process that the enclave state changed. */
+		if (ne_enclave->state != cmd_reply.state) {
+			ne_enclave->state = cmd_reply.state;
+
+			ne_enclave->has_event = true;
+
+			wake_up_interruptible(&ne_enclave->eventq);
+		}
+
+unlock:
+		 mutex_unlock(&ne_enclave->enclave_info_mutex);
+	}
+
+	mutex_unlock(&ne_pci_dev->enclaves_list_mutex);
+}
+
+/**
+ * ne_event_handler - Interrupt handler for PCI device out-of-band
+ * events. This interrupt does not supply any data in the MMIO region.
+ * It notifies a change in the state of any of the launched enclaves.
+ *
+ * @irq: received interrupt for an out-of-band event.
+ * @args: PCI device private data structure.
+ *
+ * @returns: IRQ_HANDLED on handled interrupt, IRQ_NONE otherwise.
+ */
+static irqreturn_t ne_event_handler(int irq, void *args)
+{
+	struct ne_pci_dev *ne_pci_dev = (struct ne_pci_dev *)args;
+
+	queue_work(ne_pci_dev->event_wq, &ne_pci_dev->notify_work);
+
+	return IRQ_HANDLED;
+}
+
 /**
  * ne_setup_msix - Setup MSI-X vectors for the PCI device.
  *
@@ -311,6 +390,19 @@ static int ne_setup_msix(struct pci_dev *pdev, struct ne_pci_dev *ne_pci_dev)
 		return rc;
 	}
 
+	ne_pci_dev->event_wq = create_singlethread_workqueue("ne_pci_dev_wq");
+	if (!ne_pci_dev->event_wq) {
+		rc = -ENOMEM;
+
+		dev_err_ratelimited(&pdev->dev,
+				    "Cannot get wq for device events [rc=%d]\n",
+				    rc);
+
+		goto err_create_wq;
+	}
+
+	INIT_WORK(&ne_pci_dev->notify_work, ne_event_work_handler);
+
 	rc = pci_alloc_irq_vectors(pdev, nr_vecs, nr_vecs, PCI_IRQ_MSIX);
 	if (rc < 0) {
 		dev_err_ratelimited(&pdev->dev,
@@ -335,11 +427,30 @@ static int ne_setup_msix(struct pci_dev *pdev, struct ne_pci_dev *ne_pci_dev)
 		goto err_req_irq_reply;
 	}
 
+	/*
+	 * This IRQ gets triggered every time any enclave's state changes. Its
+	 * handler then scans for the changes and propagates them to the user
+	 * space.
+	 */
+	rc = request_irq(pci_irq_vector(pdev, NE_VEC_EVENT),
+			 ne_event_handler, 0, "enclave_evt", ne_pci_dev);
+	if (rc < 0) {
+		dev_err_ratelimited(&pdev->dev,
+				    "Failure in allocating irq event [rc=%d]\n",
+				    rc);
+
+		goto err_req_irq_event;
+	}
+
 	return 0;
 
+err_req_irq_event:
+	free_irq(pci_irq_vector(pdev, NE_VEC_REPLY), ne_pci_dev);
 err_req_irq_reply:
 	pci_free_irq_vectors(pdev);
 err_alloc_irq_vecs:
+	destroy_workqueue(ne_pci_dev->event_wq);
+err_create_wq:
 	return rc;
 }
 
@@ -494,8 +605,10 @@ 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_EVENT), ne_pci_dev);
 	free_irq(pci_irq_vector(pdev, NE_VEC_REPLY), ne_pci_dev);
 	pci_free_irq_vectors(pdev);
+	destroy_workqueue(ne_pci_dev->event_wq);
 err_setup_msix:
 	pci_iounmap(pdev, ne_pci_dev->iomem_base);
 err_iomap:
@@ -518,9 +631,16 @@ static void ne_remove(struct pci_dev *pdev)
 
 	pci_set_drvdata(pdev, NULL);
 
+	free_irq(pci_irq_vector(pdev, NE_VEC_EVENT), ne_pci_dev);
 	free_irq(pci_irq_vector(pdev, NE_VEC_REPLY), ne_pci_dev);
 	pci_free_irq_vectors(pdev);
 
+	if (ne_pci_dev->event_wq) {
+		flush_work(&ne_pci_dev->notify_work);
+		flush_workqueue(ne_pci_dev->event_wq);
+		destroy_workqueue(ne_pci_dev->event_wq);
+	}
+
 	pci_iounmap(pdev, ne_pci_dev->iomem_base);
 
 	kzfree(ne_pci_dev);
-- 
2.20.1 (Apple Git-117)




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.


  parent reply index

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
2020-04-29 17:00     ` Paraschiv, Andra-Irina
2020-04-21 18:41 ` Andra Paraschiv [this message]
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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200421184150.68011-7-andraprs@amazon.com \
    --to=andraprs@amazon.com \
    --cc=aliguori@amazon.com \
    --cc=benh@amazon.com \
    --cc=colmmacc@amazon.com \
    --cc=doebel@amazon.de \
    --cc=dwmw@amazon.co.uk \
    --cc=fllinden@amazon.com \
    --cc=graf@amazon.de \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mpohlack@amazon.de \
    --cc=msw@amazon.com \
    --cc=ne-devel-upstream@amazon.com \
    --cc=pbonzini@redhat.com \
    --cc=sblbir@amazon.com \
    --cc=trawets@amazon.com \
    --cc=uwed@amazon.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git
	git clone --mirror https://lore.kernel.org/lkml/8 lkml/git/8.git
	git clone --mirror https://lore.kernel.org/lkml/9 lkml/git/9.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org
	public-inbox-index lkml

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git