7 files changed, 259 insertions, 8 deletions

diff --git a/Documentation/vfio.txt b/Documentation/vfio.txt
index b9ca02370d46..96978eced341 100644
--- a/Documentation/vfio.txt
+++ b/Documentation/vfio.txt
@@ -305,7 +305,15 @@ faster, the map/unmap handling has been implemented in real mode which provides
 an excellent performance which has limitations such as inability to do
 locked pages accounting in real time.
 
-So 3 additional ioctls have been added:
+4) According to sPAPR specification, A Partitionable Endpoint (PE) is an I/O
+subtree that can be treated as a unit for the purposes of partitioning and
+error recovery. A PE may be a single or multi-function IOA (IO Adapter), a
+function of a multi-function IOA, or multiple IOAs (possibly including switch
+and bridge structures above the multiple IOAs). PPC64 guests detect PCI errors
+and recover from them via EEH RTAS services, which works on the basis of
+additional ioctl commands.
+
+So 4 additional ioctls have been added:
 
         VFIO_IOMMU_SPAPR_TCE_GET_INFO - returns the size and the start
                 of the DMA window on the PCI bus.
@@ -316,9 +324,12 @@ So 3 additional ioctls have been added:
 
         VFIO_IOMMU_DISABLE - disables the container.
 
+        VFIO_EEH_PE_OP - provides an API for EEH setup, error detection and recovery.
 
 The code flow from the example above should be slightly changed:
 
+        struct vfio_eeh_pe_op pe_op = { .argsz = sizeof(pe_op), .flags = 0 };
+
         .....
         /* Add the group to the container */
         ioctl(group, VFIO_GROUP_SET_CONTAINER, &container);
@@ -342,9 +353,79 @@ The code flow from the example above should be slightly changed:
         dma_map.flags = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE;
 
         /* Check here is .iova/.size are within DMA window from spapr_iommu_info */
-
         ioctl(container, VFIO_IOMMU_MAP_DMA, &dma_map);
-        .....
+
+        /* Get a file descriptor for the device */
+        device = ioctl(group, VFIO_GROUP_GET_DEVICE_FD, "0000:06:0d.0");
+
+        ....
+
+        /* Gratuitous device reset and go... */
+        ioctl(device, VFIO_DEVICE_RESET);
+
+        /* Make sure EEH is supported */
+        ioctl(container, VFIO_CHECK_EXTENSION, VFIO_EEH);
+
+        /* Enable the EEH functionality on the device */
+        pe_op.op = VFIO_EEH_PE_ENABLE;
+        ioctl(container, VFIO_EEH_PE_OP, &pe_op);
+
+        /* You're suggested to create additional data struct to represent
+         * PE, and put child devices belonging to same IOMMU group to the
+         * PE instance for later reference.
+         */
+
+        /* Check the PE's state and make sure it's in functional state */
+        pe_op.op = VFIO_EEH_PE_GET_STATE;
+        ioctl(container, VFIO_EEH_PE_OP, &pe_op);
+
+        /* Save device state using pci_save_state().
+         * EEH should be enabled on the specified device.
+         */
+
+        ....
+
+        /* When 0xFF's returned from reading PCI config space or IO BARs
+         * of the PCI device. Check the PE's state to see if that has been
+         * frozen.
+         */
+        ioctl(container, VFIO_EEH_PE_OP, &pe_op);
+
+        /* Waiting for pending PCI transactions to be completed and don't
+         * produce any more PCI traffic from/to the affected PE until
+         * recovery is finished.
+         */
+
+        /* Enable IO for the affected PE and collect logs. Usually, the
+         * standard part of PCI config space, AER registers are dumped
+         * as logs for further analysis.
+         */
+        pe_op.op = VFIO_EEH_PE_UNFREEZE_IO;
+        ioctl(container, VFIO_EEH_PE_OP, &pe_op);
+
+        /*
+         * Issue PE reset: hot or fundamental reset. Usually, hot reset
+         * is enough. However, the firmware of some PCI adapters would
+         * require fundamental reset.
+         */
+        pe_op.op = VFIO_EEH_PE_RESET_HOT;
+        ioctl(container, VFIO_EEH_PE_OP, &pe_op);
+        pe_op.op = VFIO_EEH_PE_RESET_DEACTIVATE;
+        ioctl(container, VFIO_EEH_PE_OP, &pe_op);
+
+        /* Configure the PCI bridges for the affected PE */
+        pe_op.op = VFIO_EEH_PE_CONFIGURE;
+        ioctl(container, VFIO_EEH_PE_OP, &pe_op);
+
+        /* Restored state we saved at initialization time. pci_restore_state()
+         * is good enough as an example.
+         */
+
+        /* Hopefully, error is recovered successfully. Now, you can resume to
+         * start PCI traffic to/from the affected PE.
+         */
+
+        ....
 
 -------------------------------------------------------------------------------
 
diff --git a/drivers/vfio/Makefile b/drivers/vfio/Makefile
index 72bfabc8629e..50e30bc75e85 100644
--- a/drivers/vfio/Makefile
+++ b/drivers/vfio/Makefile
@@ -1,4 +1,5 @@
 obj-$(CONFIG_VFIO) += vfio.o
 obj-$(CONFIG_VFIO_IOMMU_TYPE1) += vfio_iommu_type1.o
 obj-$(CONFIG_VFIO_IOMMU_SPAPR_TCE) += vfio_iommu_spapr_tce.o
+obj-$(CONFIG_EEH) += vfio_spapr_eeh.o
 obj-$(CONFIG_VFIO_PCI) += pci/
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 010e0f8b8e4f..e2ee80f36e3e 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -157,8 +157,10 @@ static void vfio_pci_release(void *device_data)
 {
         struct vfio_pci_device *vdev = device_data;
 
-        if (atomic_dec_and_test(&vdev->refcnt))
+        if (atomic_dec_and_test(&vdev->refcnt)) {
+                vfio_spapr_pci_eeh_release(vdev->pdev);
                 vfio_pci_disable(vdev);
+        }
 
         module_put(THIS_MODULE);
 }
@@ -166,19 +168,27 @@ static void vfio_pci_release(void *device_data)
 static int vfio_pci_open(void *device_data)
 {
         struct vfio_pci_device *vdev = device_data;
+        int ret;
 
         if (!try_module_get(THIS_MODULE))
                 return -ENODEV;
 
         if (atomic_inc_return(&vdev->refcnt) == 1) {
-                int ret = vfio_pci_enable(vdev);
+                ret = vfio_pci_enable(vdev);
+                if (ret)
+                        goto error;
+
+                ret = vfio_spapr_pci_eeh_open(vdev->pdev);
                 if (ret) {
-                        module_put(THIS_MODULE);
-                        return ret;
+                        vfio_pci_disable(vdev);
+                        goto error;
                 }
         }
 
         return 0;
+error:
+        module_put(THIS_MODULE);
+        return ret;
 }
 
 static int vfio_pci_get_irq_count(struct vfio_pci_device *vdev, int irq_type)
diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
index a84788ba662c..730b4ef3e0cc 100644
--- a/drivers/vfio/vfio_iommu_spapr_tce.c
+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
@@ -156,7 +156,16 @@ static long tce_iommu_ioctl(void *iommu_data,
 
         switch (cmd) {
         case VFIO_CHECK_EXTENSION:
-                return (arg == VFIO_SPAPR_TCE_IOMMU) ? 1 : 0;
+                switch (arg) {
+                case VFIO_SPAPR_TCE_IOMMU:
+                        ret = 1;
+                        break;
+                default:
+                        ret = vfio_spapr_iommu_eeh_ioctl(NULL, cmd, arg);
+                        break;
+                }
+
+                return (ret < 0) ? 0 : ret;
 
         case VFIO_IOMMU_SPAPR_TCE_GET_INFO: {
                 struct vfio_iommu_spapr_tce_info info;
@@ -283,6 +292,12 @@ static long tce_iommu_ioctl(void *iommu_data,
                 tce_iommu_disable(container);
                 mutex_unlock(&container->lock);
                 return 0;
+        case VFIO_EEH_PE_OP:
+                if (!container->tbl || !container->tbl->it_group)
+                        return -ENODEV;
+
+                return vfio_spapr_iommu_eeh_ioctl(container->tbl->it_group,
+                                                  cmd, arg);
         }
 
         return -ENOTTY;
diff --git a/drivers/vfio/vfio_spapr_eeh.c b/drivers/vfio/vfio_spapr_eeh.c
new file mode 100644
index 000000000000..f834b4ce1431
--- /dev/null
+++ b/drivers/vfio/vfio_spapr_eeh.c
@@ -0,0 +1,87 @@
+/*
+ * EEH functionality support for VFIO devices. The feature is only
+ * available on sPAPR compatible platforms.
+ *
+ * Copyright Gavin Shan, IBM Corporation 2014.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/uaccess.h>
+#include <linux/vfio.h>
+#include <asm/eeh.h>
+
+/* We might build address mapping here for "fast" path later */
+int vfio_spapr_pci_eeh_open(struct pci_dev *pdev)
+{
+        return eeh_dev_open(pdev);
+}
+
+void vfio_spapr_pci_eeh_release(struct pci_dev *pdev)
+{
+        eeh_dev_release(pdev);
+}
+
+long vfio_spapr_iommu_eeh_ioctl(struct iommu_group *group,
+                                unsigned int cmd, unsigned long arg)
+{
+        struct eeh_pe *pe;
+        struct vfio_eeh_pe_op op;
+        unsigned long minsz;
+        long ret = -EINVAL;
+
+        switch (cmd) {
+        case VFIO_CHECK_EXTENSION:
+                if (arg == VFIO_EEH)
+                        ret = eeh_enabled() ? 1 : 0;
+                else
+                        ret = 0;
+                break;
+        case VFIO_EEH_PE_OP:
+                pe = eeh_iommu_group_to_pe(group);
+                if (!pe)
+                        return -ENODEV;
+
+                minsz = offsetofend(struct vfio_eeh_pe_op, op);
+                if (copy_from_user(&op, (void __user *)arg, minsz))
+                        return -EFAULT;
+                if (op.argsz < minsz || op.flags)
+                        return -EINVAL;
+
+                switch (op.op) {
+                case VFIO_EEH_PE_DISABLE:
+                        ret = eeh_pe_set_option(pe, EEH_OPT_DISABLE);
+                        break;
+                case VFIO_EEH_PE_ENABLE:
+                        ret = eeh_pe_set_option(pe, EEH_OPT_ENABLE);
+                        break;
+                case VFIO_EEH_PE_UNFREEZE_IO:
+                        ret = eeh_pe_set_option(pe, EEH_OPT_THAW_MMIO);
+                        break;
+                case VFIO_EEH_PE_UNFREEZE_DMA:
+                        ret = eeh_pe_set_option(pe, EEH_OPT_THAW_DMA);
+                        break;
+                case VFIO_EEH_PE_GET_STATE:
+                        ret = eeh_pe_get_state(pe);
+                        break;
+                case VFIO_EEH_PE_RESET_DEACTIVATE:
+                        ret = eeh_pe_reset(pe, EEH_RESET_DEACTIVATE);
+                        break;
+                case VFIO_EEH_PE_RESET_HOT:
+                        ret = eeh_pe_reset(pe, EEH_RESET_HOT);
+                        break;
+                case VFIO_EEH_PE_RESET_FUNDAMENTAL:
+                        ret = eeh_pe_reset(pe, EEH_RESET_FUNDAMENTAL);
+                        break;
+                case VFIO_EEH_PE_CONFIGURE:
+                        ret = eeh_pe_configure(pe);
+                        break;
+                default:
+                        ret = -EINVAL;
+                }
+        }
+
+        return ret;
+}
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 8ec980b5e3af..25a0fbd4b998 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -98,4 +98,27 @@ extern int vfio_external_user_iommu_id(struct vfio_group *group);
 extern long vfio_external_check_extension(struct vfio_group *group,
                                           unsigned long arg);
 
+#ifdef CONFIG_EEH
+extern int vfio_spapr_pci_eeh_open(struct pci_dev *pdev);
+extern void vfio_spapr_pci_eeh_release(struct pci_dev *pdev);
+extern long vfio_spapr_iommu_eeh_ioctl(struct iommu_group *group,
+                                       unsigned int cmd,
+                                       unsigned long arg);
+#else
+static inline int vfio_spapr_pci_eeh_open(struct pci_dev *pdev)
+{
+        return 0;
+}
+
+static inline void vfio_spapr_pci_eeh_release(struct pci_dev *pdev)
+{
+}
+
+static inline long vfio_spapr_iommu_eeh_ioctl(struct iommu_group *group,
+                                              unsigned int cmd,
+                                              unsigned long arg)
+{
+        return -ENOTTY;
+}
+#endif /* CONFIG_EEH */
 #endif /* VFIO_H */
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index cb9023d4f063..6612974c64bf 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -30,6 +30,9 @@
  */
 #define VFIO_DMA_CC_IOMMU               4
 
+/* Check if EEH is supported */
+#define VFIO_EEH                        5
+
 /*
  * The IOCTL interface is designed for extensibility by embedding the
  * structure length (argsz) and flags into structures passed between
@@ -455,6 +458,37 @@ struct vfio_iommu_spapr_tce_info {
 
 #define VFIO_IOMMU_SPAPR_TCE_GET_INFO   _IO(VFIO_TYPE, VFIO_BASE + 12)
 
+/*
+ * EEH PE operation struct provides ways to:
+ * - enable/disable EEH functionality;
+ * - unfreeze IO/DMA for frozen PE;
+ * - read PE state;
+ * - reset PE;
+ * - configure PE.
+ */
+struct vfio_eeh_pe_op {
+        __u32 argsz;
+        __u32 flags;
+        __u32 op;
+};
+
+#define VFIO_EEH_PE_DISABLE             0       /* Disable EEH functionality */
+#define VFIO_EEH_PE_ENABLE              1       /* Enable EEH functionality  */
+#define VFIO_EEH_PE_UNFREEZE_IO         2       /* Enable IO for frozen PE   */
+#define VFIO_EEH_PE_UNFREEZE_DMA        3       /* Enable DMA for frozen PE  */
+#define VFIO_EEH_PE_GET_STATE           4       /* PE state retrieval        */
+#define  VFIO_EEH_PE_STATE_NORMAL       0       /* PE in functional state    */
+#define  VFIO_EEH_PE_STATE_RESET        1       /* PE reset in progress      */
+#define  VFIO_EEH_PE_STATE_STOPPED      2       /* Stopped DMA and IO        */
+#define  VFIO_EEH_PE_STATE_STOPPED_DMA  4       /* Stopped DMA only          */
+#define  VFIO_EEH_PE_STATE_UNAVAIL      5       /* State unavailable         */
+#define VFIO_EEH_PE_RESET_DEACTIVATE    5       /* Deassert PE reset         */
+#define VFIO_EEH_PE_RESET_HOT           6       /* Assert hot reset          */
+#define VFIO_EEH_PE_RESET_FUNDAMENTAL   7       /* Assert fundamental reset  */
+#define VFIO_EEH_PE_CONFIGURE           8       /* PE configuration          */
+
+#define VFIO_EEH_PE_OP                  _IO(VFIO_TYPE, VFIO_BASE + 21)
+
 /* ***************************************************************** */
 
 #endif /* _UAPIVFIO_H */