On Thu, May 22, 2014 at 11:55:29AM +0200, Alexander Graf wrote:
>
>On 22.05.14 10:23, Gavin Shan wrote:
>>The patch adds new IOCTL commands for VFIO PCI device to support
>>EEH functionality for PCI devices, which have been passed through
>>from host to somebody else via VFIO.
>>
>>Signed-off-by: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx>
>
>This already looks a *lot* more sane than the previous versions.
>We're slowly getting there I think ;).
>
>Ben, could you please check through the exported EEH interface itself
>and verify whether it does all the lockings correctly, uses the API
>properly and doesn't allow for a user space program to blow up the
>system?
>
>
>>---
>> Documentation/vfio.txt | 88 ++++++++++-
>> arch/powerpc/include/asm/eeh.h | 17 +++
>> arch/powerpc/kernel/eeh.c | 321 +++++++++++++++++++++++++++++++++++++++++
>> drivers/vfio/pci/vfio_pci.c | 131 ++++++++++++++++-
>> include/uapi/linux/vfio.h | 53 +++++++
>> 5 files changed, 603 insertions(+), 7 deletions(-)
>>
>>diff --git a/Documentation/vfio.txt b/Documentation/vfio.txt
>>index b9ca023..dd13db6 100644
>>--- a/Documentation/vfio.txt
>>+++ b/Documentation/vfio.txt
>>@@ -305,7 +305,10 @@ 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) PPC64 guests detect PCI errors and recover from them via EEH RTAS services,
>>+which works on the basis of additional ioctl commands.
>>+
>>+So 8 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.
>>@@ -316,6 +319,20 @@ So 3 additional ioctls have been added:
>> VFIO_IOMMU_DISABLE - disables the container.
>>+ VFIO_EEH_PE_SET_OPTION - enables or disables EEH functinality on the
>
>functionality
>
Typo. Will fix in next revision.
>>+ specified device. Also, it can be used to remove IO or DMA
>>+ stopped state on the frozen PE.
>>+
>>+ VFIO_EEH_PE_GET_ADDR - retrieve the unique address of the specified
>>+ PE or query PE sharing mode.
>
>What is PE?
>
will add description about that to Documentation/vfio.txt.
>>+
>>+ VFIO_EEH_PE_GET_STATE - retrieve PE's state: frozen or normal state.
>>+
>>+ VFIO_EEH_PE_RESET - do PE reset, which is one of the major steps for
>>+ error recovering.
>>+
>>+ VFIO_EEH_PE_CONFIGURE - configure the PCI bridges after PE reset. It's
>>+ one of the major steps for error recoverying.
>> The code flow from the example above should be slightly changed:
>>@@ -346,6 +363,75 @@ The code flow from the example above should be slightly changed:
>> ioctl(container, VFIO_IOMMU_MAP_DMA, &dma_map);
>> .....
>>+Based on the initial example we have, the following piece of code could be
>>+reference for EEH setup and error handling:
>>+
>>+ struct vfio_eeh_pe_set_option option = { .argsz = sizeof(option) };
>>+ struct vfio_eeh_pe_get_addr addr = { .argsz = sizeof(addr) };
>>+ struct vfio_eeh_pe_get_state state = { .argsz = sizeof(state) };
>>+ struct vfio_eeh_pe_reset reset = { .argsz = sizeof(reset) };
>>+ struct vfio_eeh_pe_configure config = { .argsz = sizeof(config) };
>>+
>>+ ....
>>+
>>+ /* Get a file descriptor for the device */
>>+ device = ioctl(group, VFIO_GROUP_GET_DEVICE_FD, "0000:06:0d.0");
>>+
>>+ /* Enable the EEH functionality on the device */
>>+ option.option = EEH_OPT_ENABLE;
>>+ ioctl(device, VFIO_EEH_PE_SET_OPTION, &option);
>>+
>>+ /* Retrieve PE address and create and maintain PE by yourself */
>>+ addr.option = EEH_OPT_GET_PE_ADDR;
>>+ ioctl(device, VFIO_EEH_PE_GET_ADDR, &addr);
>>+
>>+ /* Assure EEH is supported on the PE and make PE functional */
>>+ ioctl(device, VFIO_EEH_PE_GET_STATE, &state);
>>+
>>+ /* Save device's state. pci_save_state() would be good enough
>>+ * as an example.
>>+ */
>>+
>>+ /* Test and setup the device */
>>+ ioctl(device, VFIO_DEVICE_GET_INFO, &device_info);
>>+
>>+ ....
>>+
>>+ /* When 0xFF's returned from reading PCI config space or IO BARs
>>+ * of the PCI device. Check the PE state to see if that has been
>>+ * frozen.
>>+ */
>>+ ioctl(device, VFIO_EEH_PE_GET_STATE, &state);
>>+
>>+ /* 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.
>>+ */
>>+ option.option = EEH_OPT_THAW_MMIO;
>>+ ioctl(device, VFIO_EEH_PE_SET_OPTION, &option);
>>+
>>+ /* Issue PE reset */
>>+ reset.option = EEH_RESET_HOT;
>>+ ioctl(device, VFIO_EEH_PE_RESET, &reset);
>>+
>>+ /* Configure the PCI bridges for the affected PE */
>>+ ioctl(device, VFIO_EEH_PE_CONFIGURE, NULL);
>>+
>>+ /* 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.
>>+ */
>>+
>>+ ....
>>+
>> -------------------------------------------------------------------------------
>> [1] VFIO was originally an acronym for "Virtual Function I/O" in its
>>diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h
>>index 34a2d83..dd5f1cf 100644
>>--- a/arch/powerpc/include/asm/eeh.h
>>+++ b/arch/powerpc/include/asm/eeh.h
>>@@ -191,6 +191,11 @@ enum {
>> #define EEH_OPT_ENABLE 1 /* EEH enable */
>> #define EEH_OPT_THAW_MMIO 2 /* MMIO enable */
>> #define EEH_OPT_THAW_DMA 3 /* DMA enable */
>>+#define EEH_OPT_GET_PE_ADDR 0 /* Get PE addr */
>>+#define EEH_OPT_GET_PE_MODE 1 /* Get PE mode */
>>+#define EEH_PE_MODE_NONE 0 /* Invalid mode */
>>+#define EEH_PE_MODE_NOT_SHARED 1 /* Not shared */
>>+#define EEH_PE_MODE_SHARED 2 /* Shared mode */
>> #define EEH_STATE_UNAVAILABLE (1 << 0) /* State unavailable */
>> #define EEH_STATE_NOT_SUPPORT (1 << 1) /* EEH not supported */
>> #define EEH_STATE_RESET_ACTIVE (1 << 2) /* Active reset */
>>@@ -198,6 +203,11 @@ enum {
>> #define EEH_STATE_DMA_ACTIVE (1 << 4) /* Active DMA */
>> #define EEH_STATE_MMIO_ENABLED (1 << 5) /* MMIO enabled */
>> #define EEH_STATE_DMA_ENABLED (1 << 6) /* DMA enabled */
>>+#define EEH_PE_STATE_NORMAL 0 /* Normal state */
>>+#define EEH_PE_STATE_RESET 1 /* PE reset */
>>+#define EEH_PE_STATE_STOPPED_IO_DMA 2 /* Stopped */
>>+#define EEH_PE_STATE_STOPPED_DMA 4 /* Stopped DMA */
>>+#define EEH_PE_STATE_UNAVAIL 5 /* Unavailable */
>> #define EEH_RESET_DEACTIVATE 0 /* Deactivate the PE reset */
>> #define EEH_RESET_HOT 1 /* Hot reset */
>> #define EEH_RESET_FUNDAMENTAL 3 /* Fundamental reset */
>>@@ -305,6 +315,13 @@ void eeh_add_device_late(struct pci_dev *);
>> void eeh_add_device_tree_late(struct pci_bus *);
>> void eeh_add_sysfs_files(struct pci_bus *);
>> void eeh_remove_device(struct pci_dev *);
>>+int eeh_dev_open(struct pci_dev *pdev);
>>+void eeh_dev_release(struct pci_dev *pdev);
>>+int eeh_pe_set_option(struct pci_dev *pdev, int option);
>>+int eeh_pe_get_addr(struct pci_dev *pdev, int option);
>>+int eeh_pe_get_state(struct pci_dev *pdev);
>>+int eeh_pe_reset(struct pci_dev *pdev, int option);
>>+int eeh_pe_configure(struct pci_dev *pdev);
>> /**
>> * EEH_POSSIBLE_ERROR() -- test for possible MMIO failure.
>>diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
>>index 9c6b899..b90a474 100644
>>--- a/arch/powerpc/kernel/eeh.c
>>+++ b/arch/powerpc/kernel/eeh.c
>>@@ -108,6 +108,9 @@ struct eeh_ops *eeh_ops = NULL;
>> /* Lock to avoid races due to multiple reports of an error */
>> DEFINE_RAW_SPINLOCK(confirm_error_lock);
>>+/* Lock to protect passed flags */
>>+static DEFINE_MUTEX(eeh_dev_mutex);
>>+
>> /* Buffer for reporting pci register dumps. Its here in BSS, and
>> * not dynamically alloced, so that it ends up in RMO where RTAS
>> * can access it.
>>@@ -1098,6 +1101,324 @@ void eeh_remove_device(struct pci_dev *dev)
>> edev->mode &= ~EEH_DEV_SYSFS;
>> }
>>+/**
>>+ * eeh_dev_open - Mark EEH device and PE as passed through
>>+ * @pdev: PCI device
>>+ *
>>+ * Mark the indicated EEH device and PE as passed through.
>>+ * In the result, the EEH errors detected on the PE won't be
>>+ * reported. The owner of the device will be responsible for
>>+ * detection and recovery.
>>+ */
>>+int eeh_dev_open(struct pci_dev *pdev)
>>+{
>>+ struct eeh_dev *edev;
>>+
>>+ mutex_lock(&eeh_dev_mutex);
>>+
>>+ /* No PCI device ? */
>>+ if (!pdev) {
>>+ mutex_unlock(&eeh_dev_mutex);
>>+ return -ENODEV;
>>+ }
>>+
>>+ /* No EEH device ? */
>>+ edev = pci_dev_to_eeh_dev(pdev);
>>+ if (!edev || !edev->pe) {
>>+ mutex_unlock(&eeh_dev_mutex);
>>+ return -ENODEV;
>>+ }
>>+
>>+ eeh_dev_set_passed(edev, true);
>>+ eeh_pe_set_passed(edev->pe, true);
>>+ mutex_unlock(&eeh_dev_mutex);
>>+
>>+ return 0;
>>+}
>>+EXPORT_SYMBOL_GPL(eeh_dev_open);
>>+
>>+/**
>>+ * eeh_dev_release - Reclaim the ownership of EEH device
>>+ * @pdev: PCI device
>>+ *
>>+ * Reclaim ownership of EEH device, potentially the corresponding
>>+ * PE. In the result, the EEH errors detected on the PE will be
>>+ * reported and handled as usual.
>>+ */
>>+void eeh_dev_release(struct pci_dev *pdev)
>>+{
>>+ bool release_pe = true;
>>+ struct eeh_pe *pe = NULL;
>>+ struct eeh_dev *tmp, *edev;
>>+
>>+ mutex_lock(&eeh_dev_mutex);
>>+
>>+ /* No PCI device ? */
>>+ if (!pdev) {
>>+ mutex_unlock(&eeh_dev_mutex);
>>+ return;
>>+ }
>>+
>>+ /* No EEH device ? */
>>+ edev = pci_dev_to_eeh_dev(pdev);
>>+ if (!edev || !eeh_dev_passed(edev) ||
>>+ !edev->pe || !eeh_pe_passed(pe)) {
>>+ mutex_unlock(&eeh_dev_mutex);
>>+ return;
>>+ }
>>+
>>+ /* Release device */
>>+ pe = edev->pe;
>>+ eeh_dev_set_passed(edev, false);
>>+
>>+ /* Release PE */
>>+ eeh_pe_for_each_dev(pe, edev, tmp) {
>>+ if (eeh_dev_passed(edev)) {
>>+ release_pe = false;
>>+ break;
>>+ }
>>+ }
>>+
>>+ if (release_pe)
>>+ eeh_pe_set_passed(pe, false);
>>+
>>+ mutex_unlock(&eeh_dev_mutex);
>>+}
>>+EXPORT_SYMBOL(eeh_dev_release);
>>+
>>+static int eeh_dev_check(struct pci_dev *pdev,
>>+ struct eeh_dev **pedev,
>>+ struct eeh_pe **ppe)
>>+{
>>+ struct eeh_dev *edev;
>>+
>>+ /* No device ? */
>>+ if (!pdev)
>>+ return -ENODEV;
>>+
>>+ edev = pci_dev_to_eeh_dev(pdev);
>>+ if (!edev || !eeh_dev_passed(edev) ||
>>+ !edev->pe || !eeh_pe_passed(edev->pe))
>>+ return -ENODEV;
>>+
>>+ if (pedev)
>>+ *pedev = edev;
>>+ if (ppe)
>>+ *ppe = edev->pe;
>>+
>>+ return 0;
>>+}
>>+
>>+/**
>>+ * eeh_pe_set_option - Set options for the indicated PE
>>+ * @pdev: PCI device
>>+ * @option: requested option
>>+ *
>>+ * The routine is called to enable or disable EEH functionality
>>+ * on the indicated PE, to enable IO or DMA for the frozen PE.
>>+ */
>>+int eeh_pe_set_option(struct pci_dev *pdev, int option)
>>+{
>>+ struct eeh_dev *edev;
>>+ struct eeh_pe *pe;
>>+ int ret = 0;
>>+
>>+ /* Device existing ? */
>>+ ret = eeh_dev_check(pdev, &edev, &pe);
>>+ if (ret)
>>+ return ret;
>>+
>>+ switch (option) {
>>+ case EEH_OPT_DISABLE:
>>+ case EEH_OPT_ENABLE:
>
>This deserves a comment
>
Yep. will add it, thanks.
>>+ break;
>>+ case EEH_OPT_THAW_MMIO:
>>+ case EEH_OPT_THAW_DMA:
>>+ if (!eeh_ops || !eeh_ops->set_option) {
>>+ ret = -ENOENT;
>>+ break;
>>+ }
>>+
>>+ ret = eeh_ops->set_option(pe, option);
>>+ break;
>>+ default:
>>+ pr_debug("%s: Option %d out of range (%d, %d)\n",
>>+ __func__, option, EEH_OPT_DISABLE, EEH_OPT_THAW_DMA);
>>+ ret = -EINVAL;
>>+ }
>>+
>>+ return ret;
>>+}
>>+EXPORT_SYMBOL_GPL(eeh_pe_set_option);
>>+
>>+/**
>>+ * eeh_pe_get_addr - Retrieve the PE address or sharing mode
>>+ * @pdev: PCI device
>>+ * @option: option
>>+ *
>>+ * Retrieve the PE address or sharing mode.
>>+ */
>>+int eeh_pe_get_addr(struct pci_dev *pdev, int option)
>>+{
>>+ struct pci_bus *bus;
>>+ struct eeh_dev *edev;
>>+ struct eeh_pe *pe;
>>+ int ret = 0;
>>+
>>+ /* Device existing ? */
>>+ ret = eeh_dev_check(pdev, &edev, &pe);
>>+ if (ret)
>
>Probably safer to write this as ret < 0. Positive return values are
>success now.
>
Ok. Will fix it.
>>+ return ret;
>>+
>>+ switch (option) {
>>+ case EEH_OPT_GET_PE_ADDR:
>>+ bus = eeh_pe_bus_get(pe);
>>+ if (!bus) {
>>+ ret = -ENODEV;
>>+ break;
>>+ }
>>+
>>+ /* PE address has format "00BBSS00" */
>>+ ret = bus->number << 16;
>>+ break;
>>+ case EEH_OPT_GET_PE_MODE:
>>+ /* Wa always have shared PE */
>
>Wa?
>
Basically, PE could have one single PCI device (function), or a PCI bus
(including subordinate PCI devices). we always have the later case currently.
And it's called PE in "shared mode" and I called it as "shared PE" :-)
>>+ ret = EEH_PE_MODE_SHARED;
>>+ break;
>>+ default:
>>+ pr_debug("%s: option %d out of range (0, 1)\n",
>>+ __func__, option);
>>+ ret = -EINVAL;
>>+ }
>>+
>>+ return ret;
>>+}
>>+EXPORT_SYMBOL_GPL(eeh_pe_get_addr);
>>+
>>+/**
>>+ * eeh_pe_get_state - Retrieve PE's state
>>+ * @pdev: PCI device
>>+ *
>>+ * Retrieve the PE's state, which includes 3 aspects: enabled
>>+ * DMA, enabled IO and asserted reset.
>>+ */
>>+int eeh_pe_get_state(struct pci_dev *pdev)
>>+{
>>+ struct eeh_dev *edev;
>>+ struct eeh_pe *pe;
>>+ int result, ret = 0;
>>+
>>+ /* Device existing ? */
>>+ ret = eeh_dev_check(pdev, &edev, &pe);
>>+ if (ret)
>>+ return ret;
>>+
>>+ if (!eeh_ops || !eeh_ops->get_state)
>>+ return -ENOENT;
>>+
>>+ result = eeh_ops->get_state(pe, NULL);
>>+ if (!(result & EEH_STATE_RESET_ACTIVE) &&
>>+ (result & EEH_STATE_DMA_ENABLED) &&
>>+ (result & EEH_STATE_MMIO_ENABLED))
>>+ ret = EEH_PE_STATE_NORMAL;
>>+ else if (result & EEH_STATE_RESET_ACTIVE)
>>+ ret = EEH_PE_STATE_RESET;
>>+ else if (!(result & EEH_STATE_RESET_ACTIVE) &&
>>+ !(result & EEH_STATE_DMA_ENABLED) &&
>>+ !(result & EEH_STATE_MMIO_ENABLED))
>>+ ret = EEH_PE_STATE_STOPPED_IO_DMA;
>>+ else if (!(result & EEH_STATE_RESET_ACTIVE) &&
>>+ (result & EEH_STATE_DMA_ENABLED) &&
>>+ !(result & EEH_STATE_MMIO_ENABLED))
>>+ ret = EEH_PE_STATE_STOPPED_DMA;
>>+ else
>>+ ret = EEH_PE_STATE_UNAVAIL;
>>+
>>+ return ret;
>>+}
>>+EXPORT_SYMBOL_GPL(eeh_pe_get_state);
>>+
>>+/**
>>+ * eeh_pe_reset - Issue PE reset according to specified type
>>+ * @pdev: PCI device
>>+ * @option: reset type
>>+ *
>>+ * The routine is called to reset the specified PE with the
>>+ * indicated type, either fundamental reset or hot reset.
>>+ * PE reset is the most important part for error recovery.
>>+ */
>>+int eeh_pe_reset(struct pci_dev *pdev, int option)
>>+{
>>+ struct eeh_dev *edev;
>>+ struct eeh_pe *pe;
>>+ int ret = 0;
>>+
>>+ /* Device existing ? */
>>+ ret = eeh_dev_check(pdev, &edev, &pe);
>>+ if (ret)
>>+ return ret;
>>+
>>+ if (!eeh_ops || !eeh_ops->set_option || !eeh_ops->reset)
>>+ return -ENOENT;
>>+
>>+ switch (option) {
>>+ case EEH_RESET_DEACTIVATE:
>>+ ret = eeh_ops->reset(pe, option);
>>+ if (ret)
>>+ break;
>>+
>>+ /*
>>+ * The PE is still in frozen state and we need clear
>
>to
>
Will fix, thanks.
>>+ * that. It's good to clear frozen state after deassert
>>+ * to avoid messy IO access during reset, which might
>>+ * cause recursive frozen PE.
>>+ */
>>+ ret = eeh_ops->set_option(pe, EEH_OPT_THAW_MMIO);
>>+ if (!ret)
>>+ ret = eeh_ops->set_option(pe, EEH_OPT_THAW_DMA);
>>+ if (!ret)
>>+ eeh_pe_state_clear(pe, EEH_PE_ISOLATED);
>>+ break;
>>+ case EEH_RESET_HOT:
>>+ case EEH_RESET_FUNDAMENTAL:
>>+ ret = eeh_ops->reset(pe, option);
>>+ break;
>>+ default:
>>+ pr_debug("%s: Unsupported option %d\n",
>>+ __func__, option);
>>+ ret = -EINVAL;
>>+ }
>>+
>>+ return ret;
>>+}
>>+EXPORT_SYMBOL_GPL(eeh_pe_reset);
>>+
>>+/**
>>+ * eeh_pe_configure - Configure PCI bridges after PE reset
>>+ * @pdev: PCI device
>>+ *
>>+ * The routine is called to restore the PCI config space for
>>+ * those PCI devices, especially PCI bridges affected by PE
>>+ * reset issued previously.
>
>So would it make sense to combine this with the reset call?
>
I hope to keep it as it's one of the major steps to do error
recovery. Lets keep it.
>>+ */
>>+int eeh_pe_configure(struct pci_dev *pdev)
>>+{
>>+ struct eeh_dev *edev;
>>+ struct eeh_pe *pe;
>>+ int ret = 0;
>>+
>>+ /* Device existing ? */
>>+ ret = eeh_dev_check(pdev, &edev, &pe);
>>+ if (ret)
>>+ return ret;
>>+
>>+ /* Restore config space for the affected devices */
>>+ eeh_pe_restore_bars(pe);
>>+
>>+ return ret;
>>+}
>>+EXPORT_SYMBOL_GPL(eeh_pe_configure);
>>+
>> static int proc_eeh_show(struct seq_file *m, void *v)
>> {
>> if (!eeh_enabled()) {
>>diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
>>index 7ba0424..301ac18 100644
>>--- a/drivers/vfio/pci/vfio_pci.c
>>+++ b/drivers/vfio/pci/vfio_pci.c
>>@@ -25,6 +25,9 @@
>> #include <linux/types.h>
>> #include <linux/uaccess.h>
>> #include <linux/vfio.h>
>>+#ifdef CONFIG_EEH
>>+#include <asm/eeh.h>
>>+#endif
>> #include "vfio_pci_private.h"
>>@@ -152,32 +155,57 @@ static void vfio_pci_disable(struct vfio_pci_device *vdev)
>> pci_restore_state(pdev);
>> }
>>+static void vfio_eeh_pci_release(struct pci_dev *pdev)
>>+{
>>+#ifdef CONFIG_EEH
>>+ eeh_dev_release(pdev);
>>+#endif
>>+}
>>+
>> 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_eeh_pci_release(vdev->pdev);
>> vfio_pci_disable(vdev);
>>+ }
>> module_put(THIS_MODULE);
>> }
>>+static int vfio_eeh_pci_open(struct pci_dev *pdev)
>>+{
>>+ int ret = 0;
>>+
>>+#ifdef CONFIG_EEH
>>+ ret = eeh_dev_open(pdev);
>>+#endif
>>+ return ret;
>>+}
>>+
>> 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);
>>- if (ret) {
>>- module_put(THIS_MODULE);
>>- return ret;
>>- }
>>+ ret = vfio_pci_enable(vdev);
>>+ if (ret)
>>+ goto error;
>>+
>>+ ret = vfio_eeh_pci_open(vdev->pdev);
>>+ if (ret)
>>+ 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)
>>@@ -321,6 +349,91 @@ static int vfio_pci_for_each_slot_or_bus(struct pci_dev *pdev,
>> return walk.ret;
>> }
>>+static int vfio_eeh_pci_ioctl(struct pci_dev *pdev,
>>+ unsigned int cmd,
>>+ unsigned long arg)
>>+{
>>+ unsigned long minsz;
>>+ int ret = 0;
>>+
>>+#ifdef CONFIG_EEH
>>+ switch (cmd) {
>>+ case VFIO_EEH_PE_SET_OPTION: {
>>+ struct vfio_eeh_pe_set_option option;
>>+
>>+ minsz = offsetofend(struct vfio_eeh_pe_set_option, option);
>>+ if (copy_from_user(&option, (void __user *)arg, minsz))
>>+ return -EFAULT;
>>+ if (option.argsz < minsz)
>>+ return -EINVAL;
>>+
>>+ ret = eeh_pe_set_option(pdev, option.option);
>>+ break;
>>+ }
>>+ case VFIO_EEH_PE_GET_ADDR: {
>>+ struct vfio_eeh_pe_get_addr addr;
>>+
>>+ minsz = offsetofend(struct vfio_eeh_pe_get_addr, info);
>>+ if (copy_from_user(&addr, (void __user *)arg, minsz))
>>+ return -EFAULT;
>>+ if (addr.argsz < minsz)
>>+ return -EINVAL;
>>+
>>+ ret = eeh_pe_get_addr(pdev, addr.option);
>>+ if (ret >= 0) {
>>+ addr.info = ret;
>>+ if (copy_to_user((void __user *)arg, &addr, minsz))
>>+ return -EFAULT;
>>+ ret = 0;
>>+ }
>>+
>>+ break;
>>+ }
>>+ case VFIO_EEH_PE_GET_STATE: {
>>+ struct vfio_eeh_pe_get_state state;
>>+
>>+ minsz = offsetofend(struct vfio_eeh_pe_get_state, state);
>>+ if (copy_from_user(&state, (void __user *)arg, minsz))
>>+ return -EFAULT;
>>+ if (state.argsz < minsz)
>>+ return -EINVAL;
>>+
>>+ ret = eeh_pe_get_state(pdev);
>>+ if (ret >= 0) {
>>+ state.state = ret;
>>+ if (copy_to_user((void __user *)arg, &state, minsz))
>>+ return -EFAULT;
>>+ ret = 0;
>>+ }
>>+ break;
>>+ }
>>+ case VFIO_EEH_PE_RESET: {
>>+ struct vfio_eeh_pe_reset reset;
>>+
>>+ minsz = offsetofend(struct vfio_eeh_pe_reset, option);
>>+ if (copy_from_user(&reset, (void __user *)arg, minsz))
>>+ return -EFAULT;
>>+ if (reset.argsz < minsz)
>>+ return -EINVAL;
>>+
>>+ ret = eeh_pe_reset(pdev, reset.option);
>>+ break;
>>+ }
>>+ case VFIO_EEH_PE_CONFIGURE:
>>+ ret = eeh_pe_configure(pdev);
>>+ break;
>>+ default:
>>+ ret = -EINVAL;
>>+ pr_debug("%s: Cannot handle command %d\n",
>>+ __func__, cmd);
>>+ }
>>+#else
>>+ ret = -ENOENT;
>>+#endif
>>+
>>+ return ret;
>>+}
>>+
>> static long vfio_pci_ioctl(void *device_data,
>> unsigned int cmd, unsigned long arg)
>> {
>>@@ -682,6 +795,12 @@ hot_reset_release:
>> kfree(groups);
>> return ret;
>>+ } else if (cmd == VFIO_EEH_PE_SET_OPTION ||
>>+ cmd == VFIO_EEH_PE_GET_ADDR ||
>>+ cmd == VFIO_EEH_PE_GET_STATE ||
>>+ cmd == VFIO_EEH_PE_RESET ||
>>+ cmd == VFIO_EEH_PE_CONFIGURE) {
>>+ return vfio_eeh_pci_ioctl(vdev->pdev, cmd, arg);
>> }
>> return -ENOTTY;
>>diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
>>index cb9023d..ef55682 100644
>>--- a/include/uapi/linux/vfio.h
>>+++ b/include/uapi/linux/vfio.h
>>@@ -455,6 +455,59 @@ struct vfio_iommu_spapr_tce_info {
>> #define VFIO_IOMMU_SPAPR_TCE_GET_INFO _IO(VFIO_TYPE, VFIO_BASE + 12)
>>+/*
>>+ * EEH functionality can be enabled or disabled on one specific device.
>>+ * Also, the DMA or IO frozen state can be removed from the frozen PE
>>+ * if required.
>>+ */
>>+struct vfio_eeh_pe_set_option {
>>+ __u32 argsz;
>
>What is this argsz thing? Is this your way of maintaining backwards
>compatibility when we introduce new fields? A new field will change
>the ioctl number, so I don't think that makes a lot of sense :).
>
>Just make the ioctl have a u32 as incoming argument. No fancy
>structs, no complicated code.
>
>The same applies for a number of structs below.
>
ok. Will do in next revision.
>>+ __u32 option;
>>+};
>>+
>>+#define VFIO_EEH_PE_SET_OPTION _IO(VFIO_TYPE, VFIO_BASE + 21)
>>+
>>+/*
>>+ * Each EEH PE should have unique address to be identified. The command
>>+ * helps to retrieve the address and the sharing mode of the PE.
>>+ */
>>+struct vfio_eeh_pe_get_addr {
>>+ __u32 argsz;
>>+ __u32 option;
>>+ __u32 info;
>
>Any particular reason you need the info field? Can't the return value
>of the ioctl hold this? Then you only have a single u32 argument left
>to the ioctl again.
>
ok. Will do in next revision.
>>+};
>>+
>>+#define VFIO_EEH_PE_GET_ADDR _IO(VFIO_TYPE, VFIO_BASE + 22)
>>+
>>+/*
>>+ * EEH PE might have been frozen because of PCI errors. Also, it might
>>+ * be experiencing reset for error revoery. The following command helps
>>+ * to get the state.
>>+ */
>>+struct vfio_eeh_pe_get_state {
>>+ __u32 argsz;
>>+ __u32 state;
>>+};
>>+
>>+#define VFIO_EEH_PE_GET_STATE _IO(VFIO_TYPE, VFIO_BASE + 23)
>>+
>>+/*
>>+ * Reset is the major step to recover problematic PE. The following
>>+ * command helps on that.
>>+ */
>>+struct vfio_eeh_pe_reset {
>>+ __u32 argsz;
>>+ __u32 option;
>>+};
>>+
>>+#define VFIO_EEH_PE_RESET _IO(VFIO_TYPE, VFIO_BASE + 24)
>>+
>>+/*
>>+ * One of the steps for recovery after PE reset is to configure the
>>+ * PCI bridges affected by the PE reset.
>>+ */
>>+#define VFIO_EEH_PE_CONFIGURE _IO(VFIO_TYPE, VFIO_BASE + 25)
>>+
>> /* ***************************************************************** */
>> #endif /* _UAPIVFIO_H */
Thanks,
Gavin
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