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authorLinus Torvalds <torvalds@linux-foundation.org>2014-08-14 09:41:41 -0600
committerLinus Torvalds <torvalds@linux-foundation.org>2014-08-14 09:41:41 -0600
commitcc8a44c671fd3a2c792e9e1f59ea1df52697cc8b (patch)
tree9521e782447bb95bb04772aeb274d5387e4cdda1
parent4dacb91c7d1ab30aa9aac0d55216fc177d454254 (diff)
parent9b936c960f22954bfb89f2fefd8f96916bb42908 (diff)
Merge tag 'vfio-v3.17-rc1' of git://github.com/awilliam/linux-vfio
Pull VFIO updates from Alex Williamson: - enable support for bus reset on device release - fixes for EEH support * tag 'vfio-v3.17-rc1' of git://github.com/awilliam/linux-vfio: drivers/vfio: Enable VFIO if EEH is not supported drivers/vfio: Allow EEH to be built as module drivers/vfio: Fix EEH build error vfio-pci: Attempt bus/slot reset on release vfio-pci: Use mutex around open, release, and remove vfio-pci: Release devices with BusMaster disabled
-rw-r--r--drivers/vfio/Kconfig6
-rw-r--r--drivers/vfio/Makefile2
-rw-r--r--drivers/vfio/pci/vfio_pci.c161
-rw-r--r--drivers/vfio/pci/vfio_pci_private.h3
-rw-r--r--drivers/vfio/vfio_spapr_eeh.c17
-rw-r--r--include/linux/vfio.h6
6 files changed, 170 insertions, 25 deletions
diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig
index af7b204b9215..d8c57636b9ce 100644
--- a/drivers/vfio/Kconfig
+++ b/drivers/vfio/Kconfig
@@ -8,11 +8,17 @@ config VFIO_IOMMU_SPAPR_TCE
depends on VFIO && SPAPR_TCE_IOMMU
default n
+config VFIO_SPAPR_EEH
+ tristate
+ depends on EEH && VFIO_IOMMU_SPAPR_TCE
+ default n
+
menuconfig VFIO
tristate "VFIO Non-Privileged userspace driver framework"
depends on IOMMU_API
select VFIO_IOMMU_TYPE1 if X86
select VFIO_IOMMU_SPAPR_TCE if (PPC_POWERNV || PPC_PSERIES)
+ select VFIO_SPAPR_EEH if (PPC_POWERNV || PPC_PSERIES)
select ANON_INODES
help
VFIO provides a framework for secure userspace device drivers.
diff --git a/drivers/vfio/Makefile b/drivers/vfio/Makefile
index 50e30bc75e85..0b035b12600a 100644
--- a/drivers/vfio/Makefile
+++ b/drivers/vfio/Makefile
@@ -1,5 +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-$(CONFIG_VFIO_SPAPR_EEH) += vfio_spapr_eeh.o
obj-$(CONFIG_VFIO_PCI) += pci/
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index e2ee80f36e3e..f7825332a325 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -37,6 +37,10 @@ module_param_named(nointxmask, nointxmask, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(nointxmask,
"Disable support for PCI 2.3 style INTx masking. If this resolves problems for specific devices, report lspci -vvvxxx to linux-pci@vger.kernel.org so the device can be fixed automatically via the broken_intx_masking flag.");
+static DEFINE_MUTEX(driver_lock);
+
+static void vfio_pci_try_bus_reset(struct vfio_pci_device *vdev);
+
static int vfio_pci_enable(struct vfio_pci_device *vdev)
{
struct pci_dev *pdev = vdev->pdev;
@@ -44,6 +48,9 @@ static int vfio_pci_enable(struct vfio_pci_device *vdev)
u16 cmd;
u8 msix_pos;
+ /* Don't allow our initial saved state to include busmaster */
+ pci_clear_master(pdev);
+
ret = pci_enable_device(pdev);
if (ret)
return ret;
@@ -99,7 +106,8 @@ static void vfio_pci_disable(struct vfio_pci_device *vdev)
struct pci_dev *pdev = vdev->pdev;
int bar;
- pci_disable_device(pdev);
+ /* Stop the device from further DMA */
+ pci_clear_master(pdev);
vfio_pci_set_irqs_ioctl(vdev, VFIO_IRQ_SET_DATA_NONE |
VFIO_IRQ_SET_ACTION_TRIGGER,
@@ -117,6 +125,8 @@ static void vfio_pci_disable(struct vfio_pci_device *vdev)
vdev->barmap[bar] = NULL;
}
+ vdev->needs_reset = true;
+
/*
* If we have saved state, restore it. If we can reset the device,
* even better. Resetting with current state seems better than
@@ -128,7 +138,7 @@ static void vfio_pci_disable(struct vfio_pci_device *vdev)
__func__, dev_name(&pdev->dev));
if (!vdev->reset_works)
- return;
+ goto out;
pci_save_state(pdev);
}
@@ -148,46 +158,55 @@ static void vfio_pci_disable(struct vfio_pci_device *vdev)
if (ret)
pr_warn("%s: Failed to reset device %s (%d)\n",
__func__, dev_name(&pdev->dev), ret);
+ else
+ vdev->needs_reset = false;
}
pci_restore_state(pdev);
+out:
+ pci_disable_device(pdev);
+
+ vfio_pci_try_bus_reset(vdev);
}
static void vfio_pci_release(void *device_data)
{
struct vfio_pci_device *vdev = device_data;
- if (atomic_dec_and_test(&vdev->refcnt)) {
+ mutex_lock(&driver_lock);
+
+ if (!(--vdev->refcnt)) {
vfio_spapr_pci_eeh_release(vdev->pdev);
vfio_pci_disable(vdev);
}
+ mutex_unlock(&driver_lock);
+
module_put(THIS_MODULE);
}
static int vfio_pci_open(void *device_data)
{
struct vfio_pci_device *vdev = device_data;
- int ret;
+ int ret = 0;
if (!try_module_get(THIS_MODULE))
return -ENODEV;
- if (atomic_inc_return(&vdev->refcnt) == 1) {
+ mutex_lock(&driver_lock);
+
+ if (!vdev->refcnt) {
ret = vfio_pci_enable(vdev);
if (ret)
goto error;
- ret = vfio_spapr_pci_eeh_open(vdev->pdev);
- if (ret) {
- vfio_pci_disable(vdev);
- goto error;
- }
+ vfio_spapr_pci_eeh_open(vdev->pdev);
}
-
- return 0;
+ vdev->refcnt++;
error:
- module_put(THIS_MODULE);
+ mutex_unlock(&driver_lock);
+ if (ret)
+ module_put(THIS_MODULE);
return ret;
}
@@ -843,7 +862,6 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
vdev->irq_type = VFIO_PCI_NUM_IRQS;
mutex_init(&vdev->igate);
spin_lock_init(&vdev->irqlock);
- atomic_set(&vdev->refcnt, 0);
ret = vfio_add_group_dev(&pdev->dev, &vfio_pci_ops, vdev);
if (ret) {
@@ -858,12 +876,15 @@ static void vfio_pci_remove(struct pci_dev *pdev)
{
struct vfio_pci_device *vdev;
+ mutex_lock(&driver_lock);
+
vdev = vfio_del_group_dev(&pdev->dev);
- if (!vdev)
- return;
+ if (vdev) {
+ iommu_group_put(pdev->dev.iommu_group);
+ kfree(vdev);
+ }
- iommu_group_put(pdev->dev.iommu_group);
- kfree(vdev);
+ mutex_unlock(&driver_lock);
}
static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev,
@@ -906,6 +927,110 @@ static struct pci_driver vfio_pci_driver = {
.err_handler = &vfio_err_handlers,
};
+/*
+ * Test whether a reset is necessary and possible. We mark devices as
+ * needs_reset when they are released, but don't have a function-local reset
+ * available. If any of these exist in the affected devices, we want to do
+ * a bus/slot reset. We also need all of the affected devices to be unused,
+ * so we abort if any device has a non-zero refcnt. driver_lock prevents a
+ * device from being opened during the scan or unbound from vfio-pci.
+ */
+static int vfio_pci_test_bus_reset(struct pci_dev *pdev, void *data)
+{
+ bool *needs_reset = data;
+ struct pci_driver *pci_drv = ACCESS_ONCE(pdev->driver);
+ int ret = -EBUSY;
+
+ if (pci_drv == &vfio_pci_driver) {
+ struct vfio_device *device;
+ struct vfio_pci_device *vdev;
+
+ device = vfio_device_get_from_dev(&pdev->dev);
+ if (!device)
+ return ret;
+
+ vdev = vfio_device_data(device);
+ if (vdev) {
+ if (vdev->needs_reset)
+ *needs_reset = true;
+
+ if (!vdev->refcnt)
+ ret = 0;
+ }
+
+ vfio_device_put(device);
+ }
+
+ /*
+ * TODO: vfio-core considers groups to be viable even if some devices
+ * are attached to known drivers, like pci-stub or pcieport. We can't
+ * freeze devices from being unbound to those drivers like we can
+ * here though, so it would be racy to test for them. We also can't
+ * use device_lock() to prevent changes as that would interfere with
+ * PCI-core taking device_lock during bus reset. For now, we require
+ * devices to be bound to vfio-pci to get a bus/slot reset on release.
+ */
+
+ return ret;
+}
+
+/* Clear needs_reset on all affected devices after successful bus/slot reset */
+static int vfio_pci_clear_needs_reset(struct pci_dev *pdev, void *data)
+{
+ struct pci_driver *pci_drv = ACCESS_ONCE(pdev->driver);
+
+ if (pci_drv == &vfio_pci_driver) {
+ struct vfio_device *device;
+ struct vfio_pci_device *vdev;
+
+ device = vfio_device_get_from_dev(&pdev->dev);
+ if (!device)
+ return 0;
+
+ vdev = vfio_device_data(device);
+ if (vdev)
+ vdev->needs_reset = false;
+
+ vfio_device_put(device);
+ }
+
+ return 0;
+}
+
+/*
+ * Attempt to do a bus/slot reset if there are devices affected by a reset for
+ * this device that are needs_reset and all of the affected devices are unused
+ * (!refcnt). Callers of this function are required to hold driver_lock such
+ * that devices can not be unbound from vfio-pci or opened by a user while we
+ * test for and perform a bus/slot reset.
+ */
+static void vfio_pci_try_bus_reset(struct vfio_pci_device *vdev)
+{
+ bool needs_reset = false, slot = false;
+ int ret;
+
+ if (!pci_probe_reset_slot(vdev->pdev->slot))
+ slot = true;
+ else if (pci_probe_reset_bus(vdev->pdev->bus))
+ return;
+
+ if (vfio_pci_for_each_slot_or_bus(vdev->pdev,
+ vfio_pci_test_bus_reset,
+ &needs_reset, slot) || !needs_reset)
+ return;
+
+ if (slot)
+ ret = pci_try_reset_slot(vdev->pdev->slot);
+ else
+ ret = pci_try_reset_bus(vdev->pdev->bus);
+
+ if (ret)
+ return;
+
+ vfio_pci_for_each_slot_or_bus(vdev->pdev,
+ vfio_pci_clear_needs_reset, NULL, slot);
+}
+
static void __exit vfio_pci_cleanup(void)
{
pci_unregister_driver(&vfio_pci_driver);
diff --git a/drivers/vfio/pci/vfio_pci_private.h b/drivers/vfio/pci/vfio_pci_private.h
index 9c6d5d0f3b02..671c17a6e6d0 100644
--- a/drivers/vfio/pci/vfio_pci_private.h
+++ b/drivers/vfio/pci/vfio_pci_private.h
@@ -54,8 +54,9 @@ struct vfio_pci_device {
bool extended_caps;
bool bardirty;
bool has_vga;
+ bool needs_reset;
struct pci_saved_state *pci_saved_state;
- atomic_t refcnt;
+ int refcnt;
struct eventfd_ctx *err_trigger;
};
diff --git a/drivers/vfio/vfio_spapr_eeh.c b/drivers/vfio/vfio_spapr_eeh.c
index f834b4ce1431..86dfceb9201f 100644
--- a/drivers/vfio/vfio_spapr_eeh.c
+++ b/drivers/vfio/vfio_spapr_eeh.c
@@ -9,20 +9,27 @@
* published by the Free Software Foundation.
*/
+#include <linux/module.h>
#include <linux/uaccess.h>
#include <linux/vfio.h>
#include <asm/eeh.h>
+#define DRIVER_VERSION "0.1"
+#define DRIVER_AUTHOR "Gavin Shan, IBM Corporation"
+#define DRIVER_DESC "VFIO IOMMU SPAPR EEH"
+
/* We might build address mapping here for "fast" path later */
-int vfio_spapr_pci_eeh_open(struct pci_dev *pdev)
+void vfio_spapr_pci_eeh_open(struct pci_dev *pdev)
{
- return eeh_dev_open(pdev);
+ eeh_dev_open(pdev);
}
+EXPORT_SYMBOL_GPL(vfio_spapr_pci_eeh_open);
void vfio_spapr_pci_eeh_release(struct pci_dev *pdev)
{
eeh_dev_release(pdev);
}
+EXPORT_SYMBOL_GPL(vfio_spapr_pci_eeh_release);
long vfio_spapr_iommu_eeh_ioctl(struct iommu_group *group,
unsigned int cmd, unsigned long arg)
@@ -85,3 +92,9 @@ long vfio_spapr_iommu_eeh_ioctl(struct iommu_group *group,
return ret;
}
+EXPORT_SYMBOL(vfio_spapr_iommu_eeh_ioctl);
+
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 25a0fbd4b998..d3204115f15d 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -98,16 +98,16 @@ extern int vfio_external_user_iommu_id(struct vfio_group *group);
extern long vfio_external_check_extension(struct vfio_group *group,
unsigned long arg);
+struct pci_dev;
#ifdef CONFIG_EEH
-extern int vfio_spapr_pci_eeh_open(struct pci_dev *pdev);
+extern void 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)
+static inline void vfio_spapr_pci_eeh_open(struct pci_dev *pdev)
{
- return 0;
}
static inline void vfio_spapr_pci_eeh_release(struct pci_dev *pdev)