Added sysfs interface to pin pages which will be used to test migration
when vendor driver pins pages.
Read on pin_pages shows number of pages pinned:
$ cat /sys/bus/mdev/devices/<mdev UUID>/vendor/pin_pages
Pinned 0x0 pages
Write gpfn to pin_pages to pin that page. One page pinned on write
$ echo 0x20 > /sys/bus/mdev/devices/<mdev UUID>/vendor/pin_pages
Limitation: Buffer for 2GB system memory is created to track pinned
pages.
This is for testing purpose only.
Signed-off-by: Kirti Wankhede <kwankhede@xxxxxxxxxx>
---
samples/vfio-mdev/mtty.c | 176 ++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 175 insertions(+), 1 deletion(-)
diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c
index ce84a300a4da..bf666cce5bb7 100644
--- a/samples/vfio-mdev/mtty.c
+++ b/samples/vfio-mdev/mtty.c
@@ -64,6 +64,10 @@
(((u64)(1) << MTTY_VFIO_PCI_OFFSET_SHIFT) - 1)
#define MAX_MTTYS 24
+/* Maximum pages of 4K for upto 2G RAM can be pinned */
+#define MAX_GPFN_COUNT (512 * 1024)
+#define PFN_NULL (~0UL)
+
/*
* Global Structures
*/
@@ -141,6 +145,10 @@ struct mdev_state {
struct mutex rxtx_lock;
struct vfio_device_info dev_info;
int nr_ports;
+
+ /* List of pinned gpfns, gpfn as index and content is translated hpfn */
+ unsigned long *gpfn_to_hpfn;
+ struct notifier_block nb;
};
static struct mutex mdev_list_lock;
@@ -745,6 +753,17 @@ static int mtty_create(struct kobject *kobj, struct mdev_device *mdev)
return -ENOMEM;
}
+ mdev_state->gpfn_to_hpfn =
+ kzalloc(sizeof(unsigned long) * MAX_GPFN_COUNT, GFP_KERNEL);
+ if (mdev_state->gpfn_to_hpfn == NULL) {
+ kfree(mdev_state->vconfig);
+ kfree(mdev_state);
+ return -ENOMEM;
+ }
+
+ memset(mdev_state->gpfn_to_hpfn, ~0,
+ sizeof(unsigned long) * MAX_GPFN_COUNT);
+
mutex_init(&mdev_state->ops_lock);
mdev_state->mdev = mdev;
mdev_set_drvdata(mdev, mdev_state);
@@ -769,6 +788,7 @@ static int mtty_remove(struct mdev_device *mdev)
if (mdev_state == mds) {
list_del(&mdev_state->next);
mdev_set_drvdata(mdev, NULL);
+ kfree(mdev_state->gpfn_to_hpfn);
kfree(mdev_state->vconfig);
kfree(mdev_state);
ret = 0;
@@ -1246,15 +1266,95 @@ static long mtty_ioctl(struct mdev_device *mdev, unsigned int cmd,
return -ENOTTY;
}
+static void unpin_pages_all(struct mdev_state *mdev_state)
+{
+ struct mdev_device *mdev = mdev_state->mdev;
+ unsigned long i;
+
+ mutex_lock(&mdev_state->ops_lock);
+ for (i = 0; i < MAX_GPFN_COUNT; i++) {
+ if (mdev_state->gpfn_to_hpfn[i] != PFN_NULL) {
+ int ret;
+
+ ret = vfio_unpin_pages(mdev_dev(mdev), &i, 1);
+ if (ret <= 0) {
+ pr_err("%s: 0x%lx unpin error %d\n",
+ __func__, i, ret);
+ continue;
+ }
+ mdev_state->gpfn_to_hpfn[i] = PFN_NULL;
+ }
+ }
+ mutex_unlock(&mdev_state->ops_lock);
+}
+
+static int unmap_notifier(struct notifier_block *nb, unsigned long action,
+ void *data)
+{
+ if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP) {
+ struct mdev_state *mdev_state = container_of(nb,
+ struct mdev_state, nb);
+ struct mdev_device *mdev = mdev_state->mdev;
+ struct vfio_iommu_type1_dma_unmap *unmap = data;
+ unsigned long start = unmap->iova >> PAGE_SHIFT;
+ unsigned long end = (unmap->iova + unmap->size) >> PAGE_SHIFT;
+ unsigned long i;
+
+ mutex_lock(&mdev_state->ops_lock);
+ for (i = start; i < end; i++) {
+ if (mdev_state->gpfn_to_hpfn[i] != PFN_NULL) {
+ int ret;
+
+ ret = vfio_unpin_pages(mdev_dev(mdev), &i, 1);
+ if (ret <= 0) {
+ pr_err("%s: 0x%lx unpin error %d\n",
+ __func__, i, ret);
+ continue;
+ }
+ mdev_state->gpfn_to_hpfn[i] = PFN_NULL;
+ }
+ }
+ mutex_unlock(&mdev_state->ops_lock);
+
+ }
+ return 0;
+}
+
static int mtty_open(struct mdev_device *mdev)
{
+ unsigned long events = VFIO_IOMMU_NOTIFY_DMA_UNMAP;
+ struct mdev_state *mdev_state;
+ int ret;
+
pr_info("%s\n", __func__);
- return 0;
+
+ if (!mdev)
+ return -EINVAL;
+
+ mdev_state = mdev_get_drvdata(mdev);
+ if (!mdev_state)
+ return -ENODEV;
+
+ mdev_state->nb.notifier_call = unmap_notifier;
+
+ ret = vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, &events,
+ &mdev_state->nb);
+ return ret;
}
static void mtty_close(struct mdev_device *mdev)
{
+ struct mdev_state *mdev_state;
+
pr_info("%s\n", __func__);
+
+ mdev_state = mdev_get_drvdata(mdev);
+ if (!mdev_state)
+ return;
+
+ unpin_pages_all(mdev_state);
+ vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
+ &mdev_state->nb);
}
static ssize_t
@@ -1293,8 +1393,82 @@ sample_mdev_dev_show(struct device *dev, struct device_attribute *attr,
static DEVICE_ATTR_RO(sample_mdev_dev);
+static ssize_t
+pin_pages_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct mdev_device *mdev = mdev_from_dev(dev);
+ struct mdev_state *mdev_state;
+ int i, count = 0;
+
+ if (!mdev)
+ return -EINVAL;
+
+ mdev_state = mdev_get_drvdata(mdev);
+ if (!mdev_state)
+ return -EINVAL;
+
+ mutex_lock(&mdev_state->ops_lock);
+ for (i = 0; i < MAX_GPFN_COUNT; i++) {
+ if (mdev_state->gpfn_to_hpfn[i] != PFN_NULL)
+ count++;
+ }
+ mutex_unlock(&mdev_state->ops_lock);
+ return sprintf(buf, "Pinned 0x%x pages\n", count);
+}
+
+static ssize_t
+pin_pages_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct mdev_device *mdev = mdev_from_dev(dev);
+ struct mdev_state *mdev_state;
+ unsigned long gpfn, hpfn;
+ int ret;
+
+ if (!mdev)
+ return -EINVAL;
+
+ mdev_state = mdev_get_drvdata(mdev);
+ if (!mdev_state)
+ return -EINVAL;
+
+ ret = kstrtoul(buf, 0, &gpfn);
+ if (ret)
+ return ret;
+
+ if (gpfn >= MAX_GPFN_COUNT) {
+ pr_err("Error 0x%lx > 0x%lx\n",
+ gpfn, (unsigned long)MAX_GPFN_COUNT);
+ return -EINVAL;
+ }
+
+ mutex_lock(&mdev_state->ops_lock);
+
+ if (mdev_state->gpfn_to_hpfn[gpfn] != PFN_NULL) {
+ ret = -EEXIST;
+ goto out;
+ }
+
+ ret = vfio_pin_pages(mdev_dev(mdev), &gpfn, 1,
+ IOMMU_READ | IOMMU_WRITE, &hpfn);
+
+ if (ret <= 0) {
+ pr_err("Failed to pin, ret %d\n", ret);
+ goto out;
+ }
+
+ mdev_state->gpfn_to_hpfn[gpfn] = hpfn;
+ ret = count;
+out:
+ mutex_unlock(&mdev_state->ops_lock);
+ return ret;
+}
+
+static DEVICE_ATTR_RW(pin_pages);
+
static struct attribute *mdev_dev_attrs[] = {
&dev_attr_sample_mdev_dev.attr,
+ &dev_attr_pin_pages.attr,
NULL,
};
--
2.7.0
