-From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
-From: Tarun Gupta <targupta@nvidia.com>
-Date: Thu, 18 May 2023 16:48:09 +0530
-Subject: [PATCH] UBUNTU: SAUCE: Add mdev_set_iommu_device() kABI.
-
-With below commit present from 5.16+ upstream kernel onwards, support
-mdev_set_iommu_device() kABI has been removed from kernel due to lack of
-in-tree vendor drivers using the kABI.
-
-fda49d97f2c4 ("vfio: remove the unused mdev iommu hook")
-
-This patch partially reverts the above commit so that
-mdev_set_iommu_device() kABI is still supported with HWE kernels for
-Ubuntu 22.04. In this partial revert, have not added back the code for
-"aux" variants (IOMMU_DEV_FEAT_AUX) present in
-vfio_mdev_[attach|detach]_domain as this support was never added by any
-in-tree driver or known out-of-tree driver. Nvidia vGPU doesn't make use
-of IOMMU_DEV_FEAT_AUX feature.
-
-Also, it adds back the vfio_bus_is_mdev() function which was reverted in
-below patch as there were no users of it. This patch adds it back to
-detect if this is an mdev device.
-
-c3c0fa9d94f7 ("vfio: clean up the check for mediated device in
-vfio_iommu_type1")
-
-Also, in v6.2 kernel, "mdev_bus_type" struct has been unexported as
-part of below commit because it was used only in mdev.ko. But, for
-vGPU, as mentioned above, since we use vfio_bus_is_mdev() fn
-in vfio_iommu_type1.ko, we need to again export "mdev_bus_type" struct.
-
-2815fe149ffa ("vfio/mdev: unexport mdev_bus_type")
-
-It is not a clean revert in vfio_iommu_type1_attach_group() fn as it is
-changed in v6.2 upstream kernel compared to when
-mdev_set_iommu_device() kABI was removed in 5.16 kernel.
-In 5.19 kernel, VFIO_EMULATED_IOMMU handling is introduced in
-vfio_iommu_type1_attach_group() fn which was not present when the patch
-was reverted in 5.16 kernel.
-
-But, the logic remains the same. The logic here is if this is an
-vfio-mdev device, then check by calling vfio_mdev_iommu_device() if this
-mdev device already has an backed IOMMU device (which will be provided
-by mdev_set_iommu_device kABI from vendor driver). If the mdev device
-has backed iommu device, then use that device's IOMMU domain.
-
-This kABI is used by SRIOV based Nvidia vGPU to pin all guest sysmem on
-VF during vGPU VM boot. With this patch, SRIOV based Nvidia vGPU will
-continue to work with upstream kernels. Nvidia vGPU driver calls
-mdev_set_iommu_device() for mdev device with VF as the backing IOMMU.
-
-Separately, to fix this in upstream kernels, vGPU is planning to adopt
-vfio-pci-core framework instead of using MDEV framework.
-Currently, vfio-pci-core framework works with SRIOV vGPU but lacks
-libvirt support to assign VFs using vfio-pci-core framework.
-Will work with upstream libvirt community to get libvirt support for
-vfio-pci-core devices. Post that, don't need this custom mdev patch
-and vGPU can work out-of-box on Ubuntu with vfio-pci-core frameowrk
-
-BugLink : https://bugs.launchpad.net/bugs/1988806
-
-Signed-off-by: Tarun Gupta <targupta@nvidia.com>
-Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
----
- drivers/vfio/mdev/mdev_driver.c | 1 +
- drivers/vfio/mdev/mdev_private.h | 1 -
- drivers/vfio/vfio_iommu_type1.c | 126 ++++++++++++++++++++++++++++---
- include/linux/mdev.h | 22 ++++++
- 4 files changed, 140 insertions(+), 10 deletions(-)
-
-diff --git a/drivers/vfio/mdev/mdev_driver.c b/drivers/vfio/mdev/mdev_driver.c
-index 7825d83a55f8..a4799e7d79fc 100644
---- a/drivers/vfio/mdev/mdev_driver.c
-+++ b/drivers/vfio/mdev/mdev_driver.c
-@@ -46,6 +46,7 @@ struct bus_type mdev_bus_type = {
- .remove = mdev_remove,
- .match = mdev_match,
- };
-+EXPORT_SYMBOL_GPL(mdev_bus_type);
-
- /**
- * mdev_register_driver - register a new MDEV driver
-diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h
-index af457b27f607..ba1b2dbddc0b 100644
---- a/drivers/vfio/mdev/mdev_private.h
-+++ b/drivers/vfio/mdev/mdev_private.h
-@@ -13,7 +13,6 @@
- int mdev_bus_register(void);
- void mdev_bus_unregister(void);
-
--extern struct bus_type mdev_bus_type;
- extern const struct attribute_group *mdev_device_groups[];
-
- #define to_mdev_type_attr(_attr) \
-diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
-index 7fa68dc4e938..fef221a87aa7 100644
---- a/drivers/vfio/vfio_iommu_type1.c
-+++ b/drivers/vfio/vfio_iommu_type1.c
-@@ -36,6 +36,7 @@
- #include <linux/uaccess.h>
- #include <linux/vfio.h>
- #include <linux/workqueue.h>
-+#include <linux/mdev.h>
- #include <linux/notifier.h>
- #include <linux/irqdomain.h>
- #include "vfio.h"
-@@ -115,6 +116,7 @@ struct vfio_batch {
- struct vfio_iommu_group {
- struct iommu_group *iommu_group;
- struct list_head next;
-+ bool mdev_group;
- bool pinned_page_dirty_scope;
- };
-
-@@ -1744,6 +1746,18 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu,
- return ret;
- }
-
-+static int vfio_bus_type(struct device *dev, void *data)
-+{
-+ struct bus_type **bus = data;
-+
-+ if (*bus && *bus != dev->bus)
-+ return -EINVAL;
-+
-+ *bus = dev->bus;
-+
-+ return 0;
-+}
-+
- static int vfio_iommu_replay(struct vfio_iommu *iommu,
- struct vfio_domain *domain)
- {
-@@ -1992,6 +2006,81 @@ static bool vfio_iommu_has_sw_msi(struct list_head *group_resv_regions,
- return ret;
- }
-
-+static int vfio_mdev_attach_domain(struct device *dev, void *data)
-+{
-+ struct mdev_device *mdev = to_mdev_device(dev);
-+ struct iommu_domain *domain = data;
-+ struct device *iommu_device;
-+
-+ iommu_device = mdev_get_iommu_device(mdev);
-+ if (iommu_device)
-+ return iommu_attach_device(domain, iommu_device);
-+
-+ return -EINVAL;
-+}
-+
-+static int vfio_mdev_detach_domain(struct device *dev, void *data)
-+{
-+ struct mdev_device *mdev = to_mdev_device(dev);
-+ struct iommu_domain *domain = data;
-+ struct device *iommu_device;
-+
-+ iommu_device = mdev_get_iommu_device(mdev);
-+ if (iommu_device)
-+ iommu_detach_device(domain, iommu_device);
-+
-+ return 0;
-+}
-+
-+static int vfio_iommu_attach_group(struct vfio_domain *domain,
-+ struct vfio_iommu_group *group)
-+{
-+ if (group->mdev_group)
-+ return iommu_group_for_each_dev(group->iommu_group,
-+ domain->domain,
-+ vfio_mdev_attach_domain);
-+ else
-+ return iommu_attach_group(domain->domain, group->iommu_group);
-+}
-+
-+static void vfio_iommu_detach_group(struct vfio_domain *domain,
-+ struct vfio_iommu_group *group)
-+{
-+ if (group->mdev_group)
-+ iommu_group_for_each_dev(group->iommu_group, domain->domain,
-+ vfio_mdev_detach_domain);
-+ else
-+ iommu_detach_group(domain->domain, group->iommu_group);
-+}
-+
-+static bool vfio_bus_is_mdev(struct bus_type *bus)
-+{
-+ struct bus_type *mdev_bus;
-+ bool ret = false;
-+
-+ mdev_bus = symbol_get(mdev_bus_type);
-+ if (mdev_bus) {
-+ ret = (bus == mdev_bus);
-+ symbol_put(mdev_bus_type);
-+ }
-+
-+ return ret;
-+}
-+
-+static int vfio_mdev_iommu_device(struct device *dev, void *data)
-+{
-+ struct mdev_device *mdev = to_mdev_device(dev);
-+ struct device **old = data, *new;
-+
-+ new = mdev_get_iommu_device(mdev);
-+ if (!new || (*old && *old != new))
-+ return -EINVAL;
-+
-+ *old = new;
-+
-+ return 0;
-+}
-+
- /*
- * This is a helper function to insert an address range to iova list.
- * The list is initially created with a single entry corresponding to
-@@ -2260,6 +2349,25 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
- group->iommu_group = iommu_group;
-
- if (type == VFIO_EMULATED_IOMMU) {
-+ struct bus_type *bus = NULL;
-+
-+ ret = iommu_group_for_each_dev(iommu_group, &bus, vfio_bus_type);
-+
-+ if (!ret && vfio_bus_is_mdev(bus)) {
-+ struct device *iommu_device = NULL;
-+
-+ group->mdev_group = true;
-+
-+ /* Determine the isolation type */
-+ ret = iommu_group_for_each_dev(iommu_group,
-+ &iommu_device,
-+ vfio_mdev_iommu_device);
-+ if (!ret && iommu_device) {
-+ iommu_group = iommu_device->iommu_group;
-+ goto mdev_iommu_device;
-+ }
-+ }
-+
- list_add(&group->next, &iommu->emulated_iommu_groups);
- /*
- * An emulated IOMMU group cannot dirty memory directly, it can
-@@ -2272,6 +2380,8 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
- goto out_unlock;
- }
-
-+mdev_iommu_device:
-+
- ret = -ENOMEM;
- domain = kzalloc(sizeof(*domain), GFP_KERNEL);
- if (!domain)
-@@ -2294,7 +2404,7 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
- goto out_domain;
- }
-
-- ret = iommu_attach_group(domain->domain, group->iommu_group);
-+ ret = vfio_iommu_attach_group(domain, group);
- if (ret)
- goto out_domain;
-
-@@ -2370,17 +2480,15 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
- if (d->domain->ops == domain->domain->ops &&
- d->enforce_cache_coherency ==
- domain->enforce_cache_coherency) {
-- iommu_detach_group(domain->domain, group->iommu_group);
-- if (!iommu_attach_group(d->domain,
-- group->iommu_group)) {
-+ vfio_iommu_detach_group(domain, group);
-+ if (!vfio_iommu_attach_group(d, group)) {
- list_add(&group->next, &d->group_list);
- iommu_domain_free(domain->domain);
- kfree(domain);
- goto done;
- }
-
-- ret = iommu_attach_group(domain->domain,
-- group->iommu_group);
-+ ret = vfio_iommu_attach_group(domain, group);
- if (ret)
- goto out_domain;
- }
-@@ -2417,7 +2525,7 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
- return 0;
-
- out_detach:
-- iommu_detach_group(domain->domain, group->iommu_group);
-+ vfio_iommu_detach_group(domain, group);
- out_domain:
- iommu_domain_free(domain->domain);
- vfio_iommu_iova_free(&iova_copy);
-@@ -2578,7 +2686,7 @@ static void vfio_iommu_type1_detach_group(void *iommu_data,
- if (!group)
- continue;
-
-- iommu_detach_group(domain->domain, group->iommu_group);
-+ vfio_iommu_detach_group(domain, group);
- update_dirty_scope = !group->pinned_page_dirty_scope;
- list_del(&group->next);
- kfree(group);
-@@ -2669,7 +2777,7 @@ static void vfio_release_domain(struct vfio_domain *domain)
-
- list_for_each_entry_safe(group, group_tmp,
- &domain->group_list, next) {
-- iommu_detach_group(domain->domain, group->iommu_group);
-+ vfio_iommu_detach_group(domain, group);
- list_del(&group->next);
- kfree(group);
- }
-diff --git a/include/linux/mdev.h b/include/linux/mdev.h
-index 139d05b26f82..b08163d67e63 100644
---- a/include/linux/mdev.h
-+++ b/include/linux/mdev.h
-@@ -20,6 +20,7 @@ struct mdev_device {
- guid_t uuid;
- struct list_head next;
- struct mdev_type *type;
-+ struct device *iommu_device;
- bool active;
- };
-
-@@ -53,6 +54,25 @@ static inline struct mdev_device *to_mdev_device(struct device *dev)
- return container_of(dev, struct mdev_device, dev);
- }
-
-+/*
-+ * Called by the parent device driver to set the device which represents
-+ * this mdev in iommu protection scope. By default, the iommu device is
-+ * NULL, that indicates using vendor defined isolation.
-+ *
-+ * @dev: the mediated device that iommu will isolate.
-+ * @iommu_device: a pci device which represents the iommu for @dev.
-+ */
-+static inline void mdev_set_iommu_device(struct mdev_device *mdev,
-+ struct device *iommu_device)
-+{
-+ mdev->iommu_device = iommu_device;
-+}
-+
-+static inline struct device *mdev_get_iommu_device(struct mdev_device *mdev)
-+{
-+ return mdev->iommu_device;
-+}
-+
- /**
- * struct mdev_driver - Mediated device driver
- * @device_api: string to return for the device_api sysfs
-@@ -73,6 +93,8 @@ struct mdev_driver {
- struct device_driver driver;
- };
-
-+extern struct bus_type mdev_bus_type;
-+
- int mdev_register_parent(struct mdev_parent *parent, struct device *dev,
- struct mdev_driver *mdev_driver, struct mdev_type **types,
- unsigned int nr_types);
projects / pve-kernel.git / commitdiff