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vfio/pci: Move VGA and VF initialization to functions

Browse source 
vfio_pci_probe() is quite complicated, with optional VF and VGA sub
components. Move these into clear init/uninit functions and have a linear
flow in probe/remove.

This fixes a few little buglets:
 - vfio_pci_remove() is in the wrong order, vga_client_register() removes
   a notifier and is after kfree(vdev), but the notifier refers to vdev,
   so it can use after free in a race.
 - vga_client_register() can fail but was ignored

Organize things so destruction order is the reverse of creation order.

Fixes: ecaa1f6a01 ("vfio-pci: Add VGA arbiter client")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Message-Id: <7-v3-225de1400dfc+4e074-vfio1_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This commit is contained in:
Jason Gunthorpe 2021-03-30 09:53:06 -06:00 committed by Alex Williamson
parent 0ca78666fa
commit 61e9081748
1 changed files with 74 additions and 42 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

116
drivers/vfio/pci/vfio_pci.c
View file

@ -1922,6 +1922,68 @@ static int vfio_pci_bus_notifier(struct notifier_block *nb,
return 0;
}
static int vfio_pci_vf_init(struct vfio_pci_device *vdev)
{
struct pci_dev *pdev = vdev->pdev;
int ret;
if (!pdev->is_physfn)
return 0;
vdev->vf_token = kzalloc(sizeof(*vdev->vf_token), GFP_KERNEL);
if (!vdev->vf_token)
return -ENOMEM;
mutex_init(&vdev->vf_token->lock);
uuid_gen(&vdev->vf_token->uuid);
vdev->nb.notifier_call = vfio_pci_bus_notifier;
ret = bus_register_notifier(&pci_bus_type, &vdev->nb);
if (ret) {
kfree(vdev->vf_token);
return ret;
}
return 0;
}
static void vfio_pci_vf_uninit(struct vfio_pci_device *vdev)
{
if (!vdev->vf_token)
return;
bus_unregister_notifier(&pci_bus_type, &vdev->nb);
WARN_ON(vdev->vf_token->users);
mutex_destroy(&vdev->vf_token->lock);
kfree(vdev->vf_token);
}
static int vfio_pci_vga_init(struct vfio_pci_device *vdev)
{
struct pci_dev *pdev = vdev->pdev;
int ret;
if (!vfio_pci_is_vga(pdev))
return 0;
ret = vga_client_register(pdev, vdev, NULL, vfio_pci_set_vga_decode);
if (ret)
return ret;
vga_set_legacy_decoding(pdev, vfio_pci_set_vga_decode(vdev, false));
return 0;
}
static void vfio_pci_vga_uninit(struct vfio_pci_device *vdev)
{
struct pci_dev *pdev = vdev->pdev;
if (!vfio_pci_is_vga(pdev))
return;
vga_client_register(pdev, NULL, NULL, NULL);
vga_set_legacy_decoding(pdev, VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM |
VGA_RSRC_LEGACY_IO |
VGA_RSRC_LEGACY_MEM);
}
static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
struct vfio_pci_device *vdev;
@ -1975,28 +2037,12 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
ret = vfio_pci_reflck_attach(vdev);
if (ret)
goto out_del_group_dev;
if (pdev->is_physfn) {
vdev->vf_token = kzalloc(sizeof(*vdev->vf_token), GFP_KERNEL);
if (!vdev->vf_token) {
ret = -ENOMEM;
goto out_reflck;
}
mutex_init(&vdev->vf_token->lock);
uuid_gen(&vdev->vf_token->uuid);
vdev->nb.notifier_call = vfio_pci_bus_notifier;
ret = bus_register_notifier(&pci_bus_type, &vdev->nb);
if (ret)
goto out_vf_token;
}
if (vfio_pci_is_vga(pdev)) {
vga_client_register(pdev, vdev, NULL, vfio_pci_set_vga_decode);
vga_set_legacy_decoding(pdev,
vfio_pci_set_vga_decode(vdev, false));
}
ret = vfio_pci_vf_init(vdev);
if (ret)
goto out_reflck;
ret = vfio_pci_vga_init(vdev);
if (ret)
goto out_vf;
vfio_pci_probe_power_state(vdev);
@ -2016,8 +2062,8 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
return ret;
out_vf_token:
kfree(vdev->vf_token);
out_vf:
vfio_pci_vf_uninit(vdev);
out_reflck:
vfio_pci_reflck_put(vdev->reflck);
out_del_group_dev:
@ -2039,33 +2085,19 @@ static void vfio_pci_remove(struct pci_dev *pdev)
if (!vdev)
return;
if (vdev->vf_token) {
WARN_ON(vdev->vf_token->users);
mutex_destroy(&vdev->vf_token->lock);
kfree(vdev->vf_token);
}
if (vdev->nb.notifier_call)
bus_unregister_notifier(&pci_bus_type, &vdev->nb);
vfio_pci_vf_uninit(vdev);
vfio_pci_reflck_put(vdev->reflck);
vfio_pci_vga_uninit(vdev);
vfio_iommu_group_put(pdev->dev.iommu_group, &pdev->dev);
kfree(vdev->region);
mutex_destroy(&vdev->ioeventfds_lock);
if (!disable_idle_d3)
vfio_pci_set_power_state(vdev, PCI_D0);
mutex_destroy(&vdev->ioeventfds_lock);
kfree(vdev->region);
kfree(vdev->pm_save);
kfree(vdev);
if (vfio_pci_is_vga(pdev)) {
vga_client_register(pdev, NULL, NULL, NULL);
vga_set_legacy_decoding(pdev,
VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM |
VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM);
}
}
static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev,