lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Mon, 24 Feb 2020 12:15:04 -0700 From: Alex Williamson <alex.williamson@...hat.com> To: Yan Zhao <yan.y.zhao@...el.com> Cc: zhenyuw@...ux.intel.com, intel-gvt-dev@...ts.freedesktop.org, kvm@...r.kernel.org, linux-kernel@...r.kernel.org, pbonzini@...hat.com, kevin.tian@...el.com, peterx@...hat.com Subject: Re: [PATCH v3 1/7] vfio: allow external user to get vfio group from device On Mon, 24 Feb 2020 03:46:41 -0500 Yan Zhao <yan.y.zhao@...el.com> wrote: > external user is able to > 1. add a device into an vfio group How so? The device is added via existing mechanisms, the only thing added here is an interface to get a group reference from a struct device. > 2. call vfio_group_get_external_user_from_dev() with the device pointer > to get vfio_group associated with this device and increments the container > user counter to prevent the VFIO group from disposal before KVM exits. > 3. When the external KVM finishes, it calls vfio_group_put_external_user() > to release the VFIO group. > > Suggested-by: Alex Williamson <alex.williamson@...hat.com> > Signed-off-by: Yan Zhao <yan.y.zhao@...el.com> > --- > drivers/vfio/vfio.c | 37 +++++++++++++++++++++++++++++++++++++ > include/linux/vfio.h | 2 ++ > 2 files changed, 39 insertions(+) > > diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c > index c8482624ca34..914bdf4b9d73 100644 > --- a/drivers/vfio/vfio.c > +++ b/drivers/vfio/vfio.c > @@ -1720,6 +1720,43 @@ struct vfio_group *vfio_group_get_external_user(struct file *filep) > } > EXPORT_SYMBOL_GPL(vfio_group_get_external_user); > > +/** > + * External user API, exported by symbols to be linked dynamically. > + * > + * The protocol includes: > + * 1. External user add a device into a vfio group > + * > + * 2. The external user calls vfio_group_get_external_user_from_dev() > + * with the device pointer > + * to verify that: > + * - there's a vfio group associated with it and is initialized; > + * - IOMMU is set for the vfio group. > + * If both checks passed, vfio_group_get_external_user_from_dev() > + * increments the container user counter to prevent > + * the VFIO group from disposal before KVM exits. > + * > + * 3. When the external KVM finishes, it calls > + * vfio_group_put_external_user() to release the VFIO group. > + * This call decrements the container user counter. > + */ I don't think we need to duplicate this whole comment block for a _from_dev() version of the existing vfio_group_get_external_user(). Please merge the comments. > + > +struct vfio_group *vfio_group_get_external_user_from_dev(struct device *dev) > +{ > + struct vfio_group *group; > + int ret; > + > + group = vfio_group_get_from_dev(dev); > + if (!group) > + return ERR_PTR(-ENODEV); > + > + ret = vfio_group_add_container_user(group); > + if (ret) > + return ERR_PTR(ret); Error path leaks group reference. > + > + return group; > +} > +EXPORT_SYMBOL_GPL(vfio_group_get_external_user_from_dev); > + > void vfio_group_put_external_user(struct vfio_group *group) > { > vfio_group_try_dissolve_container(group); > diff --git a/include/linux/vfio.h b/include/linux/vfio.h > index e42a711a2800..2e1fa0c7396f 100644 > --- a/include/linux/vfio.h > +++ b/include/linux/vfio.h > @@ -94,6 +94,8 @@ extern void vfio_unregister_iommu_driver( > */ > extern struct vfio_group *vfio_group_get_external_user(struct file *filep); > extern void vfio_group_put_external_user(struct vfio_group *group); > +extern > +struct vfio_group *vfio_group_get_external_user_from_dev(struct device *dev); Slight cringe at this line wrap, personally would prefer to wrap the args as done repeatedly elsewhere in this file. Thanks, Alex > extern bool vfio_external_group_match_file(struct vfio_group *group, > struct file *filep); > extern int vfio_external_user_iommu_id(struct vfio_group *group);
Powered by blists - more mailing lists