Messages in this thread | | | Date | Wed, 6 Jul 2022 23:08:48 +0530 | Subject | Re: [RFT][PATCH v2 1/9] vfio: Make vfio_unpin_pages() return void | From | Kirti Wankhede <> |
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Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
On 7/6/2022 11:57 AM, Nicolin Chen wrote: > There's only one caller that checks its return value with a WARN_ON_ONCE, > while all other callers do not check return value at all. So simplify the > API to return void by embedding similar WARN_ON_ONCEs. > > Suggested-by: Christoph Hellwig <hch@infradead.org> > Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> > --- > .../driver-api/vfio-mediated-device.rst | 2 +- > drivers/gpu/drm/i915/gvt/kvmgt.c | 5 +--- > drivers/vfio/vfio.c | 24 ++++++++----------- > drivers/vfio/vfio.h | 2 +- > drivers/vfio/vfio_iommu_type1.c | 16 ++++++------- > include/linux/vfio.h | 4 ++-- > 6 files changed, 23 insertions(+), 30 deletions(-) > > diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst > index 1c57815619fd..b0fdf76b339a 100644 > --- a/Documentation/driver-api/vfio-mediated-device.rst > +++ b/Documentation/driver-api/vfio-mediated-device.rst > @@ -265,7 +265,7 @@ driver:: > int vfio_pin_pages(struct vfio_device *device, unsigned long *user_pfn, > int npage, int prot, unsigned long *phys_pfn); > > - int vfio_unpin_pages(struct vfio_device *device, unsigned long *user_pfn, > + void vfio_unpin_pages(struct vfio_device *device, unsigned long *user_pfn, > int npage); > > These functions call back into the back-end IOMMU module by using the pin_pages > diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c > index e2f6c56ab342..8c67c9aba82d 100644 > --- a/drivers/gpu/drm/i915/gvt/kvmgt.c > +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c > @@ -231,18 +231,15 @@ static void intel_gvt_cleanup_vgpu_type_groups(struct intel_gvt *gvt) > static void gvt_unpin_guest_page(struct intel_vgpu *vgpu, unsigned long gfn, > unsigned long size) > { > - struct drm_i915_private *i915 = vgpu->gvt->gt->i915; > int total_pages; > int npage; > - int ret; > > total_pages = roundup(size, PAGE_SIZE) / PAGE_SIZE; > > for (npage = 0; npage < total_pages; npage++) { > unsigned long cur_gfn = gfn + npage; > > - ret = vfio_unpin_pages(&vgpu->vfio_device, &cur_gfn, 1); > - drm_WARN_ON(&i915->drm, ret != 1); > + vfio_unpin_pages(&vgpu->vfio_device, &cur_gfn, 1); > } > } > > diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c > index 61e71c1154be..01f45ec70a3d 100644 > --- a/drivers/vfio/vfio.c > +++ b/drivers/vfio/vfio.c > @@ -1959,31 +1959,27 @@ EXPORT_SYMBOL(vfio_pin_pages); > * PFNs should not be greater than VFIO_PIN_PAGES_MAX_ENTRIES. > * @npage [in] : count of elements in user_pfn array. This count should not > * be greater than VFIO_PIN_PAGES_MAX_ENTRIES. > - * Return error or number of pages unpinned. > */ > -int vfio_unpin_pages(struct vfio_device *device, unsigned long *user_pfn, > - int npage) > +void vfio_unpin_pages(struct vfio_device *device, unsigned long *user_pfn, > + int npage) > { > struct vfio_container *container; > struct vfio_iommu_driver *driver; > - int ret; > > - if (!user_pfn || !npage || !vfio_assert_device_open(device)) > - return -EINVAL; > + if (WARN_ON_ONCE(!user_pfn || !npage || !vfio_assert_device_open(device))) > + return; > > - if (npage > VFIO_PIN_PAGES_MAX_ENTRIES) > - return -E2BIG; > + if (WARN_ON_ONCE(npage > VFIO_PIN_PAGES_MAX_ENTRIES)) > + return; > > /* group->container cannot change while a vfio device is open */ > container = device->group->container; > driver = container->iommu_driver; > - if (likely(driver && driver->ops->unpin_pages)) > - ret = driver->ops->unpin_pages(container->iommu_data, user_pfn, > - npage); > - else > - ret = -ENOTTY; > > - return ret; > + if (WARN_ON_ONCE(unlikely(!driver || !driver->ops->unpin_pages))) > + return; > + > + driver->ops->unpin_pages(container->iommu_data, user_pfn, npage); > } > EXPORT_SYMBOL(vfio_unpin_pages); > > diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h > index a67130221151..bef4edf58138 100644 > --- a/drivers/vfio/vfio.h > +++ b/drivers/vfio/vfio.h > @@ -53,7 +53,7 @@ struct vfio_iommu_driver_ops { > unsigned long *user_pfn, > int npage, int prot, > unsigned long *phys_pfn); > - int (*unpin_pages)(void *iommu_data, > + void (*unpin_pages)(void *iommu_data, > unsigned long *user_pfn, int npage); > int (*register_notifier)(void *iommu_data, > unsigned long *events, > diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c > index c13b9290e357..08613edaf722 100644 > --- a/drivers/vfio/vfio_iommu_type1.c > +++ b/drivers/vfio/vfio_iommu_type1.c > @@ -948,20 +948,19 @@ static int vfio_iommu_type1_pin_pages(void *iommu_data, > return ret; > } > > -static int vfio_iommu_type1_unpin_pages(void *iommu_data, > - unsigned long *user_pfn, > - int npage) > +static void vfio_iommu_type1_unpin_pages(void *iommu_data, > + unsigned long *user_pfn, int npage) > { > struct vfio_iommu *iommu = iommu_data; > bool do_accounting; > int i; > > - if (!iommu || !user_pfn || npage <= 0) > - return -EINVAL; > + if (WARN_ON_ONCE(!iommu || !user_pfn || npage <= 0)) > + return; > > /* Supported for v2 version only */ > - if (!iommu->v2) > - return -EACCES; > + if (WARN_ON_ONCE(!iommu->v2)) > + return; > > mutex_lock(&iommu->lock); > > @@ -979,7 +978,8 @@ static int vfio_iommu_type1_unpin_pages(void *iommu_data, > } > > mutex_unlock(&iommu->lock); > - return i > 0 ? i : -EINVAL; > + > + WARN_ON_ONCE(i != npage); > } > > static long vfio_sync_unpin(struct vfio_dma *dma, struct vfio_domain *domain, > diff --git a/include/linux/vfio.h b/include/linux/vfio.h > index 49580fa2073a..d0844ecdc961 100644 > --- a/include/linux/vfio.h > +++ b/include/linux/vfio.h > @@ -149,8 +149,8 @@ bool vfio_file_has_dev(struct file *file, struct vfio_device *device); > > int vfio_pin_pages(struct vfio_device *device, unsigned long *user_pfn, > int npage, int prot, unsigned long *phys_pfn); > -int vfio_unpin_pages(struct vfio_device *device, unsigned long *user_pfn, > - int npage); > +void vfio_unpin_pages(struct vfio_device *device, unsigned long *user_pfn, > + int npage); > int vfio_dma_rw(struct vfio_device *device, dma_addr_t user_iova, > void *data, size_t len, bool write); >
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