On Tue, 5 May 2026 10:38:31 -0700 Matt Evans <[email protected]> wrote:
> Since "vfio/pci: Set up barmap in vfio_pci_core_enable()", the > resource request and iomap for the BARs was performed early, and > vfio_pci_core_setup_barmap() just checks those actions succeeded. > > Move this logic to a new helper that checks success and returns the > iomap address, replacing the various bare vdev->barmap[] lookups. > This maintains the error behaviour of the previous on-demand > vfio_pci_core_setup_barmap() scheme. > > Signed-off-by: Matt Evans <[email protected]> > --- > drivers/vfio/pci/nvgrace-gpu/main.c | 11 ++++------- > drivers/vfio/pci/vfio_pci_core.c | 11 +++++------ > drivers/vfio/pci/vfio_pci_dmabuf.c | 2 +- > drivers/vfio/pci/vfio_pci_rdwr.c | 30 ++++++++--------------------- > drivers/vfio/pci/virtio/legacy_io.c | 13 ++++++------- > include/linux/vfio_pci_core.h | 20 ++++++++++++++++++- > 6 files changed, 43 insertions(+), 44 deletions(-) > > diff --git a/drivers/vfio/pci/nvgrace-gpu/main.c > b/drivers/vfio/pci/nvgrace-gpu/main.c > index fa056b69f899..e153002258ce 100644 > --- a/drivers/vfio/pci/nvgrace-gpu/main.c > +++ b/drivers/vfio/pci/nvgrace-gpu/main.c > @@ -184,13 +184,10 @@ static int nvgrace_gpu_open_device(struct vfio_device > *core_vdev) > > /* > * GPU readiness is checked by reading the BAR0 registers. > - * > - * ioremap BAR0 to ensure that the BAR0 mapping is present before > - * register reads on first fault before establishing any GPU > - * memory mapping. > + * The BAR map was just set up by vfio_pci_core_enable(), so > + * check that was successful and bail early if not: > */ > - ret = vfio_pci_core_setup_barmap(vdev, 0); > - if (ret) > + if (IS_ERR(vfio_pci_core_get_iomap(vdev, 0))) > goto error_exit; Sashiko notes we're not setting ret here. The bots are also paranoid about the unreachable condition that the get_iomap below could return an ERR_PTR. Maybe head off both by adding an __iomem pointer to the nvgrace_gpu_pci_core_device struct and a temporary one here. Store the iomap in the temporary variable, use it to test for IS_ERR() and PTR_ERR(), then set the pointer in the structure after the last error condition here. Add one line in the close_device to set it NULL. Then just use nvdev->bar0_io below. > > if (nvdev->resmem.memlength) { > @@ -275,7 +272,7 @@ nvgrace_gpu_check_device_ready(struct > nvgrace_gpu_pci_core_device *nvdev) > if (!__vfio_pci_memory_enabled(vdev)) > return -EIO; > > - ret = nvgrace_gpu_wait_device_ready(vdev->barmap[0]); > + ret = nvgrace_gpu_wait_device_ready(vfio_pci_core_get_iomap(vdev, 0)); > if (ret) > return ret; > > diff --git a/drivers/vfio/pci/vfio_pci_core.c > b/drivers/vfio/pci/vfio_pci_core.c > index 62931dc381d8..5c8bd13f10d0 100644 > --- a/drivers/vfio/pci/vfio_pci_core.c > +++ b/drivers/vfio/pci/vfio_pci_core.c > @@ -1761,7 +1761,7 @@ int vfio_pci_core_mmap(struct vfio_device *core_vdev, > struct vm_area_struct *vma > struct pci_dev *pdev = vdev->pdev; > unsigned int index; > u64 phys_len, req_len, pgoff, req_start; > - int ret; > + void __iomem *bar_io; > > index = vma->vm_pgoff >> (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT); > > @@ -1795,12 +1795,11 @@ int vfio_pci_core_mmap(struct vfio_device *core_vdev, > struct vm_area_struct *vma > return -EINVAL; > > /* > - * Even though we don't make use of the barmap for the mmap, > - * we need to request the region and the barmap tracks that. > + * Ensure the BAR resource region is reserved for use. > */ > - ret = vfio_pci_core_setup_barmap(vdev, index); > - if (ret) > - return ret; > + bar_io = vfio_pci_core_get_iomap(vdev, index); > + if (IS_ERR(bar_io)) > + return PTR_ERR(bar_io); > > vma->vm_private_data = vdev; > vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); > diff --git a/drivers/vfio/pci/vfio_pci_dmabuf.c > b/drivers/vfio/pci/vfio_pci_dmabuf.c > index 69a5c2d511e6..46cd44b22c9c 100644 > --- a/drivers/vfio/pci/vfio_pci_dmabuf.c > +++ b/drivers/vfio/pci/vfio_pci_dmabuf.c > @@ -248,7 +248,7 @@ int vfio_pci_core_feature_dma_buf(struct > vfio_pci_core_device *vdev, u32 flags, > * else. Check that PCI resources have been claimed for it. > */ > if (get_dma_buf.region_index >= VFIO_PCI_ROM_REGION_INDEX || > - vfio_pci_core_setup_barmap(vdev, get_dma_buf.region_index)) > + IS_ERR(vfio_pci_core_get_iomap(vdev, get_dma_buf.region_index))) > return -ENODEV; > > dma_ranges = memdup_array_user(&arg->dma_ranges, get_dma_buf.nr_ranges, > diff --git a/drivers/vfio/pci/vfio_pci_rdwr.c > b/drivers/vfio/pci/vfio_pci_rdwr.c > index 3bfbb879a005..7f14dd46de17 100644 > --- a/drivers/vfio/pci/vfio_pci_rdwr.c > +++ b/drivers/vfio/pci/vfio_pci_rdwr.c > @@ -198,19 +198,6 @@ ssize_t vfio_pci_core_do_io_rw(struct > vfio_pci_core_device *vdev, bool test_mem, > } > EXPORT_SYMBOL_GPL(vfio_pci_core_do_io_rw); > > -/* > - * The barmap is set up in vfio_pci_core_enable(). Callers use this > - * function to check that the BAR resources are requested or that the > - * pci_iomap() was done. > - */ > -int vfio_pci_core_setup_barmap(struct vfio_pci_core_device *vdev, int bar) > -{ > - if (IS_ERR(vdev->barmap[bar])) > - return PTR_ERR(vdev->barmap[bar]); > - return 0; > -} > -EXPORT_SYMBOL_GPL(vfio_pci_core_setup_barmap); > - > ssize_t vfio_pci_bar_rw(struct vfio_pci_core_device *vdev, char __user *buf, > size_t count, loff_t *ppos, bool iswrite) > { > @@ -262,13 +249,11 @@ ssize_t vfio_pci_bar_rw(struct vfio_pci_core_device > *vdev, char __user *buf, > */ > max_width = VFIO_PCI_IO_WIDTH_4; > } else { > - int ret = vfio_pci_core_setup_barmap(vdev, bar); > - if (ret) { > - done = ret; > + io = vfio_pci_core_get_iomap(vdev, bar); > + if (IS_ERR(io)) { > + done = PTR_ERR(io); > goto out; > } > - > - io = vdev->barmap[bar]; > } > > if (bar == vdev->msix_bar) { > @@ -423,6 +408,7 @@ int vfio_pci_ioeventfd(struct vfio_pci_core_device *vdev, > loff_t offset, > loff_t pos = offset & VFIO_PCI_OFFSET_MASK; > int ret, bar = VFIO_PCI_OFFSET_TO_INDEX(offset); > struct vfio_pci_ioeventfd *ioeventfd; > + void __iomem *io; > > /* Only support ioeventfds into BARs */ > if (bar > VFIO_PCI_BAR5_REGION_INDEX) > @@ -440,9 +426,9 @@ int vfio_pci_ioeventfd(struct vfio_pci_core_device *vdev, > loff_t offset, > if (count == 8) > return -EINVAL; > > - ret = vfio_pci_core_setup_barmap(vdev, bar); > - if (ret) > - return ret; > + io = vfio_pci_core_get_iomap(vdev, bar); > + if (IS_ERR(io)) > + return PTR_ERR(io); Sashiko seems to note a real existing error here that should also be pulled out to a separate fix. Given the right offset, this could generate a negative BAR value. The test at the end of the previous chunk should should be expanded to `if (bar < 0 || bar > ...BAR5...)`. Do you want to pick that up in this series? I think it's the only case that lets that slip through. Thanks, Alex
