From: Michał Winiarski Date: Wed, 2 Jul 2025 09:35:21 +0000 (+0200) Subject: PCI/IOV: Check that VF BAR fits within the reservation X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e1ba95a168e6f771960c0afc4e44984cf5cf659c;p=thirdparty%2Fkernel%2Flinux.git PCI/IOV: Check that VF BAR fits within the reservation When the resource representing a VF MMIO BAR reservation is created, its size is always large enough to accommodate the BAR of all SR-IOV Virtual Functions that can potentially be created (total VFs). If for whatever reason it's not possible to accommodate all VFs, the resource is not assigned and no VFs can be created. An upcoming change will allow VF BAR size to be modified by drivers at a later point in time, which means that the check for resource assignment is no longer sufficient. Add an additional check that verifies that the VF BAR for all enabled VFs fits within the underlying reservation resource. Signed-off-by: Michał Winiarski Signed-off-by: Bjorn Helgaas Reviewed-by: Ilpo Järvinen Link: https://patch.msgid.link/20250702093522.518099-5-michal.winiarski@intel.com --- diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index 852424cf2ae1..f34173c70b32 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -668,9 +668,12 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn) nres = 0; for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) { int idx = pci_resource_num_from_vf_bar(i); + resource_size_t vf_bar_sz = pci_iov_resource_size(dev, idx); bars |= (1 << idx); res = &dev->resource[idx]; + if (vf_bar_sz * nr_virtfn > resource_size(res)) + continue; if (res->parent) nres++; }