Commit e1ba95a1 authored by Michał Winiarski's avatar Michał Winiarski Committed by Bjorn Helgaas
Browse files

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: default avatarMichał Winiarski <michal.winiarski@intel.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20250702093522.518099-5-michal.winiarski@intel.com
parent e200f4f7

drivers/pci/iov.c

+3 −0
Original line number Diff line number Diff line
@@ -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++;

	}