From: Selvin Xavier selvin.xavier@broadcom.com
[ Upstream commit 5ec0a6fcb60ea430f8ee7e0bec22db9b22f856d3 ]
Host crashes when pci_enable_atomic_ops_to_root() is called for VFs with virtual buses. The virtual buses added to SR-IOV have bus->self set to NULL and host crashes due to this.
PID: 4481 TASK: ffff89c6941b0000 CPU: 53 COMMAND: "bash" ... #3 [ffff9a9481713808] oops_end at ffffffffb9025cd6 #4 [ffff9a9481713828] page_fault_oops at ffffffffb906e417 #5 [ffff9a9481713888] exc_page_fault at ffffffffb9a0ad14 #6 [ffff9a94817138b0] asm_exc_page_fault at ffffffffb9c00ace [exception RIP: pcie_capability_read_dword+28] RIP: ffffffffb952fd5c RSP: ffff9a9481713960 RFLAGS: 00010246 RAX: 0000000000000001 RBX: ffff89c6b1096000 RCX: 0000000000000000 RDX: ffff9a9481713990 RSI: 0000000000000024 RDI: 0000000000000000 RBP: 0000000000000080 R8: 0000000000000008 R9: ffff89c64341a2f8 R10: 0000000000000002 R11: 0000000000000000 R12: ffff89c648bab000 R13: 0000000000000000 R14: 0000000000000000 R15: ffff89c648bab0c8 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #7 [ffff9a9481713988] pci_enable_atomic_ops_to_root at ffffffffb95359a6 #8 [ffff9a94817139c0] bnxt_qplib_determine_atomics at ffffffffc08c1a33 [bnxt_re] #9 [ffff9a94817139d0] bnxt_re_dev_init at ffffffffc08ba2d1 [bnxt_re]
Per PCIe r5.0, sec 9.3.5.10, the AtomicOp Requester Enable bit in Device Control 2 is reserved for VFs. The PF value applies to all associated VFs.
Return -EINVAL if pci_enable_atomic_ops_to_root() is called for a VF.
Link: https://lore.kernel.org/r/1631354585-16597-1-git-send-email-selvin.xavier@br... Fixes: 35f5ace5dea4 ("RDMA/bnxt_re: Enable global atomic ops if platform supports") Fixes: 430a23689dea ("PCI: Add pci_enable_atomic_ops_to_root()") Signed-off-by: Selvin Xavier selvin.xavier@broadcom.com Signed-off-by: Bjorn Helgaas bhelgaas@google.com Reviewed-by: Andy Gospodarek gospo@broadcom.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/pci/pci.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index a4eb0c042ca3e..e1de19fad9875 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3709,6 +3709,14 @@ int pci_enable_atomic_ops_to_root(struct pci_dev *dev, u32 cap_mask) struct pci_dev *bridge; u32 cap, ctl2;
+ /* + * Per PCIe r5.0, sec 9.3.5.10, the AtomicOp Requester Enable bit + * in Device Control 2 is reserved in VFs and the PF value applies + * to all associated VFs. + */ + if (dev->is_virtfn) + return -EINVAL; + if (!pci_is_pcie(dev)) return -EINVAL;