diff mbox series

[for-10.1,v9,2/9] hw/pci: Fix SR-IOV VF number calculation

Message ID 20250314-sriov-v9-2-57dae8ae3ab5@daynix.com (mailing list archive)
State New
Headers show
Series virtio-net: add support for SR-IOV emulation | expand

Commit Message

Akihiko Odaki March 14, 2025, 6:14 a.m. UTC 
pci_config_get_bar_addr() had a division by vf_stride. vf_stride needs
to be non-zero when there are multiple VFs, but the specification does
not prohibit to make it zero when there is only one VF.

Do not perform the division for the first VF to avoid division by zero.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
---
 hw/pci/pci.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 8460b6105338..2b1c7d487fc1 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -1594,7 +1594,11 @@  static pcibus_t pci_config_get_bar_addr(PCIDevice *d, int reg,
             pci_get_word(pf->config + sriov_cap + PCI_SRIOV_VF_OFFSET);
         uint16_t vf_stride =
             pci_get_word(pf->config + sriov_cap + PCI_SRIOV_VF_STRIDE);
-        uint32_t vf_num = (d->devfn - (pf->devfn + vf_offset)) / vf_stride;
+        uint32_t vf_num = d->devfn - (pf->devfn + vf_offset);
+
+        if (vf_num) {
+            vf_num /= vf_stride;
+        }
 
         if (type & PCI_BASE_ADDRESS_MEM_TYPE_64) {
             new_addr = pci_get_quad(pf->config + bar);