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[PULL,v2,29/61] hw/pci: Fix SR-IOV VF number calculation

Message ID ca6dd3aef8a103138c99788bcba8195d4905ddc5.1721731723.git.mst@redhat.com
State New
Headers show
Series [PULL,v2,01/61] hw/virtio/virtio-crypto: Fix op_code assignment in virtio_crypto_create_asym_session | expand

Commit Message

Michael S. Tsirkin July 23, 2024, 10:57 a.m. UTC 
From: Akihiko Odaki <akihiko.odaki@daynix.com>

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>
Message-Id: <20240715-sriov-v5-2-3f5539093ffc@daynix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/pci/pci.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
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Patch

diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 4c7be52951..cf2794879d 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -1437,7 +1437,11 @@  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);