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pcie_sriov: Fix PCI_SRIOV_* accesses in pcie_sriov_pf_exit()

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PCI_SRIOV_* are offsets into the SR-IOV capability, not into the PCI
config space. pcie_sriov_pf_exit() erroneously takes them as the latter,
which makes it read PCI_HEADER_TYPE and PCI_BIST when it tries to read
PCI_SRIOV_TOTAL_VF.

In many cases we're lucky enough that the PCI config space will be 0
there, so we just skip the whole for loop, but this isn't guaranteed.
For example, setting the multifunction bit on the PF and then doing a
'device_del' on it will get a larger number and cause a segfault.

Fix this and access the real PCI_SRIOV_* fields in the capability.

Cc: qemu-stable@nongnu.org
Fixes: 19e55471d4 ('pcie_sriov: Allow user to create SR-IOV device')
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20251205145718.55136-1-kwolf@redhat.com>
(cherry picked from commit f73e5ed9bc4cfacf041323a6b40a85e6b6459b75)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
This commit is contained in:
Kevin Wolf 2025-12-05 15:57:18 +01:00 • committed by Michael Tokarev
parent a440980876
commit 8c65f73b31
1 changed files with 5 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

9
hw/pci/pcie_sriov.c
View file

@ -195,14 +195,17 @@ bool pcie_sriov_pf_init(PCIDevice *dev, uint16_t offset,
void pcie_sriov_pf_exit(PCIDevice *dev)
{
uint8_t *cfg;
if (dev->exp.sriov_cap == 0) {
return;
}
cfg = dev->config + dev->exp.sriov_cap;
if (dev->exp.sriov_pf.vf_user_created) {
uint16_t ven_id = pci_get_word(dev->config + PCI_VENDOR_ID);
uint16_t total_vfs = pci_get_word(dev->config + PCI_SRIOV_TOTAL_VF);
uint16_t vf_dev_id = pci_get_word(dev->config + PCI_SRIOV_VF_DID);
uint16_t total_vfs = pci_get_word(cfg + PCI_SRIOV_TOTAL_VF);
uint16_t vf_dev_id = pci_get_word(cfg + PCI_SRIOV_VF_DID);
unregister_vfs(dev);
@ -213,8 +216,6 @@ void pcie_sriov_pf_exit(PCIDevice *dev)
pci_config_set_device_id(dev->exp.sriov_pf.vf[i]->config, vf_dev_id);
}
} else {
uint8_t *cfg = dev->config + dev->exp.sriov_cap;
unparent_vfs(dev, pci_get_word(cfg + PCI_SRIOV_TOTAL_VF));
}
}