[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen staging-4.15] PCI: don't allow "pci-phantom=" to mark real devices as phantom functions
commit 64249afeb63cf7d70b4faf02e76df5eed82371f9 Author: Jan Beulich <jbeulich@xxxxxxxx> AuthorDate: Tue Jun 7 14:23:07 2022 +0200 Commit: Jan Beulich <jbeulich@xxxxxxxx> CommitDate: Tue Jun 7 14:23:07 2022 +0200 PCI: don't allow "pci-phantom=" to mark real devices as phantom functions IOMMU code mapping / unmapping devices and interrupts will misbehave if a wrong command line option declared a function "phantom" when there's a real device at that position. Warn about this and adjust the specified stride (in the worst case ignoring the option altogether). Requested-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx> Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx> master commit: 444b555dc9e09fa3ce90f066e0c88dec9b47f422 master date: 2022-05-20 12:20:35 +0200 --- xen/drivers/passthrough/pci.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/xen/drivers/passthrough/pci.c b/xen/drivers/passthrough/pci.c index 37c2d5b1d1..bbacbe41da 100644 --- a/xen/drivers/passthrough/pci.c +++ b/xen/drivers/passthrough/pci.c @@ -403,7 +403,24 @@ static struct pci_dev *alloc_pdev(struct pci_seg *pseg, u8 bus, u8 devfn) phantom_devs[i].slot == PCI_SLOT(devfn) && phantom_devs[i].stride > PCI_FUNC(devfn) ) { - pdev->phantom_stride = phantom_devs[i].stride; + pci_sbdf_t sbdf = pdev->sbdf; + unsigned int stride = phantom_devs[i].stride; + + while ( (sbdf.fn += stride) > PCI_FUNC(devfn) ) + { + if ( pci_conf_read16(sbdf, PCI_VENDOR_ID) == 0xffff && + pci_conf_read16(sbdf, PCI_DEVICE_ID) == 0xffff ) + continue; + stride <<= 1; + printk(XENLOG_WARNING + "%pp looks to be a real device; bumping %04x:%02x:%02x stride to %u\n", + &sbdf, phantom_devs[i].seg, + phantom_devs[i].bus, phantom_devs[i].slot, + stride); + sbdf = pdev->sbdf; + } + if ( PCI_FUNC(stride) ) + pdev->phantom_stride = stride; break; } } -- generated by git-patchbot for /home/xen/git/xen.git#staging-4.15
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