> What you are suggesting is: > If table_offset is not as expected, then check if it's a chelsio device. > If it's not, then print a message. On the other hand, if it's a chelsio > device, then let msix_init() catch the error. Why ? And if we are sure that > msix_init will error out, what's the purpose of the table_offset check ?
The test needs only to check the pba_offset and reduced as following is enough ... /* * Test the size of the pba_offset variable and catch if it extends outside * of the specified BAR. If it is the case, we need to apply a hardware * specific quirk if the device is known or we have a broken configuration. */ if (vdev->msix->pba_offset >= vdev->bars[vdev->msix->pba_bar].region.size) { PCIDevice *pdev = &vdev->pdev; uint16_t vendor = pci_get_word(pdev->config + PCI_VENDOR_ID); uint16_t device = pci_get_word(pdev->config + PCI_DEVICE_ID); /* * Chelsio T5 Virtual Function devices are encoded as 0x58xx for T5 * adapters. The T5 hardware returns an incorrect value of 0x8000 for * the VF PBA offset while the BAR itself is only 8k. The correct value * is 0x1000, so we hard code that here. */ if (vendor == PCI_VENDOR_ID_CHELSIO && (device & 0xff00) == 0x5800) { vdev->msix->pba_offset = 0x1000; } else { error_report("vfio: Hardware reports invalid configuration, " "MSIX data outside of specified BAR"); return -EINVAL; } } ... As the hardware problem is only related with the pba_offset and the purpose of the quirk is to correct the known hardware error. The table_offset has never been seen as wrong. Therefore the msix_init() sanity check should take care of a "rare" potential error as you mentioned. This time I'll wait for ACKs from your side before submitting a new version :) Gabriel -----Original Message----- From: Bandan Das [mailto:b...@redhat.com] Sent: Tuesday, June 30, 2015 6:48 PM To: Gabriel Laupre Cc: jb-gnumli...@wisemo.com; Casey Leedom; m...@redhat.com; qemu-devel@nongnu.org; Anish Bhatt; Michael Boksanyi; alex.william...@redhat.com; b...@makefile.in Subject: Re: [Qemu-devel] [PATCH v3] pci : Add pba_offset PCI quirk for Chelsio T5 devices Gabriel Laupre <glau...@chelsio.com> writes: > @ Bandan ... >> > + + /* Chelsio T5 Virtual Function devices are encoded as 0x58xx >> > for T5 + * adapters. The T5 hardware returns an incorrect value of >> > 0x8000 for + * the VF PBA offset. The correct value is 0x1000, so >> > we hard code that + * here. */ + if (vendor == >> > PCI_VENDOR_ID_CHELSIO && (device & 0xff00) == 0x5800) { + >> > vdev->msix->pba_offset = 0x1000; > >> For the rare case where table_offset is wrong for the device being > checked for above and pba_offset is actually correct, shouldn't we > fail ? > > I don't know if it is relevant to do all the tests here because in the > function msix_init() all size are checked. I would prefer keeping this > test as this to simplify the quirk, i.e. just testing the device > first, and if another size than the pba_offset is wrong, then the > sanity check in the function msix_init() will catch the error. Ok, here's the excerpt: + /* Test the size of the pba variables and catch if they extend outside of + * the specified BAR. If it is the case, we have a broken configuration or + * we need to apply a hardware specific quirk. */ + if (vdev->msix->table_offset >= + vdev->bars[vdev->msix->table_bar].region.size || + vdev->msix->pba_offset >= + vdev->bars[vdev->msix->pba_bar].region.size) { + + PCIDevice *pdev = &vdev->pdev; + uint16_t vendor = pci_get_word(pdev->config + PCI_VENDOR_ID); + uint16_t device = pci_get_word(pdev->config + PCI_DEVICE_ID); + + /* Chelsio T5 Virtual Function devices are encoded as 0x58xx for T5 + * adapters. The T5 hardware returns an incorrect value of 0x8000 for + * the VF PBA offset. The correct value is 0x1000, so we hard code that + * here. */ + if (vendor == PCI_VENDOR_ID_CHELSIO && (device & 0xff00) == 0x5800) { + vdev->msix->pba_offset = 0x1000; + } else { + error_report("vfio: Hardware reports invalid configuration, " + "MSIX data outside of specified BAR"); + return -EINVAL; + } + } What you are suggesting is: If table_offset is not as expected, then check if it's a chelsio device. If it's not, then print a message. On the other hand, if it's a chelsio device, then let msix_init() catch the error. Why ? And if we are sure that msix_init will error out, what's the purpose of the table_offset check ? > @ Alex I corrected what you pointed out. I will send the patch v4 in a > minute. > > Thanks you > > Gabriel