From: Alex Williamson <[email protected]> Split the device register programming out of igb_init() into a new igb_hw_init() helper so that the same sequence can be re-run after a VFIO_DEVICE_RESET to restore the registers that CTRL.RST clears. No functional change for the initial path.
igb_init() now performs the one-shot setup: region size assertion, BAR mapping, CTRL.RST + IMC mask-all to put the device into a known state, and vfio_pci_msix_enable() to set up the kernel-side IRQ trigger. igb_hw_init() does the rest: ring pointer setup and IOVA calc, CTRL_EXT, PCI bus master, GCR, PHY loopback, descriptor rings, RCTL, TCTL, GPIE/EIAC/EIAM/EIMS/IVAR, and driver-state initialization. vfio_pci_msix_enable() moves from after RCTL/TCTL to before all device-side programming. Its only side effects are the VFIO kernel IRQ trigger setup and the PCI MSI-X capability bits in config space; neither has any ordering dependency on the 82576 device register writes performed in igb_hw_init(). Performing it once in igb_init() keeps igb_hw_init() reusable from the reset recovery path (which uses vfio_pci_irq_reenable() to re-arm the existing trigger). Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Alex Williamson <[email protected]> --- .../selftests/vfio/lib/drivers/igb/igb.c | 44 +++++++++++++------ 1 file changed, 31 insertions(+), 13 deletions(-) diff --git a/tools/testing/selftests/vfio/lib/drivers/igb/igb.c b/tools/testing/selftests/vfio/lib/drivers/igb/igb.c index 89537f8345d1..1ac0a32523ea 100644 --- a/tools/testing/selftests/vfio/lib/drivers/igb/igb.c +++ b/tools/testing/selftests/vfio/lib/drivers/igb/igb.c @@ -175,7 +175,13 @@ static int igb_probe(struct vfio_pci_device *device) return 0; } -static void igb_init(struct vfio_pci_device *device) +/* + * Program the device into a usable state. Split out of igb_init() so it + * can be reused after a device reset to re-program the registers that + * CTRL.RST clears. Expects bar0 to be mapped and MSI-X already enabled + * via VFIO. + */ +static void igb_hw_init(struct vfio_pci_device *device) { struct igb *igb = to_igb_state(device); u64 iova_tx, iova_rx; @@ -183,19 +189,10 @@ static void igb_init(struct vfio_pci_device *device) u16 cmd_reg; int retries; - VFIO_ASSERT_GE(device->driver.region.size, sizeof(struct igb)); - /* Set up rings and calculate IOVAs */ - igb->bar0 = device->bars[0].vaddr; iova_tx = to_iova(device, igb->tx_ring); iova_rx = to_iova(device, igb->rx_ring); - - /* Reset device and disable all interrupts */ - igb_write32(igb, IGB_CTRL, igb_read32(igb, IGB_CTRL) | IGB_CTRL_RST); - usleep(20000); - igb_write32(igb, IGB_IMC, 0xFFFFFFFF); - /* Signal that the driver is loaded */ ctrl = igb_read32(igb, IGB_CTRL_EXT); ctrl |= IGB_CTRL_EXT_DRV_LOAD; @@ -280,9 +277,6 @@ static void igb_init(struct vfio_pci_device *device) igb_write32(igb, IGB_RCTL, rctl); igb_write32(igb, IGB_TCTL, IGB_TCTL_EN); - /* Enable MSI-X with 1 vector for the test */ - vfio_pci_msix_enable(device, MSIX_VECTOR, 1); - /* * Program MSI-X interrupt routing per 82576 datasheet: * @@ -322,7 +316,31 @@ static void igb_init(struct vfio_pci_device *device) device->driver.msi = MSIX_VECTOR; } +static void igb_init(struct vfio_pci_device *device) +{ + struct igb *igb = to_igb_state(device); + + VFIO_ASSERT_GE(device->driver.region.size, sizeof(struct igb)); + + igb->bar0 = device->bars[0].vaddr; + + /* Reset device and disable all interrupts. */ + igb_write32(igb, IGB_CTRL, igb_read32(igb, IGB_CTRL) | IGB_CTRL_RST); + usleep(20000); + igb_write32(igb, IGB_IMC, 0xFFFFFFFF); + + /* + * Enable MSI-X via VFIO before device-side register programming. + * vfio_pci_msix_enable() only touches the VFIO IRQ machinery and the + * PCI MSI-X capability via config space; it has no ordering + * dependency on the device-side writes performed by igb_hw_init(). + * Placing it here keeps igb_hw_init() reusable from the reset + * recovery path (which calls vfio_pci_irq_reenable() instead). + */ + vfio_pci_msix_enable(device, MSIX_VECTOR, 1); + igb_hw_init(device); +} static void igb_remove(struct vfio_pci_device *device) { struct igb *igb = to_igb_state(device); -- 2.54.0.794.g4f17f83d09-goog
