From 765eed6ea5144c19658897e852efcd24fbebaf87 Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Tue, 3 Dec 2024 13:19:28 +0100 Subject: [PATCH 1/6] pci: ensure valid link status bits for downstream ports RH-Author: Sebastian Ott RH-MergeRequest: 328: pci: ensure valid link status bits for downstream ports RH-Jira: RHEL-65618 RH-Acked-by: Eric Auger RH-Acked-by: Gavin Shan RH-Acked-by: Cornelia Huck RH-Acked-by: Kashyap Chamarthy RH-Commit: [1/1] fe92e0cd7ab04bfede6d1bf416b1080061cca172 (seott1/cos-qemu-kvm) PCI hotplug for downstream endpoints on arm fails because Linux' PCIe hotplug driver doesn't like the QEMU provided LNKSTA: pcieport 0000:08:01.0: pciehp: Slot(2): Card present pcieport 0000:08:01.0: pciehp: Slot(2): Link Up pcieport 0000:08:01.0: pciehp: Slot(2): Cannot train link: status 0x2000 There's 2 cases where LNKSTA isn't setup properly: * the downstream device has no express capability * max link width of the bridge is 0 Move the sanity checks added via 88c869198aa63 ("pci: Sanity test minimum downstream LNKSTA") outside of the branch to make sure downstream ports always have a valid LNKSTA. Signed-off-by: Sebastian Ott Tested-by: Zhenyu Zhang Message-Id: <20241203121928.14861-1-sebott@redhat.com> Reviewed-by: Alex Williamson Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin (cherry picked from commit 694632fd44987cc4618612a38ad151047524a590) JIRA: https://issues.redhat.com/browse/RHEL-65618 Signed-off-by: Sebastian Ott --- hw/pci/pcie.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c index 4b2f0805c6..9cb137c30f 100644 --- a/hw/pci/pcie.c +++ b/hw/pci/pcie.c @@ -1080,18 +1080,22 @@ void pcie_sync_bridge_lnk(PCIDevice *bridge_dev) if ((lnksta & PCI_EXP_LNKSTA_NLW) > (lnkcap & PCI_EXP_LNKCAP_MLW)) { lnksta &= ~PCI_EXP_LNKSTA_NLW; lnksta |= lnkcap & PCI_EXP_LNKCAP_MLW; - } else if (!(lnksta & PCI_EXP_LNKSTA_NLW)) { - lnksta |= QEMU_PCI_EXP_LNKSTA_NLW(QEMU_PCI_EXP_LNK_X1); } if ((lnksta & PCI_EXP_LNKSTA_CLS) > (lnkcap & PCI_EXP_LNKCAP_SLS)) { lnksta &= ~PCI_EXP_LNKSTA_CLS; lnksta |= lnkcap & PCI_EXP_LNKCAP_SLS; - } else if (!(lnksta & PCI_EXP_LNKSTA_CLS)) { - lnksta |= QEMU_PCI_EXP_LNKSTA_CLS(QEMU_PCI_EXP_LNK_2_5GT); } } + if (!(lnksta & PCI_EXP_LNKSTA_NLW)) { + lnksta |= QEMU_PCI_EXP_LNKSTA_NLW(QEMU_PCI_EXP_LNK_X1); + } + + if (!(lnksta & PCI_EXP_LNKSTA_CLS)) { + lnksta |= QEMU_PCI_EXP_LNKSTA_CLS(QEMU_PCI_EXP_LNK_2_5GT); + } + pci_word_test_and_clear_mask(exp_cap + PCI_EXP_LNKSTA, PCI_EXP_LNKSTA_CLS | PCI_EXP_LNKSTA_NLW); pci_word_test_and_set_mask(exp_cap + PCI_EXP_LNKSTA, lnksta & -- 2.39.3