From 96abccb54db35e4625e0ea7b5ea72106d708e241 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Thu, 17 Jun 2010 11:51:55 -0600 Subject: [PATCH] device-assignment: be more selective in interrupt disabling An 82576 physical function assigned to a Windows 7 guest currently doesn't work because the driver seems to gratuitiously disable MSI and MSIX interrupts. When it does this, we blindly deassign the current interrupt setup, leaving the device with no interrupts. Instead let's only deassign the irq if we were previously using MSI/MSIX or if we're going to start using MSI/MSIX. Signed-off-by: Alex Williamson Acked-by: Chris Wright Signed-off-by: Avi Kivity --- hw/device-assignment.c | 34 +++++++++++++++++++++++++--------- 1 file changed, 25 insertions(+), 9 deletions(-) diff --git a/hw/device-assignment.c b/hw/device-assignment.c index 20ed9342d4..585162b163 100644 --- a/hw/device-assignment.c +++ b/hw/device-assignment.c @@ -1031,13 +1031,20 @@ static void assigned_dev_update_msi(PCIDevice *pci_dev, unsigned int ctrl_pos) calc_assigned_dev_id(assigned_dev->h_segnr, assigned_dev->h_busnr, (uint8_t)assigned_dev->h_devfn); - if (assigned_dev->irq_requested_type) { - assigned_irq_data.flags = assigned_dev->irq_requested_type; - free_dev_irq_entries(assigned_dev); - r = kvm_deassign_irq(kvm_context, &assigned_irq_data); - /* -ENXIO means no assigned irq */ - if (r && r != -ENXIO) - perror("assigned_dev_update_msi: deassign irq"); + /* Some guests gratuitously disable MSI even if they're not using it, + * try to catch this by only deassigning irqs if the guest is using + * MSI or intends to start. */ + if ((assigned_dev->irq_requested_type & KVM_DEV_IRQ_GUEST_MSI) || + (ctrl_byte & PCI_MSI_FLAGS_ENABLE)) { + + assigned_irq_data.flags = assigned_dev->irq_requested_type; + free_dev_irq_entries(assigned_dev); + r = kvm_deassign_irq(kvm_context, &assigned_irq_data); + /* -ENXIO means no assigned irq */ + if (r && r != -ENXIO) + perror("assigned_dev_update_msi: deassign irq"); + + assigned_irq_data.flags = 0; } if (ctrl_byte & PCI_MSI_FLAGS_ENABLE) { @@ -1188,17 +1195,26 @@ static void assigned_dev_update_msix(PCIDevice *pci_dev, unsigned int ctrl_pos) calc_assigned_dev_id(assigned_dev->h_segnr, assigned_dev->h_busnr, (uint8_t)assigned_dev->h_devfn); - if (assigned_dev->irq_requested_type) { + /* Some guests gratuitously disable MSIX even if they're not using it, + * try to catch this by only deassigning irqs if the guest is using + * MSIX or intends to start. */ + if ((assigned_dev->irq_requested_type & KVM_DEV_IRQ_GUEST_MSIX) || + (*ctrl_word & PCI_MSIX_ENABLE)) { + assigned_irq_data.flags = assigned_dev->irq_requested_type; free_dev_irq_entries(assigned_dev); r = kvm_deassign_irq(kvm_context, &assigned_irq_data); /* -ENXIO means no assigned irq */ if (r && r != -ENXIO) perror("assigned_dev_update_msix: deassign irq"); + + assigned_irq_data.flags = 0; } - assigned_irq_data.flags = KVM_DEV_IRQ_HOST_MSIX | KVM_DEV_IRQ_GUEST_MSIX; if (*ctrl_word & PCI_MSIX_ENABLE) { + assigned_irq_data.flags = KVM_DEV_IRQ_HOST_MSIX | + KVM_DEV_IRQ_GUEST_MSIX; + if (assigned_dev_update_msix_mmio(pci_dev) < 0) { perror("assigned_dev_update_msix_mmio"); return; -- 2.11.4.GIT