From 1f3771aa029990b917d6fc6fced8d43324601c3d Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Tue, 29 Jun 2010 17:15:45 -0300 Subject: [PATCH] device-assignment: be more selective in interrupt disabling RH-Author: Alex Williamson Message-id: <20100629171522.3167.14000.stgit@localhost.localdomain> Patchwork-id: 10348 O-Subject: [RHEL6.0 qemu-kvm PATCH v2] device-assignment: be more selective in interrupt disabling Bugzilla: 605361 RH-Acked-by: Don Dutile RH-Acked-by: Chris Wright RH-Acked-by: Juan Quintela Bugzilla: 605361 Upstream status: applied 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 --- v2: clear the assigned_dev interrupt type, not the local variable hw/device-assignment.c | 34 +++++++++++++++++++++++++--------- 1 files changed, 25 insertions(+), 9 deletions(-) Signed-off-by: Eduardo Habkost --- hw/device-assignment.c | 34 +++++++++++++++++++++++++--------- 1 files changed, 25 insertions(+), 9 deletions(-) diff --git a/hw/device-assignment.c b/hw/device-assignment.c index 5ffe6f3..eba7d8b 100644 --- a/hw/device-assignment.c +++ b/hw/device-assignment.c @@ -834,13 +834,20 @@ static void assigned_dev_update_msi(PCIDevice *pci_dev, unsigned int ctrl_pos) calc_assigned_dev_id(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_dev->irq_requested_type = 0; } if (ctrl_byte & PCI_MSI_FLAGS_ENABLE) { @@ -991,17 +998,26 @@ static void assigned_dev_update_msix(PCIDevice *pci_dev, unsigned int ctrl_pos) calc_assigned_dev_id(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_dev->irq_requested_type = 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; -- 1.7.0.3