Adds a rollback path to ivshmem_enable_irqfd() and fixes ivshmem_disable_irqfd() to bail if irqfd has not been enabled.
To reproduce, run: ivshmem-server -n 0 and QEMU with: -device ivshmem-doorbell,chardev=iv -chardev socket,path=/tmp/ivshmem_socket,id=iv then load, unload, and load again the Windows driver, at the time of writing available at: https://github.com/virtio-win/kvm-guest-drivers-windows/tree/master/ivshmem The issue is believed to have been masked by other guest drivers, notably Linux ones, not enabling MSI-X on the device. Signed-off-by: Ladi Prosek <lpro...@redhat.com> Reviewed-by: Markus Armbruster <arm...@redhat.com> --- hw/misc/ivshmem.c | 37 ++++++++++++++++++++++++------------- 1 file changed, 24 insertions(+), 13 deletions(-) diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c index 91364d8364..d1bb246d12 100644 --- a/hw/misc/ivshmem.c +++ b/hw/misc/ivshmem.c @@ -786,6 +786,20 @@ static int ivshmem_setup_interrupts(IVShmemState *s, Error **errp) return 0; } +static void ivshmem_remove_kvm_msi_virq(IVShmemState *s, int vector) +{ + IVSHMEM_DPRINTF("ivshmem_remove_kvm_msi_virq vector:%d\n", vector); + + if (s->msi_vectors[vector].pdev == NULL) { + return; + } + + /* it was cleaned when masked in the frontend. */ + kvm_irqchip_release_virq(kvm_state, s->msi_vectors[vector].virq); + + s->msi_vectors[vector].pdev = NULL; +} + static void ivshmem_enable_irqfd(IVShmemState *s) { PCIDevice *pdev = PCI_DEVICE(s); @@ -797,7 +811,7 @@ static void ivshmem_enable_irqfd(IVShmemState *s) ivshmem_add_kvm_msi_virq(s, i, &err); if (err) { error_report_err(err); - /* TODO do we need to handle the error? */ + goto undo; } } @@ -806,21 +820,14 @@ static void ivshmem_enable_irqfd(IVShmemState *s) ivshmem_vector_mask, ivshmem_vector_poll)) { error_report("ivshmem: msix_set_vector_notifiers failed"); + goto undo; } -} + return; -static void ivshmem_remove_kvm_msi_virq(IVShmemState *s, int vector) -{ - IVSHMEM_DPRINTF("ivshmem_remove_kvm_msi_virq vector:%d\n", vector); - - if (s->msi_vectors[vector].pdev == NULL) { - return; +undo: + while (--i >= 0) { + ivshmem_remove_kvm_msi_virq(s, i); } - - /* it was cleaned when masked in the frontend. */ - kvm_irqchip_release_virq(kvm_state, s->msi_vectors[vector].virq); - - s->msi_vectors[vector].pdev = NULL; } static void ivshmem_disable_irqfd(IVShmemState *s) @@ -828,6 +835,10 @@ static void ivshmem_disable_irqfd(IVShmemState *s) PCIDevice *pdev = PCI_DEVICE(s); int i; + if (!pdev->msix_vector_use_notifier) { + return; + } + msix_unset_vector_notifiers(pdev); for (i = 0; i < s->peers[s->vm_id].nb_eventfds; i++) { -- 2.13.6
