From 0b88dd942073e7e65f095551d60be5dc0c8e1413 Mon Sep 17 00:00:00 2001 From: Ladi Prosek Date: Mon, 11 Dec 2017 08:21:09 +0100 Subject: [PATCH] ivshmem: Improve MSI irqfd error handling 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 Reviewed-by: Markus Armbruster Message-Id: <20171211072110.9058-4-lprosek@redhat.com> Signed-off-by: Paolo Bonzini --- 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 95e85e4c10..fe1d8d1669 100644 --- a/hw/misc/ivshmem.c +++ b/hw/misc/ivshmem.c @@ -785,6 +785,20 @@ 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); @@ -796,7 +810,7 @@ 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; } } @@ -805,21 +819,14 @@ 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) @@ -827,6 +834,10 @@ 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++) { -- 2.11.4.GIT