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[Qemu-devel] [PATCH v2 3/3] ivshmem: Improve MSI irqfd error handling
From: |
Ladi Prosek |
Subject: |
[Qemu-devel] [PATCH v2 3/3] ivshmem: Improve MSI irqfd error handling |
Date: |
Wed, 15 Nov 2017 08:31:44 +0100 |
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 <address@hidden>
Reviewed-by: Markus Armbruster <address@hidden>
---
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++) {
--
2.13.5