[Qemu-devel] [PATCH for-1.2] msix: make [un]use vectors on reset/load optional

[Michael S. Tsirkin]

The facility to use/unuse vectors dynamically is helpful
for virtio but little else: everyone just seems to use
vectors in their init function.

Avoid clearing msix vector use info on reset and load.
For virtio, clear it explicitly.
This should fix regressions reported with ivshmem - though
I didn't test this, I verified that virtio keeps
working like it did.

Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
---
 hw/msix.c       | 13 +++++++++++--
 hw/virtio-pci.c |  2 ++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/hw/msix.c b/hw/msix.c
index 800fc32..d040cc2 100644
--- a/hw/msix.c
+++ b/hw/msix.c
@@ -340,6 +340,15 @@ static void msix_free_irq_entries(PCIDevice *dev)
     }
 }
 
+static void msix_clear_all_vectors(PCIDevice *dev)
+{
+    int vector;
+
+    for (vector = 0; vector < dev->msix_entries_nr; ++vector) {
+        msix_clr_pending(dev, vector);
+    }
+}
+
 /* Clean up resources for the device. */
 void msix_uninit(PCIDevice *dev, MemoryRegion *table_bar, MemoryRegion 
*pba_bar)
 {
@@ -394,7 +403,7 @@ void msix_load(PCIDevice *dev, QEMUFile *f)
         return;
     }
 
-    msix_free_irq_entries(dev);
+    msix_clear_all_vectors(dev);
     qemu_get_buffer(f, dev->msix_table, n * PCI_MSIX_ENTRY_SIZE);
     qemu_get_buffer(f, dev->msix_pba, (n + 7) / 8);
     msix_update_function_masked(dev);
@@ -440,7 +449,7 @@ void msix_reset(PCIDevice *dev)
     if (!msix_present(dev)) {
         return;
     }
-    msix_free_irq_entries(dev);
+    msix_clear_all_vectors(dev);
     dev->config[dev->msix_cap + MSIX_CONTROL_OFFSET] &=
            ~dev->wmask[dev->msix_cap + MSIX_CONTROL_OFFSET];
     memset(dev->msix_table, 0, dev->msix_entries_nr * PCI_MSIX_ENTRY_SIZE);
diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
index 125eded..ca0b204 100644
--- a/hw/virtio-pci.c
+++ b/hw/virtio-pci.c
@@ -131,6 +131,7 @@ static int virtio_pci_load_config(void * opaque, QEMUFile 
*f)
     if (ret) {
         return ret;
     }
+    msix_unuse_all_vectors(&proxy->pci_dev);
     msix_load(&proxy->pci_dev, f);
     if (msix_present(&proxy->pci_dev)) {
         qemu_get_be16s(f, &proxy->vdev->config_vector);
@@ -246,6 +247,7 @@ void virtio_pci_reset(DeviceState *d)
     VirtIOPCIProxy *proxy = container_of(d, VirtIOPCIProxy, pci_dev.qdev);
     virtio_pci_stop_ioeventfd(proxy);
     virtio_reset(proxy->vdev);
+    msix_unuse_all_vectors(&proxy->pci_dev);
     proxy->flags &= ~VIRTIO_PCI_FLAG_BUS_MASTER_BUG;
 }
 
-- 
MST