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path: root/hw/vfio/pci.c
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Diffstat (limited to 'hw/vfio/pci.c')
-rw-r--r--hw/vfio/pci.c40
1 files changed, 33 insertions, 7 deletions
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 8fadbcf682..1fb868c244 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -28,6 +28,7 @@
#include "config.h"
#include "hw/pci/msi.h"
#include "hw/pci/msix.h"
+#include "hw/pci/pci_bridge.h"
#include "qemu/error-report.h"
#include "qemu/range.h"
#include "sysemu/kvm.h"
@@ -586,7 +587,7 @@ static void vfio_msix_enable(VFIOPCIDevice *vdev)
{
vfio_disable_interrupts(vdev);
- vdev->msi_vectors = g_malloc0(vdev->msix->entries * sizeof(VFIOMSIVector));
+ vdev->msi_vectors = g_new0(VFIOMSIVector, vdev->msix->entries);
vdev->interrupt = VFIO_INT_MSIX;
@@ -622,7 +623,7 @@ static void vfio_msi_enable(VFIOPCIDevice *vdev)
vdev->nr_vectors = msi_nr_vectors_allocated(&vdev->pdev);
retry:
- vdev->msi_vectors = g_malloc0(vdev->nr_vectors * sizeof(VFIOMSIVector));
+ vdev->msi_vectors = g_new0(VFIOMSIVector, vdev->nr_vectors);
for (i = 0; i < vdev->nr_vectors; i++) {
VFIOMSIVector *vector = &vdev->msi_vectors[i];
@@ -1524,13 +1525,38 @@ static int vfio_setup_pcie_cap(VFIOPCIDevice *vdev, int pos, uint8_t size)
}
if (!pci_bus_is_express(vdev->pdev.bus)) {
+ PCIBus *bus = vdev->pdev.bus;
+ PCIDevice *bridge;
+
/*
- * Use express capability as-is on PCI bus. It doesn't make much
- * sense to even expose, but some drivers (ex. tg3) depend on it
- * and guests don't seem to be particular about it. We'll need
- * to revist this or force express devices to express buses if we
- * ever expose an IOMMU to the guest.
+ * Traditionally PCI device assignment exposes the PCIe capability
+ * as-is on non-express buses. The reason being that some drivers
+ * simply assume that it's there, for example tg3. However when
+ * we're running on a native PCIe machine type, like Q35, we need
+ * to hide the PCIe capability. The reason for this is twofold;
+ * first Windows guests get a Code 10 error when the PCIe capability
+ * is exposed in this configuration. Therefore express devices won't
+ * work at all unless they're attached to express buses in the VM.
+ * Second, a native PCIe machine introduces the possibility of fine
+ * granularity IOMMUs supporting both translation and isolation.
+ * Guest code to discover the IOMMU visibility of a device, such as
+ * IOMMU grouping code on Linux, is very aware of device types and
+ * valid transitions between bus types. An express device on a non-
+ * express bus is not a valid combination on bare metal systems.
+ *
+ * Drivers that require a PCIe capability to make the device
+ * functional are simply going to need to have their devices placed
+ * on a PCIe bus in the VM.
*/
+ while (!pci_bus_is_root(bus)) {
+ bridge = pci_bridge_get_device(bus);
+ bus = bridge->bus;
+ }
+
+ if (pci_bus_is_express(bus)) {
+ return 0;
+ }
+
} else if (pci_bus_is_root(vdev->pdev.bus)) {
/*
* On a Root Complex bus Endpoints become Root Complex Integrated