@@ -172,6 +172,7 @@ int vfio_get_region_info(VFIODevice *vbasedev, int index,
struct vfio_region_info **info);
int vfio_get_dev_region_info(VFIODevice *vbasedev, uint32_t type,
uint32_t subtype, struct vfio_region_info **info);
+bool vfio_is_cap_present(VFIODevice *vbasedev, uint16_t cap_type, int region);
#endif
extern const MemoryListener vfio_prereg_listener;
@@ -301,6 +301,11 @@ struct vfio_region_info_cap_type {
#define VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG (2)
#define VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG (3)
+/*
+ * The MSIX mappable capability informs that MSIX data of a BAR can be mmapped.
+ */
+#define VFIO_REGION_INFO_CAP_MSIX_MAPPABLE 3
+
/**
* VFIO_DEVICE_GET_IRQ_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 9,
* struct vfio_irq_info)
@@ -2830,6 +2830,11 @@ static void spapr_set_modern_hotplug_events(Object *obj, bool value,
spapr->use_hotplug_event_source = value;
}
+static bool spapr_get_msix_emulation(Object *obj, Error **errp)
+{
+ return true;
+}
+
static char *spapr_get_resize_hpt(Object *obj, Error **errp)
{
sPAPRMachineState *spapr = SPAPR_MACHINE(obj);
@@ -2911,6 +2916,8 @@ static void spapr_instance_init(Object *obj)
object_property_set_description(obj, "vsmt",
"Virtual SMT: KVM behaves as if this were"
" the host's SMT mode", &error_abort);
+ object_property_add_bool(obj, "vfio-no-msix-emulation",
+ spapr_get_msix_emulation, NULL, NULL);
}
static void spapr_machine_finalizefn(Object *obj)
@@ -1431,6 +1431,21 @@ int vfio_get_dev_region_info(VFIODevice *vbasedev, uint32_t type,
return -ENODEV;
}
+bool vfio_is_cap_present(VFIODevice *vbasedev, uint16_t cap_type, int region)
+{
+ struct vfio_region_info *info = NULL;
+ bool ret = false;
+
+ if (!vfio_get_region_info(vbasedev, region, &info)) {
+ if (vfio_get_region_info_cap(info, cap_type)) {
+ ret = true;
+ }
+ g_free(info);
+ }
+
+ return ret;
+}
+
/*
* Interfaces for IBM EEH (Enhanced Error Handling)
*/
@@ -1289,6 +1289,11 @@ static void vfio_pci_fixup_msix_region(VFIOPCIDevice *vdev)
off_t start, end;
VFIORegion *region = &vdev->bars[vdev->msix->table_bar].region;
+ if (vfio_is_cap_present(&vdev->vbasedev, VFIO_REGION_INFO_CAP_MSIX_MAPPABLE,
+ vdev->msix->table_bar)) {
+ return;
+ }
+
/*
* We expect to find a single mmap covering the whole BAR, anything else
* means it's either unsupported or already setup.
@@ -1473,6 +1478,11 @@ static int vfio_msix_setup(VFIOPCIDevice *vdev, int pos, Error **errp)
*/
memory_region_set_enabled(&vdev->pdev.msix_pba_mmio, false);
+ if (object_property_get_bool(OBJECT(qdev_get_machine()),
+ "vfio-no-msix-emulation", NULL)) {
+ memory_region_set_enabled(&vdev->pdev.msix_table_mmio, false);
+ }
+
return 0;
}
This makes use of a new VFIO_REGION_INFO_CAP_MSIX_MAPPABLE capability which tells that a region with MSIX data can be mapped entirely, i.e. the VFIO PCI driver won't prevent MSIX vectors area from being mapped. With this change, all BARs are mapped in a single chunk and MSIX vectors are emulated on top unless the machine requests not to by defining and enabling a new "vfio-no-msix-emulation" property. At the moment only sPAPR machine does so - it prohibits MSIX emulation and does not allow enabling it as it does not define the "set" callback for the new property; the new property also does not appear in "-machine pseries,help". This requires the kernel change - "vfio-pci: Allow mapping MSIX BAR" - for the new capability: https://www.spinics.net/lists/kvm/msg160282.html Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> --- Changes: v5: * rebased on top of 'p2p' proposed patch v4: * silenced dma map errors if unaligned mapping is attempted - they are going to fail anyway v3: * vfio_listener_region_add() won't make qemu exit if failed on MMIO MR --- include/hw/vfio/vfio-common.h | 1 + linux-headers/linux/vfio.h | 5 +++++ hw/ppc/spapr.c | 7 +++++++ hw/vfio/common.c | 15 +++++++++++++++ hw/vfio/pci.c | 10 ++++++++++ 5 files changed, 38 insertions(+)