diff options
Diffstat (limited to 'hw/vfio/pci.c')
| -rw-r--r-- | hw/vfio/pci.c | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index 6cbb8fa054..056f3a887a 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -2804,12 +2804,13 @@ static void vfio_realize(PCIDevice *pdev, Error **errp) VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev); VFIODevice *vbasedev_iter; VFIOGroup *group; - char *tmp, group_path[PATH_MAX], *group_name; + char *tmp, *subsys, group_path[PATH_MAX], *group_name; Error *err = NULL; ssize_t len; struct stat st; int groupid; int i, ret; + bool is_mdev; if (!vdev->vbasedev.sysfsdev) { if (!(~vdev->host.domain || ~vdev->host.bus || @@ -2869,6 +2870,27 @@ static void vfio_realize(PCIDevice *pdev, Error **errp) } } + /* + * Mediated devices *might* operate compatibly with memory ballooning, but + * we cannot know for certain, it depends on whether the mdev vendor driver + * stays in sync with the active working set of the guest driver. Prevent + * the x-balloon-allowed option unless this is minimally an mdev device. + */ + tmp = g_strdup_printf("%s/subsystem", vdev->vbasedev.sysfsdev); + subsys = realpath(tmp, NULL); + g_free(tmp); + is_mdev = (strcmp(subsys, "/sys/bus/mdev") == 0); + free(subsys); + + trace_vfio_mdev(vdev->vbasedev.name, is_mdev); + + if (vdev->vbasedev.balloon_allowed && !is_mdev) { + error_setg(errp, "x-balloon-allowed only potentially compatible " + "with mdev devices"); + vfio_put_group(group); + goto error; + } + ret = vfio_get_device(group, vdev->vbasedev.name, &vdev->vbasedev, errp); if (ret) { vfio_put_group(group); @@ -3170,6 +3192,8 @@ static Property vfio_pci_dev_properties[] = { DEFINE_PROP_BIT("x-igd-opregion", VFIOPCIDevice, features, VFIO_FEATURE_ENABLE_IGD_OPREGION_BIT, false), DEFINE_PROP_BOOL("x-no-mmap", VFIOPCIDevice, vbasedev.no_mmap, false), + DEFINE_PROP_BOOL("x-balloon-allowed", VFIOPCIDevice, + vbasedev.balloon_allowed, false), DEFINE_PROP_BOOL("x-no-kvm-intx", VFIOPCIDevice, no_kvm_intx, false), DEFINE_PROP_BOOL("x-no-kvm-msi", VFIOPCIDevice, no_kvm_msi, false), DEFINE_PROP_BOOL("x-no-kvm-msix", VFIOPCIDevice, no_kvm_msix, false), |