On Fri, 11 Oct 2019 13:20:15 +0200
Jens Freimann <jfreim...@redhat.com> wrote:
> As usual block all vfio-pci devices from being migrated, but make an
> exception for failover primary devices. This is achieved by setting
> unmigratable to 0 but also add a migration blocker for all vfio-pci
> devices except failover primary devices. These will be unplugged before
> migration happens by the migration handler of the corresponding
> virtio-net standby device.
>
> Signed-off-by: Jens Freimann <jfreim...@redhat.com>
> ---
> hw/vfio/pci.c | 35 ++++++++++++++++++++++++++++++++++-
> hw/vfio/pci.h | 2 ++
> 2 files changed, 36 insertions(+), 1 deletion(-)
>
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index c5e6fe61cb..64cf8e07d9 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -40,6 +40,9 @@
> #include "pci.h"
> #include "trace.h"
> #include "qapi/error.h"
> +#include "migration/blocker.h"
> +#include "qemu/option.h"
> +#include "qemu/option_int.h"
>
> #define TYPE_VFIO_PCI "vfio-pci"
> #define PCI_VFIO(obj) OBJECT_CHECK(VFIOPCIDevice, obj, TYPE_VFIO_PCI)
> @@ -2698,6 +2701,12 @@ static void vfio_unregister_req_notifier(VFIOPCIDevice
> *vdev)
> vdev->req_enabled = false;
> }
>
> +static int has_net_failover_arg(void *opaque, const char *name,
> + const char *value, Error **errp)
> +{
> + return (strcmp(name, "net_failover_pair_id") == 0);
> +}
> +
> static void vfio_realize(PCIDevice *pdev, Error **errp)
> {
> VFIOPCIDevice *vdev = PCI_VFIO(pdev);
> @@ -2710,6 +2719,20 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
> int groupid;
> int i, ret;
> bool is_mdev;
> + uint16_t class_id;
> +
> + if (qemu_opt_foreach(pdev->qdev.opts, has_net_failover_arg,
> + (void *) pdev->qdev.opts, &err) == 0) {
Why do we need a qemu_opt_foreach here versus testing
vdev->net_failover_pair_id as you do below or similar to how we test
sysfsdev immediately below this chunk?
> + error_setg(&vdev->migration_blocker,
> + "VFIO device doesn't support migration");
> + ret = migrate_add_blocker(vdev->migration_blocker, &err);
Where's the migrate_del_blocker()/error_free() for any other realize
error or device removal?
> + if (err) {
> + error_propagate(errp, err);
> + error_free(vdev->migration_blocker);
> + }
As Connie noted, unclear if this aborts or continues without a
migration blocker, which would be bad.
> + } else {
> + pdev->qdev.allow_unplug_during_migration = true;
> + }
>
> if (!vdev->vbasedev.sysfsdev) {
> if (!(~vdev->host.domain || ~vdev->host.bus ||
> @@ -2812,6 +2835,14 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
> goto error;
> }
>
> + if (vdev->net_failover_pair_id != NULL) {
> + class_id = pci_get_word(pdev->config + PCI_CLASS_DEVICE);
> + if (class_id != PCI_CLASS_NETWORK_ETHERNET) {
> + error_setg(errp, "failover device is not an Ethernet device");
> + goto error;
> + }
> + }
Not clear to me why we do this separate from setting up the migration
blocker or why we use a different mechanism to test for the property.
> +
> /* vfio emulates a lot for us, but some bits need extra love */
> vdev->emulated_config_bits = g_malloc0(vdev->config_size);
>
> @@ -3110,6 +3141,8 @@ static Property vfio_pci_dev_properties[] = {
> display, ON_OFF_AUTO_OFF),
> DEFINE_PROP_UINT32("xres", VFIOPCIDevice, display_xres, 0),
> DEFINE_PROP_UINT32("yres", VFIOPCIDevice, display_yres, 0),
> + DEFINE_PROP_STRING("net_failover_pair_id", VFIOPCIDevice,
> + net_failover_pair_id),
Should this and the Ethernet class test be done in PCIDevice? The
migration aspect is the only thing unique to vfio since we don't
otherwise support it, right? For instance, I should be able to
setup an emulated NIC with this failover pair id too, right? Thanks,
Alex
> DEFINE_PROP_UINT32("x-intx-mmap-timeout-ms", VFIOPCIDevice,
> intx.mmap_timeout, 1100),
> DEFINE_PROP_BIT("x-vga", VFIOPCIDevice, features,
> @@ -3152,7 +3185,7 @@ static Property vfio_pci_dev_properties[] = {
>
> static const VMStateDescription vfio_pci_vmstate = {
> .name = "vfio-pci",
> - .unmigratable = 1,
> + .unmigratable = 0,
> };
>
> static void vfio_pci_dev_class_init(ObjectClass *klass, void *data)
> diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
> index 834a90d646..da4417071a 100644
> --- a/hw/vfio/pci.h
> +++ b/hw/vfio/pci.h
> @@ -134,6 +134,7 @@ typedef struct VFIOPCIDevice {
> PCIHostDeviceAddress host;
> EventNotifier err_notifier;
> EventNotifier req_notifier;
> + char *net_failover_pair_id;
> int (*resetfn)(struct VFIOPCIDevice *);
> uint32_t vendor_id;
> uint32_t device_id;
> @@ -168,6 +169,7 @@ typedef struct VFIOPCIDevice {
> bool no_vfio_ioeventfd;
> bool enable_ramfb;
> VFIODisplay *dpy;
> + Error *migration_blocker;
> } VFIOPCIDevice;
>
> uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t addr, int len);
