On Wed, Jul 20, 2016 at 06:28:21PM +0300, Marcel Apfelbaum wrote:
> Enable transitional virtio devices by default.
> Enable virtio-1.0 for devices plugged into
disable legacy is better, I agree.
> PCIe ports (Root ports or Downstream ports).
>
> Using the virtio-1 mode will remove the limitation
> of the number of devices that can be attached to a machine
> by removing the need for the IO BAR.
>
> Signed-off-by: Marcel Apfelbaum <mar...@redhat.com>
I think you also want to add some comment with a description explaining
*why* you are disabling legacy for these specific devices.
> ---
>
> Hi,
>
> v2 -> v3:
> - Various code tweaks to simplify if statements (Michael)
> - Enable virtio modern by default (Gerd and Cornelia)
> - Replace virtio flags with actual fields (Gerd)
> - Wrappers for more readable code
>
> v1 -> v2:
> - Stick to existing defaults for old machine types (Michael S. Tsirkin)
>
> If everyone agrees, I am thinking about getting it into 2.7
> to avoid the ~15 virtio devices limitation per machine.
>
> My tests were limited to checking all possible disable-* configurations (and
> make check for all archs)
>
> Thanks,
> Marcel
>
> hw/display/virtio-gpu-pci.c | 4 +---
> hw/display/virtio-vga.c | 4 +---
> hw/virtio/virtio-pci.c | 34 ++++++++++++++++++----------------
> hw/virtio/virtio-pci.h | 21 +++++++++++++++++----
> include/hw/compat.h | 8 ++++++++
> 5 files changed, 45 insertions(+), 26 deletions(-)
>
> diff --git a/hw/display/virtio-gpu-pci.c b/hw/display/virtio-gpu-pci.c
> index a71b230..34a724c 100644
> --- a/hw/display/virtio-gpu-pci.c
> +++ b/hw/display/virtio-gpu-pci.c
> @@ -30,9 +30,7 @@ static void virtio_gpu_pci_realize(VirtIOPCIProxy
> *vpci_dev, Error **errp)
> int i;
>
> qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus));
> - /* force virtio-1.0 */
> - vpci_dev->flags &= ~VIRTIO_PCI_FLAG_DISABLE_MODERN;
> - vpci_dev->flags |= VIRTIO_PCI_FLAG_DISABLE_LEGACY;
> + virtio_pci_force_virtio_1(vpci_dev);
> object_property_set_bool(OBJECT(vdev), true, "realized", errp);
>
> for (i = 0; i < g->conf.max_outputs; i++) {
> diff --git a/hw/display/virtio-vga.c b/hw/display/virtio-vga.c
> index 315b7fc..5b510a1 100644
> --- a/hw/display/virtio-vga.c
> +++ b/hw/display/virtio-vga.c
> @@ -134,9 +134,7 @@ static void virtio_vga_realize(VirtIOPCIProxy *vpci_dev,
> Error **errp)
>
> /* init virtio bits */
> qdev_set_parent_bus(DEVICE(g), BUS(&vpci_dev->bus));
> - /* force virtio-1.0 */
> - vpci_dev->flags &= ~VIRTIO_PCI_FLAG_DISABLE_MODERN;
> - vpci_dev->flags |= VIRTIO_PCI_FLAG_DISABLE_LEGACY;
> + virtio_pci_force_virtio_1(vpci_dev);
> object_property_set_bool(OBJECT(g), true, "realized", &err);
> if (err) {
> error_propagate(errp, err);
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index 2b34b43..11cd634 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
> @@ -161,7 +161,7 @@ static bool virtio_pci_modern_state_needed(void *opaque)
> {
> VirtIOPCIProxy *proxy = opaque;
>
> - return !(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_MODERN);
> + return virtio_pci_modern(proxy);
> }
>
> static const VMStateDescription vmstate_virtio_pci_modern_state = {
> @@ -300,8 +300,8 @@ static int virtio_pci_ioeventfd_assign(DeviceState *d,
> EventNotifier *notifier,
> VirtIOPCIProxy *proxy = to_virtio_pci_proxy(d);
> VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
> VirtQueue *vq = virtio_get_queue(vdev, n);
> - bool legacy = !(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_LEGACY);
> - bool modern = !(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_MODERN);
> + bool legacy = virtio_pci_legacy(proxy);
> + bool modern = virtio_pci_modern(proxy);
> bool fast_mmio = kvm_ioeventfd_any_length_enabled();
> bool modern_pio = proxy->flags & VIRTIO_PCI_FLAG_MODERN_PIO_NOTIFY;
> MemoryRegion *modern_mr = &proxy->notify.mr;
> @@ -1576,8 +1576,8 @@ static void virtio_pci_device_plugged(DeviceState *d,
> Error **errp)
> {
> VirtIOPCIProxy *proxy = VIRTIO_PCI(d);
> VirtioBusState *bus = &proxy->bus;
> - bool legacy = !(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_LEGACY);
> - bool modern = !(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_MODERN);
> + bool legacy = virtio_pci_legacy(proxy);
> + bool modern = virtio_pci_modern(proxy);
> bool modern_pio = proxy->flags & VIRTIO_PCI_FLAG_MODERN_PIO_NOTIFY;
> uint8_t *config;
> uint32_t size;
> @@ -1696,7 +1696,7 @@ static void virtio_pci_device_plugged(DeviceState *d,
> Error **errp)
> static void virtio_pci_device_unplugged(DeviceState *d)
> {
> VirtIOPCIProxy *proxy = VIRTIO_PCI(d);
> - bool modern = !(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_MODERN);
> + bool modern = virtio_pci_modern(proxy);
> bool modern_pio = proxy->flags & VIRTIO_PCI_FLAG_MODERN_PIO_NOTIFY;
>
> virtio_pci_stop_ioeventfd(proxy);
> @@ -1716,6 +1716,8 @@ static void virtio_pci_realize(PCIDevice *pci_dev,
> Error **errp)
> {
> VirtIOPCIProxy *proxy = VIRTIO_PCI(pci_dev);
> VirtioPCIClass *k = VIRTIO_PCI_GET_CLASS(pci_dev);
> + bool pcie_port = pci_bus_is_express(pci_dev->bus) &&
> + !pci_bus_is_root(pci_dev->bus);
>
> /*
> * virtio pci bar layout used by default.
> @@ -1766,8 +1768,11 @@ static void virtio_pci_realize(PCIDevice *pci_dev,
> Error **errp)
>
> address_space_init(&proxy->modern_as, &proxy->modern_cfg,
> "virtio-pci-cfg-as");
>
> - if (pci_is_express(pci_dev) && pci_bus_is_express(pci_dev->bus) &&
> - !pci_bus_is_root(pci_dev->bus)) {
> + if (proxy->disable_legacy == ON_OFF_AUTO_AUTO) {
> + proxy->disable_legacy = pcie_port ? ON_OFF_AUTO_ON : ON_OFF_AUTO_OFF;
> + }
> +
> + if (pcie_port && pci_is_express(pci_dev)) {
> int pos;
>
> pos = pcie_endpoint_cap_init(pci_dev, 0);
> @@ -1821,10 +1826,9 @@ static void virtio_pci_reset(DeviceState *qdev)
> static Property virtio_pci_properties[] = {
> DEFINE_PROP_BIT("virtio-pci-bus-master-bug-migration", VirtIOPCIProxy,
> flags,
> VIRTIO_PCI_FLAG_BUS_MASTER_BUG_MIGRATION_BIT, false),
> - DEFINE_PROP_BIT("disable-legacy", VirtIOPCIProxy, flags,
> - VIRTIO_PCI_FLAG_DISABLE_LEGACY_BIT, false),
> - DEFINE_PROP_BIT("disable-modern", VirtIOPCIProxy, flags,
> - VIRTIO_PCI_FLAG_DISABLE_MODERN_BIT, true),
> + DEFINE_PROP_ON_OFF_AUTO("disable-legacy", VirtIOPCIProxy, disable_legacy,
> + ON_OFF_AUTO_AUTO),
> + DEFINE_PROP_BOOL("disable-modern", VirtIOPCIProxy, disable_modern,
> false),
> DEFINE_PROP_BIT("migrate-extra", VirtIOPCIProxy, flags,
> VIRTIO_PCI_FLAG_MIGRATE_EXTRA_BIT, true),
> DEFINE_PROP_BIT("modern-pio-notify", VirtIOPCIProxy, flags,
> @@ -1841,7 +1845,7 @@ static void virtio_pci_dc_realize(DeviceState *qdev,
> Error **errp)
> PCIDevice *pci_dev = &proxy->pci_dev;
>
> if (!(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_PCIE) &&
> - !(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_MODERN)) {
> + virtio_pci_modern(proxy)) {
> pci_dev->cap_present |= QEMU_PCI_CAP_EXPRESS;
> }
>
> @@ -2303,9 +2307,7 @@ static void virtio_input_pci_realize(VirtIOPCIProxy
> *vpci_dev, Error **errp)
> DeviceState *vdev = DEVICE(&vinput->vdev);
>
> qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus));
> - /* force virtio-1.0 */
> - vpci_dev->flags &= ~VIRTIO_PCI_FLAG_DISABLE_MODERN;
> - vpci_dev->flags |= VIRTIO_PCI_FLAG_DISABLE_LEGACY;
> + virtio_pci_force_virtio_1(vpci_dev);
> object_property_set_bool(OBJECT(vdev), true, "realized", errp);
> }
>
> diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h
> index e4548c2..25fbf8a 100644
> --- a/hw/virtio/virtio-pci.h
> +++ b/hw/virtio/virtio-pci.h
> @@ -61,8 +61,6 @@ typedef struct VirtioBusClass VirtioPCIBusClass;
> enum {
> VIRTIO_PCI_FLAG_BUS_MASTER_BUG_MIGRATION_BIT,
> VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT,
> - VIRTIO_PCI_FLAG_DISABLE_LEGACY_BIT,
> - VIRTIO_PCI_FLAG_DISABLE_MODERN_BIT,
> VIRTIO_PCI_FLAG_MIGRATE_EXTRA_BIT,
> VIRTIO_PCI_FLAG_MODERN_PIO_NOTIFY_BIT,
> VIRTIO_PCI_FLAG_DISABLE_PCIE_BIT,
> @@ -77,8 +75,6 @@ enum {
> #define VIRTIO_PCI_FLAG_USE_IOEVENTFD (1 <<
> VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT)
>
> /* virtio version flags */
> -#define VIRTIO_PCI_FLAG_DISABLE_LEGACY (1 <<
> VIRTIO_PCI_FLAG_DISABLE_LEGACY_BIT)
> -#define VIRTIO_PCI_FLAG_DISABLE_MODERN (1 <<
> VIRTIO_PCI_FLAG_DISABLE_MODERN_BIT)
> #define VIRTIO_PCI_FLAG_DISABLE_PCIE (1 << VIRTIO_PCI_FLAG_DISABLE_PCIE_BIT)
>
> /* migrate extra state */
> @@ -144,6 +140,8 @@ struct VirtIOPCIProxy {
> uint32_t modern_mem_bar;
> int config_cap;
> uint32_t flags;
> + bool disable_modern;
> + OnOffAuto disable_legacy;
> uint32_t class_code;
> uint32_t nvectors;
> uint32_t dfselect;
> @@ -158,6 +156,21 @@ struct VirtIOPCIProxy {
> VirtioBusState bus;
> };
>
> +static inline bool virtio_pci_modern(VirtIOPCIProxy *proxy)
> +{
> + return !proxy->disable_modern;
> +}
> +
> +static inline bool virtio_pci_legacy(VirtIOPCIProxy *proxy)
> +{
> + return proxy->disable_legacy == ON_OFF_AUTO_OFF;
> +}
> +
> +static inline void virtio_pci_force_virtio_1(VirtIOPCIProxy *proxy)
> +{
> + proxy->disable_modern = false;
> + proxy->disable_legacy = ON_OFF_AUTO_ON;
> +}
>
> /*
> * virtio-scsi-pci: This extends VirtioPCIProxy.
> diff --git a/include/hw/compat.h b/include/hw/compat.h
> index 9914e7a..1531399 100644
> --- a/include/hw/compat.h
> +++ b/include/hw/compat.h
> @@ -6,6 +6,14 @@
> .driver = "virtio-mmio",\
> .property = "format_transport_address",\
> .value = "off",\
> + },{\
> + .driver = "virtio-pci",\
> + .property = "disable-modern",\
> + .value = "on",\
> + },{\
> + .driver = "virtio-pci",\
> + .property = "disable-legacy",\
> + .value = "off",\
> },
>
> #define HW_COMPAT_2_5 \
> --
> 2.4.3
