On Thu, Jun 04, 2015 at 12:34:26PM +0200, Gerd Hoffmann wrote:
> Add VIRTIO_PCI_FLAG_DISABLE_LEGACY and VIRTIO_PCI_FLAG_DISABLE_MODERN
> for VirtIOPCIProxy->flags. Also add properties for them. They can be
> used to disable modern (virtio 1.0) or legacy (virtio 0.9) modes.
>
> By default only legacy is advertized, modern will be turned on by
> default once all remaining spec compilance issues are addressed.
What is the reason for adding these flags? From the pov of management
app integration I think we'd really want the front/back to be automatically
negotiating the right compatible featureset. Having mgmt need to set these
legacy/modern flags based on guest OS needs seems rather painful. As such
I'd be really loathe to support these in libvirt
>
> Signed-off-by: Gerd Hoffmann <kra...@redhat.com>
> Acked-by: Michael S. Tsirkin <m...@redhat.com>
> Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
> ---
> hw/virtio/virtio-pci.c | 48 ++++++++++++++++++++++++++++++++++--------------
> hw/virtio/virtio-pci.h | 6 ++++++
> 2 files changed, 40 insertions(+), 14 deletions(-)
>
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index ddeaf63..2182b41 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
> @@ -1190,6 +1190,8 @@ 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);
> uint8_t *config;
> uint32_t size;
> VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
> @@ -1198,13 +1200,24 @@ static void virtio_pci_device_plugged(DeviceState *d,
> Error **errp)
> if (proxy->class_code) {
> pci_config_set_class(config, proxy->class_code);
> }
> - pci_set_word(config + PCI_SUBSYSTEM_VENDOR_ID,
> - pci_get_word(config + PCI_VENDOR_ID));
> - pci_set_word(config + PCI_SUBSYSTEM_ID, virtio_bus_get_vdev_id(bus));
> +
> + if (legacy) {
> + /* legacy and transitional */
> + pci_set_word(config + PCI_SUBSYSTEM_VENDOR_ID,
> + pci_get_word(config + PCI_VENDOR_ID));
> + pci_set_word(config + PCI_SUBSYSTEM_ID, virtio_bus_get_vdev_id(bus));
> + } else {
> + /* pure virtio-1.0 */
> + pci_set_word(config + PCI_VENDOR_ID,
> + PCI_VENDOR_ID_REDHAT_QUMRANET);
> + pci_set_word(config + PCI_DEVICE_ID,
> + 0x1040 + virtio_bus_get_vdev_id(bus));
> + pci_config_set_revision(config, 1);
> + }
> config[PCI_INTERRUPT_PIN] = 1;
>
>
> - if (1) { /* TODO: Make this optional, dependent on virtio 1.0 */
> + if (modern) {
> struct virtio_pci_cap common = {
> .cfg_type = VIRTIO_PCI_CAP_COMMON_CFG,
> .cap_len = sizeof common,
> @@ -1318,18 +1331,21 @@ static void virtio_pci_device_plugged(DeviceState *d,
> Error **errp)
>
> proxy->pci_dev.config_write = virtio_write_config;
>
> - size = VIRTIO_PCI_REGION_SIZE(&proxy->pci_dev)
> - + virtio_bus_get_vdev_config_len(bus);
> - if (size & (size - 1)) {
> - size = 1 << qemu_fls(size);
> + if (legacy) {
> + size = VIRTIO_PCI_REGION_SIZE(&proxy->pci_dev)
> + + virtio_bus_get_vdev_config_len(bus);
> + if (size & (size - 1)) {
> + size = 1 << qemu_fls(size);
> + }
> +
> + memory_region_init_io(&proxy->bar, OBJECT(proxy),
> + &virtio_pci_config_ops,
> + proxy, "virtio-pci", size);
> +
> + pci_register_bar(&proxy->pci_dev, 0, PCI_BASE_ADDRESS_SPACE_IO,
> + &proxy->bar);
> }
>
> - memory_region_init_io(&proxy->bar, OBJECT(proxy), &virtio_pci_config_ops,
> - proxy, "virtio-pci", size);
> -
> - pci_register_bar(&proxy->pci_dev, 0, PCI_BASE_ADDRESS_SPACE_IO,
> - &proxy->bar);
> -
> if (!kvm_has_many_ioeventfds()) {
> proxy->flags &= ~VIRTIO_PCI_FLAG_USE_IOEVENTFD;
> }
> @@ -1372,6 +1388,10 @@ 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_END_OF_LIST(),
> };
>
> diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h
> index 7a6481f..4e9b2db 100644
> --- a/hw/virtio/virtio-pci.h
> +++ b/hw/virtio/virtio-pci.h
> @@ -63,6 +63,12 @@ typedef struct VirtioBusClass VirtioPCIBusClass;
> #define VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT 1
> #define VIRTIO_PCI_FLAG_USE_IOEVENTFD (1 <<
> VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT)
>
> +/* virtio version flags */
> +#define VIRTIO_PCI_FLAG_DISABLE_LEGACY_BIT 2
> +#define VIRTIO_PCI_FLAG_DISABLE_MODERN_BIT 3
> +#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)
> +
> typedef struct {
> MSIMessage msg;
> int virq;
> --
> 1.8.3.1
>
>
Regards,
Daniel
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