Re: [Qemu-devel] [PATCH V3] hw/virtio: Add PCIe capability to virtio devices

[Michael S. Tsirkin]

On Thu, Oct 29, 2015 at 01:56:28PM +0200, Marcel Apfelbaum wrote:
> The virtio devices are converted to PCI-Express
> if they are plugged into a PCI-Express bus and
> the 'modern' protocol is enabled.
> 
> Devices plugged directly into the Root Complex as
> Integrated Endpoints remain PCI.
> 
> Signed-off-by: Marcel Apfelbaum <address@hidden>


Looks ok. Two comments:

> ---
> v2 -> v3:
>  - Addressed Michael S. Tsirkin's comments:
>    - enable pcie only for 2.5+ machines.
> 
> v1 -> v2:
>  - Addressed Michael S. Tsirkin's comments:
>    - Added the minimum required capabilities for PCIe devices
>    - Integrated Endpoints remain PCI
> 
>  - Use pcie_endpoint_cap_init instead of manually creating the pcie 
> capability.
> 
>  - Regarding Gerd Hoffman's comments:
>    - Creating virtio-pcie devices:
>      For the moment I prefer to not duplicate the virtio definitions,
>      at least until we don't have a consensus (Personally I don't like it)
>    - Removing the IO bar:
>      This would be my next patch on the "virtio to express" series, I plan
>      to remove it only for "modern" devices.
> 
> Thanks,
> Marcel
> 
>  hw/virtio/virtio-pci.c | 22 ++++++++++++++++++++++
>  hw/virtio/virtio-pci.h |  2 ++
>  include/hw/compat.h    | 46 +++++++++++++++++++++++++++++++++++++++++++++-
>  3 files changed, 69 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index f55dd2b..a288d8b 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
> @@ -1592,6 +1592,26 @@ static void virtio_pci_realize(PCIDevice *pci_dev, 
> Error **errp)
>  
>      address_space_init(&proxy->modern_as, &proxy->modern_cfg, 
> "virtio-pci-cfg-as");
>  
> +    if (!(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_PCIE)
> +        && !(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_MODERN)
> +        && pci_bus_is_express(pci_dev->bus)
> +        && !pci_bus_is_root(pci_dev->bus)) {
> +        int pos;
> +
> +        pci_dev->cap_present |= QEMU_PCI_CAP_EXPRESS;
> +        pos = pcie_endpoint_cap_init(pci_dev, 0);
> +        assert(pos > 0);
> +
> +        pos = pci_add_capability(pci_dev, PCI_CAP_ID_PM, 0, PCI_PM_SIZEOF);
> +        assert(pos > 0);
> +
> +        /*
> +         * Indicates that this function complies with revision 1.2 of the
> +         * PCI Power Management Interface Specification.
> +         */
> +        pci_set_word(pci_dev->config + pos + PCI_PM_PMC, 0x3);
> +    }
> +
>      virtio_pci_bus_new(&proxy->bus, sizeof(proxy->bus), proxy);
>      if (k->realize) {
>          k->realize(proxy, errp);
> @@ -1622,6 +1642,8 @@ static Property virtio_pci_properties[] = {
>                      VIRTIO_PCI_FLAG_DISABLE_LEGACY_BIT, false),
>      DEFINE_PROP_BIT("disable-modern", VirtIOPCIProxy, flags,
>                      VIRTIO_PCI_FLAG_DISABLE_MODERN_BIT, true),
> +    DEFINE_PROP_BIT("disable-pcie", VirtIOPCIProxy, flags,
> +                    VIRTIO_PCI_FLAG_DISABLE_PCIE_BIT, false),

It's preferable to call this one x-disable-pcie - this
is the convention to mark it as "not for user".

>      DEFINE_PROP_END_OF_LIST(),
>  };
>  
> diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h
> index 801c23a..1a487fc 100644
> --- a/hw/virtio/virtio-pci.h
> +++ b/hw/virtio/virtio-pci.h
> @@ -72,8 +72,10 @@ typedef struct VirtioBusClass VirtioPCIBusClass;
>  /* virtio version flags */
>  #define VIRTIO_PCI_FLAG_DISABLE_LEGACY_BIT 2
>  #define VIRTIO_PCI_FLAG_DISABLE_MODERN_BIT 3
> +#define VIRTIO_PCI_FLAG_DISABLE_PCIE_BIT 4
>  #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)
>  
>  typedef struct {
>      MSIMessage msg;
> diff --git a/include/hw/compat.h b/include/hw/compat.h
> index 095de5d..0a08531 100644
> --- a/include/hw/compat.h
> +++ b/include/hw/compat.h
> @@ -2,7 +2,51 @@
>  #define HW_COMPAT_H
>  
>  #define HW_COMPAT_2_4 \
> -        /* empty */
> +        {\
> +            .driver   = "virtio-blk-pci",\
> +            .property = "disable-pcie",\
> +            .value    = "on",\
> +        },{\
> +            .driver   = "virtio-scsi-pci",\
> +            .property = "disable-pcie",\
> +            .value    = "on",\
> +        },{\
> +            .driver   = "virtio-net-pci",\
> +            .property = "disable-pcie",\
> +            .value    = "on",\
> +        },{\
> +            .driver   = "virtio-input-host-pci",\
> +            .property = "disable-pcie",\
> +            .value    = "on",\
> +        },{\
> +            .driver   = "virtio-keyboard-pci",\
> +            .property = "disable-pcie",\
> +            .value    = "on",\
> +        },{\
> +            .driver   = "virtio-mouse-pci",\
> +            .property = "disable-pcie",\
> +            .value    = "on",\
> +        },{\
> +            .driver   = "virtio-serial-pci",\
> +            .property = "disable-pcie",\
> +            .value    = "on",\
> +        },{\
> +            .driver   = "virtio-tablet-pci",\
> +            .property = "disable-pcie",\
> +            .value    = "on",\
> +        },{\
> +            .driver   = "virtio-gpu-pci",\
> +            .property = "disable-pcie",\
> +            .value    = "on",\
> +        },{\
> +            .driver   = "virtio-balloon-pci",\
> +            .property = "disable-pcie",\
> +            .value    = "on",\
> +        },{\
> +            .driver   = "virtio-rng-pci",\
> +            .property = "disable-pcie",\
> +            .value    = "on",\
> +        },

Can't these properties be defined for type virtio-pci?
If no - why not?

>  
>  #define HW_COMPAT_2_3 \
>          {\
> -- 
> 2.1.0