[libvirt] [PATCH v3 04/18] qemu: new functions qemuDomainDeviceConnectFlags*()
Andrea Bolognani
abologna at redhat.com
Sat Oct 1 18:13:32 UTC 2016
On Tue, 2016-09-20 at 15:14 -0400, Laine Stump wrote:
> The lowest level function of this trio aims to be the ultimate
> authority for the virDomainPCIConnectFlags to use for any given device
> using a particular arch/machinetype/qemu-binary.
>
> qemuDomainDeviceConnectFlagsInternal() returns the flags
>
> qemuDomainDeviceConnectFlags() sets info->pciConnectFlags in a single
> device (unless it has no virDomainDeviceInfo, in which case it's a
> NOP).
It should be called qemuDomainDeviceSetConnectFlags() then,
both to convey its purpose better and to be more consistent
with the one below.
> qemuDomainDeviceSetAllConnectFlags() sets info->pciConnectFlags in all
> devices that have a virDomainDeviceInfo (usingW
s/usingW/using/
> virDomainDeviceInfoIterate())
I would propose renaming these along the lines of
qemuDomainDeviceCalculatePCIConnectFlags()
qemuDomainFillDevicePCIConnectFlags()
qemuDomainFill[AllDevices]PCIConnectFlags()
based on what they do, the kind of object they work on, and
whether they treat the input as read-only or update it.
I know they're not great names, but at least their purpose
should be quite clear when you run into them.
In any case, the subject will have to be updated because
it's not correct even with the current naming.
> The latter two functions aren't called anywhere yet. This commit is
> just making them available.
This was already mentioned on IRC, and I think we both agreed
this patch should have appeared later in the series, ideally
right before patch 9 which actually uses the functions it
introduces.
> ---
> src/conf/device_conf.h | 5 +
> src/qemu/qemu_domain_address.c | 257 +++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 262 insertions(+)
>
> diff --git a/src/conf/device_conf.h b/src/conf/device_conf.h
> index 8443de6..f435fb5 100644
> --- a/src/conf/device_conf.h
> +++ b/src/conf/device_conf.h
> @@ -142,6 +142,11 @@ typedef struct _virDomainDeviceInfo {
> /* bootIndex is only used for disk, network interface, hostdev
> * and redirdev devices */
> unsigned int bootIndex;
> +
> + /* pciConnectFlags is only used internally during address
> + * assignment, never saved and never reported.
> + */
> + int pciConnectFlags; /* enum virDomainPCIConnectFlags */
> } virDomainDeviceInfo, *virDomainDeviceInfoPtr;
>
>
> diff --git a/src/qemu/qemu_domain_address.c b/src/qemu/qemu_domain_address.c
> index dc4e4ee..7f86c32 100644
> --- a/src/qemu/qemu_domain_address.c
> +++ b/src/qemu/qemu_domain_address.c
> @@ -398,6 +398,263 @@ qemuDomainAssignARMVirtioMMIOAddresses(virDomainDefPtr def,
> }
>
>
> +/**
> + * qemuDomainDeviceConnectFlagsInternal:
> + *
> + * Lowest level function to determine PCI connectFlags for a
> + * device.
The entire comment leaves two spaces after the asterisk, it
should be a single space instead. Same applies to all such
comments below.
> Assume HOTPLUGGABLE | PCI_ENDPOINT, then modify
> + * appropriately for exceptions.
This is an implementation detail that shouldn't leak into
the function's documentation.
> This function relies on the next
> + * higher-level function determining the value for pcieFlags and
> + * virtioFlags in advance - this is to make it more efficient to call
> + * multiple times.
> + *
> + * @dev: The device to be checked
> + *
> + * @pcieFlags: flags to use for a known PCI Express device
> + *
> + * @virtioFlags: flags to use for a virtio device (properly vetted
> + * for the current qemu binary and arch/machinetype)
> + *
> + * returns appropriate virDomainPCIConnectFlags for this device in
> + * this domain, or 0 if the device doesn't connect using PCI. There
> + * is no failure.
> + *
Remove the empty line.
> + */
> +static virDomainPCIConnectFlags
> +qemuDomainDeviceConnectFlagsInternal(virDomainDeviceDefPtr dev,
> + virDomainPCIConnectFlags pcieFlags
> + ATTRIBUTE_UNUSED,
> + virDomainPCIConnectFlags virtioFlags
> + ATTRIBUTE_UNUSED)
> +{
> + virDomainPCIConnectFlags flags = VIR_PCI_CONNECT_TYPE_PCI_DEVICE;
> +
> + /* Get these out of the way to simplify the rest */
> + if (dev->type == VIR_DOMAIN_DEVICE_CONTROLLER &&
> + dev->data.controller->type == VIR_DOMAIN_CONTROLLER_TYPE_PCI)
> + return virDomainPCIControllerModelToConnectType(dev->data.controller->model);
Please add curly braces here, as per the style guidelines.
The last line is also >80 columns.
> +
> + /* remember - default flags is PCI_DEVICE, so only set if it's different. */
> + switch (dev->type) {
> + case VIR_DOMAIN_DEVICE_CONTROLLER: {
> + virDomainControllerDefPtr cont = dev->data.controller;
> +
> + if (cont->type == VIR_DOMAIN_CONTROLLER_TYPE_FDC ||
> + cont->type == VIR_DOMAIN_CONTROLLER_TYPE_CCID ||
> + (cont->type == VIR_DOMAIN_CONTROLLER_TYPE_USB &&
> + cont->model == VIR_DOMAIN_CONTROLLER_MODEL_USB_NONE))
> + flags = 0;
Curly braces here as well.
> + break;
> + }
> +
> + case VIR_DOMAIN_DEVICE_FS:
> + /* the only type of filesystem so far is virtio-9p-pci */
> + break;
> +
> + case VIR_DOMAIN_DEVICE_NET: {
> + virDomainNetDefPtr net = dev->data.net;
> +
> + /* NB: a type='hostdev' will use PCI, but its
> + * address is assigned when we're assigning the
> + * addresses for other hostdev devices.
> + */
> + if (net->type == VIR_DOMAIN_NET_TYPE_HOSTDEV ||
> + STREQ(net->model, "usb-net"))
> + flags = 0;
Curly braces.
> + break;
> + }
> +
> + case VIR_DOMAIN_DEVICE_SOUND:
> + switch (dev->data.sound->model) {
> + case VIR_DOMAIN_SOUND_MODEL_SB16:
> + case VIR_DOMAIN_SOUND_MODEL_PCSPK:
> + case VIR_DOMAIN_SOUND_MODEL_USB:
> + flags = 0;
> + break;
> + }
> + break;
> +
> + case VIR_DOMAIN_DEVICE_DISK:
> + if (dev->data.disk->bus != VIR_DOMAIN_DISK_BUS_VIRTIO)
> + flags = 0; /* only virtio disks use PCI */
> + break;
> +
> + case VIR_DOMAIN_DEVICE_HOSTDEV:
> + break;
> +
> + case VIR_DOMAIN_DEVICE_MEMBALLOON:
> + if (dev->data.memballoon->model != VIR_DOMAIN_MEMBALLOON_MODEL_VIRTIO)
> + flags = 0;
> + break;
> +
> + case VIR_DOMAIN_DEVICE_RNG:
> + if (dev->data.rng->model != VIR_DOMAIN_RNG_MODEL_VIRTIO)
> + flags = 0;
> + break;
> +
> + case VIR_DOMAIN_DEVICE_WATCHDOG:
> + /* only one model connects using PCI */
> + if (dev->data.watchdog->model != VIR_DOMAIN_WATCHDOG_MODEL_I6300ESB)
> + flags = 0;
> + break;
> +
> + case VIR_DOMAIN_DEVICE_VIDEO:
> + break;
> +
> + case VIR_DOMAIN_DEVICE_SHMEM:
> + break;
> +
> + case VIR_DOMAIN_DEVICE_INPUT:
> + if (dev->data.input->bus != VIR_DOMAIN_INPUT_BUS_VIRTIO)
> + flags = 0;
> + break;
> +
> + case VIR_DOMAIN_DEVICE_CHR:
> + if (dev->data.chr->targetType != VIR_DOMAIN_CHR_SERIAL_TARGET_TYPE_PCI)
> + flags = 0;
> + break;
> +
> + /* These devices don't ever connect with PCI */
> + case VIR_DOMAIN_DEVICE_NVRAM:
> + case VIR_DOMAIN_DEVICE_TPM:
> + case VIR_DOMAIN_DEVICE_PANIC:
> + case VIR_DOMAIN_DEVICE_MEMORY:
> + case VIR_DOMAIN_DEVICE_HUB:
> + case VIR_DOMAIN_DEVICE_REDIRDEV:
> + case VIR_DOMAIN_DEVICE_SMARTCARD:
> + /* These devices don't even have a DeviceInfo */
> + case VIR_DOMAIN_DEVICE_LEASE:
> + case VIR_DOMAIN_DEVICE_GRAPHICS:
> + case VIR_DOMAIN_DEVICE_IOMMU:
> + case VIR_DOMAIN_DEVICE_LAST:
> + case VIR_DOMAIN_DEVICE_NONE:
> + flags = 0;
> + break;
> + }
> +
> + if (flags)
> + flags |= VIR_PCI_CONNECT_HOTPLUGGABLE;
Wouldn't it be better to start with
flags = VIR_PCI_CONNECT_TYPE_PCI_DEVICE | \
VIR_PCI_CONNECT_HOTPLUGGABLE;
and skip these two lines? That way the default is clearly
stated at the beginning of the function, and the behavior
would be the same.
> + return flags;
> +}
> +
> +
> +/**
> + * qemuDomainDeviceConnectFlags:
> + *
> + * The version of the function to call if it will be called just
> + * once.
This description won't do. How about
Set PCI connection flags for @dev based on the guest
configuration and the capabilities of the QEMU binary.
or something along those lines?
> + * @def: the entire DomainDef
> + *
> + * @dev: The device to be checked
> + *
> + * @qemuCaps: as you'd expect
> + *
> + * sets device's info->pciConnectFlags when appropriate.
> + * There is no failure, so there is no return value.
Once this is covered by the description, you can leave
the bit about the return value out entirely.
> + *
> + */
> +static void ATTRIBUTE_UNUSED
> +qemuDomainDeviceConnectFlags(virDomainDefPtr def,
> + virDomainDeviceDefPtr dev,
> + virQEMUCapsPtr qemuCaps)
> +{
> + virDomainDeviceInfoPtr info = virDomainDeviceGetInfo(dev);
> +
> + if (info) {
> + /* These flags are passed to qemuDomainDeviceConnectFlagsInternal
> + * after setting according to the machinetype and qemu
> + * capabilities. That may seem like pointless posturing, but
> + * it's done this way to eliminate duplicated code while
> + * allowing more efficient operation when it's being done
> + * repeatedly with the device iterator.
> + */
> + virDomainPCIConnectFlags virtioFlags = VIR_PCI_CONNECT_TYPE_PCI_DEVICE;
> + virDomainPCIConnectFlags pcieFlags = VIR_PCI_CONNECT_TYPE_PCI_DEVICE;
> +
> + if (qemuDomainMachineHasPCIeRoot(def))
> + pcieFlags = VIR_PCI_CONNECT_TYPE_PCIE_DEVICE;
> +
> + if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_VIRTIO_PCI_DISABLE_LEGACY))
> + virtioFlags = pcieFlags;
Of course, if the suggestion above about HOTPLUGGABLE is
followed, pcieFlags and virtioFlags should have HOTPLUGGABLE
set here as well.
Are all endpoint devices hotpluggable? It looks like it.
> + info->pciConnectFlags
> + = qemuDomainDeviceConnectFlagsInternal(dev, pcieFlags, virtioFlags);
> + }
> +}
> +
> +
> +typedef struct {
> + virDomainPCIConnectFlags virtioFlags;
> + virDomainPCIConnectFlags pcieFlags;
> +} qemuDomainDeviceConnectFlagsIteratorData;
> +
> +/**
> + * qemuDomainDeviceConnectFlagsIterator:
> + *
> + * The version of the function to call with
> + * virDomainDeviceInfoIterate()
See above, although in this case the function is a simple
implementation detail and the documentation is less crucial.
> + * @def: the entire DomainDef
> + *
> + * @dev: The device to be checked
> + *
> + * @info: virDomainDeviceInfo within the device
> + *
> + * @opaque: points to iterator data setup beforehand.
> + *
> + * Sets @info->pciConnectFlags. Always returns 0 - there
> + * is no failure.
> + *
> + */
> +static int
> +qemuDomainDeviceConnectFlagsIterator(virDomainDefPtr def ATTRIBUTE_UNUSED,
> + virDomainDeviceDefPtr dev,
> + virDomainDeviceInfoPtr info,
> + void *opaque)
> +{
> + qemuDomainDeviceConnectFlagsIteratorData *data = opaque;
> +
> + info->pciConnectFlags
> + = qemuDomainDeviceConnectFlagsInternal(dev, data->pcieFlags,
> + data->virtioFlags);
> + return 0;
> +}
> +
> +
> +/**
> + * qemuDomainDeviceSetAllConnectFlags:
> + *
> + * Set the info->pciConnectFlags for all devices in the domain.
> + *
> + * @def: the entire DomainDef
> + *
> + * @qemuCaps: as you'd expect
> + *
> + * sets info->pciConnectFlags for all devices as appropriate. returns
> + * 0 on success or -1 on failure (the only possibility of failure would
> + * be some internal problem with virDomainDeviceInfoIterate())
The purpose has already been described above, and why the
function would fail is an implementation detail. It's safe
to stick to the usual "returns 0 on success or <0 on
failure" blurb here.
> + */
> +static int ATTRIBUTE_UNUSED
> +qemuDomainDeviceSetAllConnectFlags(virDomainDefPtr def,
> + virQEMUCapsPtr qemuCaps)
> +{
> + qemuDomainDeviceConnectFlagsIteratorData data
> + = { .virtioFlags = VIR_PCI_CONNECT_TYPE_PCI_DEVICE,
Double space here; however...
> + .pcieFlags = VIR_PCI_CONNECT_TYPE_PCI_DEVICE };
> +
> + if (qemuDomainMachineHasPCIeRoot(def))
> + data.pcieFlags = VIR_PCI_CONNECT_TYPE_PCIE_DEVICE;
> +
> + if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_VIRTIO_PCI_DISABLE_LEGACY))
> + data.virtioFlags = data.pcieFlags;
... this is the same exact logic already present in
qemuDomainDeviceConnectFlags() above. We should really
try to avoid duplication - it's the whole point of this
exercise after all ;)
How about a tiny helper that initializes a IteratorData
structure based on def and qemuCaps? Then this function
can just use the IteratorData directly, and the one above
simply has to pass the two members separately.
> + return virDomainDeviceInfoIterate(def, qemuDomainDeviceConnectFlagsIterator,
> + &data);
> +}
> +
> +
> static int
> qemuDomainCollectPCIAddress(virDomainDefPtr def ATTRIBUTE_UNUSED,
> virDomainDeviceDefPtr device,
--
Andrea Bolognani / Red Hat / Virtualization
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