Re: [Qemu-devel] [PATCH RESEND v7 0/3] Red Hat PCI bridge resource reserve capability

[Aleksandr Bezzubikov]

пт, 18 авг. 2017 г. в 2:33, Aleksandr Bezzubikov <address@hidden>:

> Now PCI bridges get a bus range number on a system init,
> basing on currently plugged devices. That's why when one wants to hotplug
> another bridge,
> it needs his child bus, which the parent is unable to provide (speaking
> about virtual device).
> The suggested workaround is to have vendor-specific capability in Red Hat
> PCI bridges
> that contains number of additional bus to reserve (as well as IO/MEM/PREF
> space limit hints)
> on BIOS PCI init.
> So this capability is intended only for pure QEMU->SeaBIOS usage.
>
> Considering all aforesaid, this series is directly connected with
> QEMU series "Generic PCIE-PCI Bridge".
>
> Although the new PCI capability is supposed to contain various limits
> along with
> bus number to reserve, now only its full layout is proposed. And
> only bus_reserve field is used in QEMU and BIOS. Limits usage
> is still a subject for implementation as now
> the main goal of this series to provide necessary support from the
> firmware side to PCIE-PCI bridge hotplug.
>
> Changes v6->v7:
> 0. Resend - fix a bug with incorrect subordinate bus default value.
> 1. Do not use alignment in case of IO reservation cap usage.
> 2. Log additional buses reservation events.
>
> Changes v5->v6:
> 1. Remove unnecessary indents and line breaks (addresses Marcel's comments)
> 2. Count IO/MEM/PREF region size as a maximum of necessary size and one
> provide in
>         RESOURCE_RESERVE capability (addresses Marcel's comment).
> 3. Make the cap debug message more detailed (addresses Marcel's comment).
> 4. Change pref_32 and pref_64 cap fields comment.
>
> Changes v4->v5:
> 1. Rename capability-related #defines
> 2. Move capability IO/MEM/PREF fields values usage to the regions creation
> stage (addresses Marcel's comment)
> 3. The capability layout change: separate pref_mem into pref_mem_32 and
> pref_mem_64 fields (QEMU side has the same changes) (addresses Laszlo's
> comment)
> 4. Extract the capability lookup and check to the separate function
> (addresses Marcel's comment)
>         - despite of Marcel's comment do not extract field check for -1
> since it increases code length
>           and doesn't look nice because of different field types
> 5. Fix the capability's comment (addresses Marcel's comment)
> 6. Fix the 3rd patch message
>
> Changes v3->v4:
> 1. Use all QEMU PCI capability fields - addresses Michael's comment
> 2. Changes of the capability layout (QEMU side has the same changes):
>         - change reservation fields types: bus_res - uint32_t, others -
> uint64_t
>         - interpret -1 value as 'ignore'
>
> Changes v2->v3:
> 1. Merge commit 2 (Red Hat vendor ID) into commit 4 - addresses Marcel's
> comment,
>         and add Generic PCIE Root Port device ID - addresses Michael's
> comment.
> 2. Changes of the capability layout  (QEMU side has the same changes):
>         - add 'type' field to distinguish multiple
>                 RedHat-specific capabilities - addresses Michael's comment
>         - do not mimiс PCI Config space register layout, but use mutually
> exclusive differently
>                 sized fields for IO and prefetchable memory limits -
> addresses Laszlo's comment
>         - use defines instead of structure and offsetof - addresses
> Michael's comment
> 3. Interpret 'bus_reserve' field as a minimum necessary
>          range to reserve - addresses Gerd's comment
> 4. pci_find_capability moved to pci.c - addresses Kevin's comment
> 5. Move capability layout header to src/fw/dev-pci.h - addresses Kevin's
> comment
> 6. Add the capability documentation - addresses Michael's comment
> 7. Add capability length and bus_reserve field sanity checks - addresses
> Michael's comment
>
> Changes v1->v2:
> 1. New #define for Red Hat vendor added (addresses Konrad's comment).
> 2. Refactored pci_find_capability function (addresses Marcel's comment).
> 3. Capability reworked:
>         - data type added;
>         - reserve space in a structure for IO, memory and
>           prefetchable memory limits.
>
>
> Aleksandr Bezzubikov (3):
>   pci: refactor pci_find_capapibilty to get bdf as the first argument
>     instead of the whole pci_device
>   pci: add QEMU-specific PCI capability structure
>   pci: enable RedHat PCI bridges to reserve additional resources on PCI
>     init
>
>  src/fw/dev-pci.h    |  53 ++++++++++++++++++++++++++
>  src/fw/pciinit.c    | 108
> +++++++++++++++++++++++++++++++++++++++++++++++++---
>  src/hw/pci.c        |  25 ++++++++++++
>  src/hw/pci.h        |   1 +
>  src/hw/pci_ids.h    |   3 ++
>  src/hw/pcidevice.c  |  24 ------------
>  src/hw/pcidevice.h  |   1 -
>  src/hw/virtio-pci.c |   6 +--
>  8 files changed, 188 insertions(+), 33 deletions(-)
>  create mode 100644 src/fw/dev-pci.h
>
> --
> 2.7.4
>

And what about this series? The matching QEMU series has been applied,
that's why there should be no problems with picking this series up for
SeaBIOS


> --
Aleksandr Bezzubikov