Re: [PATCH v6 0/8] PCI: hv: Support host bridge probing on ARM64

From: Boqun Feng <boqun.feng@gmail.com>
To: Bjorn Helgaas <bhelgaas@google.com>,
	Arnd Bergmann <arnd@arndb.de>, Marc Zyngier <maz@kernel.org>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: "Catalin Marinas" <catalin.marinas@arm.com>,
	"Will Deacon" <will@kernel.org>,
	"K. Y. Srinivasan" <kys@microsoft.com>,
	"Haiyang Zhang" <haiyangz@microsoft.com>,
	"Stephen Hemminger" <sthemmin@microsoft.com>,
	"Wei Liu" <wei.liu@kernel.org>,
	"Dexuan Cui" <decui@microsoft.com>,
	"Rob Herring" <robh@kernel.org>,
	"Krzysztof Wilczyński" <kw@linux.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org,
	linux-pci@vger.kernel.org,
	"Sunil Muthuswamy" <sunilmut@microsoft.com>,
	"Mike Rapoport" <rppt@kernel.org>
Subject: Re: [PATCH v6 0/8] PCI: hv: Support host bridge probing on ARM64
Date: Mon, 2 Aug 2021 16:15:04 +0800	[thread overview]
Message-ID: <YQepiKkFoJHC0gsK@boqun-archlinux> (raw)
In-Reply-To: <20210726180657.142727-1-boqun.feng@gmail.com>

On Tue, Jul 27, 2021 at 02:06:49AM +0800, Boqun Feng wrote:
> Hi,
> 
> This is the v6 for the preparation of virtual PCI support on Hyper-V
> ARM64, Previous versions:
> 
> v1:	https://lore.kernel.org/lkml/20210319161956.2838291-1-boqun.feng@gmail.com/
> v2:	https://lore.kernel.org/lkml/20210503144635.2297386-1-boqun.feng@gmail.com/
> v3:	https://lore.kernel.org/lkml/20210609163211.3467449-1-boqun.feng@gmail.com/
> v4:	https://lore.kernel.org/lkml/20210714102737.198432-1-boqun.feng@gmail.com/
> v5:	https://lore.kernel.org/lkml/20210720134429.511541-1-boqun.feng@gmail.com/
> 
> Changes since last version:
> 
> *	Rebase to 5.14-rc3
> 
> *	Comment fixes as suggested by Bjorn.
> 
> The basic problem we need to resolve is that ARM64 is an arch with
> PCI_DOMAINS_GENERIC=y, so the bus sysdata is pci_config_window. However,
> Hyper-V PCI provides a paravirtualized PCI interface, so there is no
> actual pci_config_window for a PCI host bridge, so no information can be
> retrieve from the pci_config_window of a Hyper-V virtual PCI bus. Also
> there is no corresponding ACPI device for the Hyper-V PCI root bridge,
> which introduces a special case when trying to find the ACPI device from
> the sysdata (see patch #3).
> 
> With this patchset, we could enable the virtual PCI on Hyper-V ARM64
> guest with other code under development.
> 
> Comments and suggestions are welcome.
> 

Ping ;-)

Regards,
Boqun

> Regards,
> Boqun
> 
> Arnd Bergmann (1):
>   PCI: hv: Generify PCI probing
> 
> Boqun Feng (7):
>   PCI: Introduce domain_nr in pci_host_bridge
>   PCI: Support populating MSI domains of root buses via bridges
>   arm64: PCI: Restructure pcibios_root_bridge_prepare()
>   arm64: PCI: Support root bridge preparation for Hyper-V
>   PCI: hv: Set ->domain_nr of pci_host_bridge at probing time
>   PCI: hv: Set up MSI domain at bridge probing time
>   PCI: hv: Turn on the host bridge probing on ARM64
> 
>  arch/arm64/kernel/pci.c             | 29 +++++++---
>  drivers/pci/controller/pci-hyperv.c | 86 +++++++++++++++++------------
>  drivers/pci/probe.c                 | 12 +++-
>  include/linux/pci.h                 | 11 ++++
>  4 files changed, 93 insertions(+), 45 deletions(-)
> 
> -- 
> 2.32.0
>