Re: [PATCH v4 0/2] VMD MSI Remapping Bypass

From: "Derrick, Jonathan" <jonathan.derrick@intel.com>
To: "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
	"iommu@lists.linux-foundation.org"
	<iommu@lists.linux-foundation.org>
Cc: "Karkra, Kapil" <kapil.karkra@intel.com>,
	"lorenzo.pieralisi@arm.com" <lorenzo.pieralisi@arm.com>,
	"baolu.lu@linux.intel.com" <baolu.lu@linux.intel.com>,
	"helgaas@kernel.org" <helgaas@kernel.org>,
	"joro@8bytes.org" <joro@8bytes.org>,
	"Patel, Nirmal" <nirmal.patel@intel.com>,
	"kw@linux.com" <kw@linux.com>
Subject: Re: [PATCH v4 0/2] VMD MSI Remapping Bypass
Date: Wed, 17 Mar 2021 19:14:17 +0000	[thread overview]
Message-ID: <0a70914085c25cf99536d106a280b27819328fff.camel@intel.com> (raw)
In-Reply-To: <20210210161315.316097-1-jonathan.derrick@intel.com>

Gentle reminder, for v5.13 ?

On Wed, 2021-02-10 at 09:13 -0700, Jon Derrick wrote:
> The Intel Volume Management Device acts similar to a PCI-to-PCI bridge in that
> it changes downstream devices' requester-ids to its own. As VMD supports PCIe
> devices, it has its own MSI-X table and transmits child device MSI-X by
> remapping child device MSI-X and handling like a demultiplexer.
> 
> Some newer VMD devices (Icelake Server) have an option to bypass the VMD MSI-X
> remapping table. This allows for better performance scaling as the child device
> MSI-X won't be limited by VMD's MSI-X count and IRQ handler.
> 
> V3->V4:
> Integrated wording suggestions; no functional changes
> 
> V2->V3:
> Trivial comment fixes
> Added acks
> 
> V1->V2:
> Updated for 5.12-next
> Moved IRQ allocation and remapping enable/disable to a more logical location
> 
> V1 patches 1-4 were already merged
> V1, 5/6: https://patchwork.kernel.org/project/linux-pci/patch/20200728194945.14126-6-jonathan.derrick@intel.com/
> V1, 6/6: https://patchwork.kernel.org/project/linux-pci/patch/20200728194945.14126-7-jonathan.derrick@intel.com/
> 
> 
> Jon Derrick (2):
>   iommu/vt-d: Use Real PCI DMA device for IRTE
>   PCI: vmd: Disable MSI-X remapping when possible
> 
>  drivers/iommu/intel/irq_remapping.c |  3 +-
>  drivers/pci/controller/vmd.c        | 63 +++++++++++++++++++++++------
>  2 files changed, 53 insertions(+), 13 deletions(-)
>