From: Dexuan Cui <decui@microsoft.com>
To: Jeffrey Hugo <quic_jhugo@quicinc.com>,
KY Srinivasan <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Stephen Hemminger <sthemmin@microsoft.com>,
"wei.liu@kernel.org" <wei.liu@kernel.org>,
"lorenzo.pieralisi@arm.com" <lorenzo.pieralisi@arm.com>,
"robh@kernel.org" <robh@kernel.org>,
"kw@linux.com" <kw@linux.com>,
"bhelgaas@google.com" <bhelgaas@google.com>
Cc: Jake Oshins <jakeo@microsoft.com>,
David Zhang <dazhan@microsoft.com>,
"linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>,
"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH 2/2] PCI: hv: Fix interrupt mapping for multi-MSI
Date: Mon, 9 May 2022 23:21:43 +0000 [thread overview]
Message-ID: <BYAPR21MB1270DCF4AE2A64520E59235CBFC69@BYAPR21MB1270.namprd21.prod.outlook.com> (raw)
In-Reply-To: <1652132902-27109-3-git-send-email-quic_jhugo@quicinc.com>
> From: Jeffrey Hugo <quic_jhugo@quicinc.com>
> Sent: Monday, May 9, 2022 2:48 PM
> ...
> According to Dexuan, the hypervisor folks beleive that multi-msi
> allocations are not correct. compose_msi_msg() will allocate multi-msi
> one by one. However, multi-msi is a block of related MSIs, with alignment
> requirements. In order for the hypervisor to allocate properly aligned
> and consecutive entries in the IOMMU Interrupt Remapping Table, there
> should be a single mapping request that requests all of the multi-msi
> vectors in one shot.
>
> Dexuan suggests detecting the multi-msi case and composing a single
> request related to the first MSI. Then for the other MSIs in the same
> block, use the cached information. This appears to be viable, so do it.
>
> Suggested-by: Dexuan Cui <decui@microsoft.com>
> Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
> + if (!msi_desc->pci.msi_attrib.is_msix && msi_desc->nvec_used > 1) {
> + /*
> + * if this is not the first MSI of Multi MSI, we already have
s/if/If
next prev parent reply other threads:[~2022-05-09 23:43 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-09 21:48 [PATCH 0/2] hyperv compose_msi_msg fixups Jeffrey Hugo
2022-05-09 21:48 ` [PATCH 1/2] PCI: hv: Reuse existing ITRE allocation in compose_msi_msg() Jeffrey Hugo
2022-05-09 23:13 ` Dexuan Cui
2022-05-10 2:29 ` Jeffrey Hugo
2022-05-10 10:52 ` Wei Liu
2022-05-09 21:48 ` [PATCH 2/2] PCI: hv: Fix interrupt mapping for multi-MSI Jeffrey Hugo
2022-05-09 23:21 ` Dexuan Cui [this message]
2022-05-09 23:23 ` [PATCH 0/2] hyperv compose_msi_msg fixups Dexuan Cui
2022-05-10 2:31 ` Jeffrey Hugo
2022-05-10 18:13 ` Michael Kelley (LINUX)
2022-05-11 14:41 ` Wei Liu
2022-05-11 14:47 ` Jeffrey Hugo
2022-05-11 15:19 ` Wei Liu
2022-05-11 15:21 ` Jeffrey Hugo
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