From: Maxime Coquelin <maxime.coquelin@redhat.com>
To: jianfeng.tan@intel.com
Cc: dev@dpdk.org, stable@dpdk.org, santosh.shukla@caviumnetworks.com,
anatoly.burakov@intel.com, thomas@monjalon.net,
stephen@networkplumber.org, peterx@redhat.com
Subject: Re: [dpdk-dev] [PATCH v2] bus/pci: forbid VA as IOVA mode if IOMMU address width too small
Date: Thu, 11 Jan 2018 21:19:38 +0100 [thread overview]
Message-ID: <5c168150-7dcc-c110-a3d6-968738d781f7@redhat.com> (raw)
In-Reply-To: <20180109131801.26520-1-maxime.coquelin@redhat.com>
Hi Jianfeng,
On 01/09/2018 02:18 PM, Maxime Coquelin wrote:
> Intel VT-d supports different address widths for the IOVAs, from
> 39 bits to 56 bits.
>
> While recent processors support at least 48 bits, VT-d emulation
> currently only supports 39 bits. It makes DMA mapping to fail in this
> case when using VA as IOVA mode, as user-space virtual addresses uses
> up to 47 bits (see kernel's Documentation/x86/x86_64/mm.txt).
>
> This patch parses VT-d CAP register value available in sysfs, and
> forbid VA as IOVA mode if the GAW is 39 bits or unknown.
>
> Fixes: f37dfab21c98 ("drivers/net: enable IOVA mode for Intel PMDs")
>
> Cc: stable@dpdk.org
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>
> Changes in v2:
> ==============
> - Rework pci_one_device_iommu_support_va #ifdefery (Stephen)
> - Don't inline introduced functions (Stephen)
>
> drivers/bus/pci/linux/pci.c | 108 ++++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 99 insertions(+), 9 deletions(-)
>
Could you please try the patch and confirm it does not break your
--no-huge usecase?
Are you fine with the fix?
Thanks,
Maxime
next prev parent reply other threads:[~2018-01-11 20:19 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-09 13:18 Maxime Coquelin
2018-01-11 20:19 ` Maxime Coquelin [this message]
2018-01-12 1:15 ` Tan, Jianfeng
2018-01-12 3:00 ` Tan, Jianfeng
2018-01-12 3:28 ` Zhang, Qi Z
2018-01-12 3:56 ` Zhang, Qi Z
2018-01-12 8:21 ` Maxime Coquelin
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