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From: Thomas Monjalon <thomas@monjalon.net>
To: "Burakov, Anatoly" <anatoly.burakov@intel.com>,
	Jerin Jacob Kollanukkaran <jerinj@marvell.com>,
	David Marchand <david.marchand@redhat.com>
Cc: dev <dev@dpdk.org>, Ben Walker <benjamin.walker@intel.com>
Subject: Re: [dpdk-dev] [EXT] Re: [PATCH] bus/pci: fix IOVA as VA mode selection
Date: Tue, 09 Jul 2019 17:04:23 +0200	[thread overview]
Message-ID: <2073381.Trv6OtLvPF@xps> (raw)
In-Reply-To: <553b3a91-7458-98d0-9df6-5b53010d326f@intel.com>

09/07/2019 16:37, Burakov, Anatoly:
> My view would be to always run in IOVA as VA by default and only falling 
> back to IOVA as PA if there is a need to do that. Yet, it seems that 
> whenever i try to bring this up, the response (not necessarily from you, 
> so this is not directed at you specifically) seems to be that because of 
> hotplug, we have to start in the "safest" (from device support point of 
> view) mode - that is, in IOVA as PA. Seeing how, as you claim, some 
> devices require IOVA as VA, then IOVA as PA is no longer the "safe" 
> default that all devices will support. Perhaps we can use this 
> opportunity to finally make IOVA as VA the default :)

That's a good point Anatoly. We need to decide what is the safest default.

About the capabilities flags, please let's agree that we want
to express 3 cases, so we need 2 flags.
About the preference of a mode for a device, if a mode is really
bad for a device, I suggest to not advertise it in capabilities.

In order to take a better decision, we need a summary of the
decision algorithm per layer, involving kernel driver capabilities
and memory capabilities.



  reply	other threads:[~2019-07-09 15:04 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-08 14:24 [dpdk-dev] " jerinj
2019-07-08 18:39 ` David Marchand
2019-07-08 19:13   ` [dpdk-dev] [EXT] " Jerin Jacob Kollanukkaran
2019-07-09  8:39     ` Bruce Richardson
2019-07-09  9:05       ` Jerin Jacob Kollanukkaran
2019-07-09  9:32         ` Bruce Richardson
2019-07-09  9:44     ` Burakov, Anatoly
2019-07-09 11:13       ` Jerin Jacob Kollanukkaran
2019-07-09 11:40         ` Burakov, Anatoly
2019-07-09 12:11           ` Jerin Jacob Kollanukkaran
2019-07-09 13:30             ` Burakov, Anatoly
2019-07-09 13:50               ` Burakov, Anatoly
2019-07-09 14:19                 ` Jerin Jacob Kollanukkaran
2019-07-09 14:00               ` Jerin Jacob Kollanukkaran
2019-07-09 14:37                 ` Burakov, Anatoly
2019-07-09 15:04                   ` Thomas Monjalon [this message]
2019-07-09 15:06                     ` Burakov, Anatoly
2019-07-09 17:50                   ` Jerin Jacob Kollanukkaran
2019-07-10  8:09                     ` David Marchand
2019-07-09 14:54                 ` Burakov, Anatoly
2019-07-09 14:58                   ` Jerin Jacob Kollanukkaran
2019-07-09 15:02                     ` Burakov, Anatoly
2019-07-09 15:12                       ` Thomas Monjalon
2019-07-09 15:18                         ` Burakov, Anatoly

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