From: Stephen Hemminger <stephen@networkplumber.org>
To: "Gaëtan Rivet" <gaetan.rivet@6wind.com>
Cc: Ferruh Yigit <ferruh.yigit@intel.com>,
dev@dpdk.org, Stephen Hemminger <sthemmin@microsoft.com>
Subject: Re: [dpdk-dev] [PATCH 1/5] bus/vmbus: add devargs support
Date: Fri, 14 Sep 2018 08:21:51 -0700 [thread overview]
Message-ID: <20180914082151.389c3f13@xeon-e3> (raw)
In-Reply-To: <20180914135804.qhvusuub4kdqrhpz@bidouze.vm.6wind.com>
On Fri, 14 Sep 2018 15:58:04 +0200
Gaëtan Rivet <gaetan.rivet@6wind.com> wrote:
> On Fri, Sep 14, 2018 at 02:19:19PM +0100, Ferruh Yigit wrote:
> > On 9/14/2018 2:06 PM, Gaëtan Rivet wrote:
> > > Hi,
> > >
> > > On Fri, Sep 14, 2018 at 01:46:59PM +0100, Ferruh Yigit wrote:
> > >> On 8/30/2018 11:35 PM, Stephen Hemminger wrote:
> > >>> From: Stephen Hemminger <sthemmin@microsoft.com>
> > >>>
> > >>> Take device arguments from command line and put
> > >>> them in the device devargs.
> > >>>
> > >>> Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
> > >>
> > >> <...>
> > >>
> > >>> @@ -204,6 +203,27 @@ vmbus_parse(const char *name, void *addr)
> > >>> return ret;
> > >>> }
> > >>>
> > >>> +/*
> > >>> + * scan for matching device args on command line
> > >>> + * example:
> > >>> + * -w 'vmbus(635a7ae3-091e-4410-ad59-667c4f8c04c3,latency=20)'
> > >>
> > >> This is just in comment but,
> > >>
> > >> I guess latest syntax is:
> > >> -w "vmbus:635a7ae3-091e-4410-ad59-667c4f8c04c3,latency=20"
> > >>
> > >> @Gaetan, is latest devarg syntax documented somewhere?
> > >
> > > That's the current syntax indeed. Some documentation is found at
> > >
> > > lib/librte_eal/common/include/rte_devargs.h:100
> > >
> > > Where it is specified that the bus name can be either omitted or
> > > followed by any character, to separate it from the device identifier.
> > >
> > > This means that using ':' is fine, as well as '('. As long as the device
> > > PMD afterward ignore the dangling ')' during devargs parsing, this should
> > > be fine.
> > >
> > > I don't think this is very clean, but it works.
> >
> > Thanks for the info, I see how "(" works, but ")" is takes as part of argument
> > and causing problem, I think better to not give "()" as supported syntax at all.
> >
> > btw, now both -w and --vdev are valid and can be used interchangeably, right? I
> > mean all following are valid?
> > -w pci:0000:86:06.0,enable_floating_veb=1
> > -w vdev:net_pcap,iface=lo
> > --vdev pci:0000:86:06.0,enable_floating_veb=1
> > --vdev vdev:net_pcap,iface=lo
> >
> >
>
> They are both valid but cannot be used interchangeably.
>
> This was the case at one point, between two rcs, because I had removed
> the devtype and the bus black/white-listing was configured another way.
>
> A user complained about the API change because it was not announced in
> time IIRC, and this was scrapped. Since then, the effort has been to on
> the new syntax instead of cleaning the old system.
>
> They cannot be used interchangeably because an rte_devtype is defined by
> the parameter choosen. BLACKLISTED_PCI for -b, WHITELISTED_PCI for -w,
> and VIRTUAL for --vdev.
>
> -b will actually change the bus configuration to "blacklist mode", -w to
> "whitelist mode", and --vdev will do nothing.
>
> So a PCI device declared using --vdev, will actually be skipped during
> PCI probe because by default it operates in blacklist mode, and the
> device policy is not WHITELISTED. This could surprise the one attempting
> this trick.
>
> This semantic is subtle and bug-prone. I'm adding it to the pile of
> reasons I'd like to remove the blacklist mode altogether.
>
It would have been nice if there was a --devargs instead of overloading -w and -b.
Especially when just changing parameter on a device.
next prev parent reply other threads:[~2018-09-14 15:22 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-30 22:35 [dpdk-dev] [PATCH 0/5] netvsc changes for 18.11 Stephen Hemminger
2018-08-30 22:35 ` [dpdk-dev] [PATCH 1/5] bus/vmbus: add devargs support Stephen Hemminger
2018-09-14 12:46 ` Ferruh Yigit
2018-09-14 13:06 ` Gaëtan Rivet
2018-09-14 13:19 ` Ferruh Yigit
2018-09-14 13:58 ` Gaëtan Rivet
2018-09-14 15:21 ` Stephen Hemminger [this message]
2018-08-30 22:35 ` [dpdk-dev] [PATCH 2/5] net/netvsc: allow tuning latency with devargs Stephen Hemminger
2018-09-14 12:47 ` Ferruh Yigit
2018-08-30 22:35 ` [dpdk-dev] [PATCH 3/5] net/netvsc: exhausting transmit descriptors is not an error Stephen Hemminger
2018-08-30 22:35 ` [dpdk-dev] [PATCH 4/5] net/netvsc: implement link state change callback Stephen Hemminger
2018-08-31 8:25 ` Gaëtan Rivet
2018-08-31 15:13 ` Stephen Hemminger
2018-08-30 22:35 ` [dpdk-dev] [PATCH 5/5] net/netvsc: integrated VF support Stephen Hemminger
2018-09-14 12:57 ` Ferruh Yigit
2018-09-14 15:22 ` Stephen Hemminger
2018-08-31 12:04 ` [dpdk-dev] [PATCH 0/5] netvsc changes for 18.11 Ferruh Yigit
2018-08-31 15:15 ` Stephen Hemminger
2018-08-31 16:56 ` Thomas Monjalon
2018-09-14 13:25 ` Ferruh Yigit
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