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From: Thomas Monjalon <thomas@monjalon.net>
To: "Burakov, Anatoly" <anatoly.burakov@intel.com>
Cc: "Wang, Xiao W" <xiao.w.wang@intel.com>,
	"dev@dpdk.org" <dev@dpdk.org>,
	"Zhang, Qi Z" <qi.z.zhang@intel.com>,
	"qingfu.cqf@alibaba-inc.com" <qingfu.cqf@alibaba-inc.com>,
	"Stojaczyk, Dariusz" <dariusz.stojaczyk@intel.com>,
	"stable@dpdk.org" <stable@dpdk.org>,
	ferruh.yigit@intel.com
Subject: Re: [dpdk-stable] [PATCH v2] vfio: allow secondary process to query IOMMU type
Date: Mon, 21 Jan 2019 11:21:22 +0100	[thread overview]
Message-ID: <19848055.XTa4X5ecso@xps> (raw)
In-Reply-To: <1b5e395c-1d0e-ffd4-3eb5-8e1d4f77152d@intel.com>

21/01/2019 11:13, Burakov, Anatoly:
> On 19-Jan-19 3:23 AM, Wang, Xiao W wrote:
> > Hi Anatoly,
> > 
> > From: Burakov, Anatoly
> >>
> >> It is only possible to know IOMMU type of a given VFIO container
> >> by attempting to initialize it. Since secondary process never
> >> attempts to set up VFIO container itself (because they're shared
> >> between primary and secondary), it never knows which IOMMU type
> >> the container is using, and never sets up the appropriate config
> >> structures. This results in inability to perform DMA mappings in
> >> secondary process.
> >>
> >> Fix this by allowing secondary process to query IOMMU type of
> >> primary's default container at device initialization.
> >>
> >> Note that this fix is assuming we're only interested in default
> >> container.
> >>
> >> Bugzilla ID: 174
> >>
> >> Fixes: 6bcb7c95fe14 ("vfio: share default container in multi-process")
> >> Cc: dariusz.stojaczyk@intel.com
> >> Cc: stable@dpdk.org
> >>
> >> Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
> >> ---
> >>
> >> Notes:
> >>      v2:
> >>      - Check if we found our IOMMU type within list of IOMMU types
> >>      - Don't request new default container fd as this should have
> >>        been done during rte_vfio_enable()
> >>
> >>   lib/librte_eal/linuxapp/eal/eal_vfio.c        | 88 +++++++++++++++++++
> >>   lib/librte_eal/linuxapp/eal/eal_vfio.h        | 12 ++-
> >>   .../linuxapp/eal/eal_vfio_mp_sync.c           | 16 ++++
> >>   3 files changed, 115 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/lib/librte_eal/linuxapp/eal/eal_vfio.c
> >> b/lib/librte_eal/linuxapp/eal/eal_vfio.c
> >> index 72cc65151..c821e8382 100644
> >> --- a/lib/librte_eal/linuxapp/eal/eal_vfio.c
> >> +++ b/lib/librte_eal/linuxapp/eal/eal_vfio.c
> >> @@ -549,6 +549,65 @@ vfio_mem_event_callback(enum rte_mem_event
> >> type, const void *addr, size_t len,
> >>   	}
> >>   }
> >>
> >> +static int
> >> +vfio_sync_default_container(void)
> >> +{
> >> +	struct rte_mp_msg mp_req, *mp_rep;
> >> +	struct rte_mp_reply mp_reply;
> >> +	struct timespec ts = {.tv_sec = 5, .tv_nsec = 0};
> >> +	struct vfio_mp_param *p = (struct vfio_mp_param *)mp_req.param;
> >> +	int iommu_type_id;
> >> +	unsigned int i;
> >> +
> >> +	/* cannot be called from primary */
> >> +	if (rte_eal_process_type() != RTE_PROC_SECONDARY)
> >> +		return -1;
> >> +
> >> +	/* default container fd should have been opened in rte_vfio_enable()
> >> */
> >> +	if (!default_vfio_cfg->vfio_enabled ||
> >> +			default_vfio_cfg->vfio_container_fd < 0) {
> >> +		RTE_LOG(ERR, EAL, "VFIO support is not initialized\n");
> >> +		return -1;
> >> +	}
> >> +
> >> +	/* find default container's IOMMU type */
> >> +	p->req = SOCKET_REQ_IOMMU_TYPE;
> > 
> > Since this function is to sync IOMMU type for the default container, should we make the req type as
> > SOCKET_REQ_DEFAULT_IOMMU_TYPE?
> 
> Hi,
> 
> Sure, that can be done. However, i don't think it warrants a respin 
> unless there's more important stuff to fix also. This patch is a 
> stop-gap, and this stuff will be rewritten for 19.05, so getting this 
> right is not that important :).

Anatoly,
I don't understand what is the use case.
It does not look critical enough to be merged late in 19.02.

  reply	other threads:[~2019-01-21 10:21 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-17 17:30 [dpdk-stable] [PATCH] " Anatoly Burakov
2019-01-18 10:13 ` [dpdk-stable] [dpdk-dev] " Burakov, Anatoly
2019-01-18 10:24 ` [dpdk-stable] [PATCH v2] " Anatoly Burakov
2019-01-19  3:23   ` Wang, Xiao W
2019-01-21 10:13     ` Burakov, Anatoly
2019-01-21 10:21       ` Thomas Monjalon [this message]
2019-01-21 10:29         ` Burakov, Anatoly
2019-01-21 10:29   ` Stojaczyk, Dariusz
2019-01-21 15:19     ` Thomas Monjalon

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