From: Thomas Monjalon <thomas.monjalon@6wind.com>
To: "Xie, Huawei" <huawei.xie@intel.com>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [Question] How pmd virtio works without UIO?
Date: Wed, 23 Dec 2015 23:20:03 +0100 [thread overview]
Message-ID: <3141123.cIR0F9AJJf@xps13> (raw)
In-Reply-To: <C37D651A908B024F974696C65296B57B4C555753@SHSMSX101.ccr.corp.intel.com>
2015-12-23 05:13, Xie, Huawei:
> On 12/23/2015 10:57 AM, Yuanhan Liu wrote:
> > On Wed, Dec 23, 2015 at 10:41:57AM +0800, Peter Xu wrote:
> >> On Wed, Dec 23, 2015 at 10:01:35AM +0800, Yuanhan Liu wrote:
> >>> On Tue, Dec 22, 2015 at 05:56:41PM +0800, Peter Xu wrote:
> >>>> On Tue, Dec 22, 2015 at 04:32:46PM +0800, Yuanhan Liu wrote:
> >>>>> Actually, you are right. I mentioned in the last email that this is
> >>>>> for configuration part. To answer your question in this email, you
> >>>>> will not be able to go that further (say initiating virtio pmd) if
> >>>>> you don't unbind the origin virtio-net driver, and bind it to igb_uio
> >>>>> (or something similar).
> >>>>>
> >>>>> The start point is from rte_eal_pci_scan, where the sub-function
> >>>>> pci_san_one just initates a DPDK bond driver.
> >>>> I am not sure whether I do understand your meaning correctly
> >>>> (regarding "you willl not be able to go that furture"): The problem
> >>>> is that, we _can_ run testpmd without unbinding the ports and bind
> >>>> to UIO or something. What we need to do is boot the guest, reserve
> >>>> huge pages, and run testpmd (keeping its kernel driver as
> >>>> "virtio-pci"). In pci_scan_one():
> >>>>
> >>>> if (!ret) {
> >>>> if (!strcmp(driver, "vfio-pci"))
> >>>> dev->kdrv = RTE_KDRV_VFIO;
> >>>> else if (!strcmp(driver, "igb_uio"))
> >>>> dev->kdrv = RTE_KDRV_IGB_UIO;
> >>>> else if (!strcmp(driver, "uio_pci_generic"))
> >>>> dev->kdrv = RTE_KDRV_UIO_GENERIC;
> >>>> else
> >>>> dev->kdrv = RTE_KDRV_UNKNOWN;
> >>>> } else
> >>>> dev->kdrv = RTE_KDRV_UNKNOWN;
> >>>>
> >>>> I think it should be going to RTE_KDRV_UNKNOWN
> >>>> (driver=="virtio-pci") here.
> >>> Sorry, I simply overlook that. I was thinking it will quit here for
> >>> the RTE_KDRV_UNKNOWN case.
> >>>
> >>>> I tried to run IO and it could work,
> >>>> but I am not sure whether it is safe, and how.
> >>> I also did a quick test then, however, with the virtio 1.0 patchset
> >>> I sent before, which sets the RTE_PCI_DRV_NEED_MAPPING, resulting to
> >>> pci_map_device() failure and virtio pmd is not initiated at all.
> >> Then, will the patch work with ioport way to access virtio devices?
> > Yes.
> >
> >>>> Also, I am not sure whether I need to (at least) unbind the
> >>>> virtio-pci driver, so that there should have no kernel driver
> >>>> running for the virtio device before DPDK using it.
> >>> Why not? That's what the DPDK document asked to do
> >>> (http://dpdk.org/doc/guides/linux_gsg/build_dpdk.html):
> >>>
> >>> 3.6. Binding and Unbinding Network Ports to/from the Kernel Modules
> >>>
> >>> As of release 1.4, DPDK applications no longer automatically unbind
> >>> all supported network ports from the kernel driver in use. Instead,
> >>> all ports that are to be used by an DPDK application must be bound
> >>> to the uio_pci_generic, igb_uio or vfio-pci module before the
> >>> application is run. Any network ports under Linux* control will be
> >>> ignored by the DPDK poll-mode drivers and cannot be used by the
> >>> application.
> >> This seems obsolete? since it's not covering ioport.
> > I don't think so. Above is for how to run DPDK applications. ioport
> > is just a (optional) way to access PCI resource in a specific PMD.
> >
> > And, above speicification avoids your concerns, that two drivers try
> > to manipulate same device concurrently, doesn't it?
> >
> > And, it is saying "any network ports under Linux* control will be
> > ignored by the DPDK poll-mode drivers and cannot be used by the
> > application", so that the case you were saying that virtio pmd
> > continues to work without the bind looks like a bug to me.
> >
> > Can anyone confirm that?
>
> That document isn't accurate. virtio doesn't require binding to UIO
> driver if it uses PORT IO. The PORT IO commit said it is because UIO
> isn't secure, but avoid using uio doesn't bring more security as virtio
> PMD still could ask device to DMA into any memory.
> The thing we at least we might do is fail in virtio_resource_init if
> kernel driver is still manipulating this device. This saves the effort
> users use blacklist option and avoids the driver conflict.
+1 for checking kernel driver in use
next prev parent reply other threads:[~2015-12-23 22:21 UTC|newest]
Thread overview: 92+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-22 3:50 Peter Xu
2015-12-22 7:00 ` Yuanhan Liu
2015-12-22 8:23 ` Peter Xu
2015-12-22 8:32 ` Yuanhan Liu
2015-12-22 9:56 ` Peter Xu
2015-12-22 10:47 ` Xie, Huawei
2015-12-22 10:53 ` Xie, Huawei
2015-12-22 11:39 ` Peter Xu
2015-12-22 14:31 ` Xie, Huawei
2015-12-22 16:38 ` Xie, Huawei
2015-12-23 1:55 ` Peter Xu
2015-12-23 2:09 ` Yuanhan Liu
2015-12-23 2:38 ` Peter Xu
2015-12-23 22:26 ` Thomas Monjalon
2015-12-24 3:30 ` Yuanhan Liu
2015-12-24 17:56 ` Stephen Hemminger
2015-12-23 2:01 ` Yuanhan Liu
2015-12-23 2:41 ` Peter Xu
2015-12-23 2:58 ` Yuanhan Liu
2015-12-23 5:13 ` Xie, Huawei
2015-12-23 22:20 ` Thomas Monjalon [this message]
2015-12-24 18:38 ` [dpdk-dev] [PATCH 0/4] check if any kernel driver is manipulating the virtio device Huawei Xie
2015-12-24 18:38 ` [dpdk-dev] [PATCH 1/4] eal: make the comment more accurate Huawei Xie
2015-12-24 18:38 ` [dpdk-dev] [PATCH 2/4] eal: set kdrv to RTE_KDRV_NONE if kernel driver isn't manipulating the device Huawei Xie
2015-12-28 20:24 ` David Marchand
2015-12-24 18:38 ` [dpdk-dev] [PATCH 3/4] virtio: return 1 to tell the upper layer we don't take over this device Huawei Xie
2015-12-28 5:25 ` Yuanhan Liu
2015-12-28 5:38 ` Xie, Huawei
2015-12-24 18:38 ` [dpdk-dev] [PATCH 4/4] virtio: check if any kernel driver is manipulating the device Huawei Xie
2015-12-28 5:26 ` Yuanhan Liu
2015-12-28 5:29 ` Xie, Huawei
2016-01-04 9:02 ` Xie, Huawei
2016-01-04 17:29 ` Stephen Hemminger
2016-01-05 14:44 ` Panu Matilainen
2015-12-28 3:08 ` [dpdk-dev] [PATCH 0/4] check if any kernel driver is manipulating the virtio device Peter Xu
2016-01-03 17:56 ` [dpdk-dev] [PATCH v2 0/4] fix the issue that DPDK takes over virtio device blindly Huawei Xie
2016-01-03 17:56 ` [dpdk-dev] [PATCH v2 1/4] eal: make the comment more accurate Huawei Xie
2016-01-03 17:56 ` [dpdk-dev] [PATCH v2 2/4] eal: set kdrv to RTE_KDRV_NONE if kernel driver isn't manipulating the device Huawei Xie
2016-01-03 17:56 ` [dpdk-dev] [PATCH v2 3/4] virtio: return 1 to tell the upper layer we don't take over this device Huawei Xie
2016-01-03 17:56 ` [dpdk-dev] [PATCH v2 4/4] virtio: check if any kernel driver is manipulating the virtio device Huawei Xie
2016-01-04 17:24 ` Stephen Hemminger
2016-01-04 17:56 ` Xie, Huawei
2016-01-05 1:56 ` Yuanhan Liu
2016-01-07 13:17 ` Ferruh Yigit
2016-01-07 14:17 ` Panu Matilainen
2016-01-27 12:43 ` Thomas Monjalon
2016-01-04 17:25 ` [dpdk-dev] [PATCH v2 0/4] fix the issue that DPDK takes over virtio device blindly Stephen Hemminger
2016-01-12 3:02 ` Xie, Huawei
2016-01-12 4:23 ` Santosh Shukla
2016-01-12 5:16 ` Xie, Huawei
2016-01-13 12:17 ` Santosh Shukla
2016-01-27 15:21 ` [dpdk-dev] [PATCH v3 " Huawei Xie
2016-01-27 15:21 ` [dpdk-dev] [PATCH v3 1/4] eal: make the comment more accurate Huawei Xie
2016-01-27 15:21 ` [dpdk-dev] [PATCH v3 2/4] eal: set kdrv to RTE_KDRV_NONE if kernel driver isn't manipulating the device Huawei Xie
2016-01-27 15:21 ` [dpdk-dev] [PATCH v3 3/4] virtio: return 1 to tell the upper layer we don't take over this device Huawei Xie
2016-01-27 15:21 ` [dpdk-dev] [PATCH v3 4/4] virtio: check if kernel driver is manipulating the virtio device Huawei Xie
2016-01-28 9:55 ` Panu Matilainen
2016-01-29 7:40 ` [dpdk-dev] [PATCH v3 0/4] fix the issue that DPDK takes over virtio device blindly Yuanhan Liu
2016-02-24 12:43 ` Thomas Monjalon
2016-02-26 6:09 ` Xie, Huawei
2016-02-26 8:40 ` David Marchand
2016-02-26 9:00 ` Xie, Huawei
2016-02-26 1:53 ` [dpdk-dev] [PATCH v4 " Huawei Xie
2016-02-26 1:53 ` [dpdk-dev] [PATCH v4 1/4] eal: make the comment more accurate Huawei Xie
2016-02-29 8:48 ` David Marchand
2016-02-26 1:53 ` [dpdk-dev] [PATCH v4 2/4] eal: set kdrv to RTE_KDRV_NONE if kernel driver isn't managing the device Huawei Xie
2016-02-29 2:34 ` Xie, Huawei
2016-02-29 8:46 ` David Marchand
2016-02-29 9:00 ` Xie, Huawei
2016-02-29 9:05 ` David Marchand
2016-02-26 1:53 ` [dpdk-dev] [PATCH v4 3/4] eal: call pci_ioport_map when " Huawei Xie
2016-02-29 9:02 ` David Marchand
2016-02-26 1:53 ` [dpdk-dev] [PATCH v4 4/4] virtio: return 1 to tell the upper layer we don't take over this device Huawei Xie
2016-02-29 13:15 ` Santosh Shukla
2016-03-01 7:16 ` Thomas Monjalon
2016-03-01 7:53 ` Xie, Huawei
2016-03-01 8:20 ` Thomas Monjalon
2016-03-01 8:39 ` Xie, Huawei
2016-03-01 9:55 ` Thomas Monjalon
2016-03-01 10:08 ` Xie, Huawei
2016-03-08 17:00 ` Xie, Huawei
2016-03-08 23:01 ` Thomas Monjalon
2016-03-08 15:33 ` [dpdk-dev] [PATCH v5 0/6] fix the issue that DPDK takes over virtio device blindly Huawei Xie
2016-03-08 15:33 ` [dpdk-dev] [PATCH v5 1/6] eal: make the comment more accurate Huawei Xie
2016-03-08 15:33 ` [dpdk-dev] [PATCH v5 2/6] eal: RTE_KDRV_NONE means kernel driver isn't managing the device Huawei Xie
2016-03-08 15:33 ` [dpdk-dev] [PATCH v5 3/6] eal: use new RTE_ARCH_X86 for x86 arch Huawei Xie
2016-03-09 23:04 ` Thomas Monjalon
2016-03-08 15:33 ` [dpdk-dev] [PATCH v5 4/6] eal: simple code rework Huawei Xie
2016-03-08 15:33 ` [dpdk-dev] [PATCH v5 5/6] eal: map IO port when kernel driver isn't managing the device Huawei Xie
2016-03-08 15:33 ` [dpdk-dev] [PATCH v5 6/6] virtio: return 1 to tell the upper layer we don't take over this device Huawei Xie
2016-03-09 23:23 ` Thomas Monjalon
2016-03-09 23:35 ` [dpdk-dev] [PATCH v5 0/6] fix the issue that DPDK takes over virtio device blindly Thomas Monjalon
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