On 24/11/14 5:03 pm, "Neil Horman" <nhorman at tuxdriver.com> wrote:
>On Mon, Nov 24, 2014 at 05:45:54AM +0000, Sujith Sankar (ssujith) wrote:
>>
>>
>> On 24/11/14 5:47 am, "Neil Horman" <nhorman at tuxdriver.com> wrote:
>>
>> >On Sun, Nov 23, 2014 at 09:38:19PM +0530, Sujith Sankar wrote:
>> >> Signed-off-by: Sujith Sankar <ssujith at cisco.com>
>> >> ---
>> >> config/common_linuxapp | 5 +++++
>> >> lib/Makefile | 1 +
>> >> lib/librte_eal/linuxapp/eal/eal_pci_vfio.c | 7 +++++++
>> >> lib/librte_eal/linuxapp/eal/include/eal_pci_init.h | 1 +
>> >> mk/rte.app.mk | 4 ++++
>> >> 5 files changed, 18 insertions(+)
>> >>
>> >> diff --git a/config/common_linuxapp b/config/common_linuxapp
>> >> index 57b61c9..3c091e7 100644
>> >> --- a/config/common_linuxapp
>> >> +++ b/config/common_linuxapp
>> >> @@ -210,6 +210,11 @@ CONFIG_RTE_LIBRTE_I40E_QUEUE_NUM_PER_VM=4
>> >> CONFIG_RTE_LIBRTE_I40E_ITR_INTERVAL=-1
>> >>
>> >> #
>> >> +# Compile burst-oriented Cisco ENIC PMD driver
>> >> +#
>> >> +CONFIG_RTE_LIBRTE_ENIC_PMD=y
>> >> +
>> >> +#
>> >> # Compile burst-oriented VIRTIO PMD driver
>> >> #
>> >> CONFIG_RTE_LIBRTE_VIRTIO_PMD=y
>> >> diff --git a/lib/Makefile b/lib/Makefile
>> >> index e3237ff..1911790 100644
>> >> --- a/lib/Makefile
>> >> +++ b/lib/Makefile
>> >> @@ -43,6 +43,7 @@ DIRS-$(CONFIG_RTE_LIBRTE_CMDLINE) += librte_cmdline
>> >> DIRS-$(CONFIG_RTE_LIBRTE_ETHER) += librte_ether
>> >> DIRS-$(CONFIG_RTE_LIBRTE_E1000_PMD) += librte_pmd_e1000
>> >> DIRS-$(CONFIG_RTE_LIBRTE_IXGBE_PMD) += librte_pmd_ixgbe
>> >> +DIRS-$(CONFIG_RTE_LIBRTE_IXGBE_PMD) += librte_pmd_enic
>> >> DIRS-$(CONFIG_RTE_LIBRTE_I40E_PMD) += librte_pmd_i40e
>> >> DIRS-$(CONFIG_RTE_LIBRTE_PMD_BOND) += librte_pmd_bond
>> >> DIRS-$(CONFIG_RTE_LIBRTE_PMD_RING) += librte_pmd_ring
>> >> diff --git a/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
>> >>b/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
>> >> index c776ddc..6bf8f2e 100644
>> >> --- a/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
>> >> +++ b/lib/librte_eal/linuxapp/eal/eal_pci_vfio.c
>> >> @@ -736,6 +736,7 @@ pci_vfio_map_resource(struct rte_pci_device *dev)
>> >> maps[i].offset = reg.offset;
>> >> maps[i].size = reg.size;
>> >> dev->mem_resource[i].addr = bar_addr;
>> >> + dev->mem_resource[i].len = reg.size;
>> >> }
>> >>
>> >> /* if secondary process, do not set up interrupts */
>> >> @@ -791,4 +792,10 @@ pci_vfio_is_enabled(void)
>> >> {
>> >> return vfio_cfg.vfio_enabled;
>> >> }
>> >> +
>> >> +int
>> >> +pci_vfio_container_fd(void)
>> >> +{
>> >> + return vfio_cfg.vfio_container_fd;
>> >> +}
>> >You should move this function definition to a separate patch and put it
>> >earlier
>> >in the series, as you call this function two patches back.
>>
>> Thanks for the comment, Neil. I shall move this to a separate patch and
>> put it earlier in the series.
>>
>> >
>> >Also, this gives me pause, as it seems like you're working around the
>> >VFIO api.
>> >From what I see, you just use this to get an fd that you can use in an
>> >ioctl to
>> >set some DMA settings. First off, theres already a function called
>> >pci_vfio_get_container_fd, which does exactly what you are doing here,
>> >with
>> >additional safety checking.
>> >
>> >However, even though there is an existing function to do what you
>>want, I
>> >would
>> >recommend that you not use it for your purposes. Whenever you expose
>> >something
>> >like a file descriptor, you run the risk of multiple accessors racing
>> >trying to
>> >set/unset features and preform operations. It would be better if you
>> >could add
>> >apropriate api calls to vfio interface to set what you want. That way
>>the
>> >library can add appropriate locking if/when needed
>>
>>
>> I see that vfio_cfg.vfio_container_fd is obtained and stored in
>> pci_vfio_enable(), and this is not modified later.
>> ENIC PMD needs it to add the IOMMU mapping for buffers used for
>> communicating with adapter firmware. That?s just adding an entry, and
>> container fd is just passed as an argument. So the following addition
>>in
>> eal_pci_vfio.c should be sufficient. Since vfio_cfg is per process, I
>>do
>> not think that any other checking is required.
>>
>> int
>> pci_vfio_map_dma(struct vfio_iommu_type1_dma_map *dma_map)
>> {
>> return ioctl(vfio_cfg.vfio_container_fd, VFIO_IOMMU_MAP_DMA, dma_map);
>> }
>>
>>
>>
>> Does this look alright? Do you think that I?ve missed out anything
>>here?
>>
>It looks better yes, but I'm still confused as to why its necessecary.
>Looking
>back at your use of the fd, you're adding an iov entry for a buffer
>allocated
>via rte_memzone_reserve, which should come out of the dpdk's configured
>memory.
>In pci_vfio_setup_dma_maps, which is part of the pci probe path in eal
>library,
>all of the DPDK's physically available memory is already mapped into the
>iommu
>in a 1:1 fashion. So why do you need to do this again?
Yes, ideally all the memory allocated using rte_memzone_reserve_aligned()
should have its mapping already there in IOMMU. The code that adds the
mapping was not there initially, but while testing, I saw that it was
giving DMAR errors (like what?s shown below). Putting it back solved the
problem.
[295042.852620] DMAR:[fault reason 05] PTE Write access is not set
[295044.406282] dmar: DRHD: handling fault status reg 602
[295044.467981] dmar: DMAR:[DMA Write] Request device [86:00.0] fault addr
7fbd73b32000
Regards,
-Sujith
>
>Neil
>
