From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Burakov, Anatoly" Subject: Re: [PATCH v2] vfio: allow secondary process to query IOMMU type Date: Mon, 21 Jan 2019 10:29:31 +0000 Message-ID: <20150753-7a2b-d362-4d4d-7ce3c98232a2@intel.com> References: <1b5e395c-1d0e-ffd4-3eb5-8e1d4f77152d@intel.com> <19848055.XTa4X5ecso@xps> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: "Wang, Xiao W" , "dev@dpdk.org" , "Zhang, Qi Z" , "qingfu.cqf@alibaba-inc.com" , "Stojaczyk, Dariusz" , "stable@dpdk.org" , ferruh.yigit@intel.com To: Thomas Monjalon Return-path: In-Reply-To: <19848055.XTa4X5ecso@xps> Content-Language: en-US List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 21-Jan-19 10:21 AM, Thomas Monjalon wrote: > 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 >>>> --- >>>> >>>> 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. > This isn't "a use case", it's a bug fix. This was supposed to work, but doesn't. -- Thanks, Anatoly