Hi Alejandro, Yes, this mode datapath is through the relay thread when LM happens, it’s not the direct interaction between VM and vdpa device.
BRs, Xiao From: Alejandro Lucero [mailto:alejandro.luc...@netronome.com] Sent: Wednesday, December 12, 2018 2:15 AM To: Wang, Xiao W <xiao.w.w...@intel.com> Cc: Bie, Tiwei <tiwei....@intel.com>; Maxime Coquelin <maxime.coque...@redhat.com>; dev <dev@dpdk.org>; Wang, Zhihong <zhihong.w...@intel.com>; Ye, Xiaolong <xiaolong...@intel.com> Subject: Re: [dpdk-dev] [PATCH 6/9] net/ifc: add devarg for LM mode On Wed, Nov 28, 2018 at 9:56 AM Xiao Wang <xiao.w.w...@intel.com<mailto:xiao.w.w...@intel.com>> wrote: This patch series enables a new method for live migration, i.e. software assisted live migration. This patch provides a device argument for user to choose the methold. When "swlm=1", driver/device will do live migration with a relay thread dealing with dirty page logging. Without this parameter, device will do dirty page logging and there's no relay thread consuming CPU resource. I'm a bit confused with this mode. If it is a relay thread doing the dirty page logging, does it mean that the datapath is through the relay thread and not between the VM and the vdpa device? Signed-off-by: Xiao Wang <xiao.w.w...@intel.com<mailto:xiao.w.w...@intel.com>> --- drivers/net/ifc/ifcvf_vdpa.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/net/ifc/ifcvf_vdpa.c b/drivers/net/ifc/ifcvf_vdpa.c index c0e50354a..e9cc8d7bc 100644 --- a/drivers/net/ifc/ifcvf_vdpa.c +++ b/drivers/net/ifc/ifcvf_vdpa.c @@ -8,6 +8,7 @@ #include <sys/ioctl.h> #include <sys/epoll.h> #include <linux/virtio_net.h> +#include <stdbool.h> #include <rte_malloc.h> #include <rte_memory.h> @@ -31,9 +32,11 @@ #endif #define IFCVF_VDPA_MODE "vdpa" +#define IFCVF_SW_FALLBACK_LM "swlm" static const char * const ifcvf_valid_arguments[] = { IFCVF_VDPA_MODE, + IFCVF_SW_FALLBACK_LM, NULL }; @@ -56,6 +59,7 @@ struct ifcvf_internal { rte_atomic32_t dev_attached; rte_atomic32_t running; rte_spinlock_t lock; + bool sw_lm; }; struct internal_list { @@ -767,6 +771,7 @@ ifcvf_pci_probe(struct rte_pci_driver *pci_drv __rte_unused, struct ifcvf_internal *internal = NULL; struct internal_list *list = NULL; int vdpa_mode = 0; + int sw_fallback_lm = 0; struct rte_kvargs *kvlist = NULL; int ret = 0; @@ -826,6 +831,16 @@ ifcvf_pci_probe(struct rte_pci_driver *pci_drv __rte_unused, internal->dev_addr.type = PCI_ADDR; list->internal = internal; + if (rte_kvargs_count(kvlist, IFCVF_SW_FALLBACK_LM)) { + ret = rte_kvargs_process(kvlist, IFCVF_SW_FALLBACK_LM, + &open_int, &sw_fallback_lm); + if (ret < 0) + goto error; + internal->sw_lm = sw_fallback_lm ? true : false; + } else { + internal->sw_lm = false; + } + internal->did = rte_vdpa_register_device(&internal->dev_addr, &ifcvf_ops); if (internal->did < 0) { -- 2.15.1
