[PATCH net-next v5 1/4] net: mana: track when the HWC has been handed to the PF
From: Long Li <longli@microsoft.com>
Date: 2026-09-08 03:52:44
Also in:
linux-rdma, lkml, netdev
Subsystem:
hyper-v/azure core and drivers, networking drivers, networking [general], the rest · Maintainers:
"K. Y. Srinivasan", Haiyang Zhang, Wei Liu, Dexuan Cui, Long Li, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Track possible PF queue ownership with setup_active for HWC reinit. Set it before submitting ESTABLISH_HWC. Cleanup now attempts DESTROY_HWC after submitted setup failures even before MAX_NUM_CQS arrives, adding potentially tens of seconds of polling. Resources are still freed if teardown fails. Signed-off-by: Long Li <longli@microsoft.com> --- Changes in v5 (v4 -> v5): - Describe additional teardown attempts and polling after setup failure. - Clarify the flag's context lifetime and setup precondition. - Shorten comments; no executable changes from v4. Changes in v4 (standalone net-next rework after the v3 split): - Introduce this dedicated handover-tracking preparation patch. - Set the submission flag inside mana_smc_setup_hwc() and use it as the cleanup gate, including setup failures before MAX_NUM_CQS arrives. - Do not carry the separate net series' teardown-failure resource retention. Changes in v3 (historical net fixes-only posting): - Handover tracking remained in the teardown-safety patch (5/6). - That patch dropped pcie_flr() recovery and retained resources after failed teardown. Those changes are not part of this preparation patch. Changes in v2 (v1 -> v2): - Handover tracking remained part of teardown-safety patch 5/7. - No separate preparation patch was posted. v1: - The combined series introduced setup_active in teardown-safety patch 5/7. drivers/net/ethernet/microsoft/mana/hw_channel.c | 14 +++++++------- drivers/net/ethernet/microsoft/mana/shm_channel.c | 8 +++++++- include/net/mana/hw_channel.h | 3 +++ include/net/mana/shm_channel.h | 2 +- 4 files changed, 18 insertions(+), 9 deletions(-)
diff --git a/drivers/net/ethernet/microsoft/mana/hw_channel.c b/drivers/net/ethernet/microsoft/mana/hw_channel.c
index 263e7c4e2934186af037be4c80350a6e322b6771..88e92e94e2e90ff31ca6710a7e9b8e34b5fa191c 100644
--- a/drivers/net/ethernet/microsoft/mana/hw_channel.c
+++ b/drivers/net/ethernet/microsoft/mana/hw_channel.c@@ -683,7 +683,7 @@ static int mana_hwc_establish_channel(struct gdma_context *gc, u16 *q_depth, cq->mem_info.dma_handle, rq->mem_info.dma_handle, sq->mem_info.dma_handle, - eq->eq.msix_index); + eq->eq.msix_index, &hwc->setup_active); if (err) return err;
@@ -815,13 +815,13 @@ void mana_hwc_destroy_channel(struct gdma_context *gc) if (!hwc) return; - /* gc->max_num_cqs is set in mana_hwc_init_event_handler(). If it's - * non-zero, the HWC worked and we should tear down the HWC here. - */ - if (gc->max_num_cqs > 0) { - mana_smc_teardown_hwc(&gc->shm_channel, false); - gc->max_num_cqs = 0; + if (hwc->setup_active) { + if (!mana_smc_teardown_hwc(&gc->shm_channel, false)) + hwc->setup_active = false; + else + dev_err(hwc->dev, "Failed to tear down HWC\n"); } + gc->max_num_cqs = 0; if (hwc->txq) mana_hwc_destroy_wq(hwc, hwc->txq);
diff --git a/drivers/net/ethernet/microsoft/mana/shm_channel.c b/drivers/net/ethernet/microsoft/mana/shm_channel.c
index d21b5db06e5092d82249fb1053d07f65aa38490c..3cf6a9f8e32c4ff5e5423fc950e88082941e21a8 100644
--- a/drivers/net/ethernet/microsoft/mana/shm_channel.c
+++ b/drivers/net/ethernet/microsoft/mana/shm_channel.c@@ -129,9 +129,12 @@ void mana_smc_init(struct shm_channel *sc, struct device *dev, sc->base = base; } +/* Requires no outstanding HWC handover. *submitted records possible PF + * ownership, including when setup fails after submission. + */ int mana_smc_setup_hwc(struct shm_channel *sc, bool reset_vf, u64 eq_addr, u64 cq_addr, u64 rq_addr, u64 sq_addr, - u32 eq_msix_index) + u32 eq_msix_index, bool *submitted) { union smc_proto_hdr *hdr; u16 all_addr_h4bits = 0;
@@ -144,6 +147,8 @@ int mana_smc_setup_hwc(struct shm_channel *sc, bool reset_vf, u64 eq_addr, int err; int i; + *submitted = false; + /* Ensure VF already has possession of shared memory */ err = mana_smc_poll_register(sc->base, false); if (err) {
@@ -229,6 +234,7 @@ int mana_smc_setup_hwc(struct shm_channel *sc, bool reset_vf, u64 eq_addr, /* Write 256-message buffer to shared memory (final 32-bit write * triggers HW to set possession bit to PF). */ + *submitted = true; dword = (u32 *)shm_buf; for (i = 0; i < SMC_APERTURE_DWORDS; i++) writel(*dword++, sc->base + i * SMC_BASIC_UNIT);
diff --git a/include/net/mana/hw_channel.h b/include/net/mana/hw_channel.h
index 16feb39616c1bead1a043b3fadc2e18a90651516..befa09674ce5614a955441e75e480a21aa8695fb 100644
--- a/include/net/mana/hw_channel.h
+++ b/include/net/mana/hw_channel.h@@ -199,6 +199,9 @@ struct hw_channel_context { u32 pf_dest_vrcq_id; u32 hwc_timeout; + /* PF may own the queue mappings; state lasts only for this context. */ + bool setup_active; + struct hwc_caller_ctx *caller_ctx; };
diff --git a/include/net/mana/shm_channel.h b/include/net/mana/shm_channel.h
index dbabcfb95daf3e87b39a657e3a5f23a1508d4f31..e96387d795259d52aeec7b3fe0981825d90a3822 100644
--- a/include/net/mana/shm_channel.h
+++ b/include/net/mana/shm_channel.h@@ -20,7 +20,7 @@ void mana_smc_init(struct shm_channel *sc, struct device *dev, int mana_smc_setup_hwc(struct shm_channel *sc, bool reset_vf, u64 eq_addr, u64 cq_addr, u64 rq_addr, u64 sq_addr, - u32 eq_msix_index); + u32 eq_msix_index, bool *submitted); int mana_smc_teardown_hwc(struct shm_channel *sc, bool reset_vf);
--
2.43.0