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Sashiko AI review found 2 potential issues to consider: - [High] net/gve: sleep-in-atomic GFP_KERNEL alloc in NAPI poll during gve_turnup() - [Medium] net/gve: gve_rx_alloc_buffer() uses GFP_ATOMIC on live config pre-fill -- commit 1b07e24554dc827c263c1efbdbd4b2e0d6ee11bf Author: Luigi Rizzo net/gve: Use GFP_KERNEL when pre-filling RX rings This commit uses GFP_KERNEL instead of GFP_ATOMIC when allocating RX ring buffers in gve_alloc_from_page_pool() and gve_rx_alloc_buffer() while gve_get_napi_enabled() is false. > diff --git a/drivers/net/ethernet/google/gve/gve_buffer_mgmt_dqo.c b/driv= ers/net/ethernet/google/gve/gve_buffer_mgmt_dqo.c > index 6880d1531ba5e..3b13aa4999ae5 100644 > --- a/drivers/net/ethernet/google/gve/gve_buffer_mgmt_dqo.c > +++ b/drivers/net/ethernet/google/gve/gve_buffer_mgmt_dqo.c > @@ -223,13 +223,18 @@ void gve_free_to_page_pool(struct gve_rx_ring *rx, > static int gve_alloc_from_page_pool(struct gve_rx_ring *rx, > struct gve_rx_buf_state_dqo *buf_state) > { > + /* > + * Use GFP_KERNEL when pre-filling RX rings in process context (e.g. > + * gve_open) so PISA metadata init and CoCo page decryption can sleep. > + */ > + gfp_t gfp =3D gve_get_napi_enabled(rx->gve) ? GFP_ATOMIC : GFP_KERNEL; > netmem_ref netmem; > =20 > buf_state->page_info.buf_size =3D rx->packet_buffer_truesize; > netmem =3D page_pool_alloc_netmem(rx->dqo.page_pool, > &buf_state->page_info.page_offset, > &buf_state->page_info.buf_size, > - GFP_ATOMIC); > + gfp); [Severity: High] Can gve_alloc_from_page_pool() (and gve_rx_alloc_buffer() below) be called from NAPI poll with GFP_KERNEL during gve_turnup()? In gve_turnup(), each RX queue's NAPI is enabled, its IRQ doorbell is unmasked, and napi_schedule() is called inside the per-queue loop before GVE_PRIV_FLAGS_NAPI_ENABLED is set at the end of the function: drivers/net/ethernet/google/gve/gve_main.c:gve_turnup() { ... for (i =3D 0; i < priv->rx_cfg.num_queues; i++) { ... napi_enable_locked(&block->napi); ... mb(); napi_schedule(&block->napi); } ... gve_set_napi_enabled(priv); } CPU0 CPU1 () gve_turnup() napi_enable_locked(&block->napi) napi_schedule(&block->napi) gve_napi_poll_dqo() gve_rx_poll_dqo() ... gve_alloc_from_page_pool() gve_get_napi_enabled() -> false page_pool_alloc_netmem(..., GFP_K= ERNEL) <-- sleep in atomic context gve_set_napi_enabled(priv) If NAPI runs on another CPU or on softirq exit before gve_turnup() finishes the loop and calls gve_set_napi_enabled(priv), refilling buffers from softirq context will use GFP_KERNEL and sleep in atomic context. > diff --git a/drivers/net/ethernet/google/gve/gve_rx.c b/drivers/net/ether= net/google/gve/gve_rx.c > index 81ea800e66e94..89f287b678bf0 100644 > --- a/drivers/net/ethernet/google/gve/gve_rx.c > +++ b/drivers/net/ethernet/google/gve/gve_rx.c > @@ -161,12 +161,16 @@ static int gve_rx_alloc_buffer(struct gve_priv *pri= v, struct device *dev, > union gve_rx_data_slot *data_slot, > struct gve_rx_ring *rx) > { > + /* > + * Use GFP_KERNEL when pre-filling RX rings in process context (e.g. > + * gve_open) so PISA metadata init and CoCo page decryption can sleep. > + */ > + gfp_t gfp =3D gve_get_napi_enabled(priv) ? GFP_ATOMIC : GFP_KERNEL; > struct page *page; > dma_addr_t dma; > int err; > =20 > - err =3D gve_alloc_page(priv, dev, &page, &dma, DMA_FROM_DEVICE, > - GFP_ATOMIC); > + err =3D gve_alloc_page(priv, dev, &page, &dma, DMA_FROM_DEVICE, gfp); [Severity: Medium] Does gve_rx_alloc_buffer() still select GFP_ATOMIC when pre-filling GQI RX rings on a running interface? When reconfiguring queues or ring sizes on a live device, gve_adjust_config() calls gve_queues_mem_alloc() -> gve_rx_alloc_rings_gqi() -> gve_rx_alloc_ring_gqi() -> gve_rx_prefill_pages() before calling gve_close() to turn down the device and clear GVE_PRIV_FLAGS_NAPI_ENABLED (and similarly in gve_rx_queue_mem_alloc()). Because gve_get_napi_enabled() is still true during this process-context pre-fill, gve_rx_alloc_buffer() falls back to GFP_ATOMIC and can still exhaust atomic reserves or fail allocation. Passing a gfp_t parameter explicitly from the pre-fill vs NAPI refill callers would avoid depending on GVE_PRIV_FLAGS_NAPI_ENABLED for both issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261109182533.3594= 984-1-lrizzo@google.com?part=3D21