From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- io_uring/notif.h | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 io_uring/notif.h (limited to 'io_uring/notif.h') diff --git a/io_uring/notif.h b/io_uring/notif.h new file mode 100644 index 000000000..f3589cfef --- /dev/null +++ b/io_uring/notif.h @@ -0,0 +1,57 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include +#include + +#include "rsrc.h" + +#define IO_NOTIF_UBUF_FLAGS (SKBFL_ZEROCOPY_FRAG | SKBFL_DONT_ORPHAN) +#define IO_NOTIF_SPLICE_BATCH 32 + +struct io_notif_data { + struct file *file; + struct ubuf_info uarg; + + struct io_notif_data *next; + struct io_notif_data *head; + + unsigned account_pages; + bool zc_report; + bool zc_used; + bool zc_copied; +}; + +struct io_kiocb *io_alloc_notif(struct io_ring_ctx *ctx); +void io_tx_ubuf_complete(struct sk_buff *skb, struct ubuf_info *uarg, + bool success); + +static inline struct io_notif_data *io_notif_to_data(struct io_kiocb *notif) +{ + return io_kiocb_to_cmd(notif, struct io_notif_data); +} + +static inline void io_notif_flush(struct io_kiocb *notif) + __must_hold(¬if->ctx->uring_lock) +{ + struct io_notif_data *nd = io_notif_to_data(notif); + + io_tx_ubuf_complete(NULL, &nd->uarg, true); +} + +static inline int io_notif_account_mem(struct io_kiocb *notif, unsigned len) +{ + struct io_ring_ctx *ctx = notif->ctx; + struct io_notif_data *nd = io_notif_to_data(notif); + unsigned nr_pages = (len >> PAGE_SHIFT) + 2; + int ret; + + if (ctx->user) { + ret = __io_account_mem(ctx->user, nr_pages); + if (ret) + return ret; + nd->account_pages += nr_pages; + } + return 0; +} -- cgit v1.3.1