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[46.102.197.194]) by smtp.gmail.com with ESMTPSA id f22-20020aa7d856000000b0056b818544a9sm324882eds.90.2024.03.18.04.04.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Mar 2024 04:04:52 -0700 (PDT) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 5944d93b-e517-11ee-afdd-a90da7624cb6 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=citrix.com; s=google; t=1710759893; x=1711364693; darn=lists.xenproject.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=AWCsjWzVUd6sUyetSs9CWtqz4kTMclSOuQ/QVUP2fXQ=; b=W+TgMkZ8NmZt3fusV1/9lhb2JQoM9sEJIqY7GPGX5uYZ2zIPu7xetXvzH4c6oiGzWn ifx+sDZIjbyygSS5LsTPO9soshIE+N0O70HhWFLPZf+grseh62BoNh3vqoe/eiwDwplg qnWLY1eH6QwYZXizVSEW/0ap8h3WDhPFKhaiI= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1710759893; x=1711364693; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=AWCsjWzVUd6sUyetSs9CWtqz4kTMclSOuQ/QVUP2fXQ=; b=KPPNR6C5j6gm7Echvnuj4cdjFLMfQx2M4XE8D/9Hz6xo9Wk6exmRTgKy3nM55A4aDj 2AOWLH6eUzujhxK1y7r+9fqdUI7KO43uUvXRPy+zDUjKGOsQTmsOWeAyDSg59mvcgZm+ TLEMBtcrF4NfKigrO9DtHHUId4EclakDVPAgYyy1NEHLl+8Cd0y6isMWeV0dQnLszUlB ZUFtvP17hCRH4kdtzIb5BS+JqwZ6uvTnibaLegCXrWB1Rsfrn3pfk47p/fEpwBjKEQxS iPBTY4JglHpLLZdwu9BlH1eb99IVCk6O7GhiTL1g3mt2HUPQcyePfj8cj91GDo5NoV9X j/GQ== X-Gm-Message-State: AOJu0Yw/YHP9B+U19ijMGXcu2naaISeJmHx3VqCTa6F/MT8AIu4R7vgp QXOJUUEao4AjLHJfmT+9hxwbtNRXAb24pGxKI+mr22gRQ7nDbqi/dQoWvFtqLhE3x6D1Sl0Y7mR 0 X-Google-Smtp-Source: AGHT+IHYOf7G6CCC/WpXt7wf04NgE600a46ujZCW14kFOdpdY1FfSSehIjbad2g+Xr0NJDLNscsEVQ== X-Received: by 2002:a05:6402:3784:b0:566:9fef:1ee9 with SMTP id et4-20020a056402378400b005669fef1ee9mr7994038edb.22.1710759893206; Mon, 18 Mar 2024 04:04:53 -0700 (PDT) From: Andrew Cooper To: Xen-devel Cc: Andrew Cooper , Jan Beulich , =?UTF-8?q?Roger=20Pau=20Monn=C3=A9?= , Wei Liu , Stefano Stabellini , Julien Grall , Volodymyr Babchuk , Bertrand Marquis , Michal Orzel , Oleksii Kurochko , Shawn Anastasio , Konrad Rzeszutek Wilk , Ross Lagerwall Subject: [PATCH 3/4] xen/virtual-region: Link the list build time Date: Mon, 18 Mar 2024 11:04:41 +0000 Message-Id: <20240318110442.3653997-4-andrew.cooper3@citrix.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20240318110442.3653997-1-andrew.cooper3@citrix.com> References: <20240318110442.3653997-1-andrew.cooper3@citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Given 3 statically initialised objects, its easy to link the list at build time. There's no need to do it during runtime at boot (and with IRQs-off, even). As a consequence, register_virtual_region() can now move inside ifdef CONFIG_LIVEPATCH like unregister_virtual_region(). Signed-off-by: Andrew Cooper --- CC: Jan Beulich CC: Roger Pau Monné CC: Wei Liu CC: Stefano Stabellini CC: Julien Grall CC: Volodymyr Babchuk CC: Bertrand Marquis CC: Michal Orzel CC: Oleksii Kurochko CC: Shawn Anastasio CC: Konrad Rzeszutek Wilk CC: Ross Lagerwall --- xen/common/virtual_region.c | 45 ++++++++++++++++++++++++------------- 1 file changed, 30 insertions(+), 15 deletions(-) diff --git a/xen/common/virtual_region.c b/xen/common/virtual_region.c index eb9645daa99d..ad39bb74e15c 100644 --- a/xen/common/virtual_region.c +++ b/xen/common/virtual_region.c @@ -15,8 +15,19 @@ extern const struct bug_frame __start_bug_frames_2[], __stop_bug_frames_2[], __start_bug_frames_3[], __stop_bug_frames_3[]; +/* + * For the built-in regions, the double linked list can be constructed at + * build time. Forward-declare the elements. + */ +static struct list_head virtual_region_list; +static struct virtual_region core, core_init; + static struct virtual_region core = { - .list = LIST_HEAD_INIT(core.list), + .list = { + .next = &core_init.list, + .prev = &virtual_region_list, + }, + .text_start = _stext, .text_end = _etext, .rodata_start = _srodata, @@ -32,7 +43,11 @@ static struct virtual_region core = { /* Becomes irrelevant when __init sections are cleared. */ static struct virtual_region core_init __initdata = { - .list = LIST_HEAD_INIT(core_init.list), + .list = { + .next = &virtual_region_list, + .prev = &core.list, + }, + .text_start = _sinittext, .text_end = _einittext, @@ -50,7 +65,10 @@ static struct virtual_region core_init __initdata = { * * All readers of virtual_region_list MUST use list_for_each_entry_rcu. */ -static LIST_HEAD(virtual_region_list); +static struct list_head virtual_region_list = { + .next = &core.list, + .prev = &core_init.list, +}; static DEFINE_SPINLOCK(virtual_region_lock); static DEFINE_RCU_READ_LOCK(rcu_virtual_region_lock); @@ -73,15 +91,6 @@ const struct virtual_region *find_text_region(unsigned long addr) return region; } -void register_virtual_region(struct virtual_region *r) -{ - unsigned long flags; - - spin_lock_irqsave(&virtual_region_lock, flags); - list_add_tail_rcu(&r->list, &virtual_region_list); - spin_unlock_irqrestore(&virtual_region_lock, flags); -} - /* * Suggest inline so when !CONFIG_LIVEPATCH the function is not left * unreachable after init code is removed. @@ -96,6 +105,15 @@ static void inline remove_virtual_region(struct virtual_region *r) } #ifdef CONFIG_LIVEPATCH +void register_virtual_region(struct virtual_region *r) +{ + unsigned long flags; + + spin_lock_irqsave(&virtual_region_lock, flags); + list_add_tail_rcu(&r->list, &virtual_region_list); + spin_unlock_irqrestore(&virtual_region_lock, flags); +} + void unregister_virtual_region(struct virtual_region *r) { remove_virtual_region(r); @@ -155,9 +173,6 @@ void __init setup_virtual_regions(const struct exception_table_entry *start, { core_init.ex = core.ex = start; core_init.ex_end = core.ex_end = end; - - register_virtual_region(&core_init); - register_virtual_region(&core); } /* -- 2.30.2