From nobody Sun Feb 8 12:43:02 2026 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B1D00219F9; Wed, 10 Jul 2024 16:42:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720629772; cv=none; b=tZ5ZYsVrCr4Vn1ZOS4ruqQ0GKkthx8EHIyWbY8u7EyxG5uJdiVMKVqaRK46yVeGsF70aMkIShGZmwDCcFrDfY4dU/eBbJBtAlXYSalodVLmFOiIrhr9SEqohKYcK1MgBZQuAA8riAYGt6fsYezlo5p1sUhNjyJmJyejz4Q5F/Rs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720629772; c=relaxed/simple; bh=2taw60HFW7FPK28muL0TE7Qe830Anr/TT1eokb3iprk=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=OGkpiQ/YKrwXT83gaodlCbOji+bomq99/Qh6XiTW+jZOuTQIH7JLT+SzpR9gVCs7dUMUZ7Rsyk1bjBx3Lrlx3yA+75Wa2pbAtedGabAH6WWpMYrF7NUW9ZKJFHzVwR0rzbriM4z6mRHi+UTfB2ye3Wx8oFa9LtaPx0Lg9fff6LQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=meNXwhjR; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=ze5ice4A; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="meNXwhjR"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="ze5ice4A" Date: Wed, 10 Jul 2024 16:42:48 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1720629769; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=VTQLKsdF+AFLikkI8QkPGut6kAdkNKwmeTS8CctG8BY=; b=meNXwhjRH6D+BIwf0YG3guN3Vefisgst5ubC6338155QlFQxNuL80BmL+WM57Hn8/Zvx0U 0Yz3s7P1B5PV6l7liHCfkEllvdlf0z2q0NEgLJiztkJMh2zDIfqyN8R47srjigQORq7riO rdiqcudPTXZJHKlrnfttlYbPrFJHWZzmJFSOQ+QXTABn3K4WR0Ie88KhRwilTbWtwni0QR BBnpf43VHjcIpVdXGh5ORa2vrbWLNMXhuMu2ywB1Ee/SeB9ZM5aIwBOG1OoY6KiWvC8IQn A2Zj3CbfaDwWLlBZnqOC57laynI7hNxln3vUaZRY3GPTuVD/MhFwv89NkUdnNQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1720629769; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=VTQLKsdF+AFLikkI8QkPGut6kAdkNKwmeTS8CctG8BY=; b=ze5ice4AKkzK3gOKoiGiypNjqvU2JNDimaYuY26CPnBkjLiTO7S37nRmYPjc5D7E16GEe2 q5QdgvKGm/IH/oAg== From: "tip-bot2 for Marc Zyngier" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: irq/core] irqchip/gic-v4: Substitute vmovp_lock for a per-VM lock Cc: Marc Zyngier , Thomas Gleixner , Nianyao Tang , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20240705093155.871070-3-maz@kernel.org> References: <20240705093155.871070-3-maz@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <172062976875.2215.17731870703902999167.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the irq/core branch of tip: Commit-ID: 7ae6f82a97f6f1dc32414e09e15375721c691b3d Gitweb: https://git.kernel.org/tip/7ae6f82a97f6f1dc32414e09e15375721= c691b3d Author: Marc Zyngier AuthorDate: Fri, 05 Jul 2024 10:31:54 +01:00 Committer: Thomas Gleixner CommitterDate: Wed, 10 Jul 2024 18:40:09 +02:00 irqchip/gic-v4: Substitute vmovp_lock for a per-VM lock vmovp_lock is abused in a number of cases to serialise updates to vlpi_count[] and deal with map/unmap of a VM to ITSs. Instead, provide a per-VM lock and revisit the use of vlpi_count[] so that it is always wrapped in this per-VM vmapp_lock. This reduces the potential contention on a concurrent VMOVP command, and paves the way for subsequent VPE locking that holding vmovp_lock actively prevents due to the lock ordering. Signed-off-by: Marc Zyngier Signed-off-by: Thomas Gleixner Tested-by: Nianyao Tang Link: https://lore.kernel.org/r/20240705093155.871070-3-maz@kernel.org --- drivers/irqchip/irq-gic-v3-its.c | 27 ++++++++++++--------------- include/linux/irqchip/arm-gic-v4.h | 8 ++++++++ 2 files changed, 20 insertions(+), 15 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-= its.c index 8d31e4a..c85826a 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -1318,7 +1318,6 @@ static void its_send_vmovp(struct its_vpe *vpe) { struct its_cmd_desc desc =3D {}; struct its_node *its; - unsigned long flags; int col_id =3D vpe->col_idx; =20 desc.its_vmovp_cmd.vpe =3D vpe; @@ -1331,6 +1330,12 @@ static void its_send_vmovp(struct its_vpe *vpe) } =20 /* + * Protect against concurrent updates of the mapping state on + * individual VMs. + */ + guard(raw_spinlock_irqsave)(&vpe->its_vm->vmapp_lock); + + /* * Yet another marvel of the architecture. If using the * its_list "feature", we need to make sure that all ITSs * receive all VMOVP commands in the same order. The only way @@ -1338,8 +1343,7 @@ static void its_send_vmovp(struct its_vpe *vpe) * * Wall <-- Head. */ - raw_spin_lock_irqsave(&vmovp_lock, flags); - + guard(raw_spinlock)(&vmovp_lock); desc.its_vmovp_cmd.seq_num =3D vmovp_seq_num++; desc.its_vmovp_cmd.its_list =3D get_its_list(vpe->its_vm); =20 @@ -1354,8 +1358,6 @@ static void its_send_vmovp(struct its_vpe *vpe) desc.its_vmovp_cmd.col =3D &its->collections[col_id]; its_send_single_vcommand(its, its_build_vmovp_cmd, &desc); } - - raw_spin_unlock_irqrestore(&vmovp_lock, flags); } =20 static void its_send_vinvall(struct its_node *its, struct its_vpe *vpe) @@ -1792,12 +1794,10 @@ static bool gic_requires_eager_mapping(void) =20 static void its_map_vm(struct its_node *its, struct its_vm *vm) { - unsigned long flags; - if (gic_requires_eager_mapping()) return; =20 - raw_spin_lock_irqsave(&vmovp_lock, flags); + guard(raw_spinlock_irqsave)(&vm->vmapp_lock); =20 /* * If the VM wasn't mapped yet, iterate over the vpes and get @@ -1815,19 +1815,15 @@ static void its_map_vm(struct its_node *its, struct= its_vm *vm) its_send_vinvall(its, vpe); } } - - raw_spin_unlock_irqrestore(&vmovp_lock, flags); } =20 static void its_unmap_vm(struct its_node *its, struct its_vm *vm) { - unsigned long flags; - /* Not using the ITS list? Everything is always mapped. */ if (gic_requires_eager_mapping()) return; =20 - raw_spin_lock_irqsave(&vmovp_lock, flags); + guard(raw_spinlock_irqsave)(&vm->vmapp_lock); =20 if (!--vm->vlpi_count[its->list_nr]) { int i; @@ -1835,8 +1831,6 @@ static void its_unmap_vm(struct its_node *its, struct= its_vm *vm) for (i =3D 0; i < vm->nr_vpes; i++) its_send_vmapp(its, vm->vpes[i], false); } - - raw_spin_unlock_irqrestore(&vmovp_lock, flags); } =20 static int its_vlpi_map(struct irq_data *d, struct its_cmd_info *info) @@ -3944,6 +3938,8 @@ static void its_vpe_invall(struct its_vpe *vpe) { struct its_node *its; =20 + guard(raw_spinlock_irqsave)(&vpe->its_vm->vmapp_lock); + list_for_each_entry(its, &its_nodes, entry) { if (!is_v4(its)) continue; @@ -4549,6 +4545,7 @@ static int its_vpe_irq_domain_alloc(struct irq_domain= *domain, unsigned int virq vm->db_lpi_base =3D base; vm->nr_db_lpis =3D nr_ids; vm->vprop_page =3D vprop_page; + raw_spin_lock_init(&vm->vmapp_lock); =20 if (gic_rdists->has_rvpeid) irqchip =3D &its_vpe_4_1_irq_chip; diff --git a/include/linux/irqchip/arm-gic-v4.h b/include/linux/irqchip/arm= -gic-v4.h index 2c63375..ecabed6 100644 --- a/include/linux/irqchip/arm-gic-v4.h +++ b/include/linux/irqchip/arm-gic-v4.h @@ -25,6 +25,14 @@ struct its_vm { irq_hw_number_t db_lpi_base; unsigned long *db_bitmap; int nr_db_lpis; + /* + * Ensures mutual exclusion between updates to vlpi_count[] + * and map/unmap when using the ITSList mechanism. + * + * The lock order for any sequence involving the ITSList is + * vmapp_lock -> vpe_lock ->vmovp_lock. + */ + raw_spinlock_t vmapp_lock; u32 vlpi_count[GICv4_ITS_LIST_MAX]; };