From patchwork Wed Jan 24 20:49:04 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oliver Upton X-Patchwork-Id: 13529660 Received: from out-178.mta1.migadu.com (out-178.mta1.migadu.com [95.215.58.178]) (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 AAC3A1350DA for ; Wed, 24 Jan 2024 20:49:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.178 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706129385; cv=none; b=CcnJMFss1Pm/ZsggoLpaFfL9NB9uViRDvwAi+bULepyHWcnfQGxTWaf+kC4fUfhtRt/C0h3A1rEzC6Kp9i52JgDR/Hkyaa5eavKzgrNx/6JplNC78j5ga7yYfbJPP1VwuHTWNwjsEjU6MU63dbB2QP74ztzmj3z+bjndOhy98n8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706129385; c=relaxed/simple; bh=zn+NEwCWV2J3fnlNAv5UMIsfb2daqDGOeyb3cOTr5Hs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CJG1nAxtOxMOfrkLH1/GQNlgHgJP8B64KZ51D0GIJjK/UsFU9jhpah7aBC+O3eWCJAQIs/NF0Epwg9IvCcajFyvE8PkwILn3FXRHGmEiwiqShwlDbcuZATbkTW0pM71LUu+BSdjL0jzpIP3U8z9Qy88An2bmuI8cLwiE5hwFhjw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=oOIhrA5D; arc=none smtp.client-ip=95.215.58.178 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="oOIhrA5D" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1706129380; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=JSRHFG0+mRsPGBx4WvzyykyzgB4/zirusbi7pLa/qNU=; b=oOIhrA5D3lJg4GSUFQDL3QLVro9vo0pypba9bifO/3h2NcrwEERhgaf/6BMGpVfhsyoAK1 LTDWMeu5jXahn7CDfs2JTb8E1TK3eoWSN+PggYvbylA1EAMAXbErepMD7O34yeg4Nwezip TViXME2XGctJrav32UkOpVt4lfq8wbk= From: Oliver Upton To: kvmarm@lists.linux.dev Cc: kvm@vger.kernel.org, Marc Zyngier , James Morse , Suzuki K Poulose , Zenghui Yu , Raghavendra Rao Ananta , Jing Zhang , Oliver Upton Subject: [PATCH 10/15] KVM: arm64: vgic: Don't acquire the lpi_list_lock in vgic_put_irq() Date: Wed, 24 Jan 2024 20:49:04 +0000 Message-ID: <20240124204909.105952-11-oliver.upton@linux.dev> In-Reply-To: <20240124204909.105952-1-oliver.upton@linux.dev> References: <20240124204909.105952-1-oliver.upton@linux.dev> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT The LPI xarray's xa_lock is sufficient for synchronizing writers when freeing a given LPI. Furthermore, readers can only take a new reference on an IRQ if it was already nonzero. Stop taking the lpi_list_lock unnecessarily and get rid of __vgic_put_lpi_locked(). Signed-off-by: Oliver Upton --- arch/arm64/kvm/vgic/vgic-its.c | 4 ++-- arch/arm64/kvm/vgic/vgic.c | 21 ++++----------------- arch/arm64/kvm/vgic/vgic.h | 1 - 3 files changed, 6 insertions(+), 20 deletions(-) diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c index 7219f4a0a93d..8c026a530018 100644 --- a/arch/arm64/kvm/vgic/vgic-its.c +++ b/arch/arm64/kvm/vgic/vgic-its.c @@ -645,7 +645,7 @@ static void vgic_its_cache_translation(struct kvm *kvm, struct vgic_its *its, * was in the cache, and increment it on the new interrupt. */ if (cte->irq) - __vgic_put_lpi_locked(kvm, cte->irq); + vgic_put_irq(kvm, cte->irq); /* * The irq refcount is guaranteed to be nonzero while holding the @@ -682,7 +682,7 @@ void vgic_its_invalidate_cache(struct kvm *kvm) if (!cte->irq) break; - __vgic_put_lpi_locked(kvm, cte->irq); + vgic_put_irq(kvm, cte->irq); cte->irq = NULL; } diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c index 7e0d84906a12..6b8f440ca0fd 100644 --- a/arch/arm64/kvm/vgic/vgic.c +++ b/arch/arm64/kvm/vgic/vgic.c @@ -110,13 +110,13 @@ static void vgic_irq_release(struct kref *ref) { } -/* - * Drop the refcount on the LPI. Must be called with lpi_list_lock held. - */ -void __vgic_put_lpi_locked(struct kvm *kvm, struct vgic_irq *irq) +void vgic_put_irq(struct kvm *kvm, struct vgic_irq *irq) { struct vgic_dist *dist = &kvm->arch.vgic; + if (irq->intid < VGIC_MIN_LPI) + return; + if (!kref_put(&irq->refcount, vgic_irq_release)) return; @@ -126,19 +126,6 @@ void __vgic_put_lpi_locked(struct kvm *kvm, struct vgic_irq *irq) kfree_rcu(irq, rcu); } -void vgic_put_irq(struct kvm *kvm, struct vgic_irq *irq) -{ - struct vgic_dist *dist = &kvm->arch.vgic; - unsigned long flags; - - if (irq->intid < VGIC_MIN_LPI) - return; - - raw_spin_lock_irqsave(&dist->lpi_list_lock, flags); - __vgic_put_lpi_locked(kvm, irq); - raw_spin_unlock_irqrestore(&dist->lpi_list_lock, flags); -} - void vgic_flush_pending_lpis(struct kvm_vcpu *vcpu) { struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h index 20886f57416a..b0a2754eae93 100644 --- a/arch/arm64/kvm/vgic/vgic.h +++ b/arch/arm64/kvm/vgic/vgic.h @@ -180,7 +180,6 @@ vgic_get_mmio_region(struct kvm_vcpu *vcpu, struct vgic_io_device *iodev, gpa_t addr, int len); struct vgic_irq *vgic_get_irq(struct kvm *kvm, struct kvm_vcpu *vcpu, u32 intid); -void __vgic_put_lpi_locked(struct kvm *kvm, struct vgic_irq *irq); void vgic_put_irq(struct kvm *kvm, struct vgic_irq *irq); bool vgic_get_phys_line_level(struct vgic_irq *irq); void vgic_irq_set_phys_pending(struct vgic_irq *irq, bool pending);