From patchwork Fri Feb 16 18:41:43 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oliver Upton X-Patchwork-Id: 13560456 Received: from out-185.mta0.migadu.com (out-185.mta0.migadu.com [91.218.175.185]) (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 3492C1353E9 for ; Fri, 16 Feb 2024 18:42:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.185 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708108930; cv=none; b=KRSBztxNefebsXUicW9dBBV5GoEiR+AQF4lppLLg04dhXMha7gtUOfGsXyBJi2Q6Cfw9v0ZY+kpm10kGuLzxwA8u1zLfSt8NB20EBVvJ1D16SZ3Q9QP+RsnjGuPNTBCVeMUghm2orw8Q6tl8Pnn9RjZr2fcGceRxgitXrxHAZ6o= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708108930; c=relaxed/simple; bh=QxChEtUBGhZVQmcitgUSn661JjnUAOsMvF/MSmXznAI=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=FgyVlaUNHzUTC6q6a+7IBblXfvwV6W0mDyGfZifHCkLADPKHG2MYNvR/GG1REkOoF6dIU0ieyDtA88Dvkth+yH3B1LtXVIpt5TeWl8BJ7zYER88sRoT8VDgyjS1ns/1s/ehwT3KkfnDkyFV5eKFxWUcHZeH0I2DHE0qIxFsH7I0= 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=bShf0MgS; arc=none smtp.client-ip=91.218.175.185 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="bShf0MgS" 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=1708108925; 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; bh=dy9uGuDewCRmPkjUp3zVJbGMujkAY9qYVaz8IFv8Bxg=; b=bShf0MgSqhuWrIL+S1qXovTFCfPLEhtIccDFfHBNEfhfP5OtCcTJr+ei8OFQ2UFIe50OQW 32WQuJTz/ZgYEbAy6Hf3Hhxp2YrhqtIWgNgStHoKgVgQ1DRYMx8JH7oKcQRUFSkFrv436F WqvzO/QKMfXA7oylFbU9dCdjvrsqasU= From: Oliver Upton To: kvmarm@lists.linux.dev Cc: kvm@vger.kernel.org, Marc Zyngier , James Morse , Suzuki K Poulose , Zenghui Yu , linux-kernel@vger.kernel.org, Oliver Upton Subject: [PATCH v3 00/10] KVM: arm64: Avoid serializing LPI get() / put() Date: Fri, 16 Feb 2024 18:41:43 +0000 Message-ID: <20240216184153.2714504-1-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 As discussed, here is a slimmed-down series for addressing lock serialization in the vgic_get_irq() / vgic_put_irq() path for LPIs. The bulk of it is using an xarray to represent LPIs and leveraging RCU to avoid serializing readers of the LPI configuration state. There's a lot of potential for clean-up, but this is intentionally deferred until after we fix up the LPI translation cache. v2: https://lore.kernel.org/kvmarm/20240213093250.3960069-1-oliver.upton@linux.dev/ v2 -> v3: - Fix the stupid lock imbalance once and for all (Dan) - Drop the tracepoints / stats I used for debugging my own crap (Marc) Oliver Upton (10): KVM: arm64: vgic: Store LPIs in an xarray KVM: arm64: vgic: Use xarray to find LPI in vgic_get_lpi() KVM: arm64: vgic-v3: Iterate the xarray to find pending LPIs KVM: arm64: vgic-its: Walk the LPI xarray in vgic_copy_lpi_list() KVM: arm64: vgic: Get rid of the LPI linked-list KVM: arm64: vgic: Use atomics to count LPIs KVM: arm64: vgic: Free LPI vgic_irq structs in an RCU-safe manner KVM: arm64: vgic: Rely on RCU protection in vgic_get_lpi() KVM: arm64: vgic: Ensure the irq refcount is nonzero when taking a ref KVM: arm64: vgic: Don't acquire the lpi_list_lock in vgic_put_irq() arch/arm64/kvm/vgic/vgic-debug.c | 2 +- arch/arm64/kvm/vgic/vgic-init.c | 4 ++- arch/arm64/kvm/vgic/vgic-its.c | 53 +++++++++++++++++++----------- arch/arm64/kvm/vgic/vgic-v3.c | 3 +- arch/arm64/kvm/vgic/vgic.c | 56 ++++++++++---------------------- arch/arm64/kvm/vgic/vgic.h | 15 ++++++--- include/kvm/arm_vgic.h | 9 ++--- 7 files changed, 73 insertions(+), 69 deletions(-) base-commit: 6613476e225e090cc9aad49be7fa504e290dd33d