From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=209.127.231.28 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793262315; b=A9I80BGxB1rpcWOdMP3y9Vdrhd2Lhs/GOGGBsG3NVHkDwMqXlBwW6p65t4zYBlbyED7j u2jxNsP2/xZDyswsvzSsKAUdbUfz42cZV6PoIPBXrRVHQXPFArvclEI5BKhY1dOeHG7+H aN5Kkta2fVrVLNdiDtTp22IfYRo/S8uLooTcyDTwbtsBXaxZI0EUSSwou9wjd7kJl7Y4M tLUHt/D4f6HETXZOw6Tqt4BNScL7L/TADax99MuWgRNC3lDLEptYLYNeNAZhQvtp5LiNC gdPxNWiF5Wfayqn16N/Lf5xqXIvW94UvpEPPYk8ELbOe5H4I1PfyvJaTx/HSWdtIC1A== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793262315; h=DMARC-Filter:DKIM-Signature:X-Lms-Return-Path:To:Cc:From:Subject: X-Mailer:Content-Transfer-Encoding:Message-Id:Received:Date: Mime-Version:X-Original-From:Content-Type; bh=sDSw+quj48/Sv4K0BAesVEV8uBVWYkpg2NZQSvi+LvE=; b=T1P2uqJWAWId/LEdKH7XiC6p2WL9033pgKOfSPT3vMQ7+5fxxNvFCd6VbN3HdH3pDr7z NVJqyEvgjkrcUG8Mq2kRnT45SrRmU04q/dicanPPSv9UNSOh/aD2qdTzrK1NQrs0exUqN VqUB1UaBBlOTlLaSZSaMGcdeXxJn10qpMz2sr2jCZTGTMcRy4qSiWkVXbLXrY9V+Frth9 UucL+PfcnHKJhHGUhOaJeWbgqbT/2duif4Haz78t2L44ETBFo4cIu4OZCV5W1Td5Xh5n4 ILfZd9MJCYYUAh0+z6tijkkH1UedqNQFZpiI2wzJ/ZgqzxKTXxmWL6ORr0bUUbxGLOg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none header.from=lanxincomputing.com; spf=pass smtp.mailfrom=lanxincomputing.com; dkim=pass header.d=lanxincomputing-com.20200927.dkim.feishu.cn header.i=@lanxincomputing-com.20200927.dkim.feishu.cn header.a=rsa-sha256 header.s=s1 header.b=LziBzNF3; arc=none smtp.remote-ip=209.127.231.28 Received: from va-2-28.ptr.blmpb.com (va-2-28.ptr.blmpb.com [209.127.231.28]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 44B4A606A31C for ; Thu, 29 Oct 2026 08:25:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 44B4A606A31C Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lanxincomputing.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lanxincomputing.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lanxincomputing-com.20200927.dkim.feishu.cn header.i=@lanxincomputing-com.20200927.dkim.feishu.cn header.a=rsa-sha256 header.s=s1 header.b=LziBzNF3 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; s=s1; d=lanxincomputing-com.20200927.dkim.feishu.cn; t=1793262308; h=from:subject:mime-version:from:date:message-id:subject:to:cc: reply-to:content-type:mime-version:in-reply-to:message-id; bh=sDSw+quj48/Sv4K0BAesVEV8uBVWYkpg2NZQSvi+LvE=; b=LziBzNF3dWsH332s+G0OU0HiDC3iEztpv/epxzDd1DWfsksaoQ6ok+955/dgoMwXfRfjk2 BVM1RxDAVyAK/VsBLexqNmqKrIcdHTRiGNkgklU1WUaK8WZ9SkSctOvG1PADkCx9ITrZBH HTMe3nfcdFNPtkGNVj8EyEko7mRYdN15+orAYRXIos8MyHMocClMS13PAIhzbUwG7RcMIM l14Urll4UoYKv+fwsVianE9CicZ3PCYP8Xq1ia52Bz1w3qL5yI17AN3HrEU2xbmueX+zxE pKAZCmjLap0Fe8bx8Ch5/e8ZT7ZlrcksE4sCJs0c2cAwZh4Yyp7VRsShm4ZilA== X-Lms-Return-Path: To: Cc: , , , , , , , , , From: "BillXiang" Subject: [PATCH v2] riscv: KVM: Add hart-to-vCPU mapping for faster MSI injection X-Mailer: git-send-email 2.53.0 Content-Transfer-Encoding: 7bit Message-Id: <20261029082426.706302-1-xiangwencheng@lanxincomputing.com> Received: from lanxin-ThinkBook-16-G5-IRH ([123.120.5.129]) by smtp.feishu.cn with ESMTP; Thu, 29 Oct 2026 16:25:04 +0800 Date: Thu, 29 Oct 2026 16:24:26 +0800 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Mime-Version: 1.0 X-Original-From: BillXiang Content-Type: text/plain; charset=UTF-8 Replace linear searches over all vCPUs in MSI injection paths with a hart_index -> vCPU xarray lookup table. This avoids O(n) scans on every injected interrupt and improves performance when the number of vCPUs is large. Both kvm_riscv_aia_inject_msi_by_id() and kvm_riscv_aia_inject_msi() now use the table instead of iterating over the vCPU list. Signed-off-by: BillXiang Changes in v2: - Use xarray instead of normal array to handle incontiguous hart_index. - Link to v1: https://lore.kernel.org/kvm-riscv/20260730093614.983508-1-xiangwencheng@lanxincomputing.com/ --- arch/riscv/include/asm/kvm_aia.h | 3 ++ arch/riscv/kvm/aia_device.c | 50 +++++++++++++++++--------------- 2 files changed, 30 insertions(+), 23 deletions(-) diff --git a/arch/riscv/include/asm/kvm_aia.h b/arch/riscv/include/asm/kvm_aia.h index ab03f853e507..3b075f18e1d6 100644 --- a/arch/riscv/include/asm/kvm_aia.h +++ b/arch/riscv/include/asm/kvm_aia.h @@ -12,6 +12,7 @@ #include #include +#include #include struct kvm_aia { @@ -47,6 +48,8 @@ struct kvm_aia { /* Internal state of APLIC */ void *aplic_state; + + struct xarray hart_to_vcpu; }; struct kvm_vcpu_aia_csr { diff --git a/arch/riscv/kvm/aia_device.c b/arch/riscv/kvm/aia_device.c index efc7c0bcfba9..a415a8c10967 100644 --- a/arch/riscv/kvm/aia_device.c +++ b/arch/riscv/kvm/aia_device.c @@ -259,6 +259,8 @@ static int aia_init(struct kvm *kvm) if (ret) return ret; + xa_init(&aia->hart_to_vcpu); + /* Iterate over each VCPU */ kvm_for_each_vcpu(idx, vcpu, kvm) { vaia = &vcpu->arch.aia_context; @@ -280,6 +282,11 @@ static int aia_init(struct kvm *kvm) /* Update HART index of the IMSIC based on IMSIC base */ vaia->hart_index = aia_imsic_hart_index(aia, vaia->imsic_addr); + + ret = xa_insert(&aia->hart_to_vcpu, vaia->hart_index, vcpu, GFP_KERNEL); + if (ret) { + goto fail_cleanup_imsics; + } /* Initialize IMSIC for this VCPU */ ret = kvm_riscv_vcpu_aia_imsic_init(vcpu); @@ -299,6 +306,7 @@ static int aia_init(struct kvm *kvm) continue; kvm_riscv_vcpu_aia_imsic_cleanup(vcpu); } + xa_destroy(&aia->hart_to_vcpu); kvm_riscv_aia_aplic_cleanup(kvm); return ret; } @@ -557,30 +565,25 @@ void kvm_riscv_vcpu_aia_deinit(struct kvm_vcpu *vcpu) int kvm_riscv_aia_inject_msi_by_id(struct kvm *kvm, u32 hart_index, u32 guest_index, u32 iid) { - unsigned long idx; struct kvm_vcpu *vcpu; + struct kvm_aia *aia = &kvm->arch.aia; /* Proceed only if AIA was initialized successfully */ if (!kvm_riscv_aia_initialized(kvm)) return -EBUSY; - /* Inject MSI to matching VCPU */ - kvm_for_each_vcpu(idx, vcpu, kvm) { - if (vcpu->arch.aia_context.hart_index == hart_index) - return kvm_riscv_vcpu_aia_imsic_inject(vcpu, - guest_index, - 0, iid); - } - - return 0; + vcpu = xa_load(&aia->hart_to_vcpu, hart_index); + if (!vcpu) + return 0; + + return kvm_riscv_vcpu_aia_imsic_inject(vcpu, guest_index, 0, iid); } int kvm_riscv_aia_inject_msi(struct kvm *kvm, struct kvm_msi *msi) { gpa_t tppn, ippn; - unsigned long idx; struct kvm_vcpu *vcpu; - u32 g, toff, iid = msi->data; + u32 g, toff, iid = msi->data, hart_index; struct kvm_aia *aia = &kvm->arch.aia; gpa_t target = (((gpa_t)msi->address_hi) << 32) | msi->address_lo; @@ -595,18 +598,16 @@ int kvm_riscv_aia_inject_msi(struct kvm *kvm, struct kvm_msi *msi) g = tppn & (BIT(aia->nr_guest_bits) - 1); tppn &= ~((gpa_t)(BIT(aia->nr_guest_bits) - 1)); - /* Inject MSI to matching VCPU */ - kvm_for_each_vcpu(idx, vcpu, kvm) { - ippn = vcpu->arch.aia_context.imsic_addr >> - IMSIC_MMIO_PAGE_SHIFT; - if (ippn == tppn) { - toff = target & (IMSIC_MMIO_PAGE_SZ - 1); - return kvm_riscv_vcpu_aia_imsic_inject(vcpu, g, - toff, iid); - } - } + hart_index = aia_imsic_hart_index(aia, target); + vcpu = xa_load(&aia->hart_to_vcpu, hart_index); + if (!vcpu) + return 0; - return 0; + ippn = vcpu->arch.aia_context.imsic_addr >> IMSIC_MMIO_PAGE_SHIFT; + if (ippn != tppn) + return 0; + toff = target & (IMSIC_MMIO_PAGE_SZ - 1); + return kvm_riscv_vcpu_aia_imsic_inject(vcpu, g, toff, iid); } int kvm_riscv_aia_inject_irq(struct kvm *kvm, unsigned int irq, bool level) @@ -647,9 +648,12 @@ void kvm_riscv_aia_init_vm(struct kvm *kvm) void kvm_riscv_aia_destroy_vm(struct kvm *kvm) { + struct kvm_aia *aia = &kvm->arch.aia; /* Proceed only if AIA was initialized successfully */ if (!kvm_riscv_aia_initialized(kvm)) return; + + xa_destroy(&aia->hart_to_vcpu); /* Cleanup APLIC context */ kvm_riscv_aia_aplic_cleanup(kvm); -- 2.53.0