From patchwork Sat Mar 15 02:56:15 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 14017697 Received: from mail-pl1-f201.google.com (mail-pl1-f201.google.com [209.85.214.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8F7332E3381 for ; Sat, 15 Mar 2025 02:56:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742007380; cv=none; b=TNIfGBcEPNSkaflQa64nQOvvNOBSX3tOGNIUYaEBykdNjlO5bfyNALeRDAyiX2pdmogb2FuhVfn7gqOFp80DTS3/INdzQor59L5c/YVY4OAaqG+m2vCtpD7oag5ajAHO2gass8D6GbnQABidVt+wb8zAClKBa0gvgVmgK1HG5Hg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742007380; c=relaxed/simple; bh=+ZZX7qNnfCLLvOhiQ9gHJeVtbxbDuqzZFOIXg6bI5cw=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=kmuoexqFaZK1G7xf6HOzqtMcRiUCoYDOl1NVRM0/y5gSScSaCiBtMNNNTvQJucdeyIqVvJ4I8jsDEi8gymO8IT3Nay1oEAG4IMPP5+K1piWs7nI9HbofQqRgPSk5VtjeXKpyUDi19GmwnGUlhsCy9krTLO/B0/FlO6d0a7DvKQo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=SIHyem9I; arc=none smtp.client-ip=209.85.214.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="SIHyem9I" Received: by mail-pl1-f201.google.com with SMTP id d9443c01a7336-225505d1ca5so45119085ad.2 for ; Fri, 14 Mar 2025 19:56:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1742007378; x=1742612178; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:reply-to:from:to:cc :subject:date:message-id:reply-to; bh=Z62zBIuHLmtXad0Z5pdn1xvMGSFxR5nD2NTwFzgeqeI=; b=SIHyem9I/tewT0YmfB9bPyORS1krQQ8ZcpfxpGb763VrGWl/dSGhAEZLgtirelPzeN xfw14efMLtGu0fRrniezitc7cGjO86z0KAjHNo2775Xib4BRkf0GrRLUMkSnhBOPp8iJ oJ60m+BhGwjMKe3NTPuoyTos6JvsweZeZ2l742CYFmjns97ljT80BbHVNMY7Ud1ptdeE De09cOa5QSEO3UgFSKuQQ+dqJwBzhH/YWhkJde8SwRMgZfsswo5JJ3JLN1EOl1Nd7ivG fYbCeJlJ0uziDbZnN/f7rk8eU7vLO8sVVGzhz3GVM5Jq9EZGfyNnl1iOQW44wKAcJ7hx KiSA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1742007378; x=1742612178; h=cc:to:from:subject:message-id:mime-version:date:reply-to :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Z62zBIuHLmtXad0Z5pdn1xvMGSFxR5nD2NTwFzgeqeI=; b=ipSZpUE5HNxGJheCFoUrvzrPM4sJXz/gJB7NHpEIN42/ZBGZiLEh59eWOpgmE68Smb p/8qdH1AeOv/APn9lBui0KxRrLLN6Z3KFAez7o5PI2Mh6UndYTDcl2Yoje1mIsjsPUrU UE2eUcfAaWJP/SR+GQVV8OMjKZEuiXFyIQcu02X9wYIDwyK/l7wYNzki4xidNMcxF8OY 1dDcn/yb25rUrepu0NRzxZmR2EhyzqABsjunH+9cFuxX8Zyo90n5syCvymd/Q3upBUrm +ya0fRzF/FLYO9Y5vQAEG0rVG+nHx2dDFp2Asj5CBd0wYu5keg8UkXIed7GvWmZl/AMT NStQ== X-Gm-Message-State: AOJu0Yy9Pi9wfeN76B1UQojok/mwCMvSCt0TM5ZRiUimhkRs0tuar0U3 9N+L4/UjZ+LmkHuDmFluWXWLp7fWvjrptqqIZAliifqf/+BaeeDGyV3JQ8Twmc04pnf89p+yiD7 ncA== X-Google-Smtp-Source: AGHT+IGGn3fc2zoHlksKBIechNzdvEm7Uhf7t5xNZPQBPITxQ4BguguvN/F5A1Ol5OtNBXp+F53DF6fEjkA= X-Received: from pfu10.prod.google.com ([2002:a05:6a00:a38a:b0:736:59f0:d272]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:1950:b0:736:53bc:f1ab with SMTP id d2e1a72fcca58-737223b908dmr5473148b3a.12.1742007377854; Fri, 14 Mar 2025 19:56:17 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 14 Mar 2025 19:56:15 -0700 Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.49.0.rc1.451.g8f38331e32-goog Message-ID: <20250315025615.2367411-1-seanjc@google.com> Subject: [PATCH] KVM: x86: Add a module param to control and enumerate device posted IRQs From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Add a module param to allow disabling device posted interrupts without having to sacrifice all of APICv/AVIC, and to also effectively enumerate to userspace whether or not KVM may be utilizing device posted IRQs. Disabling device posted interrupts is very desirable for testing, and can even be desirable for production environments, e.g. if the host kernel wants to interpose on device interrupts. Signed-off-by: Sean Christopherson --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/svm/avic.c | 3 +-- arch/x86/kvm/vmx/posted_intr.c | 7 +++---- arch/x86/kvm/x86.c | 9 ++++++++- 4 files changed, 13 insertions(+), 7 deletions(-) base-commit: c9ea48bb6ee6b28bbc956c1e8af98044618fed5e diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index d881e7d276b1..bf11c5ee50cb 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1922,6 +1922,7 @@ struct kvm_arch_async_pf { extern u32 __read_mostly kvm_nr_uret_msrs; extern bool __read_mostly allow_smaller_maxphyaddr; extern bool __read_mostly enable_apicv; +extern bool __read_mostly enable_device_posted_irqs; extern struct kvm_x86_ops kvm_x86_ops; #define kvm_x86_call(func) static_call(kvm_x86_##func) diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c index 65fd245a9953..e0f519565393 100644 --- a/arch/x86/kvm/svm/avic.c +++ b/arch/x86/kvm/svm/avic.c @@ -898,8 +898,7 @@ int avic_pi_update_irte(struct kvm *kvm, unsigned int host_irq, struct kvm_irq_routing_table *irq_rt; int idx, ret = 0; - if (!kvm_arch_has_assigned_device(kvm) || - !irq_remapping_cap(IRQ_POSTING_CAP)) + if (!kvm_arch_has_assigned_device(kvm) || !enable_device_posted_irqs) return 0; pr_debug("SVM: %s: host_irq=%#x, guest_irq=%#x, set=%#x\n", diff --git a/arch/x86/kvm/vmx/posted_intr.c b/arch/x86/kvm/vmx/posted_intr.c index ec08fa3caf43..a03988a138c5 100644 --- a/arch/x86/kvm/vmx/posted_intr.c +++ b/arch/x86/kvm/vmx/posted_intr.c @@ -134,9 +134,8 @@ void vmx_vcpu_pi_load(struct kvm_vcpu *vcpu, int cpu) static bool vmx_can_use_vtd_pi(struct kvm *kvm) { - return irqchip_in_kernel(kvm) && enable_apicv && - kvm_arch_has_assigned_device(kvm) && - irq_remapping_cap(IRQ_POSTING_CAP); + return irqchip_in_kernel(kvm) && enable_device_posted_irqs && + kvm_arch_has_assigned_device(kvm); } /* @@ -254,7 +253,7 @@ bool pi_has_pending_interrupt(struct kvm_vcpu *vcpu) */ void vmx_pi_start_assignment(struct kvm *kvm) { - if (!irq_remapping_cap(IRQ_POSTING_CAP)) + if (!enable_device_posted_irqs) return; kvm_make_all_cpus_request(kvm, KVM_REQ_UNBLOCK); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 69c20a68a3f0..1b14319975b7 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -227,6 +227,10 @@ EXPORT_SYMBOL_GPL(allow_smaller_maxphyaddr); bool __read_mostly enable_apicv = true; EXPORT_SYMBOL_GPL(enable_apicv); +bool __read_mostly enable_device_posted_irqs = true; +module_param(enable_device_posted_irqs, bool, 0444); +EXPORT_SYMBOL_GPL(enable_device_posted_irqs); + const struct _kvm_stats_desc kvm_vm_stats_desc[] = { KVM_GENERIC_VM_STATS(), STATS_DESC_COUNTER(VM, mmu_shadow_zapped), @@ -9772,6 +9776,9 @@ int kvm_x86_vendor_init(struct kvm_x86_init_ops *ops) if (r != 0) goto out_mmu_exit; + enable_device_posted_irqs = enable_device_posted_irqs && enable_apicv && + irq_remapping_cap(IRQ_POSTING_CAP); + kvm_ops_update(ops); for_each_online_cpu(cpu) { @@ -13552,7 +13559,7 @@ EXPORT_SYMBOL_GPL(kvm_arch_has_noncoherent_dma); bool kvm_arch_has_irq_bypass(void) { - return enable_apicv && irq_remapping_cap(IRQ_POSTING_CAP); + return enable_device_posted_irqs; } int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,