From nobody Fri Dec 19 04:31:24 2025 Received: from mail-pl1-f202.google.com (mail-pl1-f202.google.com [209.85.214.202]) (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 7C58520E70E for ; Tue, 1 Apr 2025 16:18:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743524290; cv=none; b=n5IryaAbFLKQAF36DGl4UHN1hy9sAlUsfDjPE2dir0HLLY7mDCVz7FDDNSyi959o8c1/EDnUHF9Fxvura7hlj5UI3xGnge1OfiOhTBwtdEg/Go8m+CHv2FCM6xXydQaGY2Z6cqpxpJUnhLUAF9w4lNMVm4j6h+cr6uH61ndGO6o= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743524290; c=relaxed/simple; bh=fWIBQmUTb72aiRc41495d8ZZdXdCbxu4pWmWZnHxDTI=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=c3UAdqTX4elfROuUtYzAs1WYEKXQT+Wfl8fHqD8wYRj4aMTKmZeNtT+zpkkKgImlClrDJBh6EDp2G3n5lFz/LtEHoYSpRikMDmsTmYwOgmOuX9iymDcRMCPfZmq7WYR2UIz2lfAkcdi7PvZuWCmH6w5y3buASJ9trBNxLp7KJy4= 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=Ww4OEtH6; arc=none smtp.client-ip=209.85.214.202 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="Ww4OEtH6" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-225429696a9so167620885ad.1 for ; Tue, 01 Apr 2025 09:18:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1743524288; x=1744129088; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=i3CvVTiTohY/MD7XlD1mUCUkTV809OhWBxe9COdH9yw=; b=Ww4OEtH6tuLU/NSLZstG5erzVN/7+B0EIZapBgN3R2x3xqT464z72ozfZ5LmHgBCXv gXkomsRveJK+KlUqZk8iBHnbevFYuI1KWwtk9XJdcC5A2bM7R3nmpthidlosdcXvEpTY ivXCqQApfj0GEkl5rl46UBzFMEu0i/16zz4rS2rw6Iz8h9GH23QkjAFi+aAlU4knkZq8 6/Ps525KhbQjgP7IpiinqardQu566IpZCAUllUO4c9q2rjRh/wIk/hBLDPgLRdeTOMj6 NyPpb0oEE3/9csHvoeUqqTZg7e6qzcfyU4YRHrmqSxPqUw1ALROE93MbZfinv3WhHu/E 5C2g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1743524288; x=1744129088; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=i3CvVTiTohY/MD7XlD1mUCUkTV809OhWBxe9COdH9yw=; b=tg6DkdqoWncmnVKT79GjXSWI5OldbJeYQPk+L+MjDE6rtBQ8ZHIHubnlrQKz27VcT2 eWb/QgoXJOqOh9gc3Rb57fLs5F9ZhcGKhhohO+ahLxYSq2Rbk7YAirCwZNx8ZRh6/Led 8KysC2xFHqMRfhbzPIGr9gQQUFhkMIg5M5SvijysXbRMXPT4ap7xfVUYJOMjaB2Cw1oT Cut4n9lrlGtfe3cEYbNNqCDkuUJlXEpdT63SZIqfHB1O+P3QS6BvQMei30vIoTt2ZaKJ d92raFpQFd7mBFmJfx7XE4OwoleWFM9gfb6fk4+gfhyM9ZmvSwAoIE/Ts7ZLyKTX0tXb rC4A== X-Forwarded-Encrypted: i=1; AJvYcCX5rAAKZAasCyzCUuoAosWbe7BSKswZ4kRAnQ4SIS036xKFCjH/PnEGgwQwLKpSpXD65vkkIP+RlWACRvk=@vger.kernel.org X-Gm-Message-State: AOJu0YybU6o9e+dlzMbbGiZT+86AWJWOJtGC0jEFxQoPd+eQCulitnbL DdEbfBwQTOF35JwqsmEEbtjiRe2fKpSQ3PLdPOZU52rdsXOc6xowExpcR+YfyTiYlnKbijBv+/y sBA== X-Google-Smtp-Source: AGHT+IGYMlELE54qVypHagndgMfq83OicwY6JnNyZsP/+GL6myxIy23X8uMt9Qym6qCfe654bpzCkDka+5E= X-Received: from pfhh22.prod.google.com ([2002:a05:6a00:2316:b0:730:5761:84af]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:902:e88f:b0:223:5c33:56a8 with SMTP id d9443c01a7336-2292f9e51f9mr223551505ad.35.1743524287794; Tue, 01 Apr 2025 09:18:07 -0700 (PDT) Reply-To: Sean Christopherson Date: Tue, 1 Apr 2025 09:18:02 -0700 In-Reply-To: <20250401161804.842968-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250401161804.842968-1-seanjc@google.com> X-Mailer: git-send-email 2.49.0.472.ge94155a9ec-goog Message-ID: <20250401161804.842968-2-seanjc@google.com> Subject: [PATCH v3 1/3] KVM: VMX: Don't send UNBLOCK when starting device assignment without APICv From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Yosry Ahmed , Jim Mattson Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When starting device assignment, i.e. potential IRQ bypass, don't blast KVM_REQ_UNBLOCK if APICv is disabled/unsupported. There is no need to wake vCPUs if they can never use VT-d posted IRQs (sending UNBLOCK guards against races being vCPUs blocking and devices starting IRQ bypass). Opportunistically use kvm_arch_has_irq_bypass() for all relevant checks in the VMX Posted Interrupt code so that all checks in KVM x86 incorporate the same information (once AMD/AVIC is given similar treatment). Cc: Yosry Ahmed Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/posted_intr.c | 7 +++---- arch/x86/kvm/x86.c | 1 + 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/vmx/posted_intr.c b/arch/x86/kvm/vmx/posted_intr.c index ec08fa3caf43..16121d29dfd9 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) =20 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) && kvm_arch_has_irq_bypass() && + kvm_arch_has_assigned_device(kvm); } =20 /* @@ -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 (!kvm_arch_has_irq_bypass()) return; =20 kvm_make_all_cpus_request(kvm, KVM_REQ_UNBLOCK); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index c841817a914a..a5ea4b4c7036 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -13556,6 +13556,7 @@ bool kvm_arch_has_irq_bypass(void) { return enable_apicv && irq_remapping_cap(IRQ_POSTING_CAP); } +EXPORT_SYMBOL_GPL(kvm_arch_has_irq_bypass); =20 int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons, struct irq_bypass_producer *prod) --=20 2.49.0.472.ge94155a9ec-goog