From nobody Fri Dec 19 15:46:14 2025 Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) (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 DAEDB224B0C for ; Thu, 20 Mar 2025 14:20:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.73 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742480430; cv=none; b=qzfc9F2asQ5SuTwEm29jTfuQ6HDD2b9CQ7jOpwSdtFFiZHd0qDfcRITLkbaRPKK1sU6k5M7sXIbMZMwkzCYLjj02N5eb6TUpkP7Tz9bcQ7Ymzu3S6h+Ek2Xnv7JVdtEWOIpV621xDoc9DHXw/gYFlnSggeCYHTZ/W75Gmu/M0GU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742480430; c=relaxed/simple; bh=ovEPl2bVEO0eSqvBoa1vZD9IRo9Jr6lVc7JfrYVpvGg=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=YlV1h0BWzKoXnLa5rvsmEhOpROXYCtdupNVe0Q48BUvqH5U1UoMW2gER8yDvXBUGISOulXCqpf2oqzYT3f8GueKsKHoqr39iZve0Ju3J7A2sJU/BNKz1DdYqOj3JHd+R38IYZIlPK5glJBwkXiDNgyvUNBOzus2+P6PQohKsDPg= 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=nDY13dpN; arc=none smtp.client-ip=209.85.216.73 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="nDY13dpN" Received: by mail-pj1-f73.google.com with SMTP id 98e67ed59e1d1-2ff64898e2aso3042568a91.1 for ; Thu, 20 Mar 2025 07:20:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1742480428; x=1743085228; 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=fVHuVoUkv5HXmPF3k2h1n5WUDzdvxcafccuisAmJQYw=; b=nDY13dpNtarNCgDNOtRGa5TevRHJS+KepR5xqN11HAk2tEnw0Syc3Oj+678XSjARsD Ns2+xJdZVFGlA1F9UcHSS4lkczjNxK101nFqPlgaym5+NrHQ2wSC07hcTHLtRD2L24Re bAWZ3cy+BP+CkBSxecu1nadGgeK909gBFJocQ1dDEVZgviQ3xFG5p/VRTPMVpNwnN3tP SsVDTWnp8JZv68IbkZBjThIEZpFpbxvpPNWOjyvhQgKXmhSJm/qnyAiSb4F6t4DgKMQs r+GXHatxnohkEzV+iy1Z3hnfvCALAz2Vc4Kx0jhqrohN1f1t3biHQ39k28uEiAx5blXt tjCQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1742480428; x=1743085228; 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=fVHuVoUkv5HXmPF3k2h1n5WUDzdvxcafccuisAmJQYw=; b=n2XogqmiTu6dZfeWa4ZOJCIa29apGruUlW7qNbdA9IH9Yit6eSZ9h+Sia5CSgK2jB+ gTlcqOOB42bP0QaWvd6n/nwE+AmeakOWUVZKTJ91u8iAcdttT2RnRW9AAdY8ByX3TMzj uHsf62rs+OBxb8JXgKM6HQ94ikQYdKQJ24Vk1JZymUsYjuX4PZeNmVLk4B5HOm657bmL vIckUicnQzK2gJUp2iF+FAY1AVNPRKcogwmEfKjP8K1/XfwRQesotmrDNbVN8TEgn8RE /HmkKZzP9yCNA0K0EipkeVqZBXntZSIPOXDoklkCF3RPjH3Q8ZmctnFcF3GbGFTN5o1e YS0g== X-Forwarded-Encrypted: i=1; AJvYcCWFpODXu85FBmQbGYYKc7Ka/baxPokA8j8LxXa3OEu9io4zeaTb646xzqfLs47INnOcbKM0qLlpscKHIVg=@vger.kernel.org X-Gm-Message-State: AOJu0Yws1iIfMMllHd6fWglzkNQERiVQuquNKoEvDPS1WPNFxLQTc+J5 vdC9VS+cx4qEwlGsCiuL4uv77ZncEo0EvpmLMchPkB49MQNGPyf6++MMZYJWeXkGIf3Ark/rznn k7g== X-Google-Smtp-Source: AGHT+IFbPO/3Zgwol8ARgIf0jQNXI18k8lFWGe70dLm0WMUhi+BbpfRpAvT6wHo2NxigqM0VjclDH/escmU= X-Received: from pjbmf11.prod.google.com ([2002:a17:90b:184b:b0:2ef:d283:5089]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90a:d2cb:b0:2fa:42f3:e3e4 with SMTP id 98e67ed59e1d1-301d426aa83mr5355104a91.3.1742480428033; Thu, 20 Mar 2025 07:20:28 -0700 (PDT) Reply-To: Sean Christopherson Date: Thu, 20 Mar 2025 07:20:21 -0700 In-Reply-To: <20250320142022.766201-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250320142022.766201-1-seanjc@google.com> X-Mailer: git-send-email 2.49.0.395.g12beb8f557-goog Message-ID: <20250320142022.766201-3-seanjc@google.com> Subject: [PATCH v2 2/3] KVM: SVM: Don't update IRTEs if APICv/AVIC is disable From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Yosry Ahmed Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Skip IRTE updates if AVIC is disabled/unsupported, as forcing the IRTE into remapped mode (kvm_vcpu_apicv_active() will never be true) is unnecessary and wasteful. The IOMMU driver is responsible for putting IRTEs into remapped mode when an IRQ is allocated by a device, long before that device is assigned to a VM. I.e. the kernel as a whole has major issues if the IRTE isn't already in remapped mode. Opportunsitically kvm_arch_has_irq_bypass() to query for APICv/AVIC, so so that all checks in KVM x86 incorporate the same information. Cc: Yosry Ahmed Signed-off-by: Sean Christopherson --- arch/x86/kvm/svm/avic.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c index 65fd245a9953..901d8d2dc169 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 h= ost_irq, struct kvm_irq_routing_table *irq_rt; int idx, ret =3D 0; =20 - if (!kvm_arch_has_assigned_device(kvm) || - !irq_remapping_cap(IRQ_POSTING_CAP)) + if (!kvm_arch_has_assigned_device(kvm) || !kvm_arch_has_irq_bypass()) return 0; =20 pr_debug("SVM: %s: host_irq=3D%#x, guest_irq=3D%#x, set=3D%#x\n", --=20 2.49.0.395.g12beb8f557-goog