From nobody Fri Dec 19 15:49:16 2025 Received: from mail-pf1-f202.google.com (mail-pf1-f202.google.com [209.85.210.202]) (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 1B4082222DD for ; Mon, 19 May 2025 23:28:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747697311; cv=none; b=TZn0whUi67G1e0JBN3I8IE6DFAnQ7DIeEsEwdVlsPcXC7rgow0xuIEqXcNEwcifTgSjpKzPTDR1hV8X+P3HXlV0//TdW1aWFSXIVRQXwkxrwSb0uOWdVFN4Thaewk7SdlgILXtdfOUeLjWnQKJa+PKDRuXl/yAeScdaTgAqJWk0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747697311; c=relaxed/simple; bh=OPUsOxJQRGQw18S5qUhUF69GtSIfHQcNTuuAQQroEw8=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=Dss1JQsIQ85Bvt7vAzTkmF2hkvYrV1HHy3ZNiHE5wfVQLHDz2Zsr8tzDvsoeNS4NoGEUYhnO9Pkwbr265HRDYSP0bXSCbobvQIoKZ1WicCAoncGRIpc3dM1WC2IU95oxocKhD4l2tKfDEB/EoM+HVuG2x2mf69ODA4Oev+tqsqo= 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=K0U5Xyfq; arc=none smtp.client-ip=209.85.210.202 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="K0U5Xyfq" Received: by mail-pf1-f202.google.com with SMTP id d2e1a72fcca58-742a091d290so3301557b3a.3 for ; Mon, 19 May 2025 16:28:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1747697309; x=1748302109; 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=OzpwPK/JEQxQkuGwL5Uwcgd2u1TTmwDV5SMaEASMIM8=; b=K0U5XyfqgHrS2d9PlpRzAfQDjGsuiEqKG5sEJZDSwrpGBKOTPlolW2ZNCjJAaesWfK WPv/GR4F4SSckoZ4enIKwF6RFley8RsZ7oxr7jCJtDiUMCBCa9m3VCOwxRsZa+Oyrbn8 hr9QsW/4hgJj9B4iMtZTBEbTzIiD0sQA8JuUxOt1QhoXlLfQEoi03h266SoUOpegAFg0 oRJCzs0Zta8fHlrEDqQ77ZPi28z4qj7/x4kQdi1NsOHhyf6TshwKehBUM88WJZn1VS/r OgkjmfqMaNVp3/EamztMXO7eBe4DXdGVngYK0Y9nZ3T0Mf/5vw7EqadqAnsh1WqEs+8E pKRQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1747697309; x=1748302109; 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=OzpwPK/JEQxQkuGwL5Uwcgd2u1TTmwDV5SMaEASMIM8=; b=GT0s08AgxuQ4suh8LfUE0cyOgBFDbKtqRoYLPCN0zaCDfH9csl7Lql+oPuHmxsx1uB QMXeLuUnACKL/fFqlUGGOyTy4cAHD0L7EdtiHH99hPj1BnH6/jdYz+JbIoX5O1OHq8rm lvlTgPW7XuofH9N85zce73f0b+NYkZhx50L62YWwsN8IndDEV0/Qh4wANrgob8bQsgET 5TvKIV/3c9WR4YCqpeol5TyjwoPS71jmv6GlJkco6ifvjExIWfDJXvKN1y9YuTODPA2G 0QSM/BZ6GE8HmLc4GkBzkzc6uyvc7Km9FgHPndSV6foYbDHioXMpVOUfubv+vGUkZsvz 4qyA== X-Forwarded-Encrypted: i=1; AJvYcCUCRhqRCt2QBAmkdQg5R4U3Z0LZUaEo7OhUmZIV9tIy1RdNbA1yC0g34PSkRLrknonQNscg7TTNqoIpMMQ=@vger.kernel.org X-Gm-Message-State: AOJu0Yw45nSi2UX7h5sTxMRzNHXn2klHHjbc+296TM8te/EPpYp34CKh gIRL9pSJMkesd00nq/ZF0mfoEKHf7Nj6AApZb2RQnjF9he9pcbwC4hANTYCn4wiqpURSIWwzrAO XAZVHPA== X-Google-Smtp-Source: AGHT+IES8VHuEi1O9VM21YWHDIFRJ/0jkBwb+8TYaOYI0d7V6KDKgJQT1u+7T8XTP8XEgC0NqDqkFIUei3w= X-Received: from pjyp5.prod.google.com ([2002:a17:90a:e705:b0:30e:7783:edb6]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a21:69b:b0:1f5:7c6f:6c8a with SMTP id adf61e73a8af0-216219f8d9dmr22093394637.35.1747697309545; Mon, 19 May 2025 16:28:29 -0700 (PDT) Reply-To: Sean Christopherson Date: Mon, 19 May 2025 16:28:02 -0700 In-Reply-To: <20250519232808.2745331-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250519232808.2745331-1-seanjc@google.com> X-Mailer: git-send-email 2.49.0.1101.gccaa498523-goog Message-ID: <20250519232808.2745331-10-seanjc@google.com> Subject: [PATCH 09/15] KVM: x86: Explicitly check for in-kernel PIC when getting ExtINT From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini , Vitaly Kuznetsov Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Explicitly check for an in-kernel PIC when checking for a pending ExtINT in the PIC. Effectively swapping the split vs. full irqchip logic will allow guarding the in-kernel I/O APIC (and PIC) emulation with a Kconfig, and also makes it more obvious that kvm_pic_read_irq() won't result in a NULL pointer dereference. Opportunistically add WARNs in the fallthrough path, mostly to document that the userspace ExtINT logic is only relevant to split IRQ chips. Signed-off-by: Sean Christopherson --- arch/x86/kvm/irq.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c index 97d68d837929..b9b9df00ab77 100644 --- a/arch/x86/kvm/irq.c +++ b/arch/x86/kvm/irq.c @@ -41,6 +41,14 @@ static int pending_userspace_extint(struct kvm_vcpu *v) return v->arch.pending_external_vector !=3D -1; } =20 +static int get_userspace_extint(struct kvm_vcpu *vcpu) +{ + int vector =3D vcpu->arch.pending_external_vector; + + vcpu->arch.pending_external_vector =3D -1; + return vector; +} + /* * check if there is pending interrupt from * non-APIC source without intack. @@ -67,10 +75,11 @@ int kvm_cpu_has_extint(struct kvm_vcpu *v) if (!kvm_apic_accept_pic_intr(v)) return 0; =20 - if (irqchip_split(v->kvm)) - return pending_userspace_extint(v); - else + if (pic_in_kernel(v->kvm)) return v->kvm->arch.vpic->output; + + WARN_ON_ONCE(!irqchip_split(v->kvm)); + return pending_userspace_extint(v); } =20 /* @@ -126,13 +135,11 @@ int kvm_cpu_get_extint(struct kvm_vcpu *v) return v->kvm->arch.xen.upcall_vector; #endif =20 - if (irqchip_split(v->kvm)) { - int vector =3D v->arch.pending_external_vector; - - v->arch.pending_external_vector =3D -1; - return vector; - } else + if (pic_in_kernel(v->kvm)) return kvm_pic_read_irq(v->kvm); /* PIC */ + + WARN_ON_ONCE(!irqchip_split(v->kvm)); + return get_userspace_extint(v); } EXPORT_SYMBOL_GPL(kvm_cpu_get_extint); =20 --=20 2.49.0.1101.gccaa498523-goog