From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (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 6704320D4EE for ; Mon, 24 Feb 2025 23:55:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740441350; cv=none; b=BMYlqRWbLuLB5bKrrhJaH5IPxYlamBVbgTQuyLUkTf020mEI0vXezwYcSnCiIDaFwDGk1tiJXQ88Wl2Xqu0DjKiHexrcfyMbDifZ9ohqDFy4Osd6kfBayqRnAx8lJsVS52CWuQPjtRp/dw861/EK5STpdUAcfnH+YcfJ0gYpWJE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740441350; c=relaxed/simple; bh=Pgnsnfhe7JEsCHeo8nxgfh9t3AoyozrxKe/Nn1f4YRk=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=LVEwwL/yQ2J7ogUhx15uIeaasQMagCkKkMnWj5poiFWu05xxkFxZQPUZDKTIv9Rk+H/M1c+ZER7A+wvtIO/kHBe0IbczYC7hPJprPzD407344RAC4Lp0yCnIEWk7ETg1IHRtDukCT5lZvJWBTLcltNTCOkqLxxERKDv4sdNUC4M= 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=cS404g5M; arc=none smtp.client-ip=209.85.216.74 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="cS404g5M" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-2fc2fee4425so16668956a91.0 for ; Mon, 24 Feb 2025 15:55:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1740441349; x=1741046149; 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=TGU0ybTwy223eIpDzZVLI/W8vnqy8rZ9uLMIqzhcN/c=; b=cS404g5MRmCHdXBoRyF5yO1wQTbGnYu7txQDUK/dvXjPWEsdRNd0ftO8I8PeaOT2+4 SauNFfEuVPinGQ/Qs73c0es8Jv9qUSbmngL/qMVHaKMFbAWPYN/3hNOQh1WMCINkkgRy TbrDB1V//I6O+dpwYCghirUwbAGIAS7/SLhSBO+6Wd5nel4yfRKxqVuWdV4vbrfjHmOX DMassa/zQ9xgUkTKlXRB283Zm/xzi2k5zm3h1zH7//LwXHinUB7EHcLJKwsQzIvB46M7 mJUa/IIJAmfq4UeD8NTQpw6m+fdh5Fe+B4wp2i7Sw+yj2hrFnTkCjLdW5+DYa4k387YB cckg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1740441349; x=1741046149; 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=TGU0ybTwy223eIpDzZVLI/W8vnqy8rZ9uLMIqzhcN/c=; b=U1JDralUWEZkfi5k8uxuq8NVZLyEf0rhEbVOVBLnl6HG4YIUFEKKgJRCw+Whk3wphy CXwXzDmB/+pURhOn/W5ps8IUWjN9RsI8J70AXhg2Lae3qSCoSxvQSDmIMNYqzJKn6pjB S45g/EZ8srOEOc9bAN48ljtJPCqP6kjfne6a8gQzOz2jMK7wnyAL+7R5/ZHqQZ6LT9Ql UkpawLTgVmc9AxKLqqUIJbXmtDLsVp1zQ7hhislu6vj4bpzcA2NuG1JG6PiavM3C1NFW KuLO/cdedm/Nc3aJg4ys/kOhCbhT5/gPCQdLnmvULKNV0tmbdE6tY9d4zoNKiwH4Vzv1 MlKw== X-Forwarded-Encrypted: i=1; AJvYcCXP7Mt2tEaKWH86ZgkCrxPmN40llPZmExnc+8X2sgt8UIuGFqQJNHh34PK5+NfrY+tVRcB/0fkeKCs7unk=@vger.kernel.org X-Gm-Message-State: AOJu0YwEqo7QOac03i4YdcwUmC9qVDZWu51Nb4+53s49mnRpjGQCOV1t 4bE9qxzA3Txo2xGLgWZ2XFE21JbRZ9mK1piZLcR8gGJo+J5MniQ+AfTIRK3DMlIVyQWJcQOaEdY ZSw== X-Google-Smtp-Source: AGHT+IHcos0szxLwYcsW2Q/WbhHjoZ/1wFjhF3Xa+8fw1kzKNZT2q6/VDS58iA2uFYrVe3USusRDS/R8AlY= X-Received: from pjbnb15.prod.google.com ([2002:a17:90b:35cf:b0:2fc:b544:749e]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90a:e7cd:b0:2fa:17d2:166 with SMTP id 98e67ed59e1d1-2fce7b40077mr23992311a91.31.1740441348957; Mon, 24 Feb 2025 15:55:48 -0800 (PST) Reply-To: Sean Christopherson Date: Mon, 24 Feb 2025 15:55:37 -0800 In-Reply-To: <20250224235542.2562848-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250224235542.2562848-1-seanjc@google.com> X-Mailer: git-send-email 2.48.1.658.g4767266eb4-goog Message-ID: <20250224235542.2562848-3-seanjc@google.com> Subject: [PATCH 2/7] KVM: nVMX: Process events on nested VM-Exit if injectable IRQ or NMI is pending From: Sean Christopherson To: Marc Zyngier , Oliver Upton , Tianrui Zhao , Bibo Mao , Huacai Chen , Madhavan Srinivasan , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , Sean Christopherson , Paolo Bonzini Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, kvm@vger.kernel.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Aaron Lewis , Jim Mattson , Yan Zhao , Rick P Edgecombe , Kai Huang , Isaku Yamahata Content-Type: text/plain; charset="UTF-8" Process pending events on nested VM-Exit if the vCPU has an injectable IRQ or NMI, as the event may have become pending while L2 was active, i.e. may not be tracked in the context of vmcs01. E.g. if L1 has passed its APIC through to L2 and an IRQ arrives while L2 is active, then KVM needs to request an IRQ window prior to running L1, otherwise delivery of the IRQ will be delayed until KVM happens to process events for some other reason. The missed failure is detected by vmx_apic_passthrough_tpr_threshold_test in KVM-Unit-Tests, but has effectively been masked due to a flaw in KVM's PIC emulation that causes KVM to make spurious KVM_REQ_EVENT requests (and apparently no one ever ran the test with split IRQ chips). Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/nested.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index bca2575837ce..8220b09e91ce 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -5084,6 +5084,17 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason, load_vmcs12_host_state(vcpu, vmcs12); + /* + * Process events if an injectable IRQ or NMI is pending, even + * if the event is blocked (RFLAGS.IF is cleared on VM-Exit). + * If an event became pending while L2 was active, KVM needs to + * either inject the event or request an IRQ/NMI window. SMIs + * don't need to be processed as SMM is mutually exclusive with + * non-root mode. INIT/SIPI don't need to be checked as INIT + * is blocked post-VMXON, and SIPIs are ignored. + */ + if (kvm_cpu_has_injectable_intr(vcpu) || vcpu->arch.nmi_pending) + kvm_make_request(KVM_REQ_EVENT, vcpu); return; } -- 2.48.1.658.g4767266eb4-goog