From nobody Mon Feb 9 05:59:24 2026 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 698712D7DC1 for ; Fri, 9 Jan 2026 03:45:44 +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=1767930345; cv=none; b=FyYJouAYFN5Vaku5PTBre5AtwsfL7Np1Pn9qGYn0jWyZnkkj2jrzQxJiRNmXyDlPg32fOO5v4Hj8CkMymPZrrxVKZp44r9yT4EdOKUe1yxCcw6oOZF4zcm3MjTRusAanZvhPCbS5SYNfiV7F+g75I+mpY+d7y3xtuaTrMEKPjas= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767930345; c=relaxed/simple; bh=OHCeNRp1wt9IbXCaJRqofsAtvp1Jfc8eqsNolsnerWU=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=erIVqpyvKrsLq4662K5myjySTrZd8hL57hBQSJ7XWwuAAjFgolvHnbE+CZRzz6itIic72nQsDeq7QQk80lZ+/4Rwk8Jl411KLZIitE042rE3f+UzIU+pehkN0Eyj/MRmLbtLGIvK1b7Ipmcz+QjYmFaoem6kldpDGvb7Pe7ax4s= 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=K4/YmLM6; 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="K4/YmLM6" Received: by mail-pl1-f201.google.com with SMTP id d9443c01a7336-2a13cd9a784so36161405ad.2 for ; Thu, 08 Jan 2026 19:45:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1767930343; x=1768535143; 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=97rvvcgreI792oaYEzu9bWB1KLSBFwBggjm3Kg+Hq/c=; b=K4/YmLM6ZC6n5kuC5MD95G4CkfodphF/qjthFNP6hajh0uQMQPpZDbnExocV3x9JfX UY/crhtqjscX7j0DNgm+8Xu+85fHQnp8mrZq3XzydyIsR/NaYABDAN09LKv7PdGMjYkH IBnnDGnqWvrTz/XJRU7+TGUpD4HqwbTSGB5SZDholU68WNk0/irGPvUIpfMuEUcH4TP/ /3rmIGsSOhb1ByVqTLn92mI+nNYFzxA1pbst5F62MRUcYpbPjU4F4O5g3T3LqVB+woOX U+O3HT76kHQGBMfcgKZcitWp6uC9LwowfE6DriICqefsln/kgSA+ff3FrAEbB/VvpSmo sPJg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1767930343; x=1768535143; 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=97rvvcgreI792oaYEzu9bWB1KLSBFwBggjm3Kg+Hq/c=; b=Khj7MK3GDqfQewhynczmQrQAt/WsFYwod7X6/R+rqzo1IPMWavNh7evQgdd7CuhMc5 bsSzkHSoPPpSCraE+Ykf6JPF1a6YK85qvGhP8DyM/OIrK1ApUsO6Zpk3VXEGoW0N2B5V 7IPGtkVInMfSpA8gaKh0XD0MDZDduU2VnoJZsN/m1Vbnwj8dMcKKU+Z+dAJK7ReV+XGG JPFdpbFGh+kvZAtiSSVgnvAyZkFKSJ4HNai4/YFIWO5pzN+o352MC0iyQw6bTp8ka7TB AC5RTd/chbNrFIyV8SsG1WEoA0ehxt+xqRWQJ4NE6xTH/oiRMoDRFNZyCJQpUbslHXFK S5Tg== X-Forwarded-Encrypted: i=1; AJvYcCVabLfuvj9AHZ08nI13EZtBSxte63FsqT5tFJFjq0duTlDjW5AHoLXJ5XjNXn+fWT9hAQJTwdJH26BhhYw=@vger.kernel.org X-Gm-Message-State: AOJu0YxcLyHJlyZgyd2hL9HUSm0zz28LJ/lQvCsvNJsvrSEJ25dCJ1Or h+Kho8Z6lRVR0FENSA5R7AHwTEEE0oX/x05FYm/7ejYcktjMXYvrcw/hVE9H3jomAMZwiDycVti HN0wM7A== X-Google-Smtp-Source: AGHT+IHotUYH3uDHB5Qxo6BCx8dLSPdORnpJvhVILsX7PibbCEz7iBu1MHUFsX9Ywu0PHxLG7Hpl7nTv1K4= X-Received: from plv9.prod.google.com ([2002:a17:903:bc9:b0:29d:5afa:2d4]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:903:40ca:b0:2a0:bb11:9072 with SMTP id d9443c01a7336-2a3ee4bfe1dmr77575225ad.55.1767930343574; Thu, 08 Jan 2026 19:45:43 -0800 (PST) Reply-To: Sean Christopherson Date: Thu, 8 Jan 2026 19:45:29 -0800 In-Reply-To: <20260109034532.1012993-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260109034532.1012993-1-seanjc@google.com> X-Mailer: git-send-email 2.52.0.457.g6b5491de43-goog Message-ID: <20260109034532.1012993-6-seanjc@google.com> Subject: [PATCH v4 5/8] KVM: nVMX: Switch to vmcs01 to refresh APICv controls on-demand if L2 is active From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Chao Gao Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" If APICv is (un)inhibited while L2 is running, temporarily load vmcs01 and immediately refresh the APICv controls in vmcs01 instead of deferring the update until the next nested VM-Exit. This all but eliminates potential ordering issues due to vmcs01 not being synchronized with kvm_lapic.apicv_active, e.g. where KVM _thinks_ it refreshed APICv, but vmcs01 still contains stale state. Reviewed-by: Chao Gao Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/nested.c | 5 ----- arch/x86/kvm/vmx/vmx.c | 5 +---- arch/x86/kvm/vmx/vmx.h | 1 - 3 files changed, 1 insertion(+), 10 deletions(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index c2c96e4fe20e..2b0702349aa1 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -5155,11 +5155,6 @@ void __nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 = vm_exit_reason, kvm_make_request(KVM_REQ_APIC_PAGE_RELOAD, vcpu); } =20 - if (vmx->nested.update_vmcs01_apicv_status) { - vmx->nested.update_vmcs01_apicv_status =3D false; - vmx_refresh_apicv_exec_ctrl(vcpu); - } - if ((vm_exit_reason !=3D -1) && (enable_shadow_vmcs || nested_vmx_is_evmptr12_valid(vmx))) vmx->nested.need_vmcs12_to_shadow_sync =3D true; diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 74a815cddd37..90e167f296d0 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -4578,10 +4578,7 @@ void vmx_refresh_apicv_exec_ctrl(struct kvm_vcpu *vc= pu) { struct vcpu_vmx *vmx =3D to_vmx(vcpu); =20 - if (is_guest_mode(vcpu)) { - vmx->nested.update_vmcs01_apicv_status =3D true; - return; - } + guard(vmx_vmcs01)(vcpu); =20 pin_controls_set(vmx, vmx_pin_based_exec_ctrl(vmx)); =20 diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index 53969e49d9d1..dfc9766a7fa3 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -133,7 +133,6 @@ struct nested_vmx { =20 bool change_vmcs01_virtual_apic_mode; bool reload_vmcs01_apic_access_page; - bool update_vmcs01_apicv_status; =20 /* * Enlightened VMCS has been enabled. It does not mean that L1 has to --=20 2.52.0.457.g6b5491de43-goog