From nobody Tue Dec 16 14:52:18 2025 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 0DCCF158538 for ; Fri, 5 Dec 2025 23:19:31 +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=1764976774; cv=none; b=MocR0xrXWEa9mhzKRlOqE6RKM6hIF3hoib+MLyiIP+YGrIWgj/XpUlJ8bGngBykji83PUxwBS9+f/4ntAw5CJHMl38ancyX2zbONazBeWMwmHGsW5KhDO+6bMoYEanwDhLF6MctU0FoK5pHjXiCRtYo2XLTaUo6MULJkWnJcafQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764976774; c=relaxed/simple; bh=Y3y9z5Dem+sGP084lKmrwtv8wTb9CyaL0moHFIEpymE=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=HANKm1ctVS3lAR0bUaYULLmDfYO+NXOjiKZGfBCz9aZsA+aXTSidvGO738BRq6icsT7XKVsCO4EUJ08K1gOJsc/vtPuIby6GmIECKlCGPUe+l9bgfFAVj5JZ0etgPhntt5kaCHECnUkCUzMSGt7xIoNvm3Z4sBFTffwalbq+l8w= 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=ADTPRA4/; 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="ADTPRA4/" Received: by mail-pl1-f201.google.com with SMTP id d9443c01a7336-2982b47ce35so36472235ad.2 for ; Fri, 05 Dec 2025 15:19:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1764976770; x=1765581570; 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=zRgsu7txhPlymPyldYkGSmbzB+dNiAxZ1OO2LYHMK9o=; b=ADTPRA4/xH7V9qUeu+cvCU9Yl1pJSmYZqoKfG65JZcUBuQNNKAm8UopIPb6touMDSm P2uIBOe9cWtzLo6JtW8T5rsK7TXKCR6SINWprT6LUImShJPZ0iJxDyW4DgSssoA6Lg/w EOQqVHN6T9KCcDoKrUbbGIjpoUR9cKw2i8XzgjaTl2z6bogVN58NKtVnVbm+4E0uJTew a87gcGRt3/Yo2SWszRA/2He3sOavYNGvXcR7umi/ueV1D9z2Z7R8yM5IkPDtsQTPJCa+ 0XCtl+Hk8valmv/sBGF8OnTR/leBjjiUClVZbX+tCODHEJvHhOf3nG5gNCLuM60RDyy+ h73Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1764976770; x=1765581570; 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=zRgsu7txhPlymPyldYkGSmbzB+dNiAxZ1OO2LYHMK9o=; b=RHWE/0khUy9EiV8Fdd6ararYrzP3QG+pgaoCLRgbGuPBqGB01pfOTLpbyZ9kFe4NGD pTUsqz27q81HvrqGINmGJ9MzNc7QZT1BxNxi8e16C8xczayPCIqsixBTVmzm5515b9P8 eLb/8iLW/2bMnOHRYVpptvWpI7J5X4ePRD3Ut0I6c2Arhto+5p0zfYXHStTTyMLYtNOp rkf13alU4VjIlFM1yElHpfxHqBbg3DtnztYAVghE2hEenhtv9DX9FvLBB3tpZRfVAvM/ 1OiKLSyJzU2bGFnT/qoaT6744EcxC9Ud7wGZPdKT3hhnqAvZ5P78V83vojFLhu+LjKtF A3Dg== X-Forwarded-Encrypted: i=1; AJvYcCWkauW1Q8p9hRA2VE7Jwf7G8Ftl1GT+n40uT0PsmIQ/yeQf/WKZ8XeRbX9tpANqHoj29dD9AqBkexVmAlw=@vger.kernel.org X-Gm-Message-State: AOJu0Yy3PZos4ygb2LP1kjCfUFyqcqswpi9TWUQNhj0mL84UD0E1AkmG iqXffx2xyEewEH9Q4YKalS1bmNCA9BwKd7nAmGTRInCu3JseX4YinmYmQQsx3rs2Wx2J2dIJ35Y 7aA6uog== X-Google-Smtp-Source: AGHT+IFTYHrkH7tC3zMkHferO+2I19/FJ006vgRJJ1FgLAVFgB7GWM6536sdWq1jx6EJRqwNjneRG2Nv/4o= X-Received: from plld18.prod.google.com ([2002:a17:902:7292:b0:297:d4ca:8805]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:903:b0e:b0:295:8a21:155a with SMTP id d9443c01a7336-29df5bb4030mr5967455ad.35.1764976770121; Fri, 05 Dec 2025 15:19:30 -0800 (PST) Reply-To: Sean Christopherson Date: Fri, 5 Dec 2025 15:19:10 -0800 In-Reply-To: <20251205231913.441872-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20251205231913.441872-1-seanjc@google.com> X-Mailer: git-send-email 2.52.0.223.gf5cc29aaa4-goog Message-ID: <20251205231913.441872-8-seanjc@google.com> Subject: [PATCH v3 07/10] 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, Dongli Zhang , 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. 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 2.52.0.223.gf5cc29aaa4-goog