From nobody Mon Feb 9 08:55:02 2026 Received: from mail-pg1-f201.google.com (mail-pg1-f201.google.com [209.85.215.201]) (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 7A1CE2FDC4D for ; Fri, 9 Jan 2026 03:45:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767930343; cv=none; b=dHDIe8OOt0W7GqU/27eBVCZLqqau3czGDil6rR9tHybCQWhCyZP2k6etZ19EJd4cUvp2O3bO1V48Hx+4t4u8tBbS+Wc+taxAK+z9eQEbkCQ+Uo+61uYTBcltvfCWcwvX18GaGnPM8aYyPrO+KcztS7DNby8ZrL4hgpGIk+trgGw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767930343; c=relaxed/simple; bh=JNTMhgYGQgtyJNjtw8vToWb4WTH4XkkwCy6YSvLCHJI=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=GQ5ITMLXYFMkbHZKFKYH7lx1lNrmgWXAVFG7mAicmzOFST5o4UVSp0M9gfmwggZf3ePbkfR5vy/m4pl/YgUH2VrKeeVqKCb320POYn0MHil6dKrbhUPbrI83JvmzU5yfnVK8XcKVq7fwU9lKwwcNQaYtLIjgmgD6jitemuIyt98= 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=wzIKMCA6; arc=none smtp.client-ip=209.85.215.201 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="wzIKMCA6" Received: by mail-pg1-f201.google.com with SMTP id 41be03b00d2f7-c52743b781eso1143935a12.2 for ; Thu, 08 Jan 2026 19:45:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1767930342; x=1768535142; 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=riEO8rGkVD0LWXz3K6AdDhJyUv23hQGge3Scgd6g82Q=; b=wzIKMCA610x743KzO8Hozl2IoG93V+igQBCeERb0dzVW7vxtJZBjKBYwWBegCmYP4s 5NPYwP5JPrARfWrjIiCrxo5kGmv44PiHf+cplmp0K2IDz16plHo3L0NIWmrZG21cofdF fz885Fmx0R8qsddMPC1KeEHs0svlVXlJryQNqhhTeAlE5HkY5g0I7eryFnGx5DOEVhCR mb+3sVf9EsqTNVuZfQR/kcwXu3/F80TdHL1aJNmQub+zPqB6KCAJ3t4Yc0rcfHpBNlnr Q7FxwjQhJXgYjW26JA/amMUWy5gCbRFUCJKnXW1X8kIg4IvVydRCjjtF8CUhXUHxbT5C 3S+A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1767930342; x=1768535142; 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=riEO8rGkVD0LWXz3K6AdDhJyUv23hQGge3Scgd6g82Q=; b=JiqhKYFWiV9jlvwgVW+cyDYVVIRiJuVsD/wDqEay2pFMYIQhjVJz6NCofnpc/itOBj HorXwGx4dNB7xXiRwKCweY6pehhEE6lzasRlWTAoM6uoJQg1pZx8RptGisjtvkTs6Ilv js0mbrniIexO5ZQfEuXsPwIqHo5Xgt4baLivbNoOQ3q08cWw2jz1dX2gP77HiOV3cdMO TS6rWWcXblGvamvQE5gPlB2WYQZyTtIgQGBEEvqiAflfgcn7x9dbT9pPWqBKglL6tHYQ 2Wx5eUratSjABC1bBMLgLB5coUHIWCuHUByUhgxIIZQrtGjmot23vLa3w0hkAmwL8xhl 471g== X-Forwarded-Encrypted: i=1; AJvYcCWmqvPPlFPQCDboCjA8lcbUSri9thg1Imo1jpNgstfpALhT4gC1+cP1S1MgZjcKD1Wk89A9KxO1j0oKGUk=@vger.kernel.org X-Gm-Message-State: AOJu0YzpaHtLKI5kZ0lI+dmqkbkrAg1dTJRQWm7ZBnXpuotoKNoEK51x vWnuqjlj+IVgj4zz7RCdMO1LN7eL9vSH9TsbvLYbyipW7KJ2i/GSadl2CMCJT5w9kA3fS+2i6UL rO+FCqQ== X-Google-Smtp-Source: AGHT+IE0rWF4oD9F9ZCOJh0KeVUbkzSQAwujDJRsVmOEh0vsbQxymaB5ScAy3POMHmzqBRcqwUw8ZJ+5w5I= X-Received: from pgkh12.prod.google.com ([2002:a63:e14c:0:b0:c09:15e9:db3d]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a21:339b:b0:33f:4e3d:aff0 with SMTP id adf61e73a8af0-3898f8cbb87mr8987404637.21.1767930341668; Thu, 08 Jan 2026 19:45:41 -0800 (PST) Reply-To: Sean Christopherson Date: Thu, 8 Jan 2026 19:45:28 -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: <20260109034532.1012993-5-seanjc@google.com> Subject: [PATCH v4 4/8] KVM: nVMX: Switch to vmcs01 to update SVI 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 activated while L2 is running and triggers an SVI update, temporarily load vmcs01 and immediately update SVI instead of deferring the update until the next nested VM-Exit. This will eventually allow killing off kvm_apic_update_hwapic_isr(), and all of nVMX's deferred APICv updates. Reviewed-by: Chao Gao Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/nested.c | 5 ----- arch/x86/kvm/vmx/vmx.c | 19 +++++++------------ arch/x86/kvm/vmx/vmx.h | 1 - 3 files changed, 7 insertions(+), 18 deletions(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 8efab1cf833f..c2c96e4fe20e 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -5160,11 +5160,6 @@ void __nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 = vm_exit_reason, vmx_refresh_apicv_exec_ctrl(vcpu); } =20 - if (vmx->nested.update_vmcs01_hwapic_isr) { - vmx->nested.update_vmcs01_hwapic_isr =3D false; - kvm_apic_update_hwapic_isr(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 3ee86665d8de..74a815cddd37 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -6963,21 +6963,16 @@ void vmx_hwapic_isr_update(struct kvm_vcpu *vcpu, i= nt max_isr) u16 status; u8 old; =20 - /* - * If L2 is active, defer the SVI update until vmcs01 is loaded, as SVI - * is only relevant for if and only if Virtual Interrupt Delivery is - * enabled in vmcs12, and if VID is enabled then L2 EOIs affect L2's - * vAPIC, not L1's vAPIC. KVM must update vmcs01 on the next nested - * VM-Exit, otherwise L1 with run with a stale SVI. - */ - if (is_guest_mode(vcpu)) { - to_vmx(vcpu)->nested.update_vmcs01_hwapic_isr =3D true; - return; - } - if (max_isr =3D=3D -1) max_isr =3D 0; =20 + /* + * Always update SVI in vmcs01, as SVI is only relevant for L2 if and + * only if Virtual Interrupt Delivery is enabled in vmcs12, and if VID + * is enabled then L2 EOIs affect L2's vAPIC, not L1's vAPIC. + */ + guard(vmx_vmcs01)(vcpu); + status =3D vmcs_read16(GUEST_INTR_STATUS); old =3D status >> 8; if (max_isr !=3D old) { diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index 36f48c4b39c0..53969e49d9d1 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -134,7 +134,6 @@ struct nested_vmx { bool change_vmcs01_virtual_apic_mode; bool reload_vmcs01_apic_access_page; bool update_vmcs01_apicv_status; - bool update_vmcs01_hwapic_isr; =20 /* * Enlightened VMCS has been enabled. It does not mean that L1 has to --=20 2.52.0.457.g6b5491de43-goog