From nobody Tue Dec 16 15:10:06 2025 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 B6E602FFF81 for ; Fri, 5 Dec 2025 23:19:31 +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=1764976775; cv=none; b=uwAnYPU2ZGGkRMBrgyo4AI9/jBqO6DEgQCzpyKrgpYtnqyC8v7oTl5aG3mN6UGoiReIzpg6ZYx9aOYgSjmzLkhVcGpu1e3vNfUKqgDOEHKvHSDayDssmIkSNbTCudo1ditbwD/5BeFCq4W3t0vEAsZfgjTDs80nyHZYvHx7n1gQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764976775; c=relaxed/simple; bh=F9ad1wjbwQOARvbkDcajWfewiLy5rWUDB66kZlDmZ60=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=hN39Fvc7FIHkuDtxUg+Mel6l5ZFXGtScmDZgUhCpoyXG6bj5iMvhZiKouNuooT3Y0ztT2YZ/Krq2FzcmWIu3zn8QolQ5P6pzkUwT8Q/RRyvOSOR5oHma9rQ6sSmThnE0Z21UOgoA27wrlaHa5flOLUEO5ZOx9EVixMhUYGpg0Y8= 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=0uCEu18Y; 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="0uCEu18Y" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-349aadb8ab9so34189a91.3 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=1764976768; x=1765581568; 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=r75KP3MfE3xvB8M90mZtNcH7CuSSTaOPShGdGL5u5R8=; b=0uCEu18YIJe417Jps0aU4Xep7Jcz/n77HR2rItyibhuSDSjmHqvTM2/x2AzPgbPSsx DcBGyBJXxGAAJ2Yfig0f9bLvMVSLvGH6GfpqoO9wPS6Da8YEI+C1U20p3TZIkCed80dO qlsc91qa/Lq+TZd9eCo6O3WhSOns//GD9k7HhsL+Sefc5RMP5WvskEpUj+4CMbt0iLvJ zR/uIIfEJmaRTTHPbfTHvxmHDveC6Z2TmEh+sH6rxqEanEcgt9zGEA7jJcx6XaF/E2kd hfT2aYDy+Cc4EONSNPJhMV0j3nKEJmwKwjWTsqSngpW++zEv5GD2Q1hPtQkhUb5j1H2B aMHg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1764976768; x=1765581568; 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=r75KP3MfE3xvB8M90mZtNcH7CuSSTaOPShGdGL5u5R8=; b=mOiVKQjDdlyP9PRzEz4GlvAoHpe7YQLWJOYqwU374Luz1q19wPZr8BrPz60HNjl56Y 7gYEuYeoAGFPprWYPpa5u0NxbPhYb5UJwEGl/YnRpR79EMd1mebLfwZXN2dRoKpczfX6 iOKGp+ZttRSI1num79iNT1MPWSaPuWHrPpZ6CDTOoyKx9scdbnqDW7/XzHf06dkFUYEt YqsEbV3UY1vGbNrt7aRAR9lAtcht/os/qpV1fIbEwfedtx0AnklMtMsnVzsmimKsbMxS vLU4f1P1cv+qaQ5Ohpr/tfKJGkmVvSeIa/p6keu5Fdd0cCYBHSalkfpNi7hveHGe3WAT 7ptg== X-Forwarded-Encrypted: i=1; AJvYcCXmQMpnCD6DkD+fHbU85AOVvCSJYUKPCBYpmFa6RfvrPzHNXx2QhIu33cptKwKhn5U2h1Bm7n6RdQdnG8s=@vger.kernel.org X-Gm-Message-State: AOJu0YxF2lZMWjLtrDgH+udANXK82oEjoCr9XDdeOCLy4KqR9wYQUxJN 6F0511KGO0e57kveCklHW8P1DHS2zeKD9IPBlC4lC4HA8p6BSOKm6y3b9ZV6sCQihS3486RwVkJ JtI71WA== X-Google-Smtp-Source: AGHT+IFIPU3ezuGe142lObXM6m/a25sKwMQh+YMXUKaG0a4fm8UgxypvPkcF9Z9j64FfB0DY5nuDnt5zf3k= X-Received: from pjbmv10.prod.google.com ([2002:a17:90b:198a:b0:349:2946:c225]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:4a08:b0:339:d1f0:c740 with SMTP id 98e67ed59e1d1-349a24e48a9mr522061a91.1.1764976768536; Fri, 05 Dec 2025 15:19:28 -0800 (PST) Reply-To: Sean Christopherson Date: Fri, 5 Dec 2025 15:19:09 -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: <20251205231913.441872-7-seanjc@google.com> Subject: [PATCH v3 06/10] 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, Dongli Zhang , 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. 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 2.52.0.223.gf5cc29aaa4-goog