From nobody Sun Feb 8 21:33:56 2026 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 C1D56331238 for ; Thu, 15 Jan 2026 23:22:23 +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=1768519346; cv=none; b=DBOQh1Q6bCFS3JRyRxd2QXCPZJRJdn1gVUDGJOtuABIc7DJvZyLEqSQC1tq/LjyUx/HT+26bJBwgEStSSz1IFDpBsUUnwoGXgbxFvlyS11LSkSdkN7QXvMEeQm1ygtivMk/2Mktl8arz9y74fzCVyudZIlRUZZ1GlvMrnBiGFA0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768519346; c=relaxed/simple; bh=QGaBI2jmMXiz5Zzh8UzMEfKuZBd6orN3mlkFUEX03hI=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=E89FbT+yqDphqPQxspxlx8OzOIA7nmr942uujG3ifF+ZrzoYyjRR+Hr7zzuUKhbfSlfly8wm++Ct8W25BguoEGbXOu/aR6D1AEgSYqX2XEUgdP2Fl3coFTaTQ00bpItqmSZWFckz0jxTQPz6JXaK7K3UCMagRrq6TnZjeX2LdPA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--jmattson.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=cxPsHpYF; 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--jmattson.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="cxPsHpYF" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-34ab459c051so2814251a91.0 for ; Thu, 15 Jan 2026 15:22:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1768519343; x=1769124143; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=X41FAJWB3N1JsaEn1Z67wfrNr3PEAApqVjSGPombTu8=; b=cxPsHpYFdUSeHGJ9xX3z+/Yt6qKvljuGIAInnN2I65i78DPIUmHJV6UmYqeMdVtKkd zr9ylpi1hpiZJURV6smmbLB7kbHcIX0sQnzLXcsVEEEUkSjo2ehvXtjIIB8TmLdB3XPC hzNtEoD8mEU/XyuVQm6QbOyFHbp3YCrjD7T3NX9fu6nfYDKowuaAYpjtQtD0TO3zMdpB jir6ay6CnKDpvSzGOEHdpupD+EKaSGeGyXctWEdQ47bcmILjWFiq32uEzUb/y/51eHNZ /SHXLXH+D2WYy5i1SqJJMgmobI4LqcJ3v1BVYqVmc4oq7cLwZaRdZJgmVlRWMlwgfcyw aGmg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1768519343; x=1769124143; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=X41FAJWB3N1JsaEn1Z67wfrNr3PEAApqVjSGPombTu8=; b=b4x4m34c/SMrWxULC8jiY9xN6QtYum7F9fr0CNpcmEJYqWCU8iYL8ZzUg+90V81b2E /rItq/QzcDeBREhJlPmGXTBLMcXINN/NisJXAS5AWO19/CeI5oI//PdoO14fHHk34uiK ppC39o3OHaQMRHY4cIp8/0tb7yhauigMPWXaBLXXXTNxQqvvWMiHNeD+eyGz8fqlNmO8 CVdGrKwXAEchwxZ5Lf44pGKhULOmznJg0LXqZ/Q204YYsx6psyl1qFAQF947reZoDJkJ UNqY29OtKf200jjzNCr978kfW4QCCZO/9Guli4DDH/p/66cYFK/Yl9NNPwE77ToQCUPp JE/g== X-Forwarded-Encrypted: i=1; AJvYcCXoj9yrhgy8l1r3QaDNCogGlrXUH6FT1KKmAHVNThsQrzRPpvv4MSRHxtrAAYSXSnv0qPs/9B8XNxrWAjY=@vger.kernel.org X-Gm-Message-State: AOJu0Yzrj9aH3T4+bF/HXMhlq7FW2fjAaEEqQ3xZm9JOaJLVxJbBdA2E XXu7QTlavlTuYP+5/o12qw2CxZKSUyNRefUHP/A9fcjnujJWS54q5eAfheqnilmlYX/Mv7w5HFz 2hPRWVTlE3DBKqQ== X-Received: from pgct22.prod.google.com ([2002:a05:6a02:5296:b0:c1d:b0b3:5e63]) (user=jmattson job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a21:7116:b0:38b:e9eb:b12c with SMTP id adf61e73a8af0-38dfe67bddemr1490481637.31.1768519342651; Thu, 15 Jan 2026 15:22:22 -0800 (PST) Date: Thu, 15 Jan 2026 15:21:46 -0800 In-Reply-To: <20260115232154.3021475-1-jmattson@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260115232154.3021475-1-jmattson@google.com> X-Mailer: git-send-email 2.52.0.457.g6b5491de43-goog Message-ID: <20260115232154.3021475-8-jmattson@google.com> Subject: [PATCH v2 7/8] KVM: x86: nSVM: Handle restore of legacy nested state From: Jim Mattson To: Sean Christopherson , Paolo Bonzini , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Shuah Khan , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: Jim Mattson Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When nested NPT is enabled and KVM_SET_NESTED_STATE is used to restore an old checkpoint (without a valid gPAT), the current IA32_PAT value must be copied to vmcb02->save.g_pat. Unfortunately, the current IA32_PAT value may be restored by KVM_SET_MSRS after KVM_SET_NESTED_STATE. Introduce a new boolean, svm->nested.restore_gpat_from_pat. If set, svm_vcpu_pre_run() will copy vcpu->arch.pat to vmcb02->save.g_pat and clear the boolean. Signed-off-by: Jim Mattson --- arch/x86/kvm/svm/nested.c | 9 ++++++--- arch/x86/kvm/svm/svm.c | 8 ++++++++ arch/x86/kvm/svm/svm.h | 6 ++++++ 3 files changed, 20 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index c50fb7172672..61a3e7226cde 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -1958,9 +1958,12 @@ static int svm_set_nested_state(struct kvm_vcpu *vcp= u, if (ret) goto out_free; =20 - if (is_guest_mode(vcpu) && nested_npt_enabled(svm) && - (kvm_state.hdr.svm.flags & KVM_STATE_SVM_VALID_GPAT)) - svm->vmcb->save.g_pat =3D save_cached.g_pat; + if (is_guest_mode(vcpu) && nested_npt_enabled(svm)) { + svm->nested.restore_gpat_from_pat =3D + !(kvm_state->hdr.svm.flags & KVM_STATE_SVM_VALID_GPAT); + if (kvm_state->hdr.svm.flags & KVM_STATE_SVM_VALID_GPAT) + svm->vmcb->save.g_pat =3D save_cached.g_pat; + } =20 svm->nested.force_msr_bitmap_recalc =3D true; =20 diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 3f8581adf0c1..5dceab9f4c3f 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -4217,9 +4217,17 @@ static void svm_cancel_injection(struct kvm_vcpu *vc= pu) =20 static int svm_vcpu_pre_run(struct kvm_vcpu *vcpu) { + struct vcpu_svm *svm =3D to_svm(vcpu); + if (to_kvm_sev_info(vcpu->kvm)->need_init) return -EINVAL; =20 + if (svm->nested.restore_gpat_from_pat) { + svm->vmcb->save.g_pat =3D vcpu->arch.pat; + vmcb_mark_dirty(svm->vmcb, VMCB_NPT); + svm->nested.restore_gpat_from_pat =3D false; + } + return 1; } =20 diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index 39138378531e..1964ab6e45f4 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -219,6 +219,12 @@ struct svm_nested_state { * on its side. */ bool force_msr_bitmap_recalc; + + /* + * Indicates that vcpu->arch.pat should be copied to + * vmcb02->save.g_pat at the next vcpu_run. + */ + bool restore_gpat_from_pat; }; =20 struct vcpu_sev_es_state { --=20 2.52.0.457.g6b5491de43-goog