From nobody Wed Feb 11 01:25:45 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 B962032C333 for ; Thu, 15 Jan 2026 23:22:18 +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=1768519340; cv=none; b=d/r0JCHf96s8anIvC12XVjMI50FWCrjfH/hodpZvvdfKF5ffetyR0UHRCir36LwQeNyYiTzxbkfjd5/x7/lnRZEbu4OChlNZgPSkC07YBsFJRDUk8n/o9vW9rl5raHnVTAnjBcBK24Tm//5TBm6kVnzQFKto+/0hog2ksAqzxVk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768519340; c=relaxed/simple; bh=pQGqZHvp21TJMQpJakX2U4AKh8qO1CopjjvFOdIp6ko=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=PLPjbhkLKT9gPGxqf4mvuqwQbzd2RNJKKvi78ZmuNIG039cNVMTfwhYKEWF99eEWY6Lw1QmHe+RPq7R5GZUqG6p7OzojzXhcY9wWawUZ4b9kjABjXqgmr6vZilhgZ7XOICag4xnYNeoIOdbVnQhRIDS/HLTDWw/ldwNZ3z0D70c= 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=NpW59nio; 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--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="NpW59nio" Received: by mail-pg1-f201.google.com with SMTP id 41be03b00d2f7-c52d37d346dso770185a12.3 for ; Thu, 15 Jan 2026 15:22:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1768519338; x=1769124138; 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=M/rH7YdPCxq3Y37lIh13jkzHenRj4dLCp8dTpSUr3u0=; b=NpW59niolhJW9LTEvEBhLa2YE6rELXZZ0J3OmLd+CsODYS9fVLAzXI1U7x5YSlBOZ2 N7fvIYwYbWQwpFuUMD/rHd+4rDl4oazUHzJ2tT2fksIONqT0UktLi8d0WpXD/Btg03Vb 75snIUS5c6yZKCsBYHwr3PIqJtA5xDHwxz/qCoM3Fd9odc4C867JlGTP56MTvrbYrcRm Jsdhr/Px5Z9ChuOfkclknmlm7qQPYunxQz15KUCRqEkaR8nG/kevGeY7KwEYVZxVJrN2 x4F5EuEucQ8UracKlSQ2NBP2WyICbiLNcBNwufHpBR86hNWn8FsYoMh7l3QMm8hTsqqQ FcZA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1768519338; x=1769124138; 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=M/rH7YdPCxq3Y37lIh13jkzHenRj4dLCp8dTpSUr3u0=; b=L/tLtZOOHJ/D+DIgZZXsrMxKmw1cCN80nWLiJXTRgKs5CJwxXf2xHrYKefyu8VPV+n StVeqrAVDUcLsdLknhJTMxoP12N1+QBQMrSh+2PNrE7C0PLhHGp3ZGoooU79s7gPl/A1 Q+9jcwk16gZUoaEH6JbpqrYulxhMAN+Tgrizje/EcaXSoK9kjFaLdM2TNmWsOBkuVJZH ZngrZ6a6uPDclZ0kn4EvMYY4WqnVqnOasftz6CpCX+MZklB0HZcJiPZubYFWxdQLXyfo l3d4F6Zt3W94qkVItWYB6HG4nyrvcY0sZGBOBsMDIJsAoPOxUXV54ybdpcEtF6OHCSMw VA+w== X-Forwarded-Encrypted: i=1; AJvYcCV/b+913Clxkcw1AJgxOc0QGgwVn+2msH9Vgo9u83cfP17LC7lDYX9QRnplwr0QRIJEX9DSIIHf1MxeJK4=@vger.kernel.org X-Gm-Message-State: AOJu0YzuUEbo3GImdlOLd6gkDak63dxkLfcb38lsPYWhQhmouSSaKgOG kCxzY6zr+HhLuMjf5Ux468vwSNEywr7aZZ8qGowbl2hWLg6niuJqizLmxqgb8ke0EEjyUT1GVkB bRdrF1u25cu7WFA== X-Received: from pghi22.prod.google.com ([2002:a63:e916:0:b0:c52:7760:c1bb]) (user=jmattson job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:428b:b0:334:8a8e:6576 with SMTP id adf61e73a8af0-38dfe5e7ae7mr1184649637.29.1768519337975; Thu, 15 Jan 2026 15:22:17 -0800 (PST) Date: Thu, 15 Jan 2026 15:21:43 -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: <20260115232154.3021475-5-jmattson@google.com> Subject: [PATCH v2 4/8] KVM: x86: nSVM: Set vmcb02.g_pat correctly for nested NPT 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 in vmcb12, copy the (cached and validated) vmcb12 g_pat field to the guest PAT register. Under KVM, the guest PAT register lives in the vmcb02 g_pat field. When NPT is enabled, but nested NPT is disabled, copy L1's IA32_PAT MSR to the vmcb02 g_pat field, since L2 shares the IA32_PAT MSR with L1, When NPT is disabled, the vmcb02 g_pat field is ignored by hardware. Fixes: 15038e147247 ("KVM: SVM: obey guest PAT") Signed-off-by: Jim Mattson --- arch/x86/kvm/svm/nested.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index e65291434be9..b0c0184e6e24 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -656,9 +656,6 @@ static void nested_vmcb02_prepare_save(struct vcpu_svm = *svm, struct vmcb *vmcb12 struct vmcb *vmcb02 =3D svm->nested.vmcb02.ptr; struct kvm_vcpu *vcpu =3D &svm->vcpu; =20 - nested_vmcb02_compute_g_pat(svm); - vmcb_mark_dirty(vmcb02, VMCB_NPT); - /* Load the nested guest state */ if (svm->nested.vmcb12_gpa !=3D svm->nested.last_vmcb12_gpa) { new_vmcb12 =3D true; @@ -666,6 +663,19 @@ static void nested_vmcb02_prepare_save(struct vcpu_svm= *svm, struct vmcb *vmcb12 svm->nested.force_msr_bitmap_recalc =3D true; } =20 + if (npt_enabled) { + if (nested_npt_enabled(svm)) { + if (unlikely(new_vmcb12 || + vmcb_is_dirty(vmcb12, VMCB_NPT))) { + vmcb02->save.g_pat =3D svm->nested.save.g_pat; + vmcb_mark_dirty(vmcb02, VMCB_NPT); + } + } else { + vmcb02->save.g_pat =3D vcpu->arch.pat; + vmcb_mark_dirty(vmcb02, VMCB_NPT); + } + } + if (unlikely(new_vmcb12 || vmcb_is_dirty(vmcb12, VMCB_SEG))) { vmcb02->save.es =3D vmcb12->save.es; vmcb02->save.cs =3D vmcb12->save.cs; --=20 2.52.0.457.g6b5491de43-goog