From nobody Mon Feb 9 12:24:59 2026 Received: from mail-pl1-f202.google.com (mail-pl1-f202.google.com [209.85.214.202]) (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 C91AF334372 for ; Thu, 5 Feb 2026 21:43:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770327822; cv=none; b=EIlgzHjfD3Jx5h6qxf3VvoS3K964bGIfVR/yUlxJfru/WfZsV4FpqhkWKh8apcYpcVtjstWUH3jTxA9pMdYp+Y7YdDq1D3G2jVK1aQ/u8c8Qgat1lEdudEytXDwpgPDEf1c+kUJh/bQVVvespcFNNavoJDkLkF0IBkDvvBcNNyw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770327822; c=relaxed/simple; bh=/RX4mCH35HZdkO8HyVbrveLVnRTbZa+1vh8oTPb28F8=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=L5Abs/VIWGXBoeJ6d73CbUcjutO9jZS9WT6smlfoUUHe7GWdfcuZlryQ74pPk0B0VZntPS5OI8Dfw9rjxQS09Nx2DecePRKiEG9CSmxYknNCHTP0RqFVMH7ozbhH8XfgWU2xPVQpqmwWU/gW8Sqz/EWSXvhz9o57GpKc29RRSHE= 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=PzElm3RG; arc=none smtp.client-ip=209.85.214.202 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="PzElm3RG" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-2a07fa318fdso14634125ad.0 for ; Thu, 05 Feb 2026 13:43:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1770327822; x=1770932622; 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=Vzh3iLHAfWUF+ni0XgKYTYRZaX8q/MuSJjdjzVEy2HI=; b=PzElm3RGGIe7FaErGMIOiEXp6nZ4slLg/mnY4AHOYO2jEy4jlgRBXsBT3q6U3NQOzb y19GgpPmv9R93CFzhmpTmhYMvCVhRQx/FudrcbRX3a2WfR3rb763RWntTlC562t1TXNQ Yf9R3fbj94z4Lgi6ROTAW+jB0lXeshvyKmx9jGpJj3lluKskZX8tCm14HGiKYTJNYnCu uYLHL4UCoWkBD+q76gXuua3C9f7uwHkgiKcmCe4vDudOxjDvK8uphtA4+irSNpMsYOdd /G7rGOZ8gcpMcsoXjxTt/UGNlm1zApNTwX/ac6XUg5o/7CuK29hqAuk2FX4OClKYXK/l bcJA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1770327822; x=1770932622; 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=Vzh3iLHAfWUF+ni0XgKYTYRZaX8q/MuSJjdjzVEy2HI=; b=tVzeFDmKv7+6a8Ar2aw2UXo4dBELqt3+FeBDrZVbh6itcCSWt94ODyjtWd+6NVRMMf q069MPjmDe4xtDGMrAIZ7NowUB30GzYuVvH50YJ38SFxg313UgSNts14iNG5jnNyxw3N /DgXM+0RtrwmpE6pDV17+Q4lcsnAZTb45dVB0kdrpR5J95jAoxrEsizBIpvH+iAbnTBR 3mRpDyIv9JfFoWiecoyqZ7u76Ua2cIFBz8llLGMwPl8GRcx2JhLyCxSPaujUZX+qk9RR EwOAPEeRsUXoNlsXUdOUAYsC7GYpHVMJfOqPD/F7Kk3Yh3GRLqm9Y3jA1clA4HVIiFul LD/A== X-Forwarded-Encrypted: i=1; AJvYcCWkybTPPAdxoZ/LaEgRqS35VKjTYDfAMcz3n5WMEbqVThqMOElnkT3NmIsw64WIj7ckkMsJ58tEr0M9GcE=@vger.kernel.org X-Gm-Message-State: AOJu0YyBny0oXuD5TpUffzwlm4wxS2NTB7toWny8cxNhFMo5bQI5Rt0v 9B/RfYEbyqHwDIxBLhg9taoZ2T8cgpklTC9xfv1b73BHd9ZsEY2HH2GmQ7TO/mkisyl/jq2q1oa N4s2pcGLK+B1lTQ== X-Received: from pjq16.prod.google.com ([2002:a17:90b:5610:b0:34c:2778:11c5]) (user=jmattson job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a21:517:b0:38b:eeb9:cbb5 with SMTP id adf61e73a8af0-393af0da032mr246446637.39.1770327822187; Thu, 05 Feb 2026 13:43:42 -0800 (PST) Date: Thu, 5 Feb 2026 13:43:03 -0800 In-Reply-To: <20260205214326.1029278-1-jmattson@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260205214326.1029278-1-jmattson@google.com> X-Mailer: git-send-email 2.53.0.rc2.204.g2597b5adb4-goog Message-ID: <20260205214326.1029278-4-jmattson@google.com> Subject: [PATCH v3 3/8] 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, Yosry Ahmed 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 1d4ff6408b34..1ff2ede96094 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -646,9 +646,6 @@ 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; @@ -656,6 +653,19 @@ 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.gpat; + 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 2.53.0.rc2.204.g2597b5adb4-goog