From nobody Thu Apr 2 20:26:36 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 93ABE318BA2 for ; Thu, 12 Feb 2026 15:59:17 +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=1770911958; cv=none; b=dcNyzuYO+d9mgrR2y1dVxadpSPm6/zwG9AwFtCNSiswQgebhvSHXdS2qvPKy2uNqzyF7ObQWMJFzR2mEEmD6C01sLtMlWuQxPfmM1cr7zr8OCNm5DQbAx3ryZQQ8fdldb9gIzFFaULVuA+swMFYBafRl+xw+3Ml3hP9F1jP52zQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770911958; c=relaxed/simple; bh=s4DygJeXL0KLLS5zyD1EU8BmPQvpE/qt7AMgOQ0hWEQ=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=LpBs45eR3NJDByka6i3/hLxG+ADec1y0LJ9yechH3Yk9HlgO4K7DINfMip8vmqTcINOcaEYME3BAjytbwtK814b2YgHqk9hq8RluC18HtUCrrP4H5raY00Vadg25kuFaSTQIt1ceStudLHgXxQrVsAzwebsOPGRm/Gg8k9e205I= 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=taYhWl0V; 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="taYhWl0V" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-2aad5fc5b2fso35291065ad.1 for ; Thu, 12 Feb 2026 07:59:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1770911957; x=1771516757; 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=NXWGIZTswQvFKRAzrwUvmCg40y2DnJJnM3/XWRTJ8no=; b=taYhWl0VakB0+GWUKmGV5DQjC/DmSRoYMX3fcdswEOWsXo85OAOOeEuzw9x1nx7lhV z6QUtL2RtrTl5n1TbCjWO9juQn9hiLOLlUh7fE0eos6LYAxCkXy7dEBmjGG2o2kMADQi iTaJxSI3GxCSyvSt+gWRR79luHr1yPitmZwidq+2KmF97naRUEFMVJMYsmQHk09QL+kY dV2Eya9KLQiT7Et+pLS5R2L3tUZjdbJetRv3QKzhx+wwLXBRq2qPySCmFK+fNXv1jlzy yA1eYGC45t8YkIHRjN1DOklxmQ/zbQHCWLDoWBQ4v27dAdcr88uBXI57N5ls1c00xZjG IIEg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1770911957; x=1771516757; 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=NXWGIZTswQvFKRAzrwUvmCg40y2DnJJnM3/XWRTJ8no=; b=WKvT1Jf40rjgMbCPGB/y+Wjj8cMFKF8II3VVZl9V0Nr4jSVRwXv5I5fsmF3PnJFeup cPDqrROZ968CVkBMkLtYqf4NpX+kJysGXNq3rHkHDqEMuCBHYhbgH4eASlzVC2G17ELM 948JSu0ocw/JS+M3A3MURcuy0j5OHhfxpopsgt6eghjWCqOKUySjUV03AT1wJNMDQk3W 7LJwqUQYn5RI7ifibnnq7q+HWr0M6sN+PEz20x+EZUujofc26o+QajClNb4/O/hGen8o nf0dpqUcKk2fNjFvxdFdXD6Zv0Daq4LItEh6u0dPTX0EJwn30c46NsMf9dfsPy2rhCqn WC4g== X-Forwarded-Encrypted: i=1; AJvYcCWvh2gMAy1mAcm56JFwAiL082LLbbLfLuYmHL1EU+asyuSv+8Ozh8TkhP1O/J31z91DpcKjdE5HsnXvaOU=@vger.kernel.org X-Gm-Message-State: AOJu0Yxxv1ukRP7vSl2OTxEp6BipuBImmaVGNWfbPaTojRHMYxZZjlJ2 /OW6zoWOooQ5vDW8/CJlqXgQ4vb1VGV1tgLIvk2Pg3s2uMwBjoDR4vDtKIPdc/PqvqrNuNH0xp4 lIJh9JhSuVXungg== X-Received: from plbje12.prod.google.com ([2002:a17:903:264c:b0:2ab:f1d:4446]) (user=jmattson job=prod-delivery.src-stubby-dispatcher) by 2002:a17:902:d2d1:b0:2a9:602c:159 with SMTP id d9443c01a7336-2ab3b1a00c3mr29570985ad.19.1770911956923; Thu, 12 Feb 2026 07:59:16 -0800 (PST) Date: Thu, 12 Feb 2026 07:58:51 -0800 In-Reply-To: <20260212155905.3448571-1-jmattson@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260212155905.3448571-1-jmattson@google.com> X-Mailer: git-send-email 2.53.0.239.g8d8fc8a987-goog Message-ID: <20260212155905.3448571-4-jmattson@google.com> Subject: [PATCH v4 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 svm->nested.save.g_pat. 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 g_pat field is ignored by hardware. Fixes: 15038e147247 ("KVM: SVM: obey guest PAT") Signed-off-by: Jim Mattson Reviewed-by: Yosry Ahmed --- arch/x86/kvm/svm/nested.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 91b35adb83f8..dc8275837120 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -724,9 +724,6 @@ static void nested_vmcb02_prepare_save(struct vcpu_svm = *svm) 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; @@ -757,6 +754,13 @@ static void nested_vmcb02_prepare_save(struct vcpu_svm= *svm) vmcb_mark_dirty(vmcb02, VMCB_CET); } =20 + if (nested_npt_enabled(svm)) { + if (unlikely(new_vmcb12 || vmcb12_is_dirty(control, VMCB_NPT))) + vmcb_set_gpat(vmcb02, svm->nested.save.g_pat); + } else if (npt_enabled) { + vmcb_set_gpat(vmcb02, vcpu->arch.pat); + } + kvm_set_rflags(vcpu, save->rflags | X86_EFLAGS_FIXED); =20 svm_set_efer(vcpu, svm->nested.save.efer); --=20 2.53.0.239.g8d8fc8a987-goog