From nobody Sun Feb 8 21:47:03 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 052642868B5 for ; Tue, 13 Jan 2026 00:30:46 +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=1768264248; cv=none; b=ZBXAGQCZKbYqeDZMQPcFYfzJ1hRO0mXeqKiRYeoLAcpJGVjlNiXR7DbTu6ztnnAshrnabSpZ2RgMz2YSZMUmaGU5yE/pEeXWGlPZ0exApGkHL6uKddL9gaBaHECFpj851WERk1veiZrotqXs+gR6e/rtgxlDz/sD1rAZANLA7jk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768264248; c=relaxed/simple; bh=hX4XPV9AeeVtqdf1qUwScjy5RPlzHKp24xAasklIFrU=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=ue7x8NvOh5F5MMtjyWYX4o3SDuyCsVT4H7MMBhNU6qS8Sg+Let0Ju8FE8O5wWvwkwuihHC4JYDHdJPjCv6VGUYqAbc1oRVfiAb6jRIT8MNkG3F/iMPOVo4oQnAuKE3oZszQt3GZvJdW69I2dYAK10uDngO+IJcGkAAahRFg15Sw= 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=kUF2KvF0; 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="kUF2KvF0" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-34c21341f56so14157999a91.2 for ; Mon, 12 Jan 2026 16:30:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1768264246; x=1768869046; 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=6EcXdxHH4rwGl4QLydVFW9PObH3AsANvQWjOw22pmtw=; b=kUF2KvF0XYoZhiJ5VJMUG5IpgxcxdTRZn4DfrkSWK+1KRrvP+TA0AhxsKPWyi/bSPZ jNDHmj3/831EXUfnduxLAx78bWs5rhaa6sYQE7gZMn1MmFuKBCanY0PyZemiiRYjM45Z f/x3th3MH/W8Jgh/ldiBNcXCzM7szao/KVpm12AWmLuoI9s805hUSy4hyr6P+pxl2PwM cHfb9aFKgsSnvzFAlpjjy5z/8ugwOyGpe1JJAESln0v3MM37AYC0Z4EDuhr40cAlKIAv 20Nc2+5dysKmqOdtyF9lt+wbXVjLaRYbfxRQxqTCG1PXKgBREp93T259wIJyNak7ysjP Uymw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1768264246; x=1768869046; 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=6EcXdxHH4rwGl4QLydVFW9PObH3AsANvQWjOw22pmtw=; b=r1CBbUEiE1ZBTbEKn8RZ5Gg2rk7jBPOisIqo/aMk21KnpoY5+tk472aZ1/2AZOnWbC pdqoBAL7+bEvhtJ3i5H+nTBg6vUF/ITtE34Lcc58+3YhMbvqdoWVFJhHjwSXDlv8Pa0a DllM6PdZpV6T2h15ynbVAmIC3q6SE8Ft95SaGMbtadbDtUdkok+KnRSlbo35osQValp0 IUMcvJdmbxSSKubwXRmufGckpFJ7wryNkp7eWToaEDLYcUaty9QKWhaFRyBrDbg1X1R/ XFksxOktkLa2bNWb40MhllI/bVVWGA5edOCxIDpXTqmQ6Du6GsvFn75peAxGnSwcChYu farw== X-Forwarded-Encrypted: i=1; AJvYcCWSQNXVli9mfxR8QNfiXdX33mvbrtyVZtdTOmD6QZMpLEKBXFIuZLrpIj4Uvtp+8DXW1Ocp0JN81Vn5kB8=@vger.kernel.org X-Gm-Message-State: AOJu0YwSde38VqfEmBfphfauiFiAHdgcoXEU5zWqLvL60CpWZ9A6g/9b 1qiIcUkBDpKnjsSMKEoK0O6IP24+3frMZ9VybRjwzTONrSg3dE+dv7A1RPTWkcFI/5TXhzQk1W4 ke+eNjJGePdQE4w== X-Google-Smtp-Source: AGHT+IFhcO4kGUHRcas1ziWGAEnxOQWCZYsu3xXdMqr8zv3PecxeckJ8llCyD0ioPh/h/8s0btpYHCooQHVdTQ== X-Received: from pjqz12.prod.google.com ([2002:a17:90a:b10c:b0:34c:2156:9de7]) (user=jmattson job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:4a07:b0:339:ec9c:b275 with SMTP id 98e67ed59e1d1-34f68c308camr18893414a91.6.1768264246387; Mon, 12 Jan 2026 16:30:46 -0800 (PST) Date: Mon, 12 Jan 2026 16:30:02 -0800 In-Reply-To: <20260113003016.3511895-1-jmattson@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260113003016.3511895-1-jmattson@google.com> X-Mailer: git-send-email 2.52.0.457.g6b5491de43-goog Message-ID: <20260113003016.3511895-8-jmattson@google.com> Subject: [PATCH 07/10] 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 , Joerg Roedel , Avi Kivity , Alexander Graf , "=?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?=" , David Hildenbrand , Cathy Avery , 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 IA32_PAT MSR and to the VMCB02 g_pat field. (The latter can be skipped if the VMCB02 g_pat field already has the correct value.) When NPT is enabled, but nested NPT is disabled, copy L1's IA32_PAT MSR to the VMCB02 g_pat field (L1 and L2 share the same IA32_PAT MSR in this scenario). 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 | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 501102625f69..90edea73ec58 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 +663,26 @@ 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)) { + /* + * KVM doesn't implement a separate guest PAT + * register. Instead, the guest PAT lives in + * vcpu->arch.pat while in guest mode with + * nested NPT enabled. + */ + vcpu->arch.pat =3D svm->nested.save.g_pat; + 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