From mboxrd@z Thu Jan 1 00:00:00 1970 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 376F83A9DB6 for ; Tue, 24 Feb 2026 17:43:33 +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=1771955014; cv=none; b=LgNPObn11kKfWr4VhgY9u6nATN/paPag8wd2gkbvhCpaogVyCYBbeBggvhBP4Dut7vqqV26lKl3ws/XpTXJoff0JLPZKsJ/Q+UbZKCRbX/pGnkFUqTM0W5Y4dpgtGyDFcVr1t70Sr7oVQl0xNrNeLInqCmf0i13dSEMkTySvv9I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771955014; c=relaxed/simple; bh=CzXhE6NIlz4EonhiaZ5X2vjm+voehRbxgQYJDKg7pfY=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=F5EtVpgE1hgb0oA59ryeUDN+kKajp5SAFqGEFIjN02eurYenLsyrNxVMOqdQ1S6MOfIcBPmGx+Gy0sTPJbYOogGOc3HTb32dxanMkso9Gd0DtYZ9zwzH02xdoyRGvKgX04XiJWiYX1uBcuxWGedFF8OmybuwJtbaIERcwtD3760= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=xylueOVz; 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--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="xylueOVz" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-35449510446so5760269a91.0 for ; Tue, 24 Feb 2026 09:43:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1771955012; x=1772559812; 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=7EJ6jDZkcc54+WfMFP83ReJ+Vv39B7Cq+a8KWyoH30M=; b=xylueOVzD3NHwth8hX+kofCnh4QGm1w6LBpFpTOTc0f2m8Mh77Kct3OBXyWoj2zN0X A4d6d8HzHwoFT/4gxQ3Ky1HBcjaBgXwwzTMzuX+mrj9ZFRFBTC0JMKH3ZKj86pF35ssP fWoTzA7qkTwTf3QsxNAjiVKjwfgVq4ijw2bXdtupgzUq0oabjhgJDG5xlPXSrEqfvHBQ S4KwfzQ0mUvAzpxIeqz48Df9pugb36b47rhhaWjLTR769eDpUuMTTRcgGIfg0viyavlp +r8iRa0plO7YpdcAHbsmm1GAb9+Ia4drPeZAlUSZ1H9L4+3Y4GKuIL9CpILxY6HkZh0x b5LA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1771955012; x=1772559812; 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=7EJ6jDZkcc54+WfMFP83ReJ+Vv39B7Cq+a8KWyoH30M=; b=qXAOmTXkd/qmXq/XBMhHA0ETm6xLHWDoHnpGgKQvIqgzEWtH62/Ko4d7ZMZi4qbW2d o/kSHFZ+mG2L/aqSdvVadZNaPf70pvNOHDy1TKRdvATIAuJVkVs8+F66eLpFxdMXqzQm aQh2VPK/wSLHGjdgIiw0RNIMZ8B9XJiDMWuE1RR/bq2qawuAauzLvGm6j1ud+AoELehR A6TBbKn1ndw8+O7/9+AcKkJc2cg3wQsHoK/KI/FeXL7W14CgmM5X+6Bb3KKi4VYJGLMT 9zJFV3a0yqvRGWwUIokFjBm+9FZvrL2FA3dsOGBrmUecNOEhvwehrYAnOdUc+6ICfbrc w3dw== X-Forwarded-Encrypted: i=1; AJvYcCW2gpHYYPa/caAsbVXdMdyK3RbSvHYjXNesrhISnogT9iMPHgKL/IPi5hRM6EQjUcr13T2Q3QW9Qk0R0R4=@vger.kernel.org X-Gm-Message-State: AOJu0Yy/8+1VuufDCi7utxlMidCYedYoUgmcyjpDClqcjLe1z4sEVmNJ GVJphtmgH9at32c4Kw3+1EyUq538XloVhoyxy8gw3VXW07Gio4MSY5ANUoNA+mUKfhStPBXK0m0 /hRGyxg== X-Received: from pjqs3.prod.google.com ([2002:a17:90a:ad83:b0:358:eb53:2d1a]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:4b10:b0:356:2db3:1206 with SMTP id 98e67ed59e1d1-358ae80a6a3mr10275503a91.13.1771955012397; Tue, 24 Feb 2026 09:43:32 -0800 (PST) Date: Tue, 24 Feb 2026 09:43:31 -0800 In-Reply-To: <20260224005500.1471972-6-jmattson@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260224005500.1471972-1-jmattson@google.com> <20260224005500.1471972-6-jmattson@google.com> Message-ID: Subject: Re: [PATCH v5 05/10] KVM: x86: nSVM: Redirect IA32_PAT accesses to either hPAT or gPAT From: Sean Christopherson To: Jim Mattson Cc: 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 Content-Type: text/plain; charset="us-ascii" On Mon, Feb 23, 2026, Jim Mattson wrote: > +static void svm_set_pat(struct kvm_vcpu *vcpu, bool from_host, u64 data) > +{ > + struct vcpu_svm *svm = to_svm(vcpu); > + > + if (svm_pat_accesses_gpat(vcpu, from_host)) { > + vmcb_set_gpat(svm->vmcb, data); > + } else { > + svm->vcpu.arch.pat = data; > + if (npt_enabled) { > + vmcb_set_gpat(svm->vmcb01.ptr, data); > + if (is_guest_mode(&svm->vcpu) && > + !nested_npt_enabled(svm)) > + vmcb_set_gpat(svm->vmcb, data); > + } > + } Overall, this LGTM. For this particular code, any objection to using early returns to reduce indentation? The else branch above is a bit gnarly, especially when legacy_gpat_semantics comes along. I.e. end up with this static void svm_set_pat(struct kvm_vcpu *vcpu, bool from_host, u64 data) { struct vcpu_svm *svm = to_svm(vcpu); if (svm_pat_accesses_gpat(vcpu, from_host)) { vmcb_set_gpat(svm->vmcb, data); return; } svm->vcpu.arch.pat = data; if (!npt_enabled) return; vmcb_set_gpat(svm->vmcb01.ptr, data); if (is_guest_mode(&svm->vcpu) && (svm->nested.legacy_gpat_semantics || !nested_npt_enabled(svm))) vmcb_set_gpat(svm->vmcb, data); } I can fixup when applying (unless you and/or Yosry object).