From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 028CAC433E9 for ; Sat, 13 Feb 2021 01:06:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B1B1164E16 for ; Sat, 13 Feb 2021 01:06:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232235AbhBMBG2 (ORCPT ); Fri, 12 Feb 2021 20:06:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33044 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232065AbhBMBGK (ORCPT ); Fri, 12 Feb 2021 20:06:10 -0500 Received: from mail-qk1-x74a.google.com (mail-qk1-x74a.google.com [IPv6:2607:f8b0:4864:20::74a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A8EEAC061786 for ; Fri, 12 Feb 2021 17:05:30 -0800 (PST) Received: by mail-qk1-x74a.google.com with SMTP id z19so1036563qki.3 for ; Fri, 12 Feb 2021 17:05:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:reply-to:date:in-reply-to:message-id:mime-version:references :subject:from:to:cc; bh=OtznJizRN0hv7fVgLX6rnwrrxkCPL4lVRSWsCFjNnfE=; b=t56RiT1euE1E7CnLH3sOlDJSwYjYPxoxi/65GUwODU+vZGxsdYuG5+JudpeiQbYM/C ZFbuxsVlODgPdGNe/ORKCDGDUs6vPLRE4eEUhTNPQMTF/7ka0IiZrgOjzUUfSW1pCy8F yQexKIkRIlzOiBzSslW2f8bGyujBRRESZvdG1tDQJEuEA1sb+qmvq0d+f+dWDsOh887m rICHWD3PzXVRf37UTmBrWq6W5h+X1QzvK6HHtVDPG/lCd16qAg2vUCA4GEUP1MpAPHb1 2CwxXyh/k7TV8L3H8XmmhMcOgp4UegSpqOBvho3GdgNScCjqgwBzUv3s+SCQmCUIax6N ISVw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:reply-to:date:in-reply-to:message-id :mime-version:references:subject:from:to:cc; bh=OtznJizRN0hv7fVgLX6rnwrrxkCPL4lVRSWsCFjNnfE=; b=Do70bg5tSvCTiareANAvwgYdlBcOxqZhbvQg4TJIs2WklKrZnJp35crHianLbHS65U /qc5QlIGsmT7RbD3EN5gyPQXiA7/asMiunsTZ9cVvb+iec3cjD7GOEyUgABsDLk5A4eZ KD3nFfHzYIgJoDNV0ANtY0KWfEUa+bMVerXLrnvUD6ZZRO18j1dWW7wPkxZXMMiqT2nS BfHd6rdmyWsA3BqV6TrLV7ecxmWpSJJzG8dQoArshA0Myu3DuluCWJM4nZ584T4gG8wZ 40YACGLbJ97umSfw10Q7zMsxmZ17SYaeRbNEuBi5K/zxVR0fMqgTfwCNT6zodKdSk6Ok tZ6g== X-Gm-Message-State: AOAM530Rh/vs4bmDtdIkYKF4wOSILbSOa+hy+9j5kza0ixnywia5xLnW rzdjCJuGh2cTbYZVJo++oDsdcHygJlU= X-Google-Smtp-Source: ABdhPJyHJCYOfqtyA0CEPVTw5ctoK1eVWrcbTWX8UBaNeZKIu8zioYMpaKyl/EHcdeGYZhRTW+srES5FTOQ= Sender: "seanjc via sendgmr" X-Received: from seanjc798194.pdx.corp.google.com ([2620:15c:f:10:b407:1780:13d2:b27]) (user=seanjc job=sendgmr) by 2002:a05:6214:20a1:: with SMTP id 1mr5147613qvd.30.1613178329654; Fri, 12 Feb 2021 17:05:29 -0800 (PST) Reply-To: Sean Christopherson Date: Fri, 12 Feb 2021 17:05:10 -0800 In-Reply-To: <20210213010518.1682691-1-seanjc@google.com> Message-Id: <20210213010518.1682691-2-seanjc@google.com> Mime-Version: 1.0 References: <20210213010518.1682691-1-seanjc@google.com> X-Mailer: git-send-email 2.30.0.478.g8a0d178c01-goog Subject: [PATCH 1/9] KVM: x86: Remove emulator's broken checks on CR0/CR3/CR4 loads From: Sean Christopherson To: Paolo Bonzini Cc: Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Babu Moger , Joao Martins , David Woodhouse Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Remove the emulator's checks for illegal CR0, CR3, and CR4 values, as the checks are redundant, outdated, and in the case of SEV's C-bit, broken. The emulator manually calculates MAXPHYADDR from CPUID and neglects to mask off the C-bit. For all other checks, kvm_set_cr*() are a superset of the emulator checks, e.g. see CR4.LA57. Fixes: a780a3ea6282 ("KVM: X86: Fix reserved bits check for MOV to CR3") Cc: Babu Moger Signed-off-by: Sean Christopherson --- arch/x86/kvm/emulate.c | 68 +----------------------------------------- 1 file changed, 1 insertion(+), 67 deletions(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index f7970ba6219f..f4273b8e31fa 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -4230,75 +4230,9 @@ static int check_cr_read(struct x86_emulate_ctxt *ctxt) static int check_cr_write(struct x86_emulate_ctxt *ctxt) { - u64 new_val = ctxt->src.val64; - int cr = ctxt->modrm_reg; - u64 efer = 0; - - static u64 cr_reserved_bits[] = { - 0xffffffff00000000ULL, - 0, 0, 0, /* CR3 checked later */ - CR4_RESERVED_BITS, - 0, 0, 0, - CR8_RESERVED_BITS, - }; - - if (!valid_cr(cr)) + if (!valid_cr(ctxt->modrm_reg)) return emulate_ud(ctxt); - if (new_val & cr_reserved_bits[cr]) - return emulate_gp(ctxt, 0); - - switch (cr) { - case 0: { - u64 cr4; - if (((new_val & X86_CR0_PG) && !(new_val & X86_CR0_PE)) || - ((new_val & X86_CR0_NW) && !(new_val & X86_CR0_CD))) - return emulate_gp(ctxt, 0); - - cr4 = ctxt->ops->get_cr(ctxt, 4); - ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); - - if ((new_val & X86_CR0_PG) && (efer & EFER_LME) && - !(cr4 & X86_CR4_PAE)) - return emulate_gp(ctxt, 0); - - break; - } - case 3: { - u64 rsvd = 0; - - ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); - if (efer & EFER_LMA) { - u64 maxphyaddr; - u32 eax, ebx, ecx, edx; - - eax = 0x80000008; - ecx = 0; - if (ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, - &edx, true)) - maxphyaddr = eax & 0xff; - else - maxphyaddr = 36; - rsvd = rsvd_bits(maxphyaddr, 63); - if (ctxt->ops->get_cr(ctxt, 4) & X86_CR4_PCIDE) - rsvd &= ~X86_CR3_PCID_NOFLUSH; - } - - if (new_val & rsvd) - return emulate_gp(ctxt, 0); - - break; - } - case 4: { - ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); - - if ((efer & EFER_LMA) && !(new_val & X86_CR4_PAE)) - return emulate_gp(ctxt, 0); - - break; - } - } - return X86EMUL_CONTINUE; } -- 2.30.0.478.g8a0d178c01-goog