From patchwork Thu Mar 19 12:59:59 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 228962 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 7CD91C43332 for ; Thu, 19 Mar 2020 13:35:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 53DEB20663 for ; Thu, 19 Mar 2020 13:35:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584624933; bh=c1KzFJe5ugMP3VUC9zUPA27C2lYVFTsHoL03CCM2Mlg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=zOmswuk8526WvvcFjX3XU6kUQ7T4W2oKkerGS6ORx4lq+OoNh0TjhCyowvypomPux LaWH4r+1boVPd1P9LQ7fFCQcN4Wrhq/g7XMMYjAxEGWSMgn/vUAtKQq5gnapXrM7AP BGTBd6cXhZS2LqSH1CwiFHEd1fE3p/0o8vMM2Kq0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728262AbgCSNLg (ORCPT ); Thu, 19 Mar 2020 09:11:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:56848 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727745AbgCSNLc (ORCPT ); Thu, 19 Mar 2020 09:11:32 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 74E8220722; Thu, 19 Mar 2020 13:11:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584623491; bh=c1KzFJe5ugMP3VUC9zUPA27C2lYVFTsHoL03CCM2Mlg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=X3cbel7V5xeQMwZMkeShXABzpPdBVahBvTur1Os/MNE9qxKkjeXbwJg0Rw9UBoYUg ly7Scz7nkZlttDW/pbv72VpDdWebPXIvhU6iaBdI9nGvA9ACoSbgQ0nfUXl7PuX5pR J+0arGdgLKOnxZzPCGN/9k8BuIbL1Uo1MHFB74GQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paolo Bonzini , Vitaly Kuznetsov , Sean Christopherson Subject: [PATCH 4.9 37/90] KVM: x86: clear stale x86_emulate_ctxt->intercept value Date: Thu, 19 Mar 2020 13:59:59 +0100 Message-Id: <20200319123940.116286423@linuxfoundation.org> X-Mailer: git-send-email 2.25.2 In-Reply-To: <20200319123928.635114118@linuxfoundation.org> References: <20200319123928.635114118@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Vitaly Kuznetsov commit 342993f96ab24d5864ab1216f46c0b199c2baf8e upstream. After commit 07721feee46b ("KVM: nVMX: Don't emulate instructions in guest mode") Hyper-V guests on KVM stopped booting with: kvm_nested_vmexit: rip fffff802987d6169 reason EPT_VIOLATION info1 181 info2 0 int_info 0 int_info_err 0 kvm_page_fault: address febd0000 error_code 181 kvm_emulate_insn: 0:fffff802987d6169: f3 a5 kvm_emulate_insn: 0:fffff802987d6169: f3 a5 FAIL kvm_inj_exception: #UD (0x0) "f3 a5" is a "rep movsw" instruction, which should not be intercepted at all. Commit c44b4c6ab80e ("KVM: emulate: clean up initializations in init_decode_cache") reduced the number of fields cleared by init_decode_cache() claiming that they are being cleared elsewhere, 'intercept', however, is left uncleared if the instruction does not have any of the "slow path" flags (NotImpl, Stack, Op3264, Sse, Mmx, CheckPerm, NearBranch, No16 and of course Intercept itself). Fixes: c44b4c6ab80e ("KVM: emulate: clean up initializations in init_decode_cache") Fixes: 07721feee46b ("KVM: nVMX: Don't emulate instructions in guest mode") Cc: stable@vger.kernel.org Suggested-by: Paolo Bonzini Signed-off-by: Vitaly Kuznetsov Reviewed-by: Sean Christopherson Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/emulate.c | 1 + 1 file changed, 1 insertion(+) --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -5022,6 +5022,7 @@ int x86_decode_insn(struct x86_emulate_c ctxt->fetch.ptr = ctxt->fetch.data; ctxt->fetch.end = ctxt->fetch.data + insn_len; ctxt->opcode_len = 1; + ctxt->intercept = x86_intercept_none; if (insn_len > 0) memcpy(ctxt->fetch.data, insn, insn_len); else {