From owner-svn-src-head@freebsd.org Sat Jan 19 01:08:51 2019 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id CD5441489D79; Sat, 19 Jan 2019 01:08:51 +0000 (UTC) (envelope-from freebsd@pdx.rh.CN85.dnsmgr.net) Received: from pdx.rh.CN85.dnsmgr.net (br1.CN84in.dnsmgr.net [69.59.192.140]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 21CD185283; Sat, 19 Jan 2019 01:08:50 +0000 (UTC) (envelope-from freebsd@pdx.rh.CN85.dnsmgr.net) Received: from pdx.rh.CN85.dnsmgr.net (localhost [127.0.0.1]) by pdx.rh.CN85.dnsmgr.net (8.13.3/8.13.3) with ESMTP id x0J18kXl058216; Fri, 18 Jan 2019 17:08:46 -0800 (PST) (envelope-from freebsd@pdx.rh.CN85.dnsmgr.net) Received: (from freebsd@localhost) by pdx.rh.CN85.dnsmgr.net (8.13.3/8.13.3/Submit) id x0J18isQ058215; Fri, 18 Jan 2019 17:08:44 -0800 (PST) (envelope-from freebsd) From: "Rodney W. Grimes" Message-Id: <201901190108.x0J18isQ058215@pdx.rh.CN85.dnsmgr.net> Subject: Re: svn commit: r343166 - head/sys/amd64/vmm In-Reply-To: <201901182354.x0INspeZ015766@repo.freebsd.org> To: Conrad Meyer Date: Fri, 18 Jan 2019 17:08:44 -0800 (PST) CC: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Reply-To: rgrimes@freebsd.org X-Mailer: ELM [version 2.4ME+ PL121h (25)] MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII X-Rspamd-Queue-Id: 21CD185283 X-Spamd-Bar: ------ Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-6.97 / 15.00]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; NEURAL_HAM_SHORT(-0.97)[-0.971,0]; REPLY(-4.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000,0] X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 19 Jan 2019 01:08:52 -0000 > Author: cem > Date: Fri Jan 18 23:54:51 2019 > New Revision: 343166 > URL: https://svnweb.freebsd.org/changeset/base/343166 > > Log: > vmm(4): Mask Spectre feature bits on AMD hosts > > For parity with Intel hosts, which already mask out the CPUID feature > bits that indicate the presence of the SPEC_CTRL MSR, do the same on > AMD. > > Eventually we may want to have a better support story for guests, but > for now, limit the damage of incorrectly indicating an MSR we do not yet > support. > > Eventually, we may want a generic CPUID override system for > administrators, or for minimum supported feature set in heterogenous > environments with failover. That is a much larger scope effort than > this bug fix. This area has a MAINTAINERS line, could you please respect it. > PR: 235010 > Reported by: Rys Sommefeldt > Sponsored by: Dell EMC Isilon > > Modified: > head/sys/amd64/vmm/x86.c > > Modified: head/sys/amd64/vmm/x86.c > ============================================================================== > --- head/sys/amd64/vmm/x86.c Fri Jan 18 23:26:31 2019 (r343165) > +++ head/sys/amd64/vmm/x86.c Fri Jan 18 23:54:51 2019 (r343166) > @@ -136,6 +136,14 @@ x86_emulate_cpuid(struct vm *vm, int vcpu_id, > case CPUID_8000_0008: > cpuid_count(*eax, *ecx, regs); > if (vmm_is_amd()) { > + /* > + * As on Intel (0000_0007:0, EDX), mask out > + * unsupported or unsafe AMD extended features > + * (8000_0008 EBX). > + */ > + regs[1] &= (AMDFEID_CLZERO | AMDFEID_IRPERF | > + AMDFEID_XSAVEERPTR); > + > vm_get_topology(vm, &sockets, &cores, &threads, > &maxcpus); > /* > > -- Rod Grimes rgrimes@freebsd.org