From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boris Ostrovsky Subject: Re: [V0 PATCH 5/6] AMD-PVH: Support TSC_MODE_NEVER_EMULATE for PVH Date: Mon, 18 Aug 2014 21:43:08 -0400 Message-ID: <53F2ABAC.8030101@oracle.com> References: <1408153996-16425-1-git-send-email-mukesh.rathor@oracle.com> <1408153996-16425-6-git-send-email-mukesh.rathor@oracle.com> <53F2AA9B.40200@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1XJYS9-00055X-Ad for xen-devel@lists.xenproject.org; Tue, 19 Aug 2014 01:43:13 +0000 In-Reply-To: <53F2AA9B.40200@oracle.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Mukesh Rathor , xen-devel@lists.xenproject.org Cc: keir@xen.org, Aravind.Gopalakrishnan@amd.com, jbeulich@suse.com, suravee.suthikulpanit@amd.com List-Id: xen-devel@lists.xenproject.org On 08/18/2014 09:38 PM, Boris Ostrovsky wrote: > On 08/15/2014 09:53 PM, Mukesh Rathor wrote: >> On AMD, MSR_AMD64_TSC_RATIO must be set for rdtsc instruction in guest >> to properly read the cpu tsc. To that end, set tsc_khz in struct domain. >> >> Signed-off-by: Mukesh Rathor >> --- >> xen/arch/x86/time.c | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c >> index bd89219..7512aa4 100644 >> --- a/xen/arch/x86/time.c >> +++ b/xen/arch/x86/time.c >> @@ -1908,6 +1908,7 @@ void tsc_set_info(struct domain *d, >> * but "always_emulate" does not for some reason. Figure out >> * why. >> */ >> + d->arch.tsc_khz = cpu_khz; >> switch ( tsc_mode ) >> { >> case TSC_MODE_NEVER_EMULATE: > > I suspect that TSC_MODE DEFAULT may actually work for PVH: since we > don't support migration it should be equivalent to NEVER_EMULATE. > > If you replace in tsc_set_info() is_hvm_domain() with > is_hvm_container_domain() and allow TSC_MODE_DEFAULT along with > TSC_MODE_NEVER_EMULATE under 'if (is_pvh_domain())' then it seems to > me that things should be fine. (hit RET too soon) ... and if TSC_MODE DEFAULT does work then you don't need to set khz above since it (as well as some other things) will be set from arch_domain_create(). -boris