From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:60370) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S9lBJ-0005T0-Hc for qemu-devel@nongnu.org; Mon, 19 Mar 2012 18:36:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1S9lBH-00053r-QT for qemu-devel@nongnu.org; Mon, 19 Mar 2012 18:36:01 -0400 Received: from mx1.redhat.com ([209.132.183.28]:25933) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S9lBH-00053T-J5 for qemu-devel@nongnu.org; Mon, 19 Mar 2012 18:35:59 -0400 Message-ID: <4F67B4C9.3010502@redhat.com> Date: Mon, 19 Mar 2012 18:35:53 -0400 From: Rik van Riel MIME-Version: 1.0 References: <4F0482D6.8080705@web.de> <4F060961.9050002@web.de> <4F0A099C.5040805@web.de> <4F4BBAEC.2040603@siemens.com> <4F55E39F.6020608@siemens.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 2/2] Expose tsc deadline timer cpuid to guest List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: "Liu, Jinsong" , Eduardo Habkost On 03/09/2012 01:27 PM, Liu, Jinsong wrote: > As for 'tsc deadline' feature exposing, my patch (as attached) just obey qemu general cpuid exposing method, and also satisfied your target I think. One question. Why is TSC_DEADLINE not exposed in the cpuid allowed feature bits in do_cpuid_ent() in arch/x86/kvm/x86.c ? /* cpuid 1.ecx */ const u32 kvm_supported_word4_x86_features = F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ | 0 /* DS-CPL, VMX, SMX, EST */ | 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ | F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ | 0 /* Reserved, DCA */ | F(XMM4_1) | F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) | 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) | F(F16C) | F(RDRAND); Would it make sense to expose F(TSC_DEADLINE) above? Or is there something truly special about tsc deadline that means it should be different from everything else? -- All rights reversed