On Thu, Nov 05, 2015 at 08:51:24AM +0100, Richard Henderson wrote: > On 11/04/2015 08:35 PM, Eduardo Habkost wrote: > >On Fri, Oct 30, 2015 at 01:54:33PM -0700, Richard Henderson wrote: > >>On 10/29/2015 12:31 AM, Xiao Guangrong wrote: > >>>These instructions are used by NVDIMM drivers and the specification > >>>locates at: > >>>https://software.intel.com/sites/default/files/managed/0d/53/319433-022.pdf > >>> > >>>There instructions are available on Skylake Server > >>> > >>>Signed-off-by: Xiao Guangrong <guangrong.xiao@xxxxxxxxxxxxxxx> > >>>--- > >>> target-i386/cpu.c | 8 +++++--- > >>> target-i386/cpu.h | 3 +++ > >>> 2 files changed, 8 insertions(+), 3 deletions(-) > >> > >>Reviewed-by: Richard Henderson <rth@xxxxxxxxxxx> > >> > >>Although it would be nice to update the comments in translate.c to include the > >>new insns, since they overlap mfence and sfence. At present we only check for > >>SSE enabled when accepting these; I suppose it's easiest to consider it invalid > >>to specify +clwb,-sse? > > > >I assume you want to add the extra SSE requirement to TCG code, not to > >generic x86 code, then I have no objections. > > I don't really want to add any requirement, just point and laugh at anyone > who reports an bug for the above condition. > > >But in the case of clwb (/6 with a memory operand, modrm != 0xc0), we > >are not just requiring SSE2: we are rejecting the instruction unless > >modrm == 0xc0. That means TCG is rejecting the clwb instruction, so I > >believe we shouldn't add CLWB to TCG_7_0_EBX_FEATURES yet. > > Hmm, yes. > > I've cleaned up some of this code on a branch, but it didn't get enough > testing or review this cycle, so it's going to wait for the next. I see > you've posted a patch for this, which should be good enough until then. I will apply this patch without the TCG_*_FEATURES changes until we change TCG, then. That's OK? About the TCG patches I have sent, please let me know if they look good and appropriate for 2.5. This is the first time I have touched TCG code. -- Eduardo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
