| Message ID | 1541483728-7826-1-git-send-email-jingqi.liu@intel.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | KVM: x86: expose direct stores instructions into VM. | expand |
On 06.11.18 06:55, Liu Jingqi wrote: > Direct stores instructions MOVDIRI and MOVDIR64B will be available in > Tremont and other future x86 processors, > and need to be exposed to guest VM. > > The release document ref below link: > https://software.intel.com/sites/default/files/managed/c5/15/\ > architecture-instruction-set-extensions-programming-reference.pdf > > This series expose movdiri and movdir64b features to guest VM. > > Changelog: > v2: > Separated from the series https://lkml.org/lkml/2018/7/10/160 > since umonitor/umwait/tpause instructions patches are not ready yet. > v1: > Sent out with umonitor/umwait/tpause instructions patches. > > Liu Jingqi (2): > KVM: x86: expose MOVDIRI CPU feature into VM. > KVM: x86: expose MOVDIR64B CPU feature into VM. > > arch/x86/kvm/cpuid.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > Does it make sense to squash both patches? (into a patch named just like this cover letter? :) )
On Mon, Nov 5, 2018 at 10:01 PM Liu Jingqi <jingqi.liu@intel.com> wrote: > > Direct stores instructions MOVDIRI and MOVDIR64B will be available in > Tremont and other future x86 processors, > and need to be exposed to guest VM. It seems like KVM's emulator should be able to complete these instructions to emulated MMIO before exposing CPUID to guests in any default or supported configurations. It'll be much simpler for usermode to implement that property if the KVM-reported supported CPUID table doesn't get updated before the KVM emulator does. -Eric
On 30/11/18 21:41, Eric Northup wrote: > On Mon, Nov 5, 2018 at 10:01 PM Liu Jingqi <jingqi.liu@intel.com> wrote: >> >> Direct stores instructions MOVDIRI and MOVDIR64B will be available in >> Tremont and other future x86 processors, >> and need to be exposed to guest VM. > > It seems like KVM's emulator should be able to complete these > instructions to emulated MMIO before exposing CPUID to guests in any > default or supported configurations. > > It'll be much simpler for usermode to implement that property if the > KVM-reported supported CPUID table doesn't get updated before the KVM > emulator does. We already do not support emulation for many CPUID bits we expose (AVX and AVX512 above all), so that's not a huge problem. I suppose these instructions are unlikely to be used on MMIO areas such as legacy VGA VRAM. Paolo
On 06/11/18 06:55, Liu Jingqi wrote: > Direct stores instructions MOVDIRI and MOVDIR64B will be available in > Tremont and other future x86 processors, > and need to be exposed to guest VM. > > The release document ref below link: > https://software.intel.com/sites/default/files/managed/c5/15/\ > architecture-instruction-set-extensions-programming-reference.pdf > > This series expose movdiri and movdir64b features to guest VM. > > Changelog: > v2: > Separated from the series https://lkml.org/lkml/2018/7/10/160 > since umonitor/umwait/tpause instructions patches are not ready yet. > v1: > Sent out with umonitor/umwait/tpause instructions patches. > > Liu Jingqi (2): > KVM: x86: expose MOVDIRI CPU feature into VM. > KVM: x86: expose MOVDIR64B CPU feature into VM. > > arch/x86/kvm/cpuid.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > Queued, thanks. Paolo