Re: [RFC 0/6] Enlightened VMCS support for KVM on Hyper-V

2018-01-15 18:30+0100, Vitaly Kuznetsov: > Early RFC. I'll refer to this patchset in my DevConf/FOSDEM > presentations. > > When running nested KVM on Hyper-V it's possible to use so called > 'Enlightened VMCS' and do normal memory reads/writes instead of > doing VMWRITE/VMREAD instructions.

Re: [RFC 0/6] Enlightened VMCS support for KVM on Hyper-V

2018-01-15 18:30+0100, Vitaly Kuznetsov: > Early RFC. I'll refer to this patchset in my DevConf/FOSDEM > presentations. > > When running nested KVM on Hyper-V it's possible to use so called > 'Enlightened VMCS' and do normal memory reads/writes instead of > doing VMWRITE/VMREAD instructions.

Re: [RFC 0/6] Enlightened VMCS support for KVM on Hyper-V

On 16/01/2018 15:43, Vitaly Kuznetsov wrote: > Paolo Bonzini writes: > >> On 16/01/2018 14:58, Vitaly Kuznetsov wrote: Haven't looked into the details, but we have to watch out for other VCPUs trying to modify that vmcs12. Basically because other VCPUs

Re: [RFC 0/6] Enlightened VMCS support for KVM on Hyper-V

On 16/01/2018 15:43, Vitaly Kuznetsov wrote: > Paolo Bonzini writes: > >> On 16/01/2018 14:58, Vitaly Kuznetsov wrote: Haven't looked into the details, but we have to watch out for other VCPUs trying to modify that vmcs12. Basically because other VCPUs could try to modify

Re: [RFC 0/6] Enlightened VMCS support for KVM on Hyper-V

On 16.01.2018 15:43, Vitaly Kuznetsov wrote: > Paolo Bonzini writes: > >> On 16/01/2018 14:58, Vitaly Kuznetsov wrote: Haven't looked into the details, but we have to watch out for other VCPUs trying to modify that vmcs12. Basically because other VCPUs

Re: [RFC 0/6] Enlightened VMCS support for KVM on Hyper-V

On 16.01.2018 15:43, Vitaly Kuznetsov wrote: > Paolo Bonzini writes: > >> On 16/01/2018 14:58, Vitaly Kuznetsov wrote: Haven't looked into the details, but we have to watch out for other VCPUs trying to modify that vmcs12. Basically because other VCPUs could try to modify

Re: [RFC 0/6] Enlightened VMCS support for KVM on Hyper-V

Paolo Bonzini writes: > On 16/01/2018 14:58, Vitaly Kuznetsov wrote: >>> Haven't looked into the details, but we have to watch out for other >>> VCPUs trying to modify that vmcs12. >>> >>> Basically because other VCPUs could try to modify values in vmcs12 while >>> we are

Re: [RFC 0/6] Enlightened VMCS support for KVM on Hyper-V

Paolo Bonzini writes: > On 16/01/2018 14:58, Vitaly Kuznetsov wrote: >>> Haven't looked into the details, but we have to watch out for other >>> VCPUs trying to modify that vmcs12. >>> >>> Basically because other VCPUs could try to modify values in vmcs12 while >>> we are currently building

Re: [RFC 0/6] Enlightened VMCS support for KVM on Hyper-V

On 16/01/2018 14:58, Vitaly Kuznetsov wrote: >> Haven't looked into the details, but we have to watch out for other >> VCPUs trying to modify that vmcs12. >> >> Basically because other VCPUs could try to modify values in vmcs12 while >> we are currently building vmcs02. Nasty races could result in

Re: [RFC 0/6] Enlightened VMCS support for KVM on Hyper-V

On 16/01/2018 14:58, Vitaly Kuznetsov wrote: >> Haven't looked into the details, but we have to watch out for other >> VCPUs trying to modify that vmcs12. >> >> Basically because other VCPUs could try to modify values in vmcs12 while >> we are currently building vmcs02. Nasty races could result in

Re: [RFC 0/6] Enlightened VMCS support for KVM on Hyper-V

David Hildenbrand writes: > On 16.01.2018 13:05, Vitaly Kuznetsov wrote: >> Wanpeng Li writes: >> >>> 2018-01-16 1:30 GMT+08:00 Vitaly Kuznetsov : Early RFC. I'll refer to this patchset in my DevConf/FOSDEM presentations.

Re: [RFC 0/6] Enlightened VMCS support for KVM on Hyper-V

David Hildenbrand writes: > On 16.01.2018 13:05, Vitaly Kuznetsov wrote: >> Wanpeng Li writes: >> >>> 2018-01-16 1:30 GMT+08:00 Vitaly Kuznetsov : Early RFC. I'll refer to this patchset in my DevConf/FOSDEM presentations. When running nested KVM on Hyper-V it's possible to

Re: [RFC 0/6] Enlightened VMCS support for KVM on Hyper-V

On 16/01/2018 14:39, David Hildenbrand wrote: > On 16.01.2018 13:05, Vitaly Kuznetsov wrote: >> Wanpeng Li writes: >> >>> 2018-01-16 1:30 GMT+08:00 Vitaly Kuznetsov : Early RFC. I'll refer to this patchset in my DevConf/FOSDEM presentations.

Re: [RFC 0/6] Enlightened VMCS support for KVM on Hyper-V

On 16/01/2018 14:39, David Hildenbrand wrote: > On 16.01.2018 13:05, Vitaly Kuznetsov wrote: >> Wanpeng Li writes: >> >>> 2018-01-16 1:30 GMT+08:00 Vitaly Kuznetsov : Early RFC. I'll refer to this patchset in my DevConf/FOSDEM presentations. When running nested KVM on Hyper-V

Re: [RFC 0/6] Enlightened VMCS support for KVM on Hyper-V

On 16.01.2018 13:05, Vitaly Kuznetsov wrote: > Wanpeng Li writes: > >> 2018-01-16 1:30 GMT+08:00 Vitaly Kuznetsov : >>> Early RFC. I'll refer to this patchset in my DevConf/FOSDEM >>> presentations. >>> >>> When running nested KVM on Hyper-V it's

Re: [RFC 0/6] Enlightened VMCS support for KVM on Hyper-V

On 16.01.2018 13:05, Vitaly Kuznetsov wrote: > Wanpeng Li writes: > >> 2018-01-16 1:30 GMT+08:00 Vitaly Kuznetsov : >>> Early RFC. I'll refer to this patchset in my DevConf/FOSDEM >>> presentations. >>> >>> When running nested KVM on Hyper-V it's possible to use so called >>> 'Enlightened VMCS'

Re: [RFC 0/6] Enlightened VMCS support for KVM on Hyper-V

Wanpeng Li writes: > 2018-01-16 1:30 GMT+08:00 Vitaly Kuznetsov : >> Early RFC. I'll refer to this patchset in my DevConf/FOSDEM >> presentations. >> >> When running nested KVM on Hyper-V it's possible to use so called >> 'Enlightened VMCS' and do normal

Re: [RFC 0/6] Enlightened VMCS support for KVM on Hyper-V

Wanpeng Li writes: > 2018-01-16 1:30 GMT+08:00 Vitaly Kuznetsov : >> Early RFC. I'll refer to this patchset in my DevConf/FOSDEM >> presentations. >> >> When running nested KVM on Hyper-V it's possible to use so called >> 'Enlightened VMCS' and do normal memory reads/writes instead of >> doing

Re: [RFC 0/6] Enlightened VMCS support for KVM on Hyper-V

2018-01-16 1:30 GMT+08:00 Vitaly Kuznetsov : > Early RFC. I'll refer to this patchset in my DevConf/FOSDEM > presentations. > > When running nested KVM on Hyper-V it's possible to use so called > 'Enlightened VMCS' and do normal memory reads/writes instead of > doing

Re: [RFC 0/6] Enlightened VMCS support for KVM on Hyper-V

2018-01-16 1:30 GMT+08:00 Vitaly Kuznetsov : > Early RFC. I'll refer to this patchset in my DevConf/FOSDEM > presentations. > > When running nested KVM on Hyper-V it's possible to use so called > 'Enlightened VMCS' and do normal memory reads/writes instead of > doing VMWRITE/VMREAD instructions.

[RFC 0/6] Enlightened VMCS support for KVM on Hyper-V

Early RFC. I'll refer to this patchset in my DevConf/FOSDEM presentations. When running nested KVM on Hyper-V it's possible to use so called 'Enlightened VMCS' and do normal memory reads/writes instead of doing VMWRITE/VMREAD instructions. Tests show that this speeds up tight CPUID loop almost 3

[RFC 0/6] Enlightened VMCS support for KVM on Hyper-V

Early RFC. I'll refer to this patchset in my DevConf/FOSDEM presentations. When running nested KVM on Hyper-V it's possible to use so called 'Enlightened VMCS' and do normal memory reads/writes instead of doing VMWRITE/VMREAD instructions. Tests show that this speeds up tight CPUID loop almost 3