Re: [PATCH v3] X86/VMX: Disable VMX preemption timer if MWAIT is not intercepted

2018-04-11 Thread Raslan, KarimAllah
On Wed, 2018-04-11 at 09:24 +0800, Wanpeng Li wrote: > 2018-04-10 20:15 GMT+08:00 KarimAllah Ahmed : > > > > The VMX-preemption timer is used by KVM as a way to set deadlines for the > > guest (i.e. timer emulation). That was safe till very recently when > > capability

Re: [PATCH v3] X86/VMX: Disable VMX preemption timer if MWAIT is not intercepted

2018-04-11 Thread Raslan, KarimAllah
On Wed, 2018-04-11 at 09:24 +0800, Wanpeng Li wrote: > 2018-04-10 20:15 GMT+08:00 KarimAllah Ahmed : > > > > The VMX-preemption timer is used by KVM as a way to set deadlines for the > > guest (i.e. timer emulation). That was safe till very recently when > > capability KVM_X86_DISABLE_EXITS_MWAIT

Re: [PATCH v3] X86/VMX: Disable VMX preemption timer if MWAIT is not intercepted

2018-04-10 Thread Wanpeng Li
2018-04-10 20:15 GMT+08:00 KarimAllah Ahmed : > The VMX-preemption timer is used by KVM as a way to set deadlines for the > guest (i.e. timer emulation). That was safe till very recently when > capability KVM_X86_DISABLE_EXITS_MWAIT to disable intercepting MWAIT was >

Re: [PATCH v3] X86/VMX: Disable VMX preemption timer if MWAIT is not intercepted

2018-04-10 Thread Wanpeng Li
2018-04-10 20:15 GMT+08:00 KarimAllah Ahmed : > The VMX-preemption timer is used by KVM as a way to set deadlines for the > guest (i.e. timer emulation). That was safe till very recently when > capability KVM_X86_DISABLE_EXITS_MWAIT to disable intercepting MWAIT was > introduced. According to

Re: [PATCH v3] X86/VMX: Disable VMX preemption timer if MWAIT is not intercepted

2018-04-10 Thread Konrad Rzeszutek Wilk
On Tue, Apr 10, 2018 at 02:15:46PM +0200, KarimAllah Ahmed wrote: > The VMX-preemption timer is used by KVM as a way to set deadlines for the > guest (i.e. timer emulation). That was safe till very recently when > capability KVM_X86_DISABLE_EXITS_MWAIT to disable intercepting MWAIT was >

Re: [PATCH v3] X86/VMX: Disable VMX preemption timer if MWAIT is not intercepted

2018-04-10 Thread Konrad Rzeszutek Wilk
On Tue, Apr 10, 2018 at 02:15:46PM +0200, KarimAllah Ahmed wrote: > The VMX-preemption timer is used by KVM as a way to set deadlines for the > guest (i.e. timer emulation). That was safe till very recently when > capability KVM_X86_DISABLE_EXITS_MWAIT to disable intercepting MWAIT was >

Re: [PATCH v3] X86/VMX: Disable VMX preemption timer if MWAIT is not intercepted

2018-04-10 Thread Paolo Bonzini
On 10/04/2018 14:15, KarimAllah Ahmed wrote: > So disable the VMX-preemption timer if MWAIT is exposed to the guest! > > Cc: Paolo Bonzini > Cc: Radim Krčmář > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: H. Peter

Re: [PATCH v3] X86/VMX: Disable VMX preemption timer if MWAIT is not intercepted

2018-04-10 Thread Paolo Bonzini
On 10/04/2018 14:15, KarimAllah Ahmed wrote: > So disable the VMX-preemption timer if MWAIT is exposed to the guest! > > Cc: Paolo Bonzini > Cc: Radim Krčmář > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: H. Peter Anvin > Cc: x...@kernel.org > Cc: k...@vger.kernel.org > Cc:

[PATCH v3] X86/VMX: Disable VMX preemption timer if MWAIT is not intercepted

2018-04-10 Thread KarimAllah Ahmed
The VMX-preemption timer is used by KVM as a way to set deadlines for the guest (i.e. timer emulation). That was safe till very recently when capability KVM_X86_DISABLE_EXITS_MWAIT to disable intercepting MWAIT was introduced. According to Intel SDM 25.5.1: """ The VMX-preemption timer operates

[PATCH v3] X86/VMX: Disable VMX preemption timer if MWAIT is not intercepted

2018-04-10 Thread KarimAllah Ahmed
The VMX-preemption timer is used by KVM as a way to set deadlines for the guest (i.e. timer emulation). That was safe till very recently when capability KVM_X86_DISABLE_EXITS_MWAIT to disable intercepting MWAIT was introduced. According to Intel SDM 25.5.1: """ The VMX-preemption timer operates