Re: [PATCH v2 4/4] x86: vmx: Allow direct access to MSR_IA32_ARCH_CAPABILITIES

2018-01-29 Thread KarimAllah Ahmed
On 01/29/2018 07:55 PM, Jim Mattson wrote: Why should this MSR be pass-through? I doubt that it would be accessed frequently. True. Will update it to be emulated and allow user-space to set the value exposed. On Sun, Jan 28, 2018 at 4:58 PM, KarimAllah Ahmed wrote: Add direct access to M

Re: [PATCH v2 4/4] x86: vmx: Allow direct access to MSR_IA32_ARCH_CAPABILITIES

2018-01-29 Thread Jim Mattson
Why should this MSR be pass-through? I doubt that it would be accessed frequently. On Sun, Jan 28, 2018 at 4:58 PM, KarimAllah Ahmed wrote: > Add direct access to MSR_IA32_SPEC_CTRL for guests. Future intel processors > will use this MSR to indicate RDCL_NO (bit 0) and IBRS_ALL (bit 1). > > Cc: A

RE: [PATCH v2 4/4] x86: vmx: Allow direct access to MSR_IA32_ARCH_CAPABILITIES

2018-01-29 Thread Van De Ven, Arjan
> On 29/01/2018 01:58, KarimAllah Ahmed wrote: > > Add direct access to MSR_IA32_SPEC_CTRL for guests. Future intel processors > > will use this MSR to indicate RDCL_NO (bit 0) and IBRS_ALL (bit 1). > > This has to be customizable per-VM (similar to the patches Amazon posted > a while ago for UCOD

Re: [PATCH v2 4/4] x86: vmx: Allow direct access to MSR_IA32_ARCH_CAPABILITIES

2018-01-29 Thread Paolo Bonzini
On 29/01/2018 01:58, KarimAllah Ahmed wrote: > Add direct access to MSR_IA32_SPEC_CTRL for guests. Future intel processors > will use this MSR to indicate RDCL_NO (bit 0) and IBRS_ALL (bit 1). This has to be customizable per-VM (similar to the patches Amazon posted a while ago for UCODE_REV for ex