Re: [Xen-devel] [PATCH v2] x86/boot: enable NMIs after traps init

2018-10-25 Thread Jan Beulich
>>> On 23.10.18 at 16:33, wrote: > On the subject of having NMIs disabled, it is definitely a more robust > way of handing off between components. Until Xen has transitioned the > BSP and APs into 64bit mode and fully set the IDT up, NMIs are fatal to > the system. I don't follow the AP part her

Re: [Xen-devel] [PATCH v2] x86/boot: enable NMIs after traps init

2018-10-23 Thread Andrew Cooper
On 23/10/2018 23:01, Ross Philipson wrote: > On 10/23/2018 12:58 PM, Andrew Cooper wrote: >> On 23/10/18 17:42, Ross Philipson wrote: >>> On 10/23/2018 11:31 AM, Jason Andryuk wrote: On Tue, Oct 23, 2018 at 10:46 AM Andrew Cooper wrote: > On 23/10/18 15:01, Jason Andryuk wrote: >

Re: [Xen-devel] [PATCH v2] x86/boot: enable NMIs after traps init

2018-10-23 Thread Ross Philipson
On 10/23/2018 12:58 PM, Andrew Cooper wrote: > On 23/10/18 17:42, Ross Philipson wrote: >> On 10/23/2018 11:31 AM, Jason Andryuk wrote: >>> On Tue, Oct 23, 2018 at 10:46 AM Andrew Cooper >>> wrote: On 23/10/18 15:01, Jason Andryuk wrote: > On Tue, Oct 23, 2018 at 7:15 AM Andrew Cooper

Re: [Xen-devel] [PATCH v2] x86/boot: enable NMIs after traps init

2018-10-23 Thread Andrew Cooper
On 23/10/18 17:42, Ross Philipson wrote: > > On 10/23/2018 11:31 AM, Jason Andryuk wrote: >> On Tue, Oct 23, 2018 at 10:46 AM Andrew Cooper >> wrote: >>> On 23/10/18 15:01, Jason Andryuk wrote: On Tue, Oct 23, 2018 at 7:15 AM Andrew Cooper wrote: > On 23/10/18 11:59, Sergey Dyasli

Re: [Xen-devel] [PATCH v2] x86/boot: enable NMIs after traps init

2018-10-23 Thread Ross Philipson
On 10/23/2018 11:31 AM, Jason Andryuk wrote: > On Tue, Oct 23, 2018 at 10:46 AM Andrew Cooper > wrote: >> On 23/10/18 15:01, Jason Andryuk wrote: >>> On Tue, Oct 23, 2018 at 7:15 AM Andrew Cooper >>> wrote: On 23/10/18 11:59, Sergey Dyasli wrote: > In certain scenarios, NMIs might be

Re: [Xen-devel] [PATCH v2] x86/boot: enable NMIs after traps init

2018-10-23 Thread Jason Andryuk
On Tue, Oct 23, 2018 at 10:46 AM Andrew Cooper wrote: > > On 23/10/18 15:01, Jason Andryuk wrote: > > On Tue, Oct 23, 2018 at 7:15 AM Andrew Cooper > > wrote: > >> On 23/10/18 11:59, Sergey Dyasli wrote: > >>> In certain scenarios, NMIs might be disabled during Xen boot process. > >>> Such situa

Re: [Xen-devel] [PATCH v2] x86/boot: enable NMIs after traps init

2018-10-23 Thread Andrew Cooper
On 23/10/18 15:01, Jason Andryuk wrote: > On Tue, Oct 23, 2018 at 7:15 AM Andrew Cooper > wrote: >> On 23/10/18 11:59, Sergey Dyasli wrote: >>> In certain scenarios, NMIs might be disabled during Xen boot process. >>> Such situation will cause alternative_instructions() to: >>> >>> panic("Tim

Re: [Xen-devel] [PATCH v2] x86/boot: enable NMIs after traps init

2018-10-23 Thread Jason Andryuk
On Tue, Oct 23, 2018 at 7:15 AM Andrew Cooper wrote: > > On 23/10/18 11:59, Sergey Dyasli wrote: > > In certain scenarios, NMIs might be disabled during Xen boot process. > > Such situation will cause alternative_instructions() to: > > > > panic("Timed out waiting for alternatives self-NMI to

Re: [Xen-devel] [PATCH v2] x86/boot: enable NMIs after traps init

2018-10-23 Thread Andrew Cooper
On 23/10/18 11:59, Sergey Dyasli wrote: > In certain scenarios, NMIs might be disabled during Xen boot process. > Such situation will cause alternative_instructions() to: > > panic("Timed out waiting for alternatives self-NMI to hit"); > > This bug was originally seen when using Tboot to boot X

[Xen-devel] [PATCH v2] x86/boot: enable NMIs after traps init

2018-10-23 Thread Sergey Dyasli
In certain scenarios, NMIs might be disabled during Xen boot process. Such situation will cause alternative_instructions() to: panic("Timed out waiting for alternatives self-NMI to hit"); This bug was originally seen when using Tboot to boot Xen. To prevent this from happening, enable NMIs d