Re: [Xen-devel] [PATCH 04/20] xen/domctl: Drop vcpu_alloc_lock

2018-03-22 Thread Jan Beulich
>>> On 21.03.18 at 18:57, wrote: > On 21/03/18 05:46, Juergen Gross wrote: >> On 20/03/18 18:22, Andrew Cooper wrote: >>> On 20/03/18 16:58, Jan Beulich wrote: >>> On 19.03.18 at 20:13, wrote: > It is not entirely clear why this

Re: [Xen-devel] [PATCH 04/20] xen/domctl: Drop vcpu_alloc_lock

2018-03-21 Thread Andrew Cooper
On 21/03/18 05:46, Juergen Gross wrote: > On 20/03/18 18:22, Andrew Cooper wrote: >> On 20/03/18 16:58, Jan Beulich wrote: >> On 19.03.18 at 20:13, wrote: It is not entirely clear why this interlock was introduced in c/s 8cbb5278e "x86/AMD: Add support for

Re: [Xen-devel] [PATCH 04/20] xen/domctl: Drop vcpu_alloc_lock

2018-03-20 Thread Juergen Gross
On 20/03/18 18:22, Andrew Cooper wrote: > On 20/03/18 16:58, Jan Beulich wrote: > On 19.03.18 at 20:13, wrote: >>> It is not entirely clear why this interlock was introduced in c/s 8cbb5278e >>> "x86/AMD: Add support for AMD's OSVW feature in guests". >>> >>> At the

Re: [Xen-devel] [PATCH 04/20] xen/domctl: Drop vcpu_alloc_lock

2018-03-20 Thread Andrew Cooper
On 20/03/18 16:58, Jan Beulich wrote: On 19.03.18 at 20:13, wrote: >> It is not entirely clear why this interlock was introduced in c/s 8cbb5278e >> "x86/AMD: Add support for AMD's OSVW feature in guests". >> >> At the time, svm_handle_osvw() could have seen an

Re: [Xen-devel] [PATCH 04/20] xen/domctl: Drop vcpu_alloc_lock

2018-03-20 Thread Jan Beulich
>>> On 19.03.18 at 20:13, wrote: > It is not entirely clear why this interlock was introduced in c/s 8cbb5278e > "x86/AMD: Add support for AMD's OSVW feature in guests". > > At the time, svm_handle_osvw() could have seen an unexpected change in OSVW > (not the case

[Xen-devel] [PATCH 04/20] xen/domctl: Drop vcpu_alloc_lock

2018-03-19 Thread Andrew Cooper
It is not entirely clear why this interlock was introduced in c/s 8cbb5278e "x86/AMD: Add support for AMD's OSVW feature in guests". At the time, svm_handle_osvw() could have seen an unexpected change in OSVW (not the case now, due to the new CPUID Policy infrastructure), but even then, it would