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

[Wei Liu <wei.liu2@xxxxxxxxxx>]

On Wed, Sep 05, 2018 at 08:15:25PM +0100, Andrew Cooper wrote:
> Since its introduction in c/s 8cbb5278e "x86/AMD: Add support for AMD's OSVW
> feature in guests", the OSVW data has been corrected to be per-domain rather
> than per-vcpu, and is initialised during XEN_DOMCTL_createdomain.
> 
> Furthermore, because XENPF_microcode_update uses hypercall continuations to
> move between CPUs, it drops the vcpu_alloc_lock mid update, meaning that it
> didn't provided the interlock guarantee that the OSVW patch was looking for in
> the first place.
> 
> This interlock serves no purpose, so take the opportunity to drop it and
> remove a global spinlock from the hypervisor.
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>

Reviewed-by: Wei Liu <wei.liu2@xxxxxxxxxx>

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel