Re: [RFC PATCH 3/4] arm64/sve: KVM: Ensure user SVE use traps after vcpu execution

2017-11-23 Thread Dave Martin
On Wed, Nov 22, 2017 at 08:23:44PM +0100, Christoffer Dall wrote: > On Fri, Nov 17, 2017 at 04:38:54PM +, Dave Martin wrote: > > Currently, SVE use can remain untrapped if a KVM vcpu thread is > > preempted inside the kernel and we then switch back to some user > > thread. > > > > This patch e

Re: [RFC PATCH 3/4] arm64/sve: KVM: Ensure user SVE use traps after vcpu execution

2017-11-22 Thread Christoffer Dall
On Fri, Nov 17, 2017 at 04:38:54PM +, Dave Martin wrote: > Currently, SVE use can remain untrapped if a KVM vcpu thread is > preempted inside the kernel and we then switch back to some user > thread. > > This patch ensures that SVE traps for userspace are enabled before > switching away from t

[RFC PATCH 3/4] arm64/sve: KVM: Ensure user SVE use traps after vcpu execution

2017-11-17 Thread Dave Martin
Currently, SVE use can remain untrapped if a KVM vcpu thread is preempted inside the kernel and we then switch back to some user thread. This patch ensures that SVE traps for userspace are enabled before switching away from the vcpu thread. In an attempt to preserve some clarity about why and whe