Re: [PATCH 7/8] KVM: arm/arm64: Avoid accessing GICH registers

2016-02-10 Thread Marc Zyngier
On 10/02/16 17:30, Christoffer Dall wrote: > On Wed, Feb 10, 2016 at 01:34:44PM +, Marc Zyngier wrote: >> On 10/02/16 12:45, Christoffer Dall wrote: >>> On Mon, Feb 08, 2016 at 11:40:21AM +, Marc Zyngier wrote: GICv2 registers are *slow*. As in "terrifyingly slow". Which is bad. B

Re: [PATCH 7/8] KVM: arm/arm64: Avoid accessing GICH registers

2016-02-10 Thread Christoffer Dall
On Wed, Feb 10, 2016 at 01:34:44PM +, Marc Zyngier wrote: > On 10/02/16 12:45, Christoffer Dall wrote: > > On Mon, Feb 08, 2016 at 11:40:21AM +, Marc Zyngier wrote: > >> GICv2 registers are *slow*. As in "terrifyingly slow". Which is bad. > >> But we're equaly bad, as we make a point in acc

Re: [PATCH 7/8] KVM: arm/arm64: Avoid accessing GICH registers

2016-02-10 Thread Marc Zyngier
On 10/02/16 12:45, Christoffer Dall wrote: > On Mon, Feb 08, 2016 at 11:40:21AM +, Marc Zyngier wrote: >> GICv2 registers are *slow*. As in "terrifyingly slow". Which is bad. >> But we're equaly bad, as we make a point in accessing them even if >> we don't have any interrupt in flight. >> >> A

Re: [PATCH 7/8] KVM: arm/arm64: Avoid accessing GICH registers

2016-02-10 Thread Christoffer Dall
On Mon, Feb 08, 2016 at 11:40:21AM +, Marc Zyngier wrote: > GICv2 registers are *slow*. As in "terrifyingly slow". Which is bad. > But we're equaly bad, as we make a point in accessing them even if > we don't have any interrupt in flight. > > A good solution is to first find out if we have any

[PATCH 7/8] KVM: arm/arm64: Avoid accessing GICH registers

2016-02-08 Thread Marc Zyngier
GICv2 registers are *slow*. As in "terrifyingly slow". Which is bad. But we're equaly bad, as we make a point in accessing them even if we don't have any interrupt in flight. A good solution is to first find out if we have anything useful to write into the GIC, and if we don't, to simply not do it