Re: [PATCH v2 01/10] KVM: arm/arm64: vgic: Defer touching GICH_VMCR to vcpu_load/put

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 21/03/17 21:10, Christoffer Dall wrote:
> From: Christoffer Dall <cdall@xxxxxxxxxxxxxxx>
> 
> We don't have to save/restore the VMCR on every entry to/from the guest,
> since on GICv2 we can access the control interface from EL1 and on VHE
> systems with GICv3 we can access the control interface from KVM running
> in EL2.
> 
> GICv3 systems without VHE become the rare case, which have to
> save/restore the register in the put/load functions by doing an extra
> jump to EL2 to access the EL2-only register state.
> 
> Note that userspace accesses may see out-of-date values if the VCPU is
> running while accessing the VGIC state via the KVM device API, but this
> is already the case and it is up to userspace to quiesce the CPUs before
> reading the CPU registers from the GIC for an up-to-date view.
> 
> Signed-off-by: Christoffer Dall <cdall@xxxxxxxxxxxxxxx>
> Signed-off-by: Christoffer Dall <cdall@xxxxxxxxxx>

Reviewed-by: Marc Zyngier <marc.zyngier@xxxxxxx>

	M.
-- 
Jazz is not dead. It just smells funny...
_______________________________________________
kvmarm mailing list
kvmarm@xxxxxxxxxxxxxxxxxxxxx
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm



[Index of Archives]     [Linux KVM]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux