On Thu, Apr 16, 2020 at 10:16:22AM +0100, Mark Rutland wrote: > On Thu, Apr 16, 2020 at 05:59:33PM +1000, Gavin Shan wrote: > > However, the hypercall number and behaviors are guarded by > > specification. For example, the hypercalls used by para-virtualized > > stolen time, which are defined in include/linux/arm-smccc.h, are > > specified by ARM DEN0057A [1]. So I need a specification to be > > created, where the hypercalls used by this feature are defined? If > > it's not needed, can I pick hypercalls that aren't used and define > > their behaviors by myself? > > > > [1] http://infocenter.arm.com/help/topic/com.arm.doc.den0057a/DEN0057A_Paravirtualized_Time_for_Arm_based_Systems_v1_0.pdf > > Take a look at the SMCCC / SMC Calling Convention: > > https://developer.arm.com/docs/den0028/c > > ... that defines ranges set aside for hypervisor-specific usage, and > despite its name it also applies to HVC calls. > > There's been intermittent work to add a probing story for that, so that > part is subject to change, but for prototyping you can just choose an > arbitray number in that range -- just be suere to mention in the commit > and cover letter that this part isn't complete. Right, might be simplest to start off with: https://android-kvm.googlesource.com/linux/+/refs/heads/willdeacon/hvc Will _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
