From: Alexander Graf Date: Tue, 7 Aug 2012 07:40:26 +0000 (+0530) Subject: KVM: Add ppc hypercall documentation X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=6024f1a4dd066d54213cc17f821e19e3062298ca;p=linux-beck.git KVM: Add ppc hypercall documentation Signed-off-by: Alexander Graf Signed-off-by: Raghavendra K T Signed-off-by: Marcelo Tosatti --- diff --git a/Documentation/virtual/kvm/ppc-pv.txt b/Documentation/virtual/kvm/ppc-pv.txt index 4911cf95c67e..4cd076febb02 100644 --- a/Documentation/virtual/kvm/ppc-pv.txt +++ b/Documentation/virtual/kvm/ppc-pv.txt @@ -174,3 +174,25 @@ following: That way we can inject an arbitrary amount of code as replacement for a single instruction. This allows us to check for pending interrupts when setting EE=1 for example. + +Hypercall ABIs in KVM on PowerPC +================================= +1) KVM hypercalls (ePAPR) + +These are ePAPR compliant hypercall implementation (mentioned above). Even +generic hypercalls are implemented here, like the ePAPR idle hcall. These are +available on all targets. + +2) PAPR hypercalls + +PAPR hypercalls are needed to run server PowerPC PAPR guests (-M pseries in QEMU). +These are the same hypercalls that pHyp, the POWER hypervisor implements. Some of +them are handled in the kernel, some are handled in user space. This is only +available on book3s_64. + +3) OSI hypercalls + +Mac-on-Linux is another user of KVM on PowerPC, which has its own hypercall (long +before KVM). This is supported to maintain compatibility. All these hypercalls get +forwarded to user space. This is only useful on book3s_32, but can be used with +book3s_64 as well.