On 07/02/2013 05:07 PM, Yoder Stuart-B08248 wrote:
Version 2 changes
-remove advertising via KVM_HC_FEATURES
-define a new exit type (KVM_EXIT_EPAPR_HCALL) for user space
handled hcalls
-advertise KVM_EXIT_EPAPR_HCALL to user space via new capability
flag
-defined device tree properties to advertise the existence
of reset and shutdown hcalls to a guest
------------------------------------------------------------------------
KVM_CAP_EXIT_EPAPR_HCALL Capability
A new capability KVM_CAP_EXIT_EPAPR_HCALL is defined to advertise
the new KVM_EXIT_EPAPR_HCALL exit .
------------------------------------------------------------------------
KVM_EXIT_EPAPR_HCALL exit definition
/* KVM_EXIT_EPAPR_HCALL */
struct {
__u64 nr;
__u64 ret;
__u64 args[8];
} epapr_hcall;
This is used on e500 Power Architecture for the paravirt e500
It can also be used on book3s systems. We use the same logic for -M
g3beige and -M mac99. We even use it for -M mpc8544ds.
platform. It occurs when a guest does a hypercall (as defined
in the ePAPR 1.1) and the hcall is not handled by the kernel.
The 'nr' field contains the hypercall number (from the guest R11),
and 'args' contains the arguments (from the guest R3 - R10).
Userspace should put the return code in 'ret' and any extra returned
values in args[].
Please specify which registers ret and args will end up in.
------------------------------------------------------------------------
Advertising reset and shutdown in device tree.
A virtual machine can detect the availability of the reset
and shutdown hcalls by looking at properties on the /hypervisor
node.
Property name: has-reset
I don't remember how ePAPR specifies this. Aren't keys in /hypervisor
supposed to be common throughout hypervisors? So if Windriver wants to
add a reset hypercall, they'd also add "has-reset"? How does the guest
know which hcall number to issue?
Thanks a lot for writing all of this down :)
Alex
Value type:<none>
Definition: If the property is present the hypervisor supports
the KVM_HC_VM_RESET hcall.
Property name: has-shutdown
Value type:<none>
Definition: If the property is present the hypervisor supports
the KVM_HC_VM_SHUTDOWN hcall.
------------------------------------------------------------------------
Hypercall: KVM_HC_VM_RESET
Description: Requests that the virtual machine be reset. The
hcall takes no arguments. If successful the hcall does not
return.
Arguments:
r11 hcall-token KVM_HC_VM_RESET
Return values
r3 status Status of the hcall. If the hcall succeeds
it does not return. If an error occurs
EV_INTERNAL is returned.
------------------------------------------------------------------------
Hypercall: KVM_HC_VM_SHUTDOWN
Description: Requests that the virtual machine be powered-off/halted.
The hcall takes no arguments. If successful the hcall does not
return.
Arguments:
r11 hcall-token KVM_HC_VM_SHUTDOWN
Return values
r3 status Status of the hcall. If the hcall succeeds
it does not return. If an error occurs
EV_INTERNAL is returned.
Regards,
Stuart
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