On 07/15/2013 06:30:20 AM, Gleb Natapov wrote:
On Mon, Jul 15, 2013 at 04:41:17PM +0530, Bharat Bhushan wrote:
> KVM_HC_VM_RESET: Requests that the virtual machine be reset.
> KVM_HC_VM_SHUTDOWN: Requests that the virtual machine be
powered-off/halted.
>
> These hcalls are handled by guest userspace.
>
> Signed-off-by: Bharat Bhushan <bharat.bhushan@xxxxxxxxxxxxx>
> ---
> Documentation/virtual/kvm/hypercalls.txt | 16 ++++++++++++++++
> include/uapi/linux/kvm_para.h | 3 ++-
> 2 files changed, 18 insertions(+), 1 deletions(-)
>
> diff --git a/Documentation/virtual/kvm/hypercalls.txt
b/Documentation/virtual/kvm/hypercalls.txt
> index ea113b5..58acdc1 100644
> --- a/Documentation/virtual/kvm/hypercalls.txt
> +++ b/Documentation/virtual/kvm/hypercalls.txt
> @@ -64,3 +64,19 @@ Purpose: To enable communication between the
hypervisor and guest there is a
> shared page that contains parts of supervisor visible register
state.
> The guest can map this shared page to access its supervisor
register through
> memory using this hypercall.
> +
> +5. KVM_HC_VM_RESET
> +------------------------
> +Architecture: PPC
> +Status: active
> +Purpose: Requests that the virtual machine be reset. The hcall
takes no
> +arguments. If successful the hcall does not return. If an error
occurs it
> +returns EV_INTERNAL.
> +
> +6. KVM_HC_VM_SHUTDOWN
> +------------------------
> +Architecture: PPC
> +Status: active
> +Purpose: Requests that the virtual machine be powered-off/halted.
> +The hcall takes no arguments. If successful the hcall does not
return.
> +If an error occurs it returns EV_INTERNAL.
> diff --git a/include/uapi/linux/kvm_para.h
b/include/uapi/linux/kvm_para.h
> index cea2c5c..218882d 100644
> --- a/include/uapi/linux/kvm_para.h
> +++ b/include/uapi/linux/kvm_para.h
> @@ -19,7 +19,8 @@
> #define KVM_HC_MMU_OP 2
> #define KVM_HC_FEATURES 3
> #define KVM_HC_PPC_MAP_MAGIC_PAGE 4
> -
> +#define KVM_HC_VM_RESET 5
> +#define KVM_HC_VM_SHUTDOWN 6
There is no much sense to share hypercalls between architectures.
There
is zero probability x86 will implement those for instance
This is similar to the question of whether to keep device API
enumerations per-architecture... It costs very little to keep it in a
common place, and it's hard to go back in the other direction if we
later realize there are things that should be shared.
Keeping it in a common place also makes it more visible to people
looking to add new hcalls, which could cut down on reinventing the
wheel.
(not sure why PPC will want them either instead of emulating devices
that do
shutdown/reset).
Besides what Alex said, for shutdown we don't have any existing device
to emulate (our real hardware just doesn't have that functionality).
For reset we currently do emulate, but it's awkward to describe in the
device tree what we actually emulate since the reset functionality is
part of a kitchen-sink "device" of which we emulate virtually nothing
other than the reset. Currently we advertise the entire thing and just
ignore the rest, but that causes problems with the guest seeing the
node and trying to use that functionality.
-Scott
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
