Re: [PATCH] Documentation/kvm : Add documentation on Hypercalls

From: Randy Dunlap
Date: Thu May 31 2012 - 13:45:06 EST


On 05/31/2012 01:01 AM, Raghavendra K T wrote:

> From: Raghavendra K T <raghavendra.kt@xxxxxxxxxxxxxxxxxx>
>
> Thanks Alex for KVM_HC_FEATURES inputs and Jan for VAPIC_POLL_IRQ
>
> Signed-off-by: Raghavendra K T <raghavendra.kt@xxxxxxxxxxxxxxxxxx>
> ---
> diff --git a/Documentation/virtual/kvm/hypercalls.txt b/Documentation/virtual/kvm/hypercalls.txt
> new file mode 100644
> index 0000000..c79335a
> --- /dev/null
> +++ b/Documentation/virtual/kvm/hypercalls.txt
> @@ -0,0 +1,46 @@
> +KVM Hypercalls Documentation
> +===========================
> +The template for each hypercall is:
> +1. Hypercall name, value.
> +2. Architecture(s)
> +3. Status (deprecated, obsolete, active)
> +4. Purpose
> +
> +1. KVM_HC_VAPIC_POLL_IRQ
> +------------------------
> +Value: 1
> +Architecture: x86


No "Status", does that imply "Active" ?

> +Purpose: Trigger guest exit so that the host can check for pending
> +interrupts on reentry.
> +
> +2. KVM_HC_MMU_OP
> +------------------------
> +Value: 2
> +Architecture: x86
> +Status: deprecated.
> +Purpose: Support MMU operations such as writing to PTE,
> +flushing TLB, release PT.
> +
> +3. KVM_HC_FEATURES
> +------------------------
> +Value: 3
> +Architecture: PPC
> +Status: active
> +Purpose: Expose hypercall availability to the guest. On x86 platforms, cpuid
> +used to enumerate which hypercalls are available. On PPC, either device tree
> +based lookup ( which is also what EPAPR dictates) OR KVM specific enumeration
> +mechanism (which is this hypercall) can be used.
> +
> +4. KVM_HC_PPC_MAP_MAGIC_PAGE
> +------------------------
> +Value: 4
> +Architecture: PPC
> +Status: active
> +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.
> +
> +TODO:
> +1. more information on input and output needed?
> +2. Add more detail to purpose of hypercalls.
>
> --


--
~Randy
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