docs: kvm: Convert hypercalls.txt to ReST format

- Use document title and chapter markups;
- Convert tables;
- Add markups for literal blocks;
- use :field: for field descriptions;
- Add blank lines and adjust indentation
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Documentation/virt/kvm/hypercalls.txt → Documentation/virt/kvm/hypercalls.rst

-Linux KVM Hypercall:
+.. SPDX-License-Identifier: GPL-2.0
+
+===================
+Linux KVM Hypercall
 ===================
+
 X86:
  KVM Hypercalls have a three-byte sequence of either the vmcall or the vmmcall
  instruction. The hypervisor can replace it with instructions that are
@@ -20,7 +24,7 @@ S390:
   For further information on the S390 diagnose call as supported by KVM,
   refer to Documentation/virt/kvm/s390-diag.txt.
 
- PowerPC:
+PowerPC:
   It uses R3-R10 and hypercall number in R11. R4-R11 are used as output registers.
   Return value is placed in R3.
 
@@ -34,7 +38,8 @@ MIPS:
   the return value is placed in $2 (v0).
 
 KVM Hypercalls Documentation
-===========================
+============================
+
 The template for each hypercall is:
 1. Hypercall name.
 2. Architecture(s)
@@ -43,56 +48,64 @@ The template for each hypercall is:
 
 1. KVM_HC_VAPIC_POLL_IRQ
 ------------------------
-Architecture: x86
-Status: active
-Purpose: Trigger guest exit so that the host can check for pending
-interrupts on reentry.
+
+:Architecture: x86
+:Status: active
+:Purpose: Trigger guest exit so that the host can check for pending
+          interrupts on reentry.
 
 2. KVM_HC_MMU_OP
-------------------------
-Architecture: x86
-Status: deprecated.
-Purpose: Support MMU operations such as writing to PTE,
-flushing TLB, release PT.
+----------------
+
+:Architecture: x86
+:Status: deprecated.
+:Purpose: Support MMU operations such as writing to PTE,
+          flushing TLB, release PT.
 
 3. KVM_HC_FEATURES
-------------------------
-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.
+------------------
+
+: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
-------------------------
-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.
+----------------------------
+
+: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.
 
 5. KVM_HC_KICK_CPU
-------------------------
-Architecture: x86
-Status: active
-Purpose: Hypercall used to wakeup a vcpu from HLT state
-Usage example : A vcpu of a paravirtualized guest that is busywaiting in guest
-kernel mode for an event to occur (ex: a spinlock to become available) can
-execute HLT instruction once it has busy-waited for more than a threshold
-time-interval. Execution of HLT instruction would cause the hypervisor to put
-the vcpu to sleep until occurrence of an appropriate event. Another vcpu of the
-same guest can wakeup the sleeping vcpu by issuing KVM_HC_KICK_CPU hypercall,
-specifying APIC ID (a1) of the vcpu to be woken up. An additional argument (a0)
-is used in the hypercall for future use.
+------------------
+
+:Architecture: x86
+:Status: active
+:Purpose: Hypercall used to wakeup a vcpu from HLT state
+:Usage example:
+  A vcpu of a paravirtualized guest that is busywaiting in guest
+  kernel mode for an event to occur (ex: a spinlock to become available) can
+  execute HLT instruction once it has busy-waited for more than a threshold
+  time-interval. Execution of HLT instruction would cause the hypervisor to put
+  the vcpu to sleep until occurrence of an appropriate event. Another vcpu of the
+  same guest can wakeup the sleeping vcpu by issuing KVM_HC_KICK_CPU hypercall,
+  specifying APIC ID (a1) of the vcpu to be woken up. An additional argument (a0)
+  is used in the hypercall for future use.
 
 
 6. KVM_HC_CLOCK_PAIRING
-------------------------
-Architecture: x86
-Status: active
-Purpose: Hypercall used to synchronize host and guest clocks.
+-----------------------
+:Architecture: x86
+:Status: active
+:Purpose: Hypercall used to synchronize host and guest clocks.
+
 Usage:
 
 a0: guest physical address where host copies
@@ -101,6 +114,8 @@ a0: guest physical address where host copies
 a1: clock_type, ATM only KVM_CLOCK_PAIRING_WALLCLOCK (0)
 is supported (corresponding to the host's CLOCK_REALTIME clock).
 
+       ::
+
 		struct kvm_clock_pairing {
 			__s64 sec;
 			__s64 nsec;
@@ -123,15 +138,16 @@ Returns KVM_EOPNOTSUPP if the host does not use TSC clocksource,
 or if clock type is different than KVM_CLOCK_PAIRING_WALLCLOCK.
 
 6. KVM_HC_SEND_IPI
-------------------------
-Architecture: x86
-Status: active
-Purpose: Send IPIs to multiple vCPUs.
+------------------
+
+:Architecture: x86
+:Status: active
+:Purpose: Send IPIs to multiple vCPUs.
 
-a0: lower part of the bitmap of destination APIC IDs
-a1: higher part of the bitmap of destination APIC IDs
-a2: the lowest APIC ID in bitmap
-a3: APIC ICR
+- a0: lower part of the bitmap of destination APIC IDs
+- a1: higher part of the bitmap of destination APIC IDs
+- a2: the lowest APIC ID in bitmap
+- a3: APIC ICR
 
 The hypercall lets a guest send multicast IPIs, with at most 128
 128 destinations per hypercall in 64-bit mode and 64 vCPUs per
@@ -143,12 +159,13 @@ corresponds to the APIC ID a2+1, and so on.
 Returns the number of CPUs to which the IPIs were delivered successfully.
 
 7. KVM_HC_SCHED_YIELD
-------------------------
-Architecture: x86
-Status: active
-Purpose: Hypercall used to yield if the IPI target vCPU is preempted
+---------------------
+
+:Architecture: x86
+:Status: active
+:Purpose: Hypercall used to yield if the IPI target vCPU is preempted
 
 a0: destination APIC ID
 
-Usage example: When sending a call-function IPI-many to vCPUs, yield if
-any of the IPI target vCPUs was preempted.
+:Usage example: When sending a call-function IPI-many to vCPUs, yield if
+	        any of the IPI target vCPUs was preempted.

Documentation/virt/kvm/index.rst

@@ -11,8 +11,10 @@ KVM
    amd-memory-encryption
    cpuid
    halt-polling
+   hypercalls
    msr
    vcpu-requests
 
    arm/index
+
    devices/index