From: Mihai DONTU <mdontu@xxxxxxxxxxxxxxx>
KVM_HC_XEN_HVM_OP is used by the agent injected in the introspected guest,
while KVM_HC_MEM_MAP and KVM_HC_MEM_UNMAP are used by the introspection
tool running in another guest.
Signed-off-by: Adalbert Lazăr <alazar@xxxxxxxxxxxxxxx>
Signed-off-by: Mihai Donțu <mdontu@xxxxxxxxxxxxxxx>
---
Documentation/virtual/kvm/hypercalls.txt | 68 +++++++++++++++++++++++-
1 file changed, 67 insertions(+), 1 deletion(-)
diff --git a/Documentation/virtual/kvm/hypercalls.txt b/Documentation/virtual/kvm/hypercalls.txt
index da24c138c8d1..f59fc2c9698e 100644
--- a/Documentation/virtual/kvm/hypercalls.txt
+++ b/Documentation/virtual/kvm/hypercalls.txt
@@ -122,7 +122,7 @@ compute the CLOCK_REALTIME for its clock, at the same instant.
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
+7. KVM_HC_SEND_IPI
------------------------
Architecture: x86
Status: active
@@ -141,3 +141,69 @@ a0 corresponds to the APIC ID in the third argument (a2), bit 1
corresponds to the APIC ID a2+1, and so on.
Returns the number of CPUs to which the IPIs were delivered successfully.
+
+8. KVM_HC_XEN_HVM_OP
+--------------------
+
+Architecture: x86
+Status: active
+Purpose: To enable communication between a guest agent and a VMI application
+Usage:
+
+An event will be sent to the VMI application (see kvmi.rst) if the following
+registers, which differ between 32bit and 64bit, have the following values:
+
+ 32bit 64bit value
+ ---------------------------
+ ebx (a0) rdi KVM_HC_XEN_HVM_OP_GUEST_REQUEST_VM_EVENT
+ ecx (a1) rsi 0
+
+This specification copies Xen's { __HYPERVISOR_hvm_op,
+HVMOP_guest_request_vm_event } hypercall and can originate from kernel or
+userspace.
+
+It returns 0 if successful, or a negative POSIX.1 error code if it fails. The
+absence of an active VMI application is not signaled in any way.
+
+The following registers are clobbered:
+
+ * 32bit: edx, esi, edi, ebp
+ * 64bit: rdx, r10, r8, r9
+
+In particular, for KVM_HC_XEN_HVM_OP_GUEST_REQUEST_VM_EVENT, the last two
+registers can be poisoned deliberately and cannot be used for passing
+information.
+
+9. KVM_HC_MEM_MAP
+-----------------
+
+Architecture: x86
+Status: active
+Purpose: Map a guest physical page to another VM (the introspector).
+Usage:
+
+a0: pointer to a token obtained with a KVMI_GET_MAP_TOKEN command (see kvmi.rst)
+ struct kvmi_map_mem_token {
+ __u64 token[4];
+ };
+
+a1: guest physical address to be mapped
+
+a2: guest physical address from introspector that will be replaced
+
+Both guest physical addresses will end up poiting to the same physical page.
+
+Returns KVM_EFAULT in case of an error.
+
+10. KVM_HC_MEM_UNMAP
+-------------------
+
+Architecture: x86
+Status: active
+Purpose: Unmap a previously mapped page.
+Usage:
+
+a0: guest physical address from introspector
+
+The address will stop pointing to the introspected page and a new physical
+page is allocated for this gpa.
