doc: update hvlog kernel parameter descriptions
@@ -201,11 +201,25 @@ relevant for configuring or debugging ACRN-based systems.
* - hvlog
- Service VM
- - Reserve memory for the ACRN hypervisor log. The reserved space should not
- overlap any other blocks (e.g. hypervisor's reserved space).
+ - Sets the guest physical address and size of the dedicated hypervisor
+ log ring buffer between the hypervisor and Service VM.
+ A ``memmap`` parameter is also required to reserve the specified memory
+ from the guest VM.
+
+ If hypervisor relocation is disabled, verify that
+ :option:`CONFIG_HV_RAM_START` and :option:`CONFIG_HV_RAM_SIZE`
+ does not overlap with the hypervisor's reserved buffer space allocated
+ in the Service VM. Service VM GPA and HPA are a 1:1 mapping.
+
+ If hypervisor relocation is enabled, reserve the memory below 256MB,
+ since hypervisor could be relocated anywhere between 256MB and 4GB.
+
+ You should enable ASLR on SOS. This ensures that when guest Linux is
+ relocating kernel image, it will avoid this buffer address.
+
- ::
- hvlog=2M@0x6de00000
+ hvlog=2M@0xe00000
* - memmap
- Service VM
@@ -217,7 +231,7 @@ relevant for configuring or debugging ACRN-based systems.
Gigabytes, respectively.
- ::
- memmap=0x400000$0x6da00000
+ memmap=0x400000$0xa00000
* - ramoops.mem_address
ramoops.mem_size
@@ -228,9 +242,12 @@ relevant for configuring or debugging ACRN-based systems.
to store the dump. See `Linux Kernel Ramoops oops/panic logger
<https://www.kernel.org/doc/html/v4.19/admin-guide/ramoops.html#ramoops-oops-panic-logger>`_
for details.
+
+ This buffer should not overlap with hypervisor reserved memory and
+ guest kernel image. See ``hvlog``.
- ::
- ramoops.mem_address=0x6da00000
+ ramoops.mem_address=0xa00000
ramoops.mem_size=0x400000
ramoops.console_size=0x200000
