[doc] install: be a bit clearer about calculating the ivshmem size

This commit is contained in:
Geoffrey McRae 2022-09-19 22:11:17 +10:00
parent 646a725c0e
commit 136410daac

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@ -70,9 +70,11 @@ Determining memory
You will need to adjust the memory size to be suitable for your desired maximum
resolution, with the following formula:
``width x height x pixel size x 2 = total bytes``
``width x height x pixel size x 2 = frame bytes``
``total bytes / 1024 / 1024 = total megabytes + 10``
``total bytes / 1024 / 1024 = frame megabytes``
``total megabytes + 10 = total size required``
Where `pixel size` is 4 for 32-bit RGB (SDR) or 8 for 64-bit
(HDR :ref:`* <libvirt_determining_memory_hdr>`).
@ -85,7 +87,9 @@ For example, for a resolution of 1920x1080 (1080p):
``1920 x 1080 x 4 x 2 = 16,588,800 bytes``
``16,588,800 / 1024 / 1024 = 15.82 MiB + 10 = 25.82 MiB``
``16,588,800 / 1024 / 1024 = 15.82 MiB``
``15.82 MiB + 10 MiB = 25.82 MiB``
You must round this value up to the nearest power of two, which for the
provided example is 32 MiB.