[PAL/vm-common] Get memory regions from VMM using "etc/e820" fw_cfg file #28
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dimakuv
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May 7, 2024
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Blocking: must test and understand all reserved ranges on new QEMU/on different environments.
Previously on the VM PAL, we hard-coded a single memory region that is RAM (i.e., not reserved) via `FW_CFG_RAM_SIZE`. This is a dangerous assumption which may break in the future. This commit uses a proper source of E820 info: the `etc/e820` fw_cfg file. As a side effect, `find_fw_cfg_selector()` function was slightly modified to also return the size of the object. All callers of this function now use this returned size. Signed-off-by: Dmitrii Kuvaiskii <dmitrii.kuvaiskii@intel.com>
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dimakuv
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May 8, 2024
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Previously, dimakuv (Dmitrii Kuvaiskii) wrote…
Blocking: must test and understand all reserved ranges on new QEMU/on different environments.
Update: the problem was not related to some new reserved memory ranges on newer QEMU (v8.0).
The root cause was that docker run ... by default sets 64MB of /dev/shm. As soon as I set this limit to the one used by Gramine VMs, it started working: e.g. docker run --shm-size 4G.
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Description of the changes
Previously on the VM PAL, we hard-coded a single memory region that is RAM (i.e., not reserved) via
FW_CFG_RAM_SIZE. This is a dangerous assumption which may break in the future. This commit uses a proper source of E820 info: theetc/e820fw_cfg file.As a side effect,
find_fw_cfg_selector()function was slightly modified to also return the size of the object. All callers of this function now use this returned size.Fixes #27.
How to test this PR?
Run on newer QEMU.
This change is