feat: Enable explicit hugepages for the GuestVM#9027
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frankdavid merged 2 commits intomasterfrom Feb 25, 2026
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Using hugepages helps the host reduce the work of managing the memory pages of the QEMU process. The host already uses transparent huge pages, but the amount of hugepages fluctuates quite a bit during the lifetime of the VM (anywhere between 20-95% of the QEMU's process memory is backed by hugepages). Using explicit hugepages should give more consistent behavior across nodes. The downside: - The Host must allocate the hugepages during startup, this adds ~30 seconds to the Host startup. - QEMU allocates hugepages eagerly during startup, this adds ~5 seconds to the startup time of the Guest VM. However, we save on the QEMU process cleanup time which can be anywhere between 30s and 100s.
Bownairo
approved these changes
Feb 24, 2026
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Using hugepages helps the host reduce the work of managing the memory pages of the QEMU process. The host already uses transparent huge pages, but the amount of hugepages fluctuates quite a bit during the lifetime of the VM (anywhere between 20-95% of the QEMU's process memory is backed by hugepages). Using explicit hugepages should give more consistent behavior across nodes. We only enable hugepages for non-SEV nodes because the Linux kernel does not support hugepages yet for VMs with encrypted memory.
The downside: