qemu/contrib/systemd/qemu-vmsr-helper.service

[Unit]
Description=Virtual RAPL MSR Daemon for QEMU

[Service]
WorkingDirectory=/tmp
Type=simple
ExecStart=/usr/bin/qemu-vmsr-helper
PrivateTmp=yes
ProtectSystem=strict
ReadWritePaths=/var/run
RestrictAddressFamilies=AF_UNIX
Restart=always
RestartSec=0

[Install]
tools: build qemu-vmsr-helper Introduce a privileged helper to access RAPL MSR. The privileged helper tool, qemu-vmsr-helper, is designed to provide virtual machines with the ability to read specific RAPL (Running Average Power Limit) MSRs without requiring CAP_SYS_RAWIO privileges or relying on external, out-of-tree patches. The helper tool leverages Unix permissions and SO_PEERCRED socket options to enforce access control, ensuring that only processes explicitly requesting read access via readmsr() from a valid Thread ID can access these MSRs. The list of RAPL MSRs that are allowed to be read by the helper tool is defined in rapl-msr-index.h. This list corresponds to the RAPL MSRs that will be supported in the next commit titled "Add support for RAPL MSRs in KVM/QEMU." The tool is intentionally designed to run on the Linux x86 platform. This initial implementation is tailored for Intel CPUs but can be extended to support AMD CPUs in the future. Signed-off-by: Anthony Harivel <aharivel@redhat.com> Link: https://lore.kernel.org/r/20240522153453.1230389-3-aharivel@redhat.com Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> 2024-05-22 17:34:51 +02:00			`[Unit]`
			`Description=Virtual RAPL MSR Daemon for QEMU`

			`[Service]`
			`WorkingDirectory=/tmp`
			`Type=simple`
			`ExecStart=/usr/bin/qemu-vmsr-helper`
			`PrivateTmp=yes`
			`ProtectSystem=strict`
			`ReadWritePaths=/var/run`
			`RestrictAddressFamilies=AF_UNIX`
			`Restart=always`
			`RestartSec=0`

			`[Install]`