Platform Runtime Mechanism became integrated into the ACPI 6.4 specification earlier this year and allows transferring some system management interrupt (SMI) handlers out of the system management mode (SMM) “dark field” and into the OS/VMM execution context. With Linux 5.14 preliminary work on ACPI Platform Runtime Mechanism is made up our minds to land.
Platform Runtime Mechanism, allows transferring of the SMI handlers that attain no longer require SMM privileges to be punted into the OS/VMM context. There are security and performance advantages of PRM and with it now being phase of the public ACPI specification, the Linux kernel enhance is on its scheme. Microsoft for his or her phase has already supplied PRM enhance as phase of Home windows Insider Preview builds for months.
More background knowledge on the Platform Runtime Mechanism may perhaps possibly perhaps perhaps additionally even be found during the prior article Intel + Microsoft Proceed Work On Replacing More SMM “Dusky Boxes” With PRM.
Now on the kernel entrance for the upcoming Linux 5.14, an preliminary PRM pull has landed into linux-pm’s -next code. The pull has the preliminary adjustments for PRM and enforcing the OperationRegion handler for this mechanism. A brand unique Kconfig make time knob of ACPI_PRMT is added for that Platform Runtime Mechanism enhance.
More PRM technical knowledge in standard is on hand from the documentation.