| Message ID | 20240405121128.260493-1-fouad.hilly@cloud.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | x86/xen-ucode: Introduce --force option | expand |
On 05/04/2024 1:11 pm, Fouad Hilly wrote: > Refactor and introduce --force option to xen-ucode, which skips microcode > version check when updating x86 CPU micocode. A new hypercall introduced > with flags field to facilitate the new option and allow for future flags > as needed. It's worth giving a bit of background for reviewers. Basically, my "ucode=allow-same" for testing purposes has proved insufficient, so we're wanting to replace it with a "user knows what they're doing and gets to keep the pieces" option instead. Upcoming is the Intel microcode-revision extension, which has different implications for Xen than it does for Linux, by virtue of our proto-support to re-scan CPUID and cope with new things appearing. Also, while not a consideration for this issue, it subsequently turns out that there is a microcode bug on Gemini Lake CPUs for which downgrading the microcode is a viable and practical fix. In all cases, having an ability to say "trust me, I know what I'm doing, really try and give this blob to the CPU" would help in some corner cases. ~Andrew
Refactor and introduce --force option to xen-ucode, which skips microcode version check when updating x86 CPU micocode. A new hypercall introduced with flags field to facilitate the new option and allow for future flags as needed. Fouad Hilly (5): x86: Remove x86 low level version check of microcode x86: Refactor microcode_update() hypercall with flags field x86: Add usage() to print out usage message x86: Use getopt to handle command line args x86: Add --force option to xen-ucode to override microcode version check tools/include/xenctrl.h | 2 +- tools/libs/ctrl/xc_misc.c | 12 ++++- tools/misc/xen-ucode.c | 69 +++++++++++++++++++++++----- xen/arch/x86/cpu/microcode/amd.c | 8 +--- xen/arch/x86/cpu/microcode/core.c | 12 +++-- xen/arch/x86/cpu/microcode/intel.c | 11 ++--- xen/arch/x86/include/asm/microcode.h | 2 +- xen/arch/x86/platform_hypercall.c | 12 ++++- xen/include/public/platform.h | 8 ++++ 9 files changed, 102 insertions(+), 34 deletions(-)