| Message ID | 1564654971-31328-1-git-send-email-chao.gao@intel.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | improve late microcode loading | expand |
On 01/08/2019 11:22, Chao Gao wrote: > This series includes below changes: > 1. Patch 1: always read microcode revision at boot time > 2. Patch 2: an userspace tool for late microcode update To get things started, I've committed these two changes. I'm afraid I don't have time immediately to review the rest of the series, but will try to find time. ~Andrew
On Thu, Aug 01, 2019 at 06:22:35PM +0800, Chao Gao wrote: > Changes in version 8: > - block #NMI handling during microcode loading (Patch 16) > - Don't assume that all CPUs in the system have loaded a same ucode. > So when parsing a blob, we attempt to save a patch as long as it matches > with current cpu signature regardless of the revision of the patch. > And also for loading, we only require the patch to be loaded isn't old > than the cached one. > - store an update after the first successful loading on a CPU > - remove the patch that calls wbinvd() unconditionally before microcode > loading. It is under internal discussion. > - divide two big patches into several patches to improve readability. Thanks for following up on this! I will try to review it between Monday and Tuesday. Roger.
Changes in version 8: - block #NMI handling during microcode loading (Patch 16) - Don't assume that all CPUs in the system have loaded a same ucode. So when parsing a blob, we attempt to save a patch as long as it matches with current cpu signature regardless of the revision of the patch. And also for loading, we only require the patch to be loaded isn't old than the cached one. - store an update after the first successful loading on a CPU - remove the patch that calls wbinvd() unconditionally before microcode loading. It is under internal discussion. - divide two big patches into several patches to improve readability. Sergey, could you help to test this series on an AMD machine? Regarding changes to AMD side, I didn't do any test for them due to lack of hardware. At least, two basic tests are needed: * do a microcode update after system bootup * don't bring all pCPUs up at bootup by specifying maxcpus option in xen command line and then do a microcode update and online all offlined CPUs via 'xen-hptool'. The intention of this series is to make the late microcode loading more reliable by rendezvousing all cpus in stop_machine context. This idea comes from Ashok. I am porting his linux patch to Xen (see patch 14 and 15 for more details). This series includes below changes: 1. Patch 1: always read microcode revision at boot time 2. Patch 2: an userspace tool for late microcode update 3. Patch 3-13: introduce a global microcode cache and some cleanup 4. Patch 14: synchronize late microcode loading 5. Patch 15: support parallel microcodes update on different cores 6. Patch 16: block #NMI handling during microcode loading Currently, late microcode loading does a lot of things including parsing microcode blob, checking the signature/revision and performing update. Putting all of them into stop_machine context is a bad idea because of complexity (one issue I observed is memory allocation triggered one assertion in stop_machine context). To simplify the load process, parsing microcode is moved out of the load process. Remaining parts of load process is put to stop_machine context. Previous change log: Changes in version 7: - cache one microcode update rather than a list of it. Assuming that all CPUs (including those will be plugged in later) in the system have the same signature, one update matches with one CPU should match with others. Thus, one update is enough for microcode updating during CPU hot-plug and resuming. - To handle load failure, microcode update is cached after it is applied to avoid a broken update overriding a validated one. Unvalidated microcode updates are passed by arguments rather than another global variable, where this series slightly differs from Roger's suggestion in: https://lists.xen.org/archives/html/xen-devel/2019-03/msg00776.html - incorporate Sergey's patch (patch 10) to fix a bug: we maintain a variable to reflect current microcode revision. But in some cases, this variable isn't initialized during system boot time, which results in falsely reporting that processor is susceptible to some known vulnerabilities. - fix issues reported by Sergey: https://lists.xenproject.org/archives/html/xen-devel/2019-03/msg00901.html - Responses to Sergey/Roger/Wei/Ashok's other comments. Major changes in version 6: - run wbinvd before updating microcode (patch 10) - add an userspace tool for late microcode update (patch 1) - scale time to wait by the number of remaining CPUs to respond - remove 'cpu' parameters from some related callbacks and functins - save an ucode patch only if its supported CPU is allowed to mix with current cpu. Changes in version 5: - support parallel microcode updates for all cores (see patch 8) - Address Roger's comments on the last version. Chao Gao (15): misc/xen-ucode: Upload a microcode blob to the hypervisor microcode/intel: extend microcode_update_match() microcode/amd: fix memory leak microcode/amd: distinguish old and mismatched ucode in microcode_fits() microcode: introduce a global cache of ucode patch microcode: clean up microcode_resume_cpu microcode: remove struct ucode_cpu_info microcode: remove pointless 'cpu' parameter microcode/amd: call svm_host_osvw_init() in common code microcode: pass a patch pointer to apply_microcode() microcode: split out apply_microcode() from cpu_request_microcode() microcode: unify loading update during CPU resuming and AP wakeup x86/microcode: Synchronize late microcode loading microcode: remove microcode_update_lock microcode: block #NMI handling when loading an ucode Sergey Dyasli (1): x86/microcode: always collect_cpu_info() during boot tools/libxc/include/xenctrl.h | 1 + tools/libxc/xc_misc.c | 23 ++ tools/misc/Makefile | 4 + tools/misc/xen-ucode.c | 73 +++++++ xen/arch/x86/acpi/power.c | 2 +- xen/arch/x86/apic.c | 2 +- xen/arch/x86/microcode.c | 464 +++++++++++++++++++++++++++++++--------- xen/arch/x86/microcode_amd.c | 282 ++++++++++++------------ xen/arch/x86/microcode_intel.c | 204 ++++++++++-------- xen/arch/x86/smpboot.c | 5 +- xen/arch/x86/spec_ctrl.c | 2 +- xen/include/asm-x86/microcode.h | 43 ++-- xen/include/asm-x86/processor.h | 4 +- 13 files changed, 740 insertions(+), 369 deletions(-) create mode 100644 tools/misc/xen-ucode.c