[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 1/7] x86/ucode: Document the behaviour of the microcode_ops hooks
... and struct cpu_signature for good measure. No comment is passed on the suitability of the behaviour... Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> --- CC: Jan Beulich <JBeulich@xxxxxxxx> CC: Wei Liu <wl@xxxxxxx> CC: Roger Pau Monné <roger.pau@xxxxxxxxxx> --- xen/arch/x86/cpu/microcode/private.h | 46 ++++++++++++++++++++++++++++++++++++ xen/include/asm-x86/microcode.h | 5 ++++ 2 files changed, 51 insertions(+) diff --git a/xen/arch/x86/cpu/microcode/private.h b/xen/arch/x86/cpu/microcode/private.h index e64168a502..a2aec53047 100644 --- a/xen/arch/x86/cpu/microcode/private.h +++ b/xen/arch/x86/cpu/microcode/private.h @@ -14,14 +14,60 @@ enum microcode_match_result { struct microcode_patch; /* Opaque */ struct microcode_ops { + /* + * Parse a microcode container. Format is vendor-specific. + * + * Search within the container for the patch, suitable for the current + * CPU, which has the highest revision. (Note: May be a patch which is + * older that what is running in the CPU. This is a feature, to better + * cope with corner cases from buggy firmware.) + * + * If one is found, allocate and return a struct microcode_patch + * encapsulating the appropriate microcode patch. Does not alias the + * original buffer. + * + * If one is not found, (nothing matches the current CPU), return NULL. + * Also may return ERR_PTR(-err), e.g. bad container, out of memory. + */ struct microcode_patch *(*cpu_request_microcode)(const void *buf, size_t size); + + /* Obtain microcode-relevant details for the current CPU. */ int (*collect_cpu_info)(struct cpu_signature *csig); + + /* + * Attempt to load the provided patch into the CPU. Returns -EIO if + * anything didn't go as expected. + */ int (*apply_microcode)(const struct microcode_patch *patch); + + /* + * Optional. If provided and applicable to the specific update attempt, + * is run once by the initiating CPU. Returning an error will abort the + * load attempt. + */ int (*start_update)(void); + + /* + * Optional. If provided, called on every CPU which completes a microcode + * load. May be called in the case of some errors, and not others. May + * be called even if start_update() wasn't. + */ void (*end_update_percpu)(void); + + /* Free a patch previously allocated by cpu_request_microcode(). */ void (*free_patch)(struct microcode_patch *patch); + + /* + * Is the microcode patch applicable for the current CPU, and newer than + * the currently running patch? + */ bool (*match_cpu)(const struct microcode_patch *patch); + + /* + * Given two patches, are they both applicable to the current CPU, and is + * new a higher revision than old? + */ enum microcode_match_result (*compare_patch)( const struct microcode_patch *new, const struct microcode_patch *old); }; diff --git a/xen/include/asm-x86/microcode.h b/xen/include/asm-x86/microcode.h index 89b9aaa02d..41e85a24d2 100644 --- a/xen/include/asm-x86/microcode.h +++ b/xen/include/asm-x86/microcode.h @@ -7,8 +7,13 @@ #include <public/xen.h> struct cpu_signature { + /* CPU signature (CPUID.1.EAX). Only written on Intel. */ unsigned int sig; + + /* Platform Flags (only actually 1 bit). Only applicable to Intel. */ unsigned int pf; + + /* Microcode Revision. */ unsigned int rev; }; -- 2.11.0 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/mailman/listinfo/xen-devel
|
Lists.xenproject.org is hosted with RackSpace, monitoring our |