[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [PATCH v2 1/5] x86: Update x86 low level version check of microcode
On 16.04.2024 11:15, Fouad Hilly wrote: > Update microcode version check at Intel and AMD Level by: > Preventing the low level code from sending errors if the microcode > version provided is not a newer version. And why is this change (a) wanted and (b) correct? > Other errors will be sent like before. > When the provided microcode version is the same as the current one, code > to point to microcode provided. I'm afraid I can't interpret this sentence. > Microcode version check happens at higher and common level in core.c. > Keep all the required code at low level that checks for signature and CPU > compatibility > > [v2] > Update message description to better describe the changes This belongs ... > Signed-off-by: Fouad Hilly <fouad.hilly@xxxxxxxxx> > --- ... below the separator. > --- a/xen/arch/x86/cpu/microcode/amd.c > +++ b/xen/arch/x86/cpu/microcode/amd.c > @@ -383,12 +383,8 @@ static struct microcode_patch *cf_check > cpu_request_microcode( > goto skip; > } > > - /* > - * If the new ucode covers current CPU, compare ucodes and store > the > - * one with higher revision. > - */ > - if ( (microcode_fits(mc->patch) != MIS_UCODE) && > - (!saved || (compare_header(mc->patch, saved) == NEW_UCODE)) > ) > + /* If the provided ucode covers current CPU, then store its > revision. */ > + if ( (microcode_fits(mc->patch) != MIS_UCODE) && !saved ) > { > saved = mc->patch; > saved_size = mc->len; > --- a/xen/arch/x86/cpu/microcode/intel.c > +++ b/xen/arch/x86/cpu/microcode/intel.c > @@ -294,8 +294,7 @@ static int cf_check apply_microcode(const struct > microcode_patch *patch) > > result = microcode_update_match(patch); > > - if ( result != NEW_UCODE && > - !(opt_ucode_allow_same && result == SAME_UCODE) ) > + if ( result != NEW_UCODE && result != SAME_UCODE ) > return -EINVAL; Unlike the other two adjustments this one results in still permitting only same-or-newer. How does this fit with the AMD change above and the other Intel change ... > @@ -354,12 +353,8 @@ static struct microcode_patch *cf_check > cpu_request_microcode( > if ( error ) > break; > > - /* > - * If the new update covers current CPU, compare updates and store > the > - * one with higher revision. > - */ > - if ( (microcode_update_match(mc) != MIS_UCODE) && > - (!saved || compare_revisions(saved->rev, mc->rev) == NEW_UCODE) > ) > + /* If the provided ucode covers current CPU, then store its > revision. */ > + if ( (microcode_update_match(mc) != MIS_UCODE) && !saved ) > saved = mc; ... here? Jan
|
![]() |
Lists.xenproject.org is hosted with RackSpace, monitoring our |