forked from SLFO-pool/xen
74 lines
2.7 KiB
Diff
74 lines
2.7 KiB
Diff
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# Commit 977d98e67c2e929c62aa1f495fc4c6341c45abb5
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# Date 2024-05-16 13:59:11 +0100
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# Author Andrew Cooper <andrew.cooper3@citrix.com>
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# Committer Andrew Cooper <andrew.cooper3@citrix.com>
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x86/ucode: Further fixes to identify "ucode already up to date"
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When the revision in hardware is newer than anything Xen has to hand,
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'microcode_cache' isn't set up. Then, `xen-ucode` initiates the update
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because it doesn't know whether the revisions across the system are symmetric
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or not. This involves the patch getting all the way into the
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apply_microcode() hooks before being found to be too old.
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This is all a giant mess and needs an overhaul, but in the short term simply
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adjust the apply_microcode() to return -EEXIST.
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Also, unconditionally print the preexisting microcode revision on boot. It's
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relevant information which is otherwise unavailable if Xen doesn't find new
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microcode to use.
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Fixes: 648db37a155a ("x86/ucode: Distinguish "ucode already up to date"")
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Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
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Reviewed-by: Jan Beulich <jbeulich@suse.com>
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Acked-by: Roger Pau Monné <roger.pau@citrix.com>
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--- a/xen/arch/x86/cpu/microcode/amd.c
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+++ b/xen/arch/x86/cpu/microcode/amd.c
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@@ -222,12 +222,15 @@ static int cf_check apply_microcode(cons
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uint32_t rev, old_rev = sig->rev;
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enum microcode_match_result result = microcode_fits(patch);
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+ if ( result == MIS_UCODE )
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+ return -EINVAL;
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+
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/*
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* Allow application of the same revision to pick up SMT-specific changes
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* even if the revision of the other SMT thread is already up-to-date.
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*/
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- if ( result != NEW_UCODE && result != SAME_UCODE )
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- return -EINVAL;
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+ if ( result == OLD_UCODE )
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+ return -EEXIST;
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if ( check_final_patch_levels(sig) )
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{
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--- a/xen/arch/x86/cpu/microcode/core.c
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+++ b/xen/arch/x86/cpu/microcode/core.c
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@@ -887,6 +887,8 @@ int __init early_microcode_init(unsigned
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ucode_ops.collect_cpu_info();
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+ printk(XENLOG_INFO "BSP microcode revision: 0x%08x\n", this_cpu(cpu_sig).rev);
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+
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/*
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* Some hypervisors deliberately report a microcode revision of -1 to
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* mean that they will not accept microcode updates.
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--- a/xen/arch/x86/cpu/microcode/intel.c
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+++ b/xen/arch/x86/cpu/microcode/intel.c
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@@ -294,10 +294,13 @@ static int cf_check apply_microcode(cons
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result = microcode_update_match(patch);
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- if ( result != NEW_UCODE &&
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- !(opt_ucode_allow_same && result == SAME_UCODE) )
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+ if ( result == MIS_UCODE )
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return -EINVAL;
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+ if ( result == OLD_UCODE ||
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+ (result == SAME_UCODE && !opt_ucode_allow_same) )
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+ return -EEXIST;
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+
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wbinvd();
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wrmsrl(MSR_IA32_UCODE_WRITE, (unsigned long)patch->data);
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