Mailing List Archive

On 21/10/2011 09:37, "Jan Beulich" <JBeulich@xxxxxxxx> wrote:

> microcode_fits() must return distinct values for the success and
> no-fit-but-no-error cases, so the caller can react accordingly. Make
> it return 1 in the success case, and adjust its single caller.
>
> Also remove an impossible code path - install_equiv_cpu_table(), which
> gets called prior to microcode_fits(), never leaves equiv_cpu_table
> being NULL without also returning an error.
>
> Note that this is still awaiting testing on a system where the
> regression was actually observed (which also requires a new enough
> microcode_ctl package). Note also that this will need to be
> backported to 4.0 and 4.1 (or the broken c/s that got backported
> there reverted).
>
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
>
> --- a/xen/arch/x86/microcode_amd.c
> +++ b/xen/arch/x86/microcode_amd.c
> @@ -76,14 +76,6 @@ static int microcode_fits(void *mc, int
> /* We should bind the task to the CPU */
> BUG_ON(cpu != raw_smp_processor_id());
>
> - if ( equiv_cpu_table == NULL )
> - {
> - printk(KERN_INFO "microcode: CPU%d microcode update with "
> - "version 0x%x (current=0x%x)\n",
> - cpu, mc_header->patch_id, uci->cpu_sig.rev);
> - goto out;
> - }
> -
> current_cpu_id = cpuid_eax(0x00000001);
>
> for ( i = 0; equiv_cpu_table[i].installed_cpu != 0; i++ )
> @@ -96,7 +88,7 @@ static int microcode_fits(void *mc, int
> }
>
> if ( !equiv_cpu_id )
> - return 0;
> + return 0;
>
> if ( (mc_header->processor_rev_id) != equiv_cpu_id )
> {
> @@ -113,8 +105,7 @@ static int microcode_fits(void *mc, int
> "update with version 0x%x (current=0x%x)\n",
> cpu, mc_header->patch_id, uci->cpu_sig.rev);
>
> -out:
> - return 0;
> + return 1;
> }
>
> static int apply_microcode(int cpu)
> @@ -285,7 +276,7 @@ static int cpu_request_microcode(int cpu
> while ( (ret = get_next_ucode_from_buffer_amd(mc, buf, size, &offset))
> ==
> 0)
> {
> error = microcode_fits(mc, cpu);
> - if (error != 0)
> + if (error <= 0)
> continue;
>
> error = apply_microcode(cpu);
>

Our internal testing confirms that this patch fixes the boot problem.
Comment from Bugzilla states,
"Both affected systems (with most recent microcode_ctl-1.17-102.38.1 installed
and insserv'ed) are now booting well."

- Charles



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