Commit-ID: a18a0f6850d4b286a5ebf02cd5b22fe496b86349 Gitweb: http://git.kernel.org/tip/a18a0f6850d4b286a5ebf02cd5b22fe496b86349 Author: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> AuthorDate: Mon, 1 Dec 2014 16:27:44 -0500 Committer: Borislav Petkov <bp@xxxxxxx> CommitDate: Sat, 6 Dec 2014 12:59:03 +0100 x86, microcode: Don't initialize microcode code on paravirt Paravirtual guests are not expected to load microcode into processors and therefore it is not necessary to initialize microcode loading logic. In fact, under certain circumstances initializing this logic may cause the guest to crash. Specifically, 32-bit kernels use __pa_nodebug() macro which does not work in Xen (the code path that leads to this macro happens during resume when we call mc_bp_resume()->load_ucode_ap() ->check_loader_disabled_ap()) Signed-off-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> Link: http://lkml.kernel.org/r/1417469264-31470-1-git-send-email-boris.ostrovsky@xxxxxxxxxx Signed-off-by: Borislav Petkov <bp@xxxxxxx> --- arch/x86/kernel/cpu/microcode/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c index 2ce9051..ebd232d 100644 --- a/arch/x86/kernel/cpu/microcode/core.c +++ b/arch/x86/kernel/cpu/microcode/core.c @@ -557,7 +557,7 @@ static int __init microcode_init(void) struct cpuinfo_x86 *c = &cpu_data(0); int error; - if (dis_ucode_ldr) + if (paravirt_enabled() || dis_ucode_ldr) return 0; if (c->x86_vendor == X86_VENDOR_INTEL) -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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