From 76f80eaf70b2fafa12f8533cf6aa700efa541a82 Mon Sep 17 00:00:00 2001 From: Andrew Cooper Date: Mon, 17 Nov 2025 21:11:36 +0000 Subject: [PATCH] x86/ucode: Drop structurally unreachable ASSERT()s It's impossible for wait_for_state() to return false when looking for LOADING_EXIT, so much so that the optimiser can drop the ASSERT()s. No functional change. Fixes: 5ed12565aa32 ("microcode: rendezvous CPUs in NMI handler and load ucode") Signed-off-by: Andrew Cooper Reviewed-by: Jan Beulich --- xen/arch/x86/cpu/microcode/core.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) diff --git a/xen/arch/x86/cpu/microcode/core.c b/xen/arch/x86/cpu/microcode/core.c index ecee400f28..7aaf62839f 100644 --- a/xen/arch/x86/cpu/microcode/core.c +++ b/xen/arch/x86/cpu/microcode/core.c @@ -320,12 +320,10 @@ static int secondary_thread_fn(void) self_nmi(); /* - * Wait for ucode loading is done in case that the NMI does not arrive - * synchronously, which may lead to a not-yet-updated CPU signature is - * copied below. + * NMIs may not be delivered synchronously. Wait for the primary threads + * to be done. */ - if ( unlikely(!wait_for_state(LOADING_EXIT)) ) - ASSERT_UNREACHABLE(); + wait_for_state(LOADING_EXIT); /* Copy update revision from the primary thread. */ this_cpu(cpu_sig).rev = @@ -345,12 +343,10 @@ static int primary_thread_fn(const struct microcode_patch *patch, self_nmi(); /* - * Wait for ucode loading is done in case that the NMI does not arrive - * synchronously, which may lead to a not-yet-updated error is returned - * below. + * NMIs may not be delivered synchronously. Wait for the primary + * threads to be done. */ - if ( unlikely(!wait_for_state(LOADING_EXIT)) ) - ASSERT_UNREACHABLE(); + wait_for_state(LOADING_EXIT); return this_cpu(loading_err); }