From 486a8e4ead87b388efa97ef37d5fd9818de32acd Mon Sep 17 00:00:00 2001 From: Jiaqing Zhao Date: Mon, 12 May 2025 08:41:08 +0000 Subject: [PATCH] x86/mtrr: Check if fixed-range MTRR exists in mtrr_save_fixed_ranges() When suspending, save_processor_state() calls mtrr_save_fixed_ranges() to save fixed-range MTRRs. On platforms without fixed-range MTRRs, accessing these MSRs will trigger unchecked MSR access error. Make sure fixed-range MTRRs are supported before access to prevent such error. Since mtrr_state.have_fixed is only set when MTRRs are present and enabled, checking the CPU feature flag in mtrr_save_fixed_ranges() is unnecessary. Fixes: 3ebad5905609 ("[PATCH] x86: Save and restore the fixed-range MTRRs of the BSP when suspending") Tracked-On: OAM-132455 Signed-off-by: Jiaqing Zhao --- arch/x86/kernel/cpu/mtrr/generic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c index 7b29ebda024f..1ececfce7a46 100644 --- a/arch/x86/kernel/cpu/mtrr/generic.c +++ b/arch/x86/kernel/cpu/mtrr/generic.c @@ -591,7 +591,7 @@ static void get_fixed_ranges(mtrr_type *frs) void mtrr_save_fixed_ranges(void *info) { - if (boot_cpu_has(X86_FEATURE_MTRR)) + if (mtrr_state.have_fixed) get_fixed_ranges(mtrr_state.fixed_ranges); }