diff options
| author | Jiaqing Zhao <jiaqing.zhao@linux.intel.com> | 2025-05-09 17:06:33 +0000 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2025-05-12 13:04:40 +0200 |
| commit | 824c6384e8d9275d4ec7204f3f79a4ac6bc10379 (patch) | |
| tree | 7bef58fba2f2a048024cf699be5bcc652a863555 | |
| parent | 82f2b0b97b36ee3fcddf0f0780a9a0825d52fec3 (diff) | |
x86/mtrr: Check if fixed-range MTRRs exist 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 like the ACRN hypervisor which
has removed fixed-range MTRR emulation, accessing these MSRs will
trigger an 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")
Signed-off-by: Jiaqing Zhao <jiaqing.zhao@linux.intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/20250509170633.3411169-2-jiaqing.zhao@linux.intel.com
| -rw-r--r-- | arch/x86/kernel/cpu/mtrr/generic.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c index e2c6b471d230..8c18327eb10b 100644 --- a/arch/x86/kernel/cpu/mtrr/generic.c +++ b/arch/x86/kernel/cpu/mtrr/generic.c @@ -593,7 +593,7 @@ 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); } |