When crosvm is used to boot a kernel as a VM, the SMP MP-table is found at physical address 0x0. This causes mpf_base to be set to 0 and a subsequent "if (!mpf_base)" check in default_get_smp_config() results in the MP-table not being parsed. Further into the boot this results in an oops when attempting a read_apic_id().
Add a boolean variable that is set to true when the MP-table is found. Use this variable for testing if the MP-table was found so that even a value of 0 for mpf_base will result in continued parsing of the MP-table. Reported-by: Tomeu Vizoso <[email protected]> Signed-off-by: Tom Lendacky <[email protected]> --- arch/x86/kernel/mpparse.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c index 5cbb317..c3d3094 100644 --- a/arch/x86/kernel/mpparse.c +++ b/arch/x86/kernel/mpparse.c @@ -430,6 +430,7 @@ static inline void __init construct_default_ISA_mptable(int mpc_default_type) } static unsigned long mpf_base; +static bool mpf_found; static unsigned long __init get_mpc_size(unsigned long physptr) { @@ -503,7 +504,7 @@ void __init default_get_smp_config(unsigned int early) if (!smp_found_config) return; - if (!mpf_base) + if (!mpf_found) return; if (acpi_lapic && early) @@ -592,6 +593,7 @@ static int __init smp_scan_config(unsigned long base, unsigned long length) smp_found_config = 1; #endif mpf_base = base; + mpf_found = true; pr_info("found SMP MP-table at [mem %#010lx-%#010lx] mapped at [%p]\n", base, base + sizeof(*mpf) - 1, mpf); @@ -857,7 +859,7 @@ static int __init update_mp_table(void) if (!enable_update_mptable) return 0; - if (!mpf_base) + if (!mpf_found) return 0; mpf = early_memremap(mpf_base, sizeof(*mpf));
