The per CPU array 'cea_exception_stacks' points to per CPU stacks for #DB, NMI and #DF. It is normally referenced via the #define: __this_cpu_ist_top_va(). FRED introduced new fields in the host-state area of the VMCS for stack levels 1->3 (HOST_IA32_FRED_RSP[123]), each respectively corresponding to per CPU stacks for #DB, NMI and #DF. KVM must populate these each time a vCPU is loaded onto a CPU. Signed-off-by: Xin Li (Intel) <xin@xxxxxxxxx> Tested-by: Shan Kang <shan.kang@xxxxxxxxx> --- Change in v4: * Rewrite the change log and add comments to the export (Dave Hansen). --- arch/x86/mm/cpu_entry_area.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/x86/mm/cpu_entry_area.c b/arch/x86/mm/cpu_entry_area.c index 575f863f3c75..bc0d687de376 100644 --- a/arch/x86/mm/cpu_entry_area.c +++ b/arch/x86/mm/cpu_entry_area.c @@ -17,6 +17,13 @@ static DEFINE_PER_CPU_PAGE_ALIGNED(struct entry_stack_page, entry_stack_storage) #ifdef CONFIG_X86_64 static DEFINE_PER_CPU_PAGE_ALIGNED(struct exception_stacks, exception_stacks); DEFINE_PER_CPU(struct cea_exception_stacks*, cea_exception_stacks); +/* + * FRED introduced new fields in the host-state area of the VMCS for + * stack levels 1->3 (HOST_IA32_FRED_RSP[123]), each respectively + * corresponding to per CPU stacks for #DB, NMI and #DF. KVM must + * populate these each time a vCPU is loaded onto a CPU. + */ +EXPORT_PER_CPU_SYMBOL(cea_exception_stacks); static DEFINE_PER_CPU_READ_MOSTLY(unsigned long, _cea_offset); -- 2.48.1
