From: Joerg Roedel <[email protected]> Load the IDT right after switching to virtual addresses in head_64.S so that the kernel can handle #VC exceptions.
Signed-off-by: Joerg Roedel <[email protected]> --- arch/x86/include/asm/desc.h | 1 + arch/x86/kernel/head64.c | 7 +++++++ arch/x86/kernel/head_64.S | 17 +++++++++++++++++ arch/x86/kernel/idt.c | 22 ++++++++++++++++++++++ 4 files changed, 47 insertions(+) diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h index 68a99d2a5f33..8a4c642ee2b3 100644 --- a/arch/x86/include/asm/desc.h +++ b/arch/x86/include/asm/desc.h @@ -440,6 +440,7 @@ extern void idt_setup_apic_and_irq_gates(void); extern void idt_setup_early_pf(void); extern void idt_setup_ist_traps(void); extern void idt_setup_debugidt_traps(void); +extern void setup_early_handlers(gate_desc *idt); #else static inline void idt_setup_early_pf(void) { } static inline void idt_setup_ist_traps(void) { } diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 206a4b6144c2..7cdfb7113811 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -489,3 +489,10 @@ void __init x86_64_start_reservations(char *real_mode_data) start_kernel(); } + +void __head early_idt_setup_early_handler(unsigned long physaddr) +{ + gate_desc *idt = fixup_pointer(idt_table, physaddr); + + setup_early_handlers(idt); +} diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index eefd6838b895..0af79f783659 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -98,6 +98,20 @@ SYM_CODE_START_NOALIGN(startup_64) leaq _text(%rip), %rdi pushq %rsi call __startup_64 + /* Save return value */ + pushq %rax + + /* + * Load IDT with early handlers - needed for SEV-ES + * Do this here because this must only happen on the boot CPU + * and the code below is shared with secondary CPU bringup. + */ + leaq _text(%rip), %rdi + call early_idt_setup_early_handler + + /* Restore __startup_64 return value*/ + popq %rax + /* Restore pointer to real_mode_data */ popq %rsi /* Form the CR3 value being sure to include the CR3 modifier */ @@ -194,6 +208,9 @@ SYM_CODE_START(secondary_startup_64) */ movq initial_stack(%rip), %rsp + /* Load IDT */ + lidt idt_descr(%rip) + /* Check if nx is implemented */ movl $0x80000001, %eax cpuid diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c index 7d8fa631dca9..84250c090596 100644 --- a/arch/x86/kernel/idt.c +++ b/arch/x86/kernel/idt.c @@ -347,6 +347,28 @@ void __init idt_setup_early_handler(void) load_idt(&idt_descr); } +#ifdef CONFIG_X86_64 +/* + * This function does the same as idt_setup_early_handler(), but is + * called directly from head_64.S before the kernel switches to virtual + * addresses. PV-ops don't work at that point, so set_intr_gate() can't + * be used here. + */ +void __init setup_early_handlers(gate_desc *idt) +{ + int i; + + for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) { + struct idt_data data; + gate_desc desc; + + init_idt_data(&data, i, early_idt_handler_array[i]); + idt_init_desc(&desc, &data); + native_write_idt_entry(idt, i, &desc); + } +} +#endif + /** * idt_invalidate - Invalidate interrupt descriptor table * @addr: The virtual address of the 'invalid' IDT -- 2.17.1 _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
