diff options
author | Juergen Gross <jgross@suse.com> | 2017-08-31 19:42:49 +0200 |
---|---|---|
committer | Thomas Gleixner <tglx@linutronix.de> | 2017-08-31 21:35:10 +0200 |
commit | 5878d5d6fdef6447d73b0acc121ba445bef37f53 (patch) | |
tree | b4d36a16451274496a02a43adef75a68b84fdf6f /arch/x86/xen/enlighten_pv.c | |
parent | ef1d4deab953ecb1dfcf9f167043bda8b3f14a11 (diff) | |
download | linux-5878d5d6fdef6447d73b0acc121ba445bef37f53.tar.bz2 |
x86/xen: Get rid of paravirt op adjust_exception_frame
When running as Xen pv-guest the exception frame on the stack contains
%r11 and %rcx additional to the other data pushed by the processor.
Instead of having a paravirt op being called for each exception type
prepend the Xen specific code to each exception entry. When running as
Xen pv-guest just use the exception entry with prepended instructions,
otherwise use the entry without the Xen specific code.
[ tglx: Merged through tip to avoid ugly merge conflict ]
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: xen-devel@lists.xenproject.org
Cc: boris.ostrovsky@oracle.com
Cc: luto@amacapital.net
Link: http://lkml.kernel.org/r/20170831174249.26853-1-jg@pfupf.net
Diffstat (limited to 'arch/x86/xen/enlighten_pv.c')
-rw-r--r-- | arch/x86/xen/enlighten_pv.c | 98 |
1 files changed, 65 insertions, 33 deletions
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c index 03fb07d28299..3859fc19164a 100644 --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -579,6 +579,70 @@ static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum, preempt_enable(); } +#ifdef CONFIG_X86_64 +struct trap_array_entry { + void (*orig)(void); + void (*xen)(void); + bool ist_okay; +}; + +static struct trap_array_entry trap_array[] = { + { debug, xen_xendebug, true }, + { int3, xen_xenint3, true }, + { double_fault, xen_double_fault, true }, +#ifdef CONFIG_X86_MCE + { machine_check, xen_machine_check, true }, +#endif + { nmi, xen_nmi, true }, + { overflow, xen_overflow, false }, +#ifdef CONFIG_IA32_EMULATION + { entry_INT80_compat, xen_entry_INT80_compat, false }, +#endif + { page_fault, xen_page_fault, false }, + { divide_error, xen_divide_error, false }, + { bounds, xen_bounds, false }, + { invalid_op, xen_invalid_op, false }, + { device_not_available, xen_device_not_available, false }, + { coprocessor_segment_overrun, xen_coprocessor_segment_overrun, false }, + { invalid_TSS, xen_invalid_TSS, false }, + { segment_not_present, xen_segment_not_present, false }, + { stack_segment, xen_stack_segment, false }, + { general_protection, xen_general_protection, false }, + { spurious_interrupt_bug, xen_spurious_interrupt_bug, false }, + { coprocessor_error, xen_coprocessor_error, false }, + { alignment_check, xen_alignment_check, false }, + { simd_coprocessor_error, xen_simd_coprocessor_error, false }, +}; + +static bool get_trap_addr(void **addr, unsigned int ist) +{ + unsigned int nr; + bool ist_okay = false; + + /* + * Replace trap handler addresses by Xen specific ones. + * Check for known traps using IST and whitelist them. + * The debugger ones are the only ones we care about. + * Xen will handle faults like double_fault, * so we should never see + * them. Warn if there's an unexpected IST-using fault handler. + */ + for (nr = 0; nr < ARRAY_SIZE(trap_array); nr++) { + struct trap_array_entry *entry = trap_array + nr; + + if (*addr == entry->orig) { + *addr = entry->xen; + ist_okay = entry->ist_okay; + break; + } + } + + if (WARN_ON(ist != 0 && !ist_okay)) + return false; + + return true; +} +#endif + static int cvt_gate_to_trap(int vector, const gate_desc *val, struct trap_info *info) { @@ -591,40 +655,8 @@ static int cvt_gate_to_trap(int vector, const gate_desc *val, addr = gate_offset(val); #ifdef CONFIG_X86_64 - /* - * Look for known traps using IST, and substitute them - * appropriately. The debugger ones are the only ones we care - * about. Xen will handle faults like double_fault, - * so we should never see them. Warn if - * there's an unexpected IST-using fault handler. - */ - if (addr == (unsigned long)debug) - addr = (unsigned long)xen_debug; - else if (addr == (unsigned long)int3) - addr = (unsigned long)xen_int3; - else if (addr == (unsigned long)stack_segment) - addr = (unsigned long)xen_stack_segment; - else if (addr == (unsigned long)double_fault) { - /* Don't need to handle these */ + if (!get_trap_addr((void **)&addr, val->bits.ist)) return 0; -#ifdef CONFIG_X86_MCE - } else if (addr == (unsigned long)machine_check) { - /* - * when xen hypervisor inject vMCE to guest, - * use native mce handler to handle it - */ - ; -#endif - } else if (addr == (unsigned long)nmi) - /* - * Use the native version as well. - */ - ; - else { - /* Some other trap using IST? */ - if (WARN_ON(val->bits.ist != 0)) - return 0; - } #endif /* CONFIG_X86_64 */ info->address = addr; |