diff options
| -rw-r--r-- | arch/x86/kernel/sev.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index a6895e440bc3..2de1f3604b7e 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -1319,13 +1319,26 @@ static __always_inline void vc_forward_exception(struct es_em_ctxt *ctxt) } } -static __always_inline bool on_vc_fallback_stack(struct pt_regs *regs) +static __always_inline bool is_vc2_stack(unsigned long sp) { - unsigned long sp = (unsigned long)regs; - return (sp >= __this_cpu_ist_bottom_va(VC2) && sp < __this_cpu_ist_top_va(VC2)); } +static __always_inline bool vc_from_invalid_context(struct pt_regs *regs) +{ + unsigned long sp, prev_sp; + + sp = (unsigned long)regs; + prev_sp = regs->sp; + + /* + * If the code was already executing on the VC2 stack when the #VC + * happened, let it proceed to the normal handling routine. This way the + * code executing on the VC2 stack can cause #VC exceptions to get handled. + */ + return is_vc2_stack(sp) && !is_vc2_stack(prev_sp); +} + static bool vc_raw_handle_exception(struct pt_regs *regs, unsigned long error_code) { struct ghcb_state state; @@ -1406,7 +1419,7 @@ DEFINE_IDTENTRY_VC_KERNEL(exc_vmm_communication) * But keep this here in case the noinstr annotations are violated due * to bug elsewhere. */ - if (unlikely(on_vc_fallback_stack(regs))) { + if (unlikely(vc_from_invalid_context(regs))) { instrumentation_begin(); panic("Can't handle #VC exception from unsupported context\n"); instrumentation_end(); |