[PATCH v3 02/15] x86/xen: use specific Xen pv interrupt entry for DF

Juergen Gross
2020-12-17T09:32:50Z

Xen PV guests don't use IST. For double fault interrupts switch to
the same model as NMI.

Correct a typo in a comment while copying it.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
---
V2:
- fix typo (Andy Lutomirski)
---
arch/x86/include/asm/idtentry.h | 3 +++
arch/x86/xen/enlighten_pv.c | 10 ++++++++--
arch/x86/xen/xen-asm.S | 2 +-
3 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index 5dd64404715a..3ac84cb702fc 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -608,6 +608,9 @@ DECLARE_IDTENTRY_RAW(X86_TRAP_DB, xenpv_exc_debug);

/* #DF */
DECLARE_IDTENTRY_DF(X86_TRAP_DF, exc_double_fault);
+#ifdef CONFIG_XEN_PV
+DECLARE_IDTENTRY_RAW_ERRORCODE(X86_TRAP_DF, xenpv_exc_double_fault);
+#endif

/* #VC */
#ifdef CONFIG_AMD_MEM_ENCRYPT
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 9f5e44c1f70a..76616024129e 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -567,10 +567,16 @@ void noist_exc_debug(struct pt_regs *regs);

DEFINE_IDTENTRY_RAW(xenpv_exc_nmi)
{
- /* On Xen PV, NMI doesn't use IST. The C part is the sane as native. */
+ /* On Xen PV, NMI doesn't use IST. The C part is the same as native. */
exc_nmi(regs);
}

+DEFINE_IDTENTRY_RAW_ERRORCODE(xenpv_exc_double_fault)
+{
+ /* On Xen PV, DF doesn't use IST. The C part is the same as native. */
+ exc_double_fault(regs, error_code);
+}
+
DEFINE_IDTENTRY_RAW(xenpv_exc_debug)
{
/*
@@ -615,7 +621,7 @@ struct trap_array_entry {

static struct trap_array_entry trap_array[] = {
TRAP_ENTRY_REDIR(exc_debug, true ),
- TRAP_ENTRY(exc_double_fault, true ),
+ TRAP_ENTRY_REDIR(exc_double_fault, true ),
#ifdef CONFIG_X86_MCE
TRAP_ENTRY_REDIR(exc_machine_check, true ),
#endif
diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S
index bc2586730a5b..1d054c915046 100644
--- a/arch/x86/xen/xen-asm.S
+++ b/arch/x86/xen/xen-asm.S
@@ -161,7 +161,7 @@ xen_pv_trap asm_exc_overflow
xen_pv_trap asm_exc_bounds
xen_pv_trap asm_exc_invalid_op
xen_pv_trap asm_exc_device_not_available
-xen_pv_trap asm_exc_double_fault
+xen_pv_trap asm_xenpv_exc_double_fault
xen_pv_trap asm_exc_coproc_segment_overrun
xen_pv_trap asm_exc_invalid_tss
xen_pv_trap asm_exc_segment_not_present
--
2.26.2