[v2,02/12] x86/xen: use specific Xen pv interrupt entry for DF

Commit Message

Jürgen Groß Nov. 20, 2020, 11:46 a.m. UTC

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 <[e-mail]>
Acked-by: Peter Zijlstra (Intel) <[e-mail]>
---
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(-)

Comments

Thomas Gleixner Dec. 9, 2020, 9:03 p.m. UTC | #1

On Fri, Nov 20 2020 at 12:46, Juergen Gross wrote:
> 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 <[e-mail]>
> Acked-by: Peter Zijlstra (Intel) <[e-mail]>

Reviewed-by: Thomas Gleixner <[e-mail]>

Patch

diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index 3505c0396fa5..b35825392547 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -611,6 +611,9 @@  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