[tip: x86/paravirt] x86/xen: Use specific Xen pv interrupt entry for DF

[tip-bot2 for Juergen Gross]

The following commit has been merged into the x86/paravirt branch of tip:

Commit-ID:     5b4c6d65019bff65757f61adbbad5e45a333b800
Gitweb:        https://git.kernel.org/tip/5b4c6d65019bff65757f61adbbad5e45a333b800
Author:        Juergen Gross <jgross@xxxxxxxx>
AuthorDate:    Wed, 20 Jan 2021 14:55:43 +01:00
Committer:     Borislav Petkov <bp@xxxxxxx>
CommitterDate: Wed, 10 Feb 2021 12:13:40 +01:00

x86/xen: Use specific Xen pv interrupt entry for DF

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@xxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20210120135555.32594-4-jgross@xxxxxxxx
---
 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 616909e..41e2e2e 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 9db1d31..1fec2ee 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)
 {
 	/*
@@ -622,7 +628,7 @@ 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 cd330ce..eac9dac 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