[PATCH v4 03/15] x86/xen: use specific Xen pv interrupt entry for DF

From: Juergen Gross <jgross@suse.com>
To: xen-devel@lists.xenproject.org, x86@kernel.org,
	linux-kernel@vger.kernel.org
Cc: Juergen Gross <jgross@suse.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Boris Ostrovsky <boris.ostrovsky@oracle.com>,
	Stefano Stabellini <sstabellini@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>
Subject: [PATCH v4 03/15] x86/xen: use specific Xen pv interrupt entry for DF
Date: Wed, 20 Jan 2021 14:55:43 +0100	[thread overview]
Message-ID: <20210120135555.32594-4-jgross@suse.com> (raw)
In-Reply-To: <20210120135555.32594-1-jgross@suse.com>

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

