Patch-mainline: v5.19-rc3
Git-commit: 60428d8bc27f52e8f1540f98e1b6ef0156d43f0d
References: jsc#PED-342
From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Date: Tue, 14 Jun 2022 15:01:33 +0300
Subject: [PATCH] x86/tdx: Fix early #VE handling

tdx_early_handle_ve() does not increment RIP after successfully
handling the exception.  That leads to infinite loop of exceptions.

Move RIP when exceptions are successfully handled.

[ dhansen: make problem statement more clear ]

Fixes: 32e72854fa5f ("x86/tdx: Port I/O: Add early boot support")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Link: https://lkml.kernel.org/r/20220614120135.14812-2-kirill.shutemov@linux.intel.com
Signed-off-by: Juergen Gross <jgross@suse.com>
---
 arch/x86/coco/tdx/tdx.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c
index 03deb4d6920d..faae53f8d559 100644
--- a/arch/x86/coco/tdx/tdx.c
+++ b/arch/x86/coco/tdx/tdx.c
@@ -447,13 +447,17 @@ static bool handle_io(struct pt_regs *regs, u32 exit_qual)
 __init bool tdx_early_handle_ve(struct pt_regs *regs)
 {
 	struct ve_info ve;
+	bool ret;
 
 	tdx_get_ve_info(&ve);
 
 	if (ve.exit_reason != EXIT_REASON_IO_INSTRUCTION)
 		return false;
 
-	return handle_io(regs, ve.exit_qual);
+	ret = handle_io(regs, ve.exit_qual);
+	if (ret)
+		regs->ip += ve.instr_len;
+	return ret;
 }
 
 void tdx_get_ve_info(struct ve_info *ve)
-- 
2.35.3