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From:   "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To:     tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
        dave.hansen@intel.com, luto@kernel.org, peterz@infradead.org
Cc:     ak@linux.intel.com, dan.j.williams@intel.com, david@redhat.com,
        hpa@zytor.com, linux-kernel@vger.kernel.org,
        sathyanarayanan.kuppuswamy@linux.intel.com, seanjc@google.com,
        thomas.lendacky@amd.com, x86@kernel.org,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Subject: [PATCHv4 1/3] x86/tdx: Fix early #VE handling
Date:   Tue, 14 Jun 2022 15:01:33 +0300
Message-Id: <20220614120135.14812-2-kirill.shutemov@linux.intel.com>
In-Reply-To: <20220614120135.14812-1-kirill.shutemov@linux.intel.com>
References: <20220614120135.14812-1-kirill.shutemov@linux.intel.com>
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Move RIP in tdx_early_handle_ve() after handling the exception. Failure
to do that leads to infinite loop of exceptions.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Fixes: 32e72854fa5f ("x86/tdx: Port I/O: Add early boot support")
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.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)
-- 
2.35.1