linux-kernel - [PATCH 18/20] x86/tdx: Convert VP_VEINFO_GET tdcall to use new TDCALL

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Date: Fri, 17 May 2024 17:19:36 +0300
From: "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
To: Sean Christopherson <seanjc@...gle.com>,
	Paolo Bonzini <pbonzini@...hat.com>,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	Borislav Petkov <bp@...en8.de>,
	x86@...nel.org,
	"H. Peter Anvin" <hpa@...or.com>,
	"K. Y. Srinivasan" <kys@...rosoft.com>,
	Haiyang Zhang <haiyangz@...rosoft.com>,
	Wei Liu <wei.liu@...nel.org>,
	Dexuan Cui <decui@...rosoft.com>,
	Josh Poimboeuf <jpoimboe@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>
Cc: linux-coco@...ts.linux.dev,
	linux-kernel@...r.kernel.org,
	linux-hyperv@...r.kernel.org,
	"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
Subject: [PATCH 18/20] x86/tdx: Convert VP_VEINFO_GET tdcall to use new TDCALL_5() macro

Use newly introduced TDCALL_5() instead of tdcall() to issue
VP_VEINFO_GET tdcall.

It cuts code bloat substantially:

Function                                     old     new   delta
tdx_get_ve_info                              253     116    -137

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com>
---
 arch/x86/coco/tdx/tdx.c | 31 +++++++------------------------
 1 file changed, 7 insertions(+), 24 deletions(-)

diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c
index 6559f3842f67..42436a43bb49 100644
--- a/arch/x86/coco/tdx/tdx.c
+++ b/arch/x86/coco/tdx/tdx.c
@@ -615,32 +615,15 @@ __init bool tdx_early_handle_ve(struct pt_regs *regs)
 
 void tdx_get_ve_info(struct ve_info *ve)
 {
-	struct tdx_module_args args = {};
+	u64 instr_info, ret;
 
-	/*
-	 * Called during #VE handling to retrieve the #VE info from the
-	 * TDX module.
-	 *
-	 * This has to be called early in #VE handling.  A "nested" #VE which
-	 * occurs before this will raise a #DF and is not recoverable.
-	 *
-	 * The call retrieves the #VE info from the TDX module, which also
-	 * clears the "#VE valid" flag. This must be done before anything else
-	 * because any #VE that occurs while the valid flag is set will lead to
-	 * #DF.
-	 *
-	 * Note, the TDX module treats virtual NMIs as inhibited if the #VE
-	 * valid flag is set. It means that NMI=>#VE will not result in a #DF.
-	 */
-	tdcall(TDG_VP_VEINFO_GET, &args);
+	ret = TDCALL_5(TDG_VP_VEINFO_GET, 0, 0, 0, 0,
+		 ve->exit_reason, ve->exit_qual, ve->gla, ve->gpa, instr_info);
 
-	/* Transfer the output parameters */
-	ve->exit_reason = args.rcx;
-	ve->exit_qual   = args.rdx;
-	ve->gla         = args.r8;
-	ve->gpa         = args.r9;
-	ve->instr_len   = lower_32_bits(args.r10);
-	ve->instr_info  = upper_32_bits(args.r10);
+	BUG_ON(ret);
+
+	ve->instr_len   = lower_32_bits(instr_info);
+	ve->instr_info  = upper_32_bits(instr_info);
 }
 
 /*
-- 
2.43.0