[PATCH 05/20] x86/tdx: Convert MSR read handling to use new TDVMCALL_1()

[Kirill A. Shutemov]

Use newly introduced TDVMCALL_1() instead of __tdx_hypercall() to handle
MSR read emulation.

It cuts code bloat substantially:

Function                                     old     new   delta
tdx_handle_virt_exception                   2052    1947    -105

Signed-off-by: Kirill A. Shutemov <kirill.shute...@linux.intel.com>
---
 arch/x86/coco/tdx/tdx.c | 15 +++++++--------
 arch/x86/hyperv/ivm.c   | 10 ++--------
 2 files changed, 9 insertions(+), 16 deletions(-)

diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c
index dce7d6f9f895..32c519d096de 100644
--- a/arch/x86/coco/tdx/tdx.c
+++ b/arch/x86/coco/tdx/tdx.c
@@ -379,22 +379,21 @@ void __cpuidle tdx_safe_halt(void)
 
 static int read_msr(struct pt_regs *regs, struct ve_info *ve)
 {
-       struct tdx_module_args args = {
-               .r10 = TDX_HYPERCALL_STANDARD,
-               .r11 = hcall_func(EXIT_REASON_MSR_READ),
-               .r12 = regs->cx,
-       };
+       u64 val;
 
        /*
         * Emulate the MSR read via hypercall. More info about ABI
         * can be found in TDX Guest-Host-Communication Interface
         * (GHCI), section titled "TDG.VP.VMCALL<Instruction.RDMSR>".
         */
-       if (__tdx_hypercall(&args))
+       if (TDVMCALL_1(hcall_func(EXIT_REASON_MSR_READ),
+                      regs->cx, 0, 0, 0, val)) {
                return -EIO;
+       }
+
+       regs->ax = lower_32_bits(val);
+       regs->dx = upper_32_bits(val);
 
-       regs->ax = lower_32_bits(args.r11);
-       regs->dx = upper_32_bits(args.r11);
        return ve_instr_len(ve);
 }
 
diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
index b4a851d27c7c..3e2cbfb2203d 100644
--- a/arch/x86/hyperv/ivm.c
+++ b/arch/x86/hyperv/ivm.c
@@ -399,18 +399,12 @@ static void hv_tdx_msr_write(u64 msr, u64 val)
 
 static void hv_tdx_msr_read(u64 msr, u64 *val)
 {
-       struct tdx_module_args args = {
-               .r10 = TDX_HYPERCALL_STANDARD,
-               .r11 = EXIT_REASON_MSR_READ,
-               .r12 = msr,
-       };
+       u64 ret;
 
-       u64 ret = __tdx_hypercall(&args);
+       ret = TDVMCALL_1(hcall_func(EXIT_REASON_MSR_READ), msr, 0, 0, 0, *val);
 
        if (WARN_ONCE(ret, "Failed to emulate MSR read: %lld\n", ret))
                *val = 0;
-       else
-               *val = args.r11;
 }
 
 u64 hv_tdx_hypercall(u64 control, u64 param1, u64 param2)
-- 
2.43.0