[PATCH v5 4/5] x86/tdx: tdx_mcall_get_report0: Return -EBUSY on TDCALL_OPERAND_BUSY error

Cedric Xing
2025-04-24T20:13:00Z

Return `-EBUSY` from tdx_mcall_get_report0() when `TDG.MR.REPORT` returns
`TDCALL_OPERAND_BUSY`. This enables the caller to retry obtaining a
TDREPORT later if another VCPU is extending an RTMR concurrently.

Signed-off-by: Cedric Xing <cedric.xing@intel.com>
---
arch/x86/coco/tdx/tdx.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c
index 0b6804d2a5e1..7b2833705d47 100644
--- a/arch/x86/coco/tdx/tdx.c
+++ b/arch/x86/coco/tdx/tdx.c
@@ -110,12 +110,13 @@ static inline u64 tdg_vm_wr(u64 field, u64 value, u64 mask)
* REPORTDATA to be included into TDREPORT.
* @tdreport: Address of the output buffer to store TDREPORT.
*
- * Refer to section titled "TDG.MR.REPORT leaf" in the TDX Module
- * v1.0 specification for more information on TDG.MR.REPORT TDCALL.
+ * Refer to section titled "TDG.MR.REPORT leaf" in the TDX Module v1.0
+ * specification for more information on TDG.MR.REPORT TDCALL.
+ *
* It is used in the TDX guest driver module to get the TDREPORT0.
*
- * Return 0 on success, -EINVAL for invalid operands, or -EIO on
- * other TDCALL failures.
+ * Return 0 on success, -ENXIO for invalid operands, -EBUSY for busy operation,
+ * or -EIO on other TDCALL failures.
*/
int tdx_mcall_get_report0(u8 *reportdata, u8 *tdreport)
{
@@ -129,7 +130,9 @@ int tdx_mcall_get_report0(u8 *reportdata, u8 *tdreport)
ret = __tdcall(TDG_MR_REPORT, &args);
if (ret) {
if (TDCALL_RETURN_CODE(ret) == TDCALL_INVALID_OPERAND)
- return -EINVAL;
+ return -ENXIO;
+ else if (TDCALL_RETURN_CODE(ret) == TDCALL_OPERAND_BUSY)
+ return -EBUSY;
return -EIO;
}

--
2.43.0