KVM: TDX: retry TDH.VP.ENTER on TDX_OPERATION_BUSY

TDH.VP.ENTER may return TDX_OPERATION_BUSY to KVM (e.g. some internal lock is busy), which expects KVM to retry TDH.VP.ENTER. Change KVM to retry on TDX_OPERATION_BUSY for a limited number of times. Signed-off-by: Wei Wang <wei.w.wang@intel.com>
intel · Mar 8, 2023 · 16e2ccd · 16e2ccd
1 parent 18998e6
commit 16e2ccd
Showing 1 changed file with 14 additions and 2 deletions.
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
@@ -904,9 +904,21 @@ u64 __tdx_vcpu_run(hpa_t tdvpr, void *regs, u32 regs_mask);
 static noinstr void tdx_vcpu_enter_exit(struct kvm_vcpu *vcpu,
 					struct vcpu_tdx *tdx)
 {
+	u64 err, retries = 0;
+
 	guest_enter_irqoff();
-	tdx->exit_reason.full = __tdx_vcpu_run(tdx->tdvpr_pa, vcpu->arch.regs,
-					tdx->tdvmcall.regs_mask);
+	do {
+		tdx->exit_reason.full = __tdx_vcpu_run(tdx->tdvpr_pa,
+						     vcpu->arch.regs,
+					    tdx->tdvmcall.regs_mask);
+		err = tdx->exit_reason.full & TDX_SEAMCALL_STATUS_MASK;
+
+		if (retries++ > TDX_SEAMCALL_RETRY_MAX) {
+			KVM_BUG_ON(err, vcpu->kvm);
+			pr_tdx_error(TDH_VP_ENTER, err, NULL);
+			break;
+		}
+	} while (err == TDX_OPERAND_BUSY);
 	guest_exit_irqoff();
 }