Re: [PATCH v19 078/130] KVM: TDX: Implement TDX vcpu enter/exit path

Kirill A. Shutemov
2024-04-04T13:22:31Z

On Mon, Feb 26, 2024 at 12:26:20AM -0800, isaku.yamahata@intel.com wrote:
> @@ -491,6 +494,87 @@ void tdx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
> */
> }
>
> +static noinstr void tdx_vcpu_enter_exit(struct vcpu_tdx *tdx)
> +{

...

> + tdx->exit_reason.full = __seamcall_saved_ret(TDH_VP_ENTER, &args);

Call to __seamcall_saved_ret() leaves noinstr section.

__seamcall_saved_ret() has to be moved:

diff --git a/arch/x86/virt/vmx/tdx/seamcall.S b/arch/x86/virt/vmx/tdx/seamcall.S
index e32cf82ed47e..6b434ab12db6 100644
--- a/arch/x86/virt/vmx/tdx/seamcall.S
+++ b/arch/x86/virt/vmx/tdx/seamcall.S
@@ -44,6 +44,8 @@ SYM_FUNC_START(__seamcall_ret)
SYM_FUNC_END(__seamcall_ret)
EXPORT_SYMBOL_GPL(__seamcall_ret);

+.section .noinstr.text, "ax"
+
/*
* __seamcall_saved_ret() - Host-side interface functions to SEAM software
* (the P-SEAMLDR or the TDX module), with saving output registers to the
--
Kiryl Shutsemau / Kirill A. Shutemov