| Message ID | 70784afc0a42d4dc1b1e743f90d89f7728496add.1689151537.git.kai.huang@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Unify TDCALL/SEAMCALL and TDVMCALL assembly | expand |
On 7/12/23 1:55 AM, Kai Huang wrote: > Change 'jnc .Lno_vmfailinvalid' to 'cmovc %rdi, %rax' to save the > .Lno_vmfailinvalid label in the TDX_MODULE_CALL asm macro. You are removing the label, right? What use "save"? > > Note %rdi, which is used as the first argument, has been saved to %rax > as TDCALL leaf ID thus is free to hold the error code for cmovc. > > This is basically based on Peter's code. > > Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > Cc: Dave Hansen <dave.hansen@linux.intel.com> > Cc: Peter Zijlstra <peterz@infradead.org> > Suggested-by: Peter Zijlstra <peterz@infradead.org> > Signed-off-by: Kai Huang <kai.huang@intel.com> > --- > arch/x86/virt/vmx/tdx/tdxcall.S | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/virt/vmx/tdx/tdxcall.S b/arch/x86/virt/vmx/tdx/tdxcall.S > index 49a54356ae99..3524915d8bd9 100644 > --- a/arch/x86/virt/vmx/tdx/tdxcall.S > +++ b/arch/x86/virt/vmx/tdx/tdxcall.S > @@ -57,10 +57,8 @@ > * This value will never be used as actual SEAMCALL error code as > * it is from the Reserved status code class. > */ > - jnc .Lno_vmfailinvalid > - mov $TDX_SEAMCALL_VMFAILINVALID, %rax > -.Lno_vmfailinvalid: > - > + mov $TDX_SEAMCALL_VMFAILINVALID, %rdi > + cmovc %rdi, %rax > .else > tdcall > .endif
On Wed, 2023-07-12 at 12:27 -0700, Sathyanarayanan Kuppuswamy wrote: > > On 7/12/23 1:55 AM, Kai Huang wrote: > > Change 'jnc .Lno_vmfailinvalid' to 'cmovc %rdi, %rax' to save the > > .Lno_vmfailinvalid label in the TDX_MODULE_CALL asm macro. > > You are removing the label, right? What use "save"? Per comments to patch 10 I'll drop this patch, so doesn't matter anymore.
diff --git a/arch/x86/virt/vmx/tdx/tdxcall.S b/arch/x86/virt/vmx/tdx/tdxcall.S index 49a54356ae99..3524915d8bd9 100644 --- a/arch/x86/virt/vmx/tdx/tdxcall.S +++ b/arch/x86/virt/vmx/tdx/tdxcall.S @@ -57,10 +57,8 @@ * This value will never be used as actual SEAMCALL error code as * it is from the Reserved status code class. */ - jnc .Lno_vmfailinvalid - mov $TDX_SEAMCALL_VMFAILINVALID, %rax -.Lno_vmfailinvalid: - + mov $TDX_SEAMCALL_VMFAILINVALID, %rdi + cmovc %rdi, %rax .else tdcall .endif
Change 'jnc .Lno_vmfailinvalid' to 'cmovc %rdi, %rax' to save the .Lno_vmfailinvalid label in the TDX_MODULE_CALL asm macro. Note %rdi, which is used as the first argument, has been saved to %rax as TDCALL leaf ID thus is free to hold the error code for cmovc. This is basically based on Peter's code. Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Kai Huang <kai.huang@intel.com> --- arch/x86/virt/vmx/tdx/tdxcall.S | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)