diff options
| author | Kai Huang <kai.huang@intel.com> | 2023-08-15 14:02:02 +0300 |
|---|---|---|
| committer | Dave Hansen <dave.hansen@linux.intel.com> | 2023-09-13 02:30:14 +0300 |
| commit | 90f5ecd37faed9a59eb2788a56dac8deeee0a508 (patch) | |
| tree | 2c100cb8bc92233b7d5fbabb92480463c6b73069 /arch/x86/virt | |
| parent | c641cfb5c157b6c3062a824fd8ba190bf06fb952 (diff) | |
| download | linux-90f5ecd37faed9a59eb2788a56dac8deeee0a508.tar.xz | |
x86/tdx: Reimplement __tdx_hypercall() using TDX_MODULE_CALL asm
Now the TDX_HYPERCALL asm is basically identical to the TDX_MODULE_CALL
with both '\saved' and '\ret' enabled, with two minor things though:
1) The way to restore the structure pointer is different
The TDX_HYPERCALL uses RCX as spare to restore the structure pointer,
but the TDX_MODULE_CALL assumes no spare register can be used. In other
words, TDX_MODULE_CALL already covers what TDX_HYPERCALL does.
2) TDX_MODULE_CALL only clears shared registers for TDH.VP.ENTER
For this just need to make that code available for the non-host case.
Thus, remove the TDX_HYPERCALL and reimplement the __tdx_hypercall()
using the TDX_MODULE_CALL.
Extend the TDX_MODULE_CALL to cover "clear shared registers" for
TDG.VP.VMCALL. Introduce a new __tdcall_saved_ret() to replace the
temporary __tdcall_hypercall().
The __tdcall_saved_ret() can also be used for those new TDCALLs which
require more input/output registers than the basic TDCALLs do.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/e68a2473fb6f5bcd78b078cae7510e9d0753b3df.1692096753.git.kai.huang%40intel.com
Diffstat (limited to 'arch/x86/virt')
| -rw-r--r-- | arch/x86/virt/vmx/tdx/tdxcall.S | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/x86/virt/vmx/tdx/tdxcall.S b/arch/x86/virt/vmx/tdx/tdxcall.S index c54ea009b241..3f0b83a9977e 100644 --- a/arch/x86/virt/vmx/tdx/tdxcall.S +++ b/arch/x86/virt/vmx/tdx/tdxcall.S @@ -142,10 +142,10 @@ movq %r11, TDX_MODULE_r11(%rsi) .endif /* \ret */ -.if \host && \saved && \ret +.if \saved && \ret /* - * Clear registers shared by guest for VP.ENTER to prevent - * speculative use of guest's values, including those are + * Clear registers shared by guest for VP.VMCALL/VP.ENTER to prevent + * speculative use of guest's/VMM's values, including those are * restored from the stack. * * See arch/x86/kvm/vmx/vmenter.S: @@ -170,7 +170,7 @@ xorl %r15d, %r15d xorl %ebx, %ebx xorl %edi, %edi -.endif /* \host && \ret && \host */ +.endif /* \ret && \host */ .if \host .Lout\@: |