diff options
| author | Kai Huang <kai.huang@intel.com> | 2023-08-15 23:02:00 +1200 |
|---|---|---|
| committer | Dave Hansen <dave.hansen@linux.intel.com> | 2023-09-11 16:33:51 -0700 |
| commit | 12f34ed8622aafd3bbd9d8aa4550dcb7016ea1e6 (patch) | |
| tree | de9b82710da67007a27f2e54c95c88218bb63601 /arch/x86/include/asm/shared | |
| parent | 57a420bb8186d1d0178b857e5dd5026093641654 (diff) | |
x86/tdx: Extend TDX_MODULE_CALL to support more TDCALL/SEAMCALL leafs
The TDX guest live migration support (TDX 1.5) adds new TDCALL/SEAMCALL
leaf functions. Those new TDCALLs/SEAMCALLs take additional registers
for input (R10-R13) and output (R12-R13). TDG.SERVTD.RD is an example.
Also, the current TDX_MODULE_CALL doesn't aim to handle TDH.VP.ENTER
SEAMCALL, which monitors the TDG.VP.VMCALL in input/output registers
when it returns in case of VMCALL from TDX guest.
With those new TDCALLs/SEAMCALLs and the TDH.VP.ENTER covered, the
TDX_MODULE_CALL macro basically needs to handle the same input/output
registers as the TDX_HYPERCALL does. And as a result, they also share
similar logic in the assembly, thus should be unified to use one common
assembly.
Extend the TDX_MODULE_CALL asm to support the new TDCALLs/SEAMCALLs and
also the TDH.VP.ENTER SEAMCALL. Eventually it will be unified with the
TDX_HYPERCALL.
The new input/output registers fit with the "callee-saved" registers in
the x86 calling convention. Add a new "saved" parameter to support
those new TDCALLs/SEAMCALLs and TDH.VP.ENTER and keep the existing
TDCALLs/SEAMCALLs minimally impacted.
For TDH.VP.ENTER, after it returns the registers shared by the guest
contain guest's values. Explicitly clear them to prevent speculative
use of guest's values.
Note most TDX live migration related SEAMCALLs may also clobber AVX*
state ("AVX, AVX2 and AVX512 state: may be reset to the architectural
INIT state" -- see TDH.EXPORT.MEM for example). And TDH.VP.ENTER also
clobbers XMM0-XMM15 when the corresponding bit is set in RCX. Don't
handle them in the TDX_MODULE_CALL macro but let the caller save and
restore when needed.
This is basically based on Peter's code.
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/d4785de7c392f7c5684407f6c24a73b92148ec49.1692096753.git.kai.huang%40intel.com
Diffstat (limited to 'arch/x86/include/asm/shared')
| -rw-r--r-- | arch/x86/include/asm/shared/tdx.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/include/asm/shared/tdx.h b/arch/x86/include/asm/shared/tdx.h index ca8a681ad497..669749a22d8c 100644 --- a/arch/x86/include/asm/shared/tdx.h +++ b/arch/x86/include/asm/shared/tdx.h @@ -81,12 +81,22 @@ void __tdx_hypercall_failed(void); * software only structure and not part of the TDX module/VMM ABI */ struct tdx_module_args { + /* callee-clobbered */ u64 rcx; u64 rdx; u64 r8; u64 r9; + /* extra callee-clobbered */ u64 r10; u64 r11; + /* callee-saved + rdi/rsi */ + u64 r12; + u64 r13; + u64 r14; + u64 r15; + u64 rbx; + u64 rdi; + u64 rsi; }; /* Used to communicate with the TDX module */ |