| Message ID | 20231124055330.138870-8-weijiang.yang@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Enable CET Virtualization | expand |
On Fri, 2023-11-24 at 00:53 -0500, Yang Weijiang wrote: > Kernel dynamic xfeatures now are __ONLY__ enabled for guest fpstate, > i.e., > none for normal kernel fpstate. The bits are added when guest FPU ^never? > config > is initialized. Guest fpstate is allocated with fpstate->is_guest set > to > %true. > > For normal fpstate, the bits should have been removed when > initializes > kernel FPU config settings, WARN_ONCE() if kernel detects normal > fpstate > xfeatures contains kernel dynamic xfeatures before executes xsaves. > > Signed-off-by: Yang Weijiang <weijiang.yang@intel.com> Otherwise... Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
On 11/28/2023 11:25 PM, Edgecombe, Rick P wrote: > On Fri, 2023-11-24 at 00:53 -0500, Yang Weijiang wrote: >> Kernel dynamic xfeatures now are __ONLY__ enabled for guest fpstate, >> i.e., >> none for normal kernel fpstate. The bits are added when guest FPU > ^never? Sure, will change it, thank you! >> config >> is initialized. Guest fpstate is allocated with fpstate->is_guest set >> to >> %true. >> >> For normal fpstate, the bits should have been removed when >> initializes >> kernel FPU config settings, WARN_ONCE() if kernel detects normal >> fpstate >> xfeatures contains kernel dynamic xfeatures before executes xsaves. >> >> Signed-off-by: Yang Weijiang <weijiang.yang@intel.com> > Otherwise... > > Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
diff --git a/arch/x86/kernel/fpu/xstate.h b/arch/x86/kernel/fpu/xstate.h index c032acb56306..d45f3e570e69 100644 --- a/arch/x86/kernel/fpu/xstate.h +++ b/arch/x86/kernel/fpu/xstate.h @@ -186,6 +186,9 @@ static inline void os_xsave(struct fpstate *fpstate) WARN_ON_FPU(!alternatives_patched); xfd_validate_state(fpstate, mask, false); + WARN_ON_FPU(!fpstate->is_guest && + (mask & XFEATURE_MASK_KERNEL_DYNAMIC)); + XSTATE_XSAVE(&fpstate->regs.xsave, lmask, hmask, err); /* We should never fault when copying to a kernel buffer: */
Kernel dynamic xfeatures now are __ONLY__ enabled for guest fpstate, i.e., none for normal kernel fpstate. The bits are added when guest FPU config is initialized. Guest fpstate is allocated with fpstate->is_guest set to %true. For normal fpstate, the bits should have been removed when initializes kernel FPU config settings, WARN_ONCE() if kernel detects normal fpstate xfeatures contains kernel dynamic xfeatures before executes xsaves. Signed-off-by: Yang Weijiang <weijiang.yang@intel.com> --- arch/x86/kernel/fpu/xstate.h | 3 +++ 1 file changed, 3 insertions(+)