On Mon, Jun 05, 2023 at 02:27:31AM +1200, Kai Huang wrote: > diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c > index 8ff07256a515..0aa413b712e8 100644 > --- a/arch/x86/virt/vmx/tdx/tdx.c > +++ b/arch/x86/virt/vmx/tdx/tdx.c > @@ -587,6 +587,14 @@ static int tdmr_set_up_pamt(struct tdmr_info *tdmr, > tdmr_pamt_base += pamt_size[pgsz]; > } > > + /* > + * tdx_memory_shutdown() also reads TDMR's PAMT during > + * kexec() or reboot, which could happen at anytime, even > + * during this particular code. Make sure pamt_4k_base > + * is firstly set otherwise tdx_memory_shutdown() may > + * get an invalid PAMT base when it sees a valid number > + * of PAMT pages. > + */ Hmm? What prevents compiler from messing this up. It can reorder as it wishes, no? Maybe add a proper locking? Anything that prevent preemption would do, right? > tdmr->pamt_4k_base = pamt_base[TDX_PS_4K]; > tdmr->pamt_4k_size = pamt_size[TDX_PS_4K]; > tdmr->pamt_2m_base = pamt_base[TDX_PS_2M]; -- Kiryl Shutsemau / Kirill A. Shutemov
