On Mon, Mar 17, 2025 at 11:32:42AM +0000, David Woodhouse wrote: > > And we don't want MCE to be enabled during kexec for !TDX_GUEST: > > > > https://lore.kernel.org/all/1144340e-dd95-ee3b-dabb-579f9a65b3c7@xxxxxxxxxx/ > > Actually now I've added proper exception handling in relocate_kernel > perhaps we could rethink that. But that's for the future. There still going to be a gap once the new kernel is started until it gets proper exception handling in place. > > I think we should patch AND instruction to include X86_CR4_MCE on > > TDX_GUEST: > > ... > > - andl $(X86_CR4_PAE | X86_CR4_LA57), %r13d > > - ALTERNATIVE "", __stringify(orl $X86_CR4_MCE, %r13d), X86_FEATURE_TDX_GUEST > > + ALTERNATIVE __stringify(andl $(X86_CR4_PAE | X86_CR4_LA57), %r13d), \ > > + __stringify(andl $(X86_CR4_PAE | X86_CR4_LA57 | X86_CR4_MCE), %r13d), X86_FEATURE_TDX_GUEST > > Yeah... although the reason I'm looking at this is because I want to > kill the ALTERNATIVE so that I can move the relocate_kernel() function > into a data section: > https://lore.kernel.org/all/20241218212326.44qff3i5n6cxuu5d@jpoimboe/ > > So I think I'll do it like this instead: Looks good to me. Thanks for the cleanup you are doing! -- Kiryl Shutsemau / Kirill A. Shutemov
