On 01/25/18 at 06:50pm, Kirill A. Shutemov wrote: > On Wed, Jan 17, 2018 at 01:24:54PM +0800, Baoquan He wrote: > > Hi Kirill, > > > > I setup qemu 2.9.0 to test 5-level on kexec/kdump support. While both > > kexec and kdump reset to BIOS immediately after triggering. I saw your > > patch adding 5-level paging support for kexec. Wonder if your test > > succeeded to jump into kexec/kdump kernel, and what else I need to > > make it. By the way, I just tested the latest upstream kernel. > > > > commit 7f6890418 x86/kexec: Add 5-level paging support > > > > [ ~]$ qemu-system-x86_64 --version > > QEMU emulator version 2.9.0(qemu-2.9.0-1.fc26.1) > > Copyright (c) 2003-2017 Fabrice Bellard and the QEMU Project developers > > Sorry for delay. > > I didn't tested it in 5-level paging mode :-/ > > The patch below helps in my case. Could you test it? Thanks, Kirill. Seems it doesn't work. I have some confusion about the process, will send you a private mail. Thanks Baoquan > > diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S > index 307d3bac5f04..65a98cf2307d 100644 > --- a/arch/x86/kernel/relocate_kernel_64.S > +++ b/arch/x86/kernel/relocate_kernel_64.S > @@ -126,8 +126,12 @@ identity_mapped: > /* > * Set cr4 to a known state: > * - physical address extension enabled > + * - 5-level paging, if enabled > */ > movl $X86_CR4_PAE, %eax > +#ifdef CONFIG_X86_5LEVEL > + orl $X86_CR4_LA57, %eax > +#endif > movq %rax, %cr4 > > jmp 1f > -- > Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
