Right, it's the ljmpq issue. Borislav Petkov <b...@alien8.de> wrote:
>On Mon, Dec 24, 2012 at 05:06:01PM -0800, H. Peter Anvin wrote: >> Could this be the ljmpq problem that Borislav reported >> (Intel implemented ljmpq, AMD didn't, and I was tempted by a >> micro-optimization which broke AMD which made it into the patchset)? > >It has to be. Just booted Yinghai's -v8 in kvm on an AMD host and it >worked fine. > >With the change below it keeps rebooting like I reported earlier. I'd >go >out on a limb here and guess that the guest is triple-faulting due to >an >unhandled #GP caused by an invalid opcode or similar. > >--- >diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S >index d94f6d68be2a..1842d30c96a2 100644 >--- a/arch/x86/kernel/head_64.S >+++ b/arch/x86/kernel/head_64.S >@@ -279,11 +279,8 @@ ENTRY(secondary_startup_64) > * REX.W + FF /5 JMP m16:64 Jump far, absolute indirect, > * address given in m16:64. > */ >- movq initial_code(%rip),%rax > pushq $0 # fake return address to stop unwinder >- pushq $__KERNEL_CS # set correct cs >- pushq %rax # target address in negative space >- lretq >+ rex64 ljmp *initial_code(%rip) > > #ifdef CONFIG_HOTPLUG_CPU > /* -- Sent from my mobile phone. Please excuse brevity and lack of formatting. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
