Marc, On 03/30/2015 05:54 PM, AKASHI Takahiro wrote: > On 03/30/2015 04:16 PM, Marc Zyngier wrote: >> On Mon, 30 Mar 2015 02:39:53 +0100 >> AKASHI Takahiro <takahiro.akashi at linaro.org> wrote: >> >>> On 03/28/2015 02:40 AM, Kyle McMartin wrote: >>>> On Fri, Mar 27, 2015 at 03:37:04PM +0000, Marc Zyngier wrote: >>>>>> [ 236.260863] Kernel panic - not syncing: HYP panic: >>>>>> [ 236.260863] PS:600003c9 PC:000003ffffff0830 ESR:0000000096000006 >>>>> >>>>> It would be interesting if you could find out what you have at offset >>>>> 0x830 of hyp-init.o (the stack trace is for EL1, and is not going to >>>>> help much). >>>>> >>>> >>>> Given the alignment, i'm going to assume i'm looking at the right thing: >>>> >>>> 0000000000000820 <__kvm_hyp_reset>: >>>> 820: d51c2000 msr ttbr0_el2, x0 >>>> 824: d5033fdf isb >>>> 828: d50c871f tlbi alle2 >>>> 82c: d5033f9f dsb sy >>>> 830: 10000060 adr x0, 83c <__kvm_hyp_reset+0x1c> >>>> 834: b3403c01 bfxil x1, x0, #0, #16 >>>> 838: d61f0020 br x1 >>>> 83c: d53c1000 mrs x0, sctlr_el2 >>>> >>>> but it seems fairly implausible to be trapping on ADR x0, 1f... >>> >>> >>> I've never seen this panic on fast model... >>> >>> ESR shows that >>> - Exception class: Data abort taken without a change in Exception level >>> - Data fault status code: Translation fault at EL2 >>> >>> and FAR seems not to be a proper address. >> >> ... which is consistent with what we're seeing here (data fault on >> something that doesn't generate a load/store). I'm pretty sure the >> page tables are screwed. >> >> Have you tested it with 64k pages? > > Hmm... It seems that I was able to reproduce the problem if 64k pages enabled. The entry address in trampoline code calc'ed by kvm_virt_to_trampoline(__kvm_hyp_reset) seems to be wrong due to improper page-alignment in hyp-init.S. The following patch fixed this problem, at least, in my environment(fast model). (I don't know why it's PAGE_SHIFT - 1, not PAGE_SHIFT.) >diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S >index d212990..45b8d98 100644 >--- a/arch/arm64/kvm/hyp-init.S >+++ b/arch/arm64/kvm/hyp-init.S >@@ -24,7 +24,7 @@ > .text > .pushsection .hyp.idmap.text, "ax" > >- .align 11 >+ .align (PAGE_SHIFT - 1) > > ENTRY(__kvm_hyp_init) > ventry __invalid // Synchronous EL2t After applying this patch, I got another problem with kexec-tools on 64k page kernel, but I've already modified kexec-tools. Thanks, -Takahiro AKASHI > -Takahiro AKASHI > >> Thanks, >> >> M. >>
