On 10/04/2025 1:09 am, Jason Andryuk wrote: > On 2025-04-09 13:01, Andrew Cooper wrote: >> On 09/04/2025 5:36 pm, Andrew Cooper wrote: >>> Various bits of cleanup, and support for arm64 Linux builds. >>> >>> Run using the new Linux 6.6.86 on (most) x86, and ARM64: >>> >>> https://gitlab.com/xen-project/hardware/xen-staging/-/pipelines/1760667411 >> >> Lovely, Linux 6.6.86 is broken for x86 PVH. It triple faults very >> early on. >> >> Sample log: >> https://gitlab.com/xen-project/hardware/xen-staging/-/jobs/9673797450 >> >> I guess we'll have to stay on 6.6.56 for now. (Only affects the final >> patch.) > > This is an AMD system: > > (XEN) [ 2.577549] d0v0 Triple fault - invoking HVM shutdown action 1 > (XEN) [ 2.577557] RIP: 0008:[<0000000001f851d4>] > > The instruction: > ffffffff81f851d4: 0f 01 c1 vmcall > > vmcall is the Intel instruction, and vmmcall is the AMD one, so CPU > detection is malfunctioning. > > (Early PVH is running identity mapped, so it's offset from > ffffffff80000000) > > There are no debug symbols in the vmlinux I extracted from the bzImage > from gitlab, but I can repro locally with on 6.6.86. It's unclear to > me why it's failing. > > Trying: > diff --git i/arch/x86/xen/enlighten.c w/arch/x86/xen/enlighten.c > index 0219f1c90202..fb4ad7fe3e34 100644 > --- i/arch/x86/xen/enlighten.c > +++ w/arch/x86/xen/enlighten.c > @@ -123,11 +123,10 @@ noinstr void *__xen_hypercall_setfunc(void) > if (!boot_cpu_has(X86_FEATURE_CPUID)) > xen_get_vendor(); > > - if ((boot_cpu_data.x86_vendor == X86_VENDOR_AMD || > - boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)) > - func = xen_hypercall_amd; > - else > + if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL ) > func = xen_hypercall_intel; > + else > + func = xen_hypercall_amd; > > static_call_update_early(xen_hypercall, func); > > But it still calls xen_hypercall_intel(). So maybe x86_vendor isn't > getting set and ends up as 0 (X86_VENDOR_INTEL)? > > That's as far as I got here. > > Different but related, on mainline master, I also get a fail in > vmcall. There, I see in the disassembly that > __xen_hypercall_setfunc()'s calls to xen_get_vendor() is gone. > xen_get_vendor() seems to have been DCE-ed. There is some new code > that hardcodes features - "x86/cpufeatures: Add {REQUIRED,DISABLED} > feature configs" - which may be responsible.
6.6.74 is broken too. (That's the revision that the ARM tests want). So it broke somewhere between .56 and .74 which narrows the bisect a little. https://gitlab.com/xen-project/hardware/xen-staging/-/pipelines/1761323774 In Gitlab, both AMD and Intel are failing in roughly the same way. ~Andrew
