> -----Original Message----- > From: Nadav Amit <nadav.amit@xxxxxxxxx> > Sent: Monday, October 12, 2020 2:37 PM > To: Qi, Yadong <yadong.qi@xxxxxxxxx> > Cc: kvm@xxxxxxxxxxxxxxx; pbonzini@xxxxxxxxxx > Subject: Re: [kvm-unit-tests PATCH] x86: vmx: Add test for SIPI signal processing > > > On Oct 11, 2020, at 6:19 PM, Qi, Yadong <yadong.qi@xxxxxxxxx> wrote: > > > >> On my bare-metal machine, I get a #GP on the WRMSR that writes the > >> EOI inside > >> ipi() : > >> > >> Test suite: vmx_sipi_signal_test > >> Unhandled exception 13 #GP at ip 0000000000417eba > >> error_code=0000 rflags=00010002 cs=00000008 > >> rax=0000000000000000 rcx=000000000000080b rdx=0000000000000000 > >> rbx=0000000000000000 > >> rbp=000000000053a238 rsi=0000000000000000 rdi=000000000000000b > >> r8=000000000000000a r9=00000000000003f8 r10=000000000000000d > >> r11=0000000000000000 > >> r12=000000000040c7a5 r13=0000000000000000 r14=0000000000000000 > >> r15=0000000000000000 > >> cr0=0000000080000011 cr2=0000000000000000 cr3=000000000041f000 > >> cr4=0000000000000020 > >> cr8=0000000000000000 > >> STACK: @417eba 417f36 417481 417383 > >> > >> I did not dig much deeper. Could it be that there is some confusion > >> between xapic/x2apic ? > > > > Thanks, Nadav. > > I cannot reproduce the #GP issue on my bare metal machine. > > And I am a little bit confused, there is no EOI MSR write in this test > > suite, how the #GP comes out... > > Could you provide more info for me to reproduce the issue? > > We might have different definitions for “bare-metal” :) > > I meant that I ran it directly on the machine without KVM. See [1]. You do need > some access serial console through the iDRAC/ilo/etc.. Oh, I see. Thank you for clarifying it. > > Anyhow, I figured out that you forgot to setup CR3 on the AP. > > Doing something like: > > + on_cpu(1, update_cr3, (void *)read_cr3()); > > /* start AP */ > on_cpu_async(1, sipi_test_ap_thread, NULL); > > > Solves the problem. You may want to do it in a slightly cleaner way, or extract > update_cr3() to one of the libs to avoid further code duplication. Thanks very much for figuring out the issue. Will update the patch in next version. Best Regard Yadong > > Regards, > Nadav > > > [1] https://patchwork.kernel.org/patch/11053903/
