> -----Original Message----- > From: Kevin O'Connor [mailto:kevin@xxxxxxxxxxxx] > Sent: Tuesday, December 22, 2015 2:47 AM > To: Gonglei (Arei) > Cc: Xulei (Stone); Paolo Bonzini; qemu-devel; seabios@xxxxxxxxxxx; > Huangweidong (C); kvm@xxxxxxxxxxxxxxx; Radim Krcmar > Subject: Re: [Qemu-devel] [PATCH] SeaBios: Fix reset procedure reentrancy > problem on qemu-kvm platform > > On Mon, Dec 21, 2015 at 09:41:32AM +0000, Gonglei (Arei) wrote: > > When the gurb of OS is booting, then the softirq and C function > > send_disk_op() may use extra stack of SeaBIOS. If we inject a NMI, > > romlayout.S: irqentry_extrastack is invoked, and the extra stack will > > be used again. And the stack of first calling will be broken, so that the > SeaBIOS stuck. > > > > You can easily reproduce the problem. > > > > 1. start on guest > > 2. reset the guest > > 3. inject a NMI when the guest show the grub surface 4. then the guest > > stuck > > Does the SeaBIOS patch below help? Sorry, it doesn't work. What's worse is we cannot stop SeaBIOS stuck by Setting "CONFIG_ENTRY_EXTRASTACK=n" after applying this patch. > I'm not familiar with how to "inject a > NMI" - can you describe the process in more detail? > 1. Qemu Command line: #: /home/qemu/x86_64-softmmu/qemu-system-x86_64 -enable-kvm -m 4096 -smp 8 -name suse -vnc 0.0.0.0:10 \ -device virtio-scsi-pci,id=scsi0 -drive file=/home/suse11_sp3_32_2,if=none,id=drive-scsi0-0-0-0,format=raw,cache=none,aio=native \ -device scsi-hd,bus=scsi0.0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0 \ -chardev file,id=seabios,path=/home/seabios.log -device isa-debugcon,iobase=0x402,chardev=seabios \ -monitor stdio -qmp unix:/tmp/qmp,server,nowait 2. Inject a NMI by QMP: #: /home/qemu/scripts/qmp # ./qmp-shell /tmp/qmp Welcome to the QMP low-level shell! Connected to QEMU 2.5.0 (QEMU) system_reset {"return": {}} (QEMU) inject-nmi {"return": {}} (QEMU) inject-nmi {"return": {}} Regards, -Gonglei > -Kevin > > > --- a/src/romlayout.S > +++ b/src/romlayout.S > @@ -548,7 +548,9 @@ entry_post: > ENTRY_INTO32 _cfunc32flat_handle_post // Normal entry point > > ORG 0xe2c3 > - IRQ_ENTRY 02 > + .global entry_02 > +entry_02: > + ENTRY handle_02 // NMI handler does not switch onto extra > +stack > > ORG 0xe3fe > .global entry_13_official -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
