On Tue, Dec 22, 2015 at 02:14:12AM +0000, Gonglei (Arei) wrote: > > 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. Oops, can you try with the patch below instead? > > 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": {}} > I tried a few simple tests but was not able to reproduce. -Kevin --- a/src/romlayout.S +++ b/src/romlayout.S @@ -548,7 +548,10 @@ 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 + iretw 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
