public inbox for kvm@vger.kernel.org
 help / color / mirror / Atom feed
From: "H. Peter Anvin" <hpa@zytor.com>
To: kvm@vger.kernel.org
Subject: KVM crash on unusual PM->RM transition
Date: Mon, 13 Apr 2009 16:42:25 -0700	[thread overview]
Message-ID: <49E3CDE1.8010001@zytor.com> (raw)

The current test branch of Syslinux does PM->RM transition via a stub 
which can be located in high memory.  This is correct and valid (x86 
CPUs rely on this to boot): after clearing CR0.PE, CS.base retains its 
previous value until CS is reloaded by a far JMP (which in this case is 
the very next instruction).

Unfortunately, at least on a stock Fedora 10 system, KVM doesn't agree:

: anacreon 67 ; qemu-kvm -boot d -cdrom image.iso

unhandled vm exit: 0x80000021 vcpu_id 0
rax 0000000000000012 rbx 0000000007ade342 rcx 0000000000000000 rdx 
0000000007ade388
rsi 0000000000000000 rdi 0000000000800000 rsp 0000000007ade448 rbp 
0000000000007b94
r8  0000000000000000 r9  0000000000000000 r10 0000000000000000 r11 
0000000000000000
r12 0000000000000000 r13 0000000000000000 r14 0000000000000000 r15 
0000000000000000
rip 0000000000000008 rflags 00023006
cs de36 (07ade36e/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
ds 0000 (00000000/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
es 0000 (00000000/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
ss 0000 (00000000/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
fs 0000 (00000000/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
gs 0000 (00000000/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
tr 0030 (fffbd000/00002088 p 1 dpl 0 db 0 s 0 type b l 0 g 0 avl 0)
ldt 0000 (00000000/ffffffff p 0 dpl 0 db 0 s 0 type 0 l 0 g 0 avl 0)
gdt 7ade388/3f
idt 0/ffff
cr0 12 cr2 0 cr3 0 cr4 0 cr8 0 efer 0
Abort

Kernel 2.6.27.21-170.2.56.fc10.x86_64, kvm-74-10.fc10.x86_64.

	-hpa


             reply	other threads:[~2009-04-13 23:42 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-04-13 23:42 H. Peter Anvin [this message]
2009-04-14  5:42 ` KVM crash on unusual PM->RM transition H. Peter Anvin
2009-04-14  8:14   ` Avi Kivity
2009-04-14 15:48     ` H. Peter Anvin
2009-04-14 16:07       ` Avi Kivity
2009-04-14 16:10         ` H. Peter Anvin
2009-04-14 16:16           ` Avi Kivity
2009-04-14 16:17             ` H. Peter Anvin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=49E3CDE1.8010001@zytor.com \
    --to=hpa@zytor.com \
    --cc=kvm@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox