Re: regression bisected; KVM: entry failed, hardware error 0x80000021

Chen, Tiejun
2014-12-25T07:46:33Z

On 2014/12/24 19:02, Jamie Heilman wrote:
> Chen, Tiejun wrote:
>> On 2014/12/23 15:26, Jamie Heilman wrote:
>>> Chen, Tiejun wrote:
>>>> On 2014/12/23 9:50, Chen, Tiejun wrote:
>>>>> On 2014/12/22 17:23, Jamie Heilman wrote:
>>>>>> KVM internal error. Suberror: 1
>>>>>> emulation failure
>>>>>> EAX=000de494 EBX=00000000 ECX=00000000 EDX=00000cfd
>>>>>> ESI=00000059 EDI=00000000 EBP=00000000 ESP=00006fb4
>>>>>> EIP=000f15c1 EFL=00010016 [----AP-] CPL=0 II=0 A20=1 SMM=0 HLT=0
>>>>>> ES =0010 00000000 ffffffff 00c09300 DPL=0 DS [-WA]
>>>>>> CS =0008 00000000 ffffffff 00c09b00 DPL=0 CS32 [-RA]
>>>>>> SS =0010 00000000 ffffffff 00c09300 DPL=0 DS [-WA]
>>>>>> DS =0010 00000000 ffffffff 00c09300 DPL=0 DS [-WA]
>>>>>> FS =0010 00000000 ffffffff 00c09300 DPL=0 DS [-WA]
>>>>>> GS =0010 00000000 ffffffff 00c09300 DPL=0 DS [-WA]
>>>>>> LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT
>>>>>> TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy
>>>>>> GDT= 000f6be8 00000037
>>>>>> IDT= 000f6c26 00000000
>>>>>> CR0=60000011 CR2=00000000 CR3=00000000 CR4=00000000
>>>>>> DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000
>>>>>> DR3=0000000000000000
>>>>>> DR6=00000000ffff0ff0 DR7=0000000000000400
>>>>>> EFER=0000000000000000
>>>>>> Code=e8 ae fc ff ff 89 f2 a8 10 89 d8 75 0a b9 41 15 ff ff ff d1 <5b>
>>>>>> 5e c3 5b 5e e9 76 ff ff ff b0 11 e6 20 e6 a0 b0 08 e6 21 b0 70 e6 a1
>>>>>> b0 04 e6 21 b0 02
>>>>>>
>>>>>> FWIW, I get the same thing with 34a1cd60d17 reverted. Maybe there are
>>>>>> two bugs, maybe there's more to this first one. I can repro this
>>>>>
>>>>> So if my understanding is correct, this is probably another bug. And
>>>>> especially, I already saw the same log in another thread, "Cleaning up
>>>>> the KVM clock". Maybe you can continue to `git bisect` to locate that
>>>>> bad commit.
>>>>>
>>>>
>>>> Looks just now Andy found that commit,
>>>> 0e60b0799fedc495a5c57dbd669de3c10d72edd2 "kvm: change memslot sorting rule
>>> >from size to GFN", maybe you can try to revert this to try yours again.
>>>
>>> That doesn't revert cleanly for me, and I don't have much time to
>>> fiddle with it until the 24th---so checked out the commit before it
>>> (d4ae84a0), applied your patch, built, and yes, everything works fine
>>> at that point. I'll probably have time for another full bisection
>>> later, assuming things aren't ironed out already by then.
>
> 3.18.0-rc3-00120-gd4ae84a0 + vmx reorder msr writes patch = OK
> 3.18.0-rc3-00121-g0e60b07 + vmx reorder msr writes patch = emulation failure
>
> So that certainly points to 0e60b0799fedc495a5c57dbd669de3c10d72edd2
> as well.
>
>> Could you try this to fix your last error?
>
> Running qemu-system-x86_64 -machine pc,accel=kvm -nodefaults works,
> my real (headless) kvm guests work, but this new patch makes running
> "qemu-system-x86_64 -machine pc,accel=kvm" fail again, this time with

Are you sure? From my test based on 3.19-rc1 that it owns top commit,

aa39477b5692611b91ac9455ae588738852b3f60

just plus my previous patch, "kvm: x86: vmx: reorder some msr writing"

I already can execute such a command successfully,

qemu-system-x86_64 -machine pc,accel=kvm -m 2048 -smp 2 -hda ubuntu.img

And your log below seems not to relate mem_slot issue we're discussing,
I guess you need to update qemu as well.

But I also found my new patch just work out Andy's next case, its really
bringing a new issue in !next case. So I tried to refine that patch
again as follows,

Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
---
virt/kvm/kvm_main.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index f528343..910bc48 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -672,6 +672,7 @@ static void update_memslots(struct kvm_memslots *slots,
WARN_ON(mslots[i].id != id);
if (!new->npages) {
new->base_gfn = 0;
+ new->flags = 0;
if (mslots[i].npages)
slots->used_slots--;
} else {
@@ -688,7 +689,9 @@ static void update_memslots(struct kvm_memslots *slots,
i++;
}
while (i > 0 &&
- new->base_gfn > mslots[i - 1].base_gfn) {
+ ((new->base_gfn > mslots[i - 1].base_gfn) ||
+ (!new->base_gfn &&
+ !mslots[i - 1].base_gfn && !mslots[i - 1].npages))) {
mslots[i] = mslots[i - 1];
slots->id_to_index[mslots[i].id] = i;
i--;

Tiejun

> errors in the host to the tune of:
>
> ------------[ cut here ]------------
> WARNING: CPU: 1 PID: 3901 at arch/x86/kvm/x86.c:6575 kvm_arch_vcpu_ioctl_run+0xd63/0xe5b [kvm]()
> Modules linked in: nfsv4 cpufreq_userspace cpufreq_stats cpufreq_powersave cpufreq_ondemand cpufreq_conservative autofs4 fan nfsd auth_rpcgss nfs lockd grace fscache sunrpc bridge stp llc vhost_net tun vhost macvtap macvlan fuse cbc dm_crypt usb_storage snd_hda_codec_analog snd_hda_codec_generic kvm_intel kvm tg3 ptp pps_core sr_mod snd_hda_intel snd_hda_controller snd_hda_codec snd_hwdep snd_pcm snd_timer snd sg dcdbas cdrom psmouse soundcore floppy evdev xfs dm_mod raid1 md_mod
> CPU: 1 PID: 3901 Comm: qemu-system-x86 Not tainted 3.19.0-rc1-00011-g53262d1-dirty #1
> Hardware name: Dell Inc. Precision WorkStation T3400 /0TP412, BIOS A14 04/30/2012
> 0000000000000000 000000007e052328 ffff8800c25ffcf8 ffffffff813defbe
> 0000000000000000 0000000000000000 ffff8800c25ffd38 ffffffff8103b517
> ffff8800c25ffd28 ffffffffa019bdec ffff8800caf1d000 ffff8800c2774800
> Call Trace:
> [<ffffffff813defbe>] dump_stack+0x4c/0x6e
> [<ffffffff8103b517>] warn_slowpath_common+0x97/0xb1
> [<ffffffffa019bdec>] ? kvm_arch_vcpu_ioctl_run+0xd63/0xe5b [kvm]
> [<ffffffff8103b60b>] warn_slowpath_null+0x15/0x17
> [<ffffffffa019bdec>] kvm_arch_vcpu_ioctl_run+0xd63/0xe5b [kvm]
> [<ffffffffa02308b9>] ? vmcs_load+0x20/0x62 [kvm_intel]
> [<ffffffffa0231e03>] ? vmx_vcpu_load+0x140/0x16a [kvm_intel]
> [<ffffffffa0196ba3>] ? kvm_arch_vcpu_load+0x15c/0x161 [kvm]
> [<ffffffffa018d8b1>] kvm_vcpu_ioctl+0x189/0x4bd [kvm]
> [<ffffffff8104647a>] ? do_sigtimedwait+0x12f/0x189
> [<ffffffff810ea316>] do_vfs_ioctl+0x370/0x436
> [<ffffffff810f24f2>] ? __fget+0x67/0x72
> [<ffffffff810ea41b>] SyS_ioctl+0x3f/0x5e
> [<ffffffff813e34d2>] system_call_fastpath+0x12/0x17
> ---[ end trace 46abac932fb3b4a1 ]---
> ------------[ cut here ]------------
> WARNING: CPU: 1 PID: 3901 at arch/x86/kvm/x86.c:6575 kvm_arch_vcpu_ioctl_run+0xd63/0xe5b [kvm]()
> Modules linked in: nfsv4 cpufreq_userspace cpufreq_stats cpufreq_powersave cpufreq_ondemand cpufreq_conservative autofs4 fan nfsd auth_rpcgss nfs lockd grace fscache sunrpc bridge stp llc vhost_net tun vhost macvtap macvlan fuse cbc dm_crypt usb_storage snd_hda_codec_analog snd_hda_codec_generic kvm_intel kvm tg3 ptp pps_core sr_mod snd_hda_intel snd_hda_controller snd_hda_codec snd_hwdep snd_pcm snd_timer snd sg dcdbas cdrom psmouse soundcore floppy evdev xfs dm_mod raid1 md_mod
> CPU: 1 PID: 3901 Comm: qemu-system-x86 Tainted: G W 3.19.0-rc1-00011-g53262d1-dirty #1
> Hardware name: Dell Inc. Precision WorkStation T3400 /0TP412, BIOS A14 04/30/2012
> 0000000000000000 000000007e052328 ffff8800c25ffcf8 ffffffff813defbe
> 0000000000000000 0000000000000000 ffff8800c25ffd38 ffffffff8103b517
> ffff8800c25ffd28 ffffffffa019bdec ffff8800caf1d000 ffff8800c2774800
> Call Trace:
> [<ffffffff813defbe>] dump_stack+0x4c/0x6e
> [<ffffffff8103b517>] warn_slowpath_common+0x97/0xb1
> [<ffffffffa019bdec>] ? kvm_arch_vcpu_ioctl_run+0xd63/0xe5b [kvm]
> [<ffffffff8103b60b>] warn_slowpath_null+0x15/0x17
> [<ffffffffa019bdec>] kvm_arch_vcpu_ioctl_run+0xd63/0xe5b [kvm]
> [<ffffffffa02308b9>] ? vmcs_load+0x20/0x62 [kvm_intel]
> [<ffffffffa0231e03>] ? vmx_vcpu_load+0x140/0x16a [kvm_intel]
> [<ffffffffa0196ba3>] ? kvm_arch_vcpu_load+0x15c/0x161 [kvm]
> [<ffffffffa018d8b1>] kvm_vcpu_ioctl+0x189/0x4bd [kvm]
> [<ffffffff8104647a>] ? do_sigtimedwait+0x12f/0x189
> [<ffffffff810ea316>] do_vfs_ioctl+0x370/0x436
> [<ffffffff810f24f2>] ? __fget+0x67/0x72
> [<ffffffff810ea41b>] SyS_ioctl+0x3f/0x5e
> [<ffffffff813e34d2>] system_call_fastpath+0x12/0x17
> ---[ end trace 46abac932fb3b4a2 ]---
>
> over and over and over ad nauseum, or until I kill the qemu command,
> it also eats a core's worth of cpu.
>
>