KVM: MTRR: fix memory type handling if MTRR is completely disabled

Hello,

I am writting about this patch that was posted by Xiao:
http://www.spinics.net/lists/kvm/msg119044.html and this:
http://www.spinics.net/lists/kvm/msg119045.html
I've tested both kernel 4.2 and 4.3 and problem still exists when I use OVMF - 100% cpu usage, VM resetting, while it works properly on kernel 4.1

_______________________________________________
edk2-devel mailing list
[email protected]
https://lists.01.org/mailman/listinfo/edk2-devel

Quoted 7 lines

Hello,

I am writting about this patch that was posted by Xiao:
http://www.spinics.net/lists/kvm/msg119044.html and this:
http://www.spinics.net/lists/kvm/msg119045.html
I've tested both kernel 4.2 and 4.3 and problem still exists when I use OVMF - 100% cpu usage, VM resetting, while it works properly on kernel 4.1

My last (still current) request remains "please quirk it". See the end of <http://thread.gmane.org/gmane.linux.kernel/1952205/focus=1996025>,
and other messages in that subthread.

I haven't been following kernel development, so maybe the quirk has not happened. No clue.

... "VM resetting" looks something different though; I've been under the impression that the pedantic (=unquirked) MTRR configuration didn't impact other things than speed. Janusz, maybe you could contribute with a host kernel bisection for the VM reset symptom.

Thanks
Laszlo

Quoted 5 lines

_______________________________________________
edk2-devel mailing list
[email protected]
https://lists.01.org/mailman/listinfo/edk2-devel

W dniu 18.09.2015 o 12:07, Laszlo Ersek pisze:

Quoted 11 lines · Janusz

Quoted 7 lines

Hello,

I am writting about this patch that was posted by Xiao:
http://www.spinics.net/lists/kvm/msg119044.html and this:
http://www.spinics.net/lists/kvm/msg119045.html
I've tested both kernel 4.2 and 4.3 and problem still exists when I use OVMF - 100% cpu usage, VM resetting, while it works properly on kernel 4.1

My last (still current) request remains "please quirk it". See the end of <http://thread.gmane.org/gmane.linux.kernel/1952205/focus=1996025>,
and other messages in that subthread.

when I saw message from Xiao that he posted patch for it and have seen this code in kernel sources (landed in 4.2-rc3) I though that the status is not "please quirk it" anymore

Quoted 8 lines

I haven't been following kernel development, so maybe the quirk has not happened. No clue.

... "VM resetting" looks something different though; I've been under the impression that the pedantic (=unquirked) MTRR configuration didn't impact other things than speed. Janusz, maybe you could contribute with a host kernel bisection for the VM reset symptom.

To be more exact - VM is mostly not starting or its starting after long time and then resetting it self at random time (but before system boots) or gets very high cpu usage or sometimes boots without problem (the least possible case scenario). When I start VM with -vga std, not with my gpu passthrough - in most of the time I get this:
http://pastebin.com/raw.php?i=CKrNsueS

Result of bisect:

git bisect start
# bad: [d770e558e21961ad6cfdf0ff7df0eb5d7d4f0754] Linux 4.2-rc1 git bisect bad d770e558e21961ad6cfdf0ff7df0eb5d7d4f0754
# good: [b953c0d234bc72e8489d3bf51a276c5c4ec85345] Linux 4.1
git bisect good b953c0d234bc72e8489d3bf51a276c5c4ec85345
# good: [4570a37169d4b44d316f40b2ccc681dc93fedc7b] Merge tag 'sound-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
git bisect good 4570a37169d4b44d316f40b2ccc681dc93fedc7b
# good: [8d7804a2f03dbd34940fcb426450c730adf29dae] Merge tag 'driver-core-4.2-rc1' of
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
git bisect good 8d7804a2f03dbd34940fcb426450c730adf29dae
# bad: [78c10e556ed904d5bfbd71e9cadd8ce8f25d6982] Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
git bisect bad 78c10e556ed904d5bfbd71e9cadd8ce8f25d6982
# good: [623f0e137c0fedb81bbf3d88be4ed300eee163da] Staging: lustre: fix space before and after comma in dt_object.c
git bisect good 623f0e137c0fedb81bbf3d88be4ed300eee163da
# bad: [8c7febe83915332276cab49e89f6580bb963fb9a] Merge tag 'tty-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
git bisect bad 8c7febe83915332276cab49e89f6580bb963fb9a
# good: [bcf5b92d9bbf0b7683199615f0f184e89fa486bc] staging: rtl8192e:
Remove rt_hi_throughput::ChnkOp
git bisect good bcf5b92d9bbf0b7683199615f0f184e89fa486bc
# good: [71eec4836b834b992e0cefeefc8b85efe4cb185b] drivers: PL011: allow avoiding UART enabling/disabling
git bisect good 71eec4836b834b992e0cefeefc8b85efe4cb185b
# good: [49ef9c850154756cf2fbc50fd3804c44675d4633] staging: comedi:
me4000: rename 'thisboard' variables
git bisect good 49ef9c850154756cf2fbc50fd3804c44675d4633
# good: [2a4462418af771ef9f1f1d1532bcbb8799df842d] tty/serial: kill off set_irq_flags usage
git bisect good 2a4462418af771ef9f1f1d1532bcbb8799df842d
# good: [6d43b0f482561ab421a91ebf59a51192d66cf8a7] Staging: sm750fb:
ddk750_swi2c.c: Insert spaces around operators
git bisect good 6d43b0f482561ab421a91ebf59a51192d66cf8a7
# good: [84e1eb83d0b9e0969a59b6848d718eaf71e98fcb] MAINTAINERS: tty: add serial docs directory
git bisect good 84e1eb83d0b9e0969a59b6848d718eaf71e98fcb
# good: [53a20e9e378ecd52f0afa4b60f8f8c81b6f97c27] staging: wilc1000:
disable driver due to build warnings
git bisect good 53a20e9e378ecd52f0afa4b60f8f8c81b6f97c27
# good: [71206b9f8120eb513c621d4f31906577bb658df3] Doc:
serial-rs485.txt: update RS485 driver interface
git bisect good 71206b9f8120eb513c621d4f31906577bb658df3
# bad: [23908db413eccd77084b09c9b0a4451dfb0524c0] Merge tag 'staging-4.2-rc1' of
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
git bisect bad 23908db413eccd77084b09c9b0a4451dfb0524c0

# first bad commit: [23908db413eccd77084b09c9b0a4451dfb0524c0] Merge tag
'staging-4.2-rc1' of
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Thanks for your report and analysis, Janusz!

Quoted 23 lines · Janusz

W dniu 18.09.2015 o 12:07, Laszlo Ersek pisze:

Quoted 11 lines · Janusz

Quoted 7 lines

Hello,

I am writting about this patch that was posted by Xiao:
http://www.spinics.net/lists/kvm/msg119044.html and this:
http://www.spinics.net/lists/kvm/msg119045.html
I've tested both kernel 4.2 and 4.3 and problem still exists when I use OVMF - 100% cpu usage, VM resetting, while it works properly on kernel 4.1

My last (still current) request remains "please quirk it". See the end of <http://thread.gmane.org/gmane.linux.kernel/1952205/focus=1996025>,
and other messages in that subthread.

when I saw message from Xiao that he posted patch for it and have seen this code in kernel sources (landed in 4.2-rc3) I though that the status is not "please quirk it" anymore

Quoted 8 lines

I haven't been following kernel development, so maybe the quirk has not happened. No clue.

... "VM resetting" looks something different though; I've been under the impression that the pedantic (=unquirked) MTRR configuration didn't impact other things than speed. Janusz, maybe you could contribute with a host kernel bisection for the VM reset symptom.

Quoted 6 lines

To be more exact - VM is mostly not starting or its starting after long time and then resetting it self at random time (but before system boots) or gets very high cpu usage or sometimes boots without problem (the least possible case scenario). When I start VM with -vga std, not with my gpu passthrough - in most of the time I get this:
http://pastebin.com/raw.php?i=CKrNsueS

It seems the behaviour is different with previous (previously, it can boot but slowly), right?

The URL cat not be accessed, i do not know it's your web server issue or our networking issue.

Quoted 34 lines · Xiao Guangrong

Thanks for your report and analysis, Janusz!

Quoted 23 lines · Janusz

W dniu 18.09.2015 o 12:07, Laszlo Ersek pisze:

Quoted 11 lines · Janusz

Quoted 7 lines

Hello,

I am writting about this patch that was posted by Xiao:
http://www.spinics.net/lists/kvm/msg119044.html and this:
http://www.spinics.net/lists/kvm/msg119045.html
I've tested both kernel 4.2 and 4.3 and problem still exists when I use OVMF - 100% cpu usage, VM resetting, while it works properly on kernel 4.1

My last (still current) request remains "please quirk it". See the end of <http://thread.gmane.org/gmane.linux.kernel/1952205/focus=1996025>,
and other messages in that subthread.

when I saw message from Xiao that he posted patch for it and have seen this code in kernel sources (landed in 4.2-rc3) I though that the status is not "please quirk it" anymore

Quoted 8 lines

I haven't been following kernel development, so maybe the quirk has not happened. No clue.

... "VM resetting" looks something different though; I've been under the impression that the pedantic (=unquirked) MTRR configuration didn't impact other things than speed. Janusz, maybe you could contribute with a host kernel bisection for the VM reset symptom.

Quoted 6 lines

To be more exact - VM is mostly not starting or its starting after long time and then resetting it self at random time (but before system boots) or gets very high cpu usage or sometimes boots without problem (the least possible case scenario). When I start VM with -vga std, not with my gpu passthrough - in most of the time I get this:
http://pastebin.com/raw.php?i=CKrNsueS

Quoted 6 lines

It seems the behaviour is different with previous (previously, it can boot but slowly), right?

The URL cat not be accessed, i do not know it's your web server issue or our networking issue.

It can be accessed and dump as below:

KVM internal error. Suberror: 1
emulation failure
KVM internal error. Suberror: 1
emulation failure
KVM internal error. Suberror: 1
emulation failure
KVM internal error. Suberror: 1
emulation failure
KVM internal error. Suberror: 1
emulation failure
KVM internal error. Suberror: 1
emulation failure
KVM internal error. Suberror: 1
emulation failure
EAX=bfefa000 EBX=00000002 ECX=00000000 EDX=00000600 ESI=00000000 EDI=00003eb8 EBP=00000000 ESP=00000000 EIP=000a0000 EFL=00010086 [--S--P-] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0008 00000000 ffffffff 00c09300 DPL=0 DS [-WA]
CS =0010 00000000 ffffffff 00c09b00 DPL=0 CS32 [-RA]

SS =0008 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
DS =0008 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
FS =0008 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
GS =0008 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= bfee87d8 0000003f
IDT= 00000000 0000ffff
CR0=00000033 CR2=00000000 CR3=bfefa000 CR4=00000640
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000 DR6=00000000ffff0ff0 DR7=0000000000000400
EFER=0000000000000000
Code=af af af af af af af af af af af af af af af af af af af af <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
EAX=bfefa000 EBX=00000002 ECX=00000000 EDX=00000600
ESI=00000000 EDI=00003eb8 EBP=00000000 ESP=00000000
EIP=000a0000 EFL=00010086 [--S--P-] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0008 00000000 ffffffff 00c09300 DPL=0 DS [-WA]
CS =0010 00000000 ffffffff 00c09b00 DPL=0 CS32 [-RA]

SS =0008 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
DS =0008 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
FS =0008 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
GS =0008 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= bfee87d8 0000003f
IDT= 00000000 0000ffff
CR0=00000033 CR2=00000000 CR3=bfefa000 CR4=00000640
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000 DR6=00000000ffff0ff0 DR7=0000000000000400
EFER=0000000000000000
Code=af af af af af af af af af af af af af af af af af af af af <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
EAX=00000000 EBX=00000000 ECX=00000000 EDX=00000600
ESI=00000000 EDI=00002000 EBP=00000000 ESP=00000000
EIP=00001000 EFL=00010046 [---Z-P-] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0000 00000000 0000ffff 00009300
CS =9f00 0009f000 0000ffff 00009b00
SS =0000 00000000 0000ffff 00009300
DS =0000 00000000 0000ffff 00009300
FS =0000 00000000 0000ffff 00009300
GS =0000 00000000 0000ffff 00009300
LDT=0000 00000000 0000ffff 00008200
TR =0000 00000000 0000ffff 00008b00
GDT= 00000000 0000ffff
IDT= 00000000 0000ffff
CR0=60000010 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000 DR6=00000000ffff0ff0 DR7=0000000000000400
EFER=0000000000000000
Code=af af af af af af af af af af af af af af af af af af af af <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
EAX=00000023 EBX=00000002 ECX=00000000 EDX=00000600
ESI=00000000 EDI=00001fc2 EBP=00000000 ESP=00000000
EIP=00001000 EFL=00010002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0000 00000000 0000ffff 00009300 DPL=0 DS16 [-WA]
CS =9f00 0009f000 0000ffff 00009b00 DPL=0 CS16 [-RA]
SS =0000 00000000 0000ffff 00009300 DPL=0 DS16 [-WA]
DS =9f00 0009f000 0000ffff 00009300 DPL=0 DS16 [-WA]
FS =0000 00000000 0000ffff 00009300 DPL=0 DS16 [-WA]
GS =0000 00000000 0000ffff 00009300 DPL=0 DS16 [-WA]
LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT
TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy
GDT= bfee87d8 0000003f
IDT= 00000000 0000ffff
CR0=00000033 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000 DR6=00000000ffff0ff0 DR7=0000000000000400
EFER=0000000000000000
Code=af af af af af af af af af af af af af af af af af af af af <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
EAX=00000023 EBX=00000002 ECX=00000000 EDX=00000600
ESI=00000000 EDI=00001fc2 EBP=00000000 ESP=00000000
EIP=00001000 EFL=00010002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0000 00000000 0000ffff 00009300 DPL=0 DS16 [-WA]
CS =9f00 0009f000 0000ffff 00009b00 DPL=0 CS16 [-RA]
SS =0000 00000000 0000ffff 00009300 DPL=0 DS16 [-WA]
DS =9f00 0009f000 0000ffff 00009300 DPL=0 DS16 [-WA]
FS =0000 00000000 0000ffff 00009300 DPL=0 DS16 [-WA]
GS =0000 00000000 0000ffff 00009300 DPL=0 DS16 [-WA]
LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT
TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy
GDT= bfee87d8 0000003f
IDT= 00000000 0000ffff
CR0=00000033 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000 DR6=00000000ffff0ff0 DR7=0000000000000400
EFER=0000000000000000
Code=af af af af af af af af af af af af af af af af af af af af <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
EAX=00000023 EBX=00000002 ECX=00000000 EDX=00000600
ESI=00000000 EDI=00001fc2 EBP=00000000 ESP=00000000
EIP=00001000 EFL=00010002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0000 00000000 0000ffff 00009300 DPL=0 DS16 [-WA]
CS =9f00 0009f000 0000ffff 00009b00 DPL=0 CS16 [-RA]
SS =0000 00000000 0000ffff 00009300 DPL=0 DS16 [-WA]
DS =9f00 0009f000 0000ffff 00009300 DPL=0 DS16 [-WA]
FS =0000 00000000 0000ffff 00009300 DPL=0 DS16 [-WA]
GS =0000 00000000 0000ffff 00009300 DPL=0 DS16 [-WA]
LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT
TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy
GDT= bfee87d8 0000003f
IDT= 00000000 0000ffff
CR0=00000033 CR2=00000000 CR3=00000000 CR4=00000000
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000 DR6=00000000ffff0ff0 DR7=0000000000000400
EFER=0000000000000000
Code=af af af af af af af af af af af af af af af af af af af af <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
EAX=bfefa000 EBX=00000002 ECX=00000000 EDX=00000600
ESI=00000000 EDI=00003eb8 EBP=00000000 ESP=00000000
EIP=000a0000 EFL=00010086 [--S--P-] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0008 00000000 ffffffff 00c09300 DPL=0 DS [-WA]
CS =0010 00000000 ffffffff 00c09b00 DPL=0 CS32 [-RA]

SS =0008 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
DS =0008 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
FS =0008 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
GS =0008 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= bfee87d8 0000003f
IDT= 00000000 0000ffff
CR0=00000033 CR2=00000000 CR3=bfefa000 CR4=00000640
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000 DR6=00000000ffff0ff0 DR7=0000000000000400
EFER=0000000000000000
Code=af af af af af af af af af af af af af af af af af af af af <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Quoted 204 lines · Xiao Guangrong

Quoted 43 lines

Thanks for your report and analysis, Janusz!

Quoted 30 lines · Janusz

W dniu 18.09.2015 o 12:07, Laszlo Ersek pisze:

Quoted 10 lines · Janusz

Quoted 9 lines

Hello,

I am writting about this patch that was posted by Xiao:
http://www.spinics.net/lists/kvm/msg119044.html and this:
http://www.spinics.net/lists/kvm/msg119045.html
I've tested both kernel 4.2 and 4.3 and problem still exists when I use
OVMF - 100% cpu usage, VM resetting, while it works properly on kernel 4.1

Quoted 4 lines

My last (still current) request remains "please quirk it". See the end
of <http://thread.gmane.org/gmane.linux.kernel/1952205/focus=1996025>,
and other messages in that subthread.

when I saw message from Xiao that he posted patch for it and have seen this code in kernel sources (landed in 4.2-rc3) I though that the status
is not "please quirk it" anymore

Quoted 11 lines

I haven't been following kernel development, so maybe the quirk has not
happened. No clue.

... "VM resetting" looks something different though; I've been under the
impression that the pedantic (=unquirked) MTRR configuration didn't impact other things than speed. Janusz, maybe you could contribute with
a host kernel bisection for the VM reset symptom.

Quoted 8 lines

To be more exact - VM is mostly not starting or its starting after long
time and then resetting it self at random time (but before system boots)
or gets very high cpu usage or sometimes boots without problem (the least possible case scenario). When I start VM with -vga std, not with my gpu passthrough - in most of the time I get this:
http://pastebin.com/raw.php?i=CKrNsueS

Quoted 8 lines

It seems the behaviour is different with previous (previously, it can boot
but slowly), right?

The URL cat not be accessed, i do not know it's your web server issue or
our networking issue.

It can be accessed and dump as below:

KVM internal error. Suberror: 1
emulation failure
KVM internal error. Suberror: 1
emulation failure
KVM internal error. Suberror: 1
emulation failure
KVM internal error. Suberror: 1
emulation failure
KVM internal error. Suberror: 1
emulation failure
KVM internal error. Suberror: 1
emulation failure
KVM internal error. Suberror: 1
emulation failure
EAX=bfefa000 EBX=00000002 ECX=00000000 EDX=00000600 ESI=00000000 EDI=00003eb8 EBP=00000000 ESP=00000000 EIP=000a0000 EFL=00010086 [--S--P-] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0008 00000000 ffffffff 00c09300 DPL=0 DS [-WA]
CS =0010 00000000 ffffffff 00c09b00 DPL=0 CS32 [-RA]

SS =0008 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
DS =0008 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
FS =0008 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
GS =0008 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= bfee87d8 0000003f
IDT= 00000000 0000ffff
CR0=00000033 CR2=00000000 CR3=bfefa000 CR4=00000640 DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400 EFER=0000000000000000
Code=af af af af af af af af af af af af af af af af af af af af <00> 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 EAX=bfefa000 EBX=00000002 ECX=00000000 EDX=00000600 ESI=00000000 EDI=00003eb8 EBP=00000000 ESP=00000000 EIP=000a0000 EFL=00010086 [--S--P-] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0008 00000000 ffffffff 00c09300 DPL=0 DS [-WA]
CS =0010 00000000 ffffffff 00c09b00 DPL=0 CS32 [-RA]

SS =0008 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
DS =0008 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
FS =0008 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
GS =0008 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= bfee87d8 0000003f
IDT= 00000000 0000ffff
CR0=00000033 CR2=00000000 CR3=bfefa000 CR4=00000640 DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400 EFER=0000000000000000
Code=af af af af af af af af af af af af af af af af af af af af <00> 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 EAX=00000000 EBX=00000000 ECX=00000000 EDX=00000600 ESI=00000000 EDI=00002000 EBP=00000000 ESP=00000000 EIP=00001000 EFL=00010046 [---Z-P-] CPL=0 II=0 A20=1 SMM=0 HLT=0 ES =0000 00000000 0000ffff 00009300
CS =9f00 0009f000 0000ffff 00009b00
SS =0000 00000000 0000ffff 00009300
DS =0000 00000000 0000ffff 00009300
FS =0000 00000000 0000ffff 00009300
GS =0000 00000000 0000ffff 00009300
LDT=0000 00000000 0000ffff 00008200
TR =0000 00000000 0000ffff 00008b00
GDT= 00000000 0000ffff
IDT= 00000000 0000ffff
CR0=60000010 CR2=00000000 CR3=00000000 CR4=00000000 DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400 EFER=0000000000000000
Code=af af af af af af af af af af af af af af af af af af af af <00> 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 EAX=00000023 EBX=00000002 ECX=00000000 EDX=00000600 ESI=00000000 EDI=00001fc2 EBP=00000000 ESP=00000000 EIP=00001000 EFL=00010002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0 ES =0000 00000000 0000ffff 00009300 DPL=0 DS16 [-WA]
CS =9f00 0009f000 0000ffff 00009b00 DPL=0 CS16 [-RA]
SS =0000 00000000 0000ffff 00009300 DPL=0 DS16 [-WA]
DS =9f00 0009f000 0000ffff 00009300 DPL=0 DS16 [-WA]
FS =0000 00000000 0000ffff 00009300 DPL=0 DS16 [-WA]
GS =0000 00000000 0000ffff 00009300 DPL=0 DS16 [-WA] LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT
TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy
GDT= bfee87d8 0000003f
IDT= 00000000 0000ffff
CR0=00000033 CR2=00000000 CR3=00000000 CR4=00000000 DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400 EFER=0000000000000000
Code=af af af af af af af af af af af af af af af af af af af af <00> 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 EAX=00000023 EBX=00000002 ECX=00000000 EDX=00000600 ESI=00000000 EDI=00001fc2 EBP=00000000 ESP=00000000 EIP=00001000 EFL=00010002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0 ES =0000 00000000 0000ffff 00009300 DPL=0 DS16 [-WA]
CS =9f00 0009f000 0000ffff 00009b00 DPL=0 CS16 [-RA]
SS =0000 00000000 0000ffff 00009300 DPL=0 DS16 [-WA]
DS =9f00 0009f000 0000ffff 00009300 DPL=0 DS16 [-WA]
FS =0000 00000000 0000ffff 00009300 DPL=0 DS16 [-WA]
GS =0000 00000000 0000ffff 00009300 DPL=0 DS16 [-WA] LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT
TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy
GDT= bfee87d8 0000003f
IDT= 00000000 0000ffff
CR0=00000033 CR2=00000000 CR3=00000000 CR4=00000000 DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400 EFER=0000000000000000
Code=af af af af af af af af af af af af af af af af af af af af <00> 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 EAX=00000023 EBX=00000002 ECX=00000000 EDX=00000600 ESI=00000000 EDI=00001fc2 EBP=00000000 ESP=00000000 EIP=00001000 EFL=00010002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0 ES =0000 00000000 0000ffff 00009300 DPL=0 DS16 [-WA]
CS =9f00 0009f000 0000ffff 00009b00 DPL=0 CS16 [-RA]
SS =0000 00000000 0000ffff 00009300 DPL=0 DS16 [-WA]
DS =9f00 0009f000 0000ffff 00009300 DPL=0 DS16 [-WA]
FS =0000 00000000 0000ffff 00009300 DPL=0 DS16 [-WA]
GS =0000 00000000 0000ffff 00009300 DPL=0 DS16 [-WA] LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT
TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy
GDT= bfee87d8 0000003f
IDT= 00000000 0000ffff
CR0=00000033 CR2=00000000 CR3=00000000 CR4=00000000 DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400 EFER=0000000000000000
Code=af af af af af af af af af af af af af af af af af af af af <00> 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 EAX=bfefa000 EBX=00000002 ECX=00000000 EDX=00000600 ESI=00000000 EDI=00003eb8 EBP=00000000 ESP=00000000 EIP=000a0000 EFL=00010086 [--S--P-] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0008 00000000 ffffffff 00c09300 DPL=0 DS [-WA]
CS =0010 00000000 ffffffff 00c09b00 DPL=0 CS32 [-RA]

SS =0008 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
DS =0008 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
FS =0008 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]
GS =0008 00000000 ffffffff 00c09300 DPL=0 DS   [-WA]

Quoted 13 lines

LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT
TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy
GDT= bfee87d8 0000003f
IDT= 00000000 0000ffff
CR0=00000033 CR2=00000000 CR3=bfefa000 CR4=00000640 DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000ffff0ff0 DR7=0000000000000400 EFER=0000000000000000
Code=af af af af af af af af af af af af af af af af af af af af <00> 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Got it, thank you!

Now, I can also add, that the problem is only when I allow VM to use more than one core, so with option for example:
-smp 8,cores=4,threads=2,sockets=1 and other combinations like -smp 4,threads=1 its not working, and without it I am always running VM without problems

Any ideas what can it be? or any idea what would help to find out what is causing this?

Quoted 6 lines

Now, I can also add, that the problem is only when I allow VM to use more than one core, so with option for example:
-smp 8,cores=4,threads=2,sockets=1 and other combinations like -smp 4,threads=1 its not working, and without it I am always running VM without problems

Quoted 2 lines

Any ideas what can it be? or any idea what would help to find out what is causing this?

I am going to send a revert of the patch tomorrow.

Paolo

W dniu 01.10.2015 o 16:18, Paolo Bonzini pisze:

Quoted 8 lines · Janusz

Quoted 6 lines

Now, I can also add, that the problem is only when I allow VM to use more than one core, so with option for example:
-smp 8,cores=4,threads=2,sockets=1 and other combinations like -smp 4,threads=1 its not working, and without it I am always running VM without problems

Quoted 5 lines

Quoted 2 lines

Any ideas what can it be? or any idea what would help to find out what is causing this?

I am going to send a revert of the patch tomorrow.

Paolo

Thanks, but revert patch doesn't help, so something else is wrong here

Quoted 13 lines · Janusz

W dniu 01.10.2015 o 16:18, Paolo Bonzini pisze:

Quoted 12 lines · Janusz

Quoted 8 lines

Now, I can also add, that the problem is only when I allow VM to use more than one core, so with option for example:
-smp 8,cores=4,threads=2,sockets=1 and other combinations like -smp 4,threads=1 its not working, and without it I am always running VM without problems

Any ideas what can it be? or any idea what would help to find out what is causing this?

I am going to send a revert of the patch tomorrow.

Quoted 3 lines

Quoted 1 line

Paolo

Thanks, but revert patch doesn't help, so something else is wrong here

It seems i can reproduce it now ... and finally i get little free time now :( I will dig into it and fix it asap.

Thank you, Janusz and Paolo!

Quoted 16 lines · Xiao Guangrong

Quoted 13 lines · Janusz

W dniu 01.10.2015 o 16:18, Paolo Bonzini pisze:

Quoted 12 lines · Janusz

Quoted 8 lines

Now, I can also add, that the problem is only when I allow VM to use more than one core, so with option for example:
-smp 8,cores=4,threads=2,sockets=1 and other combinations like -smp 4,threads=1 its not working, and without it I am always running VM without problems

Any ideas what can it be? or any idea what would help to find out what is causing this?

I am going to send a revert of the patch tomorrow.

Quoted 8 lines

Quoted 3 lines

Quoted 1 line

Paolo

Thanks, but revert patch doesn't help, so something else is wrong here

It seems i can reproduce it now ... and finally i get little free time now :( I will dig into it and fix it asap.

Thank you, Janusz and Paolo!

I think i have figured out the root case, i got these traces:
<...>-47935 [052] d... 20017.763244: kvm_exit: reason EPT_VIOLATION rip 0xa0000 info 184 0

            <...>-47935 [052] .... 20017.763244: kvm_page_fault: address a0000 error_code 184
            <...>-47935 [052] .... 20017.763269: mark_mmio_spte: sptep:ffff880841c3d500 gfn a0
access 6 gen fff94
            <...>-47935 [052] .... 20017.763272: kvm_mmu_pagetable_walk: addr a0000 pferr 10 F
            <...>-47935 [052] .... 20017.763272: kvm_mmu_paging_element: pte bfeff023 level 4
            <...>-47935 [052] .... 20017.763273: kvm_mmu_paging_element: pte bff00023 level 3
            <...>-47935 [052] .... 20017.763273: kvm_mmu_paging_element: pte e3 level 2
            <...>-47935 [052] .... 20017.763274: kvm_emulate_insn: 0:a0000: (prot32)
            <...>-47935 [052] .... 20017.763274: kvm_emulate_insn: 0:a0000: (prot32) failed
            <...>-

It told me that guest is executing on address 0xa0000 but it is a MMIO address, so KVM can not emulate it and complained with internal error.

Actually, 0xa0000 is belong to SMRAM (0x30000 is SMRAM base and 0x80000 is EIP offset, 0x30000 + 0x80000 = 0xa0000), however, from QEMU's dump:

W dniu 01.10.2015 o 16:18, Paolo Bonzini pisze:

Quoted 8 lines · Janusz

Quoted 6 lines

Now, I can also add, that the problem is only when I allow VM to use more than one core, so with option for example:
-smp 8,cores=4,threads=2,sockets=1 and other combinations like -smp 4,threads=1 its not working, and without it I am always running VM without problems

Quoted 5 lines

Quoted 2 lines

Any ideas what can it be? or any idea what would help to find out what is causing this?

I am going to send a revert of the patch tomorrow.

Paolo

Thanks, but revert patch doesn't help, so something else is wrong here

Janusz,

Could you please try this:

$ git diff

arch/x86/kvm/x86.c +2 -0

index 185fc16..bdd564f 100644
@@ -4957,12 +4957,14 @@ static int handle_emulation_failure(struct
 kvm_vcpu *vcpu)
 
        ++vcpu->stat.insn_emulation_fail;
        trace_kvm_emulate_insn_failed(vcpu);
+#if 0
        if (!is_guest_mode(vcpu) && kvm_x86_ops->get_cpl(vcpu) == 0) {
                vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
                vcpu->run->internal.suberror =
 KVM_INTERNAL_ERROR_EMULATION;
                vcpu->run->internal.ndata = 0;
                r = EMULATE_FAIL;
        }
+#endif
        kvm_queue_exception(vcpu, UD_VECTOR);

        return r;

To see if the issue still there?

Quoted 16 lines · Janusz

W dniu 01.10.2015 o 16:18, Paolo Bonzini pisze:

Quoted 8 lines · Janusz

Quoted 6 lines

Now, I can also add, that the problem is only when I allow VM to use more than one core, so with option for example:
-smp 8,cores=4,threads=2,sockets=1 and other combinations like -smp 4,threads=1 its not working, and without it I am always running VM without problems

Quoted 5 lines

Quoted 2 lines

Any ideas what can it be? or any idea what would help to find out what is causing this?

I am going to send a revert of the patch tomorrow.

Paolo

Thanks, but revert patch doesn't help, so something else is wrong here

I was able to run my virtual machine with this, but had very high cpu usage when something happen in it like booting system. once, my virtual machine hang and I couln't even get my mouse / keyboard back from qemu. When I did vga passthrough, I didn't get any video output, and cpu usage was also high. Tried it on 4.3

W dniu 14.10.2015 o 05:58, Xiao Guangrong pisze:

Quoted 48 lines

Janusz,

Could you please try this:

$ git diff

arch/x86/kvm/x86.c +2 -0

index 185fc16..bdd564f 100644
@@ -4957,12 +4957,14 @@ static int handle_emulation_failure(struct
 kvm_vcpu *vcpu)
 
         ++vcpu->stat.insn_emulation_fail;
         trace_kvm_emulate_insn_failed(vcpu);
+#if 0
         if (!is_guest_mode(vcpu) && kvm_x86_ops->get_cpl(vcpu) == 0) {
                 vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
                 vcpu->run->internal.suberror =
 KVM_INTERNAL_ERROR_EMULATION;
                 vcpu->run->internal.ndata = 0;
                 r = EMULATE_FAIL;
         }
+#endif
         kvm_queue_exception(vcpu, UD_VECTOR);

         return r;

To see if the issue still there?

Quoted 16 lines · Janusz

W dniu 01.10.2015 o 16:18, Paolo Bonzini pisze:

Quoted 8 lines · Janusz

Quoted 6 lines

Now, I can also add, that the problem is only when I allow VM to use more than one core, so with option for example:
-smp 8,cores=4,threads=2,sockets=1 and other combinations like -smp 4,threads=1 its not working, and without it I am always running VM without problems

Quoted 5 lines

Quoted 2 lines

Any ideas what can it be? or any idea what would help to find out what is causing this?

I am going to send a revert of the patch tomorrow.

Paolo

Thanks, but revert patch doesn't help, so something else is wrong here

Quoted 5 lines · Janusz

I was able to run my virtual machine with this, but had very high cpu usage when something happen in it like booting system. once, my virtual machine hang and I couln't even get my mouse / keyboard back from qemu. When I did vga passthrough, I didn't get any video output, and cpu usage was also high. Tried it on 4.3

Which tree are you using? Is it kvm tree?
Could you please work on queue brancn on current kvm tree based on top commit 73917739334c6509: KVM: x86: fix SMI to halted VCPU.

Hmm... interesting, this diff works on my box...

Quoted 10 lines · Janusz

Quoted 6 lines

I was able to run my virtual machine with this, but had very high cpu usage when something happen in it like booting system. once, my virtual machine hang and I couln't even get my mouse / keyboard back from qemu. When I did vga passthrough, I didn't get any video output, and cpu usage
was also high. Tried it on 4.3

Quoted 5 lines

Which tree are you using? Is it kvm tree?
Could you please work on queue brancn on current kvm tree based on top commit 73917739334c6509: KVM: x86: fix SMI to halted VCPU.

Hmm... interesting, this diff works on my box...

Forgot to say that i built my test env following the instructions on kvm-wiki:
http://www.linux-kvm.org/page/OVMF

My test script is attached, and i will try to build the env like yours as much
as possible...

W dniu 14.10.2015 o 10:32, Xiao Guangrong pisze:

Quoted 19 lines · Xiao Guangrong

Quoted 8 lines · Janusz

Quoted 6 lines

I was able to run my virtual machine with this, but had very high cpu usage when something happen in it like booting system. once, my virtual machine hang and I couln't even get my mouse / keyboard back from qemu. When I did vga passthrough, I didn't get any video output, and cpu usage
was also high. Tried it on 4.3

Quoted 5 lines

Which tree are you using? Is it kvm tree?
Could you please work on queue brancn on current kvm tree based on top commit 73917739334c6509: KVM: x86: fix SMI to halted VCPU.

Hmm... interesting, this diff works on my box...

Forgot to say that i built my test env following the instructions on kvm-wiki:
http://www.linux-kvm.org/page/OVMF

Quoted 3 lines

My test script is attached, and i will try to build the env like yours as much
as possible...

I attach my script. I see that you are using pc-i440fx-2.1 - I use default, I think its pc-i440fx-2.4, tried 2.3 some time ago and I get the same problem. I will try with 2.1 after work
I am using master from main kernel tree, will also try this tree you mentioned after work

Quoted 13 lines · Xiao Guangrong

Quoted 5 lines · Janusz

I was able to run my virtual machine with this, but had very high cpu usage when something happen in it like booting system. once, my virtual machine hang and I couln't even get my mouse / keyboard back from qemu. When I did vga passthrough, I didn't get any video output, and cpu usage was also high. Tried it on 4.3

Which tree are you using? Is it kvm tree?
Could you please work on queue brancn on current kvm tree based on top commit 73917739334c6509: KVM: x86: fix SMI to halted VCPU.

Quoted 1 line

Hmm... interesting, this diff works on my box...

Forgot to say that i built my test env following the instructions on kvm-wiki:
http://www.linux-kvm.org/page/OVMF

My test script is attached, and i will try to build the env like yours as much
as possible...

Quoted 16 lines · Xiao Guangrong

Quoted 13 lines · Xiao Guangrong

Quoted 5 lines · Janusz

I was able to run my virtual machine with this, but had very high cpu usage when something happen in it like booting system. once, my virtual machine hang and I couln't even get my mouse / keyboard back from qemu. When I did vga passthrough, I didn't get any video output, and cpu usage was also high. Tried it on 4.3

Which tree are you using? Is it kvm tree?
Could you please work on queue brancn on current kvm tree based on top commit 73917739334c6509: KVM: x86: fix SMI to halted VCPU.

Quoted 5 lines

Quoted 1 line

Hmm... interesting, this diff works on my box...

Forgot to say that i built my test env following the instructions on kvm-wiki:
http://www.linux-kvm.org/page/OVMF

Wow! Someone actually cares about the whitepaper. Thank you. :)

Quoted 10 lines · Janusz

Quoted 6 lines

I was able to run my virtual machine with this, but had very high cpu usage when something happen in it like booting system. once, my virtual machine hang and I couln't even get my mouse / keyboard back from qemu. When I did vga passthrough, I didn't get any video output, and cpu usage
was also high. Tried it on 4.3

Quoted 5 lines

Which tree are you using? Is it kvm tree?
Could you please work on queue brancn on current kvm tree based on top commit 73917739334c6509: KVM: x86: fix SMI to halted VCPU.

Hmm... interesting, this diff works on my box...

Forgot to say that i built my test env following the instructions on kvm-wiki:
http://www.linux-kvm.org/page/OVMF

My test script is attached, and i will try to build the env like yours as much
as possible...

W dniu 14.10.2015 o 10:32, Xiao Guangrong pisze:

Quoted 19 lines · Xiao Guangrong

Quoted 10 lines · Janusz

Quoted 6 lines

I was able to run my virtual machine with this, but had very high cpu usage when something happen in it like booting system. once, my virtual machine hang and I couln't even get my mouse / keyboard back from qemu. When I did vga passthrough, I didn't get any video output, and cpu usage
was also high. Tried it on 4.3

Quoted 5 lines

Which tree are you using? Is it kvm tree?
Could you please work on queue brancn on current kvm tree based on top commit 73917739334c6509: KVM: x86: fix SMI to halted VCPU.

Hmm... interesting, this diff works on my box...

Quoted 7 lines

Forgot to say that i built my test env following the instructions on kvm-wiki:
http://www.linux-kvm.org/page/OVMF

My test script is attached, and i will try to build the env like yours as much
as possible...

I cloned git://git.kernel.org/pub/scm/virt/kvm/kvm.git 73917739334c6509 commit, but this is breaking my system...
Slim is not able to start i3, xdm is not killing X when I stop xdm, qemu is not able to start when I don't use option -nographic
log from qemu on that kernel version:
xcb_connection_has_error() returned true
No protocol specified
Could not initialize SDL(No available video device) - exiting

On main kernel branch I don't have those problems.

I tried to run with -nographic, and tried pc-i440fx-2.1 but the same problem as before, high cpu usage and no graphic on my GPU. I don't know if that will help by this is my log from option -global isa-debugcon.iobase=0x402 -debugcon file:fedora.ovmf.log:
https://bpaste.net/show/36c54dba68c2

Well, the bug may be not in KVM. When this bug happened, i saw OVMF only checked 1 CPU out, there is the log from OVMF's debug input:

Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCDs
Detect CPU count: 1

So that the startup code has been freed however the APs are still running,
i think that why we saw the vCPUs executed on unexpected address.

After digging into OVMF's code, i noticed that BSP CPU waits for APs for a fixed timer period, however, KVM recent changes require zap all mappings if CR0.CD is changed, that means the APs need more time to startup.

After following changes to OVMF, the bug is completely gone on my side:

UefiCpuPkg/CpuDxe/ApStartup.c +1 -1

@@ -454,7 +454,9 @@ StartApsStackless (
   //
   // Wait 100 milliseconds for APs to arrive at the ApEntryPoint routine
   //
-  MicroSecondDelay (100 * 1000);
+  MicroSecondDelay (10 * 100 * 1000);
 
   return EFI_SUCCESS;
 }

Janusz, could you please check this instead? You can switch to your previous kernel to do this test.

W dniu 15.10.2015 o 06:19, Xiao Guangrong pisze:

Quoted 41 lines

Well, the bug may be not in KVM. When this bug happened, i saw OVMF only checked 1 CPU out, there is the log from OVMF's debug input:

Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCDs
Detect CPU count: 1

So that the startup code has been freed however the APs are still running,
i think that why we saw the vCPUs executed on unexpected address.

After digging into OVMF's code, i noticed that BSP CPU waits for APs for a fixed timer period, however, KVM recent changes require zap all mappings if CR0.CD is changed, that means the APs need more time to startup.

After following changes to OVMF, the bug is completely gone on my side:

UefiCpuPkg/CpuDxe/ApStartup.c +1 -1

@@ -454,7 +454,9 @@ StartApsStackless (
    //
    // Wait 100 milliseconds for APs to arrive at the ApEntryPoint routine
    //
-  MicroSecondDelay (100 * 1000);
+  MicroSecondDelay (10 * 100 * 1000);
 
    return EFI_SUCCESS;
  }

Quoted 4 lines

Janusz, could you please check this instead? You can switch to your previous kernel to do this test.

Ok, now first time when I started VM I was able to start system successfully. When I turned it off and started it again, it restarted my vm at system boot couple of times. Sometimes I also get very high cpu usage for no reason. Also, I get less fps in GTA 5 than in kernel 4.1, I get something like 30-55, but on 4.1 I get all the time 60 fps. This is my new log: https://bpaste.net/show/61a122ad7fe5

Quoted 43 lines

W dniu 15.10.2015 o 06:19, Xiao Guangrong pisze:

Quoted 42 lines

Well, the bug may be not in KVM. When this bug happened, i saw OVMF only checked 1 CPU out, there is the log from OVMF's debug input:

Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCDs
Detect CPU count: 1

So that the startup code has been freed however the APs are still running,
i think that why we saw the vCPUs executed on unexpected address.

After digging into OVMF's code, i noticed that BSP CPU waits for APs for a fixed timer period, however, KVM recent changes require zap all mappings if CR0.CD is changed, that means the APs need more time to startup.

After following changes to OVMF, the bug is completely gone on my side:

UefiCpuPkg/CpuDxe/ApStartup.c +0 -0

@@ -454,7 +454,9 @@ StartApsStackless (
    //
    // Wait 100 milliseconds for APs to arrive at the ApEntryPoint

routine

    //

UefiCpuPkg/CpuDxe/ApStartup.c +1 -1

-  MicroSecondDelay (100 * 1000);
+  MicroSecondDelay (10 * 100 * 1000);
 
    return EFI_SUCCESS;
  }

Quoted 11 lines

Quoted 4 lines

Janusz, could you please check this instead? You can switch to your previous kernel to do this test.

Ok, now first time when I started VM I was able to start system successfully. When I turned it off and started it again, it restarted my vm at system boot couple of times. Sometimes I also get very high cpu usage for no reason. Also, I get less fps in GTA 5 than in kernel 4.1, I get something like 30-55, but on 4.1 I get all the time 60 fps. This is my new log: https://bpaste.net/show/61a122ad7fe5

Just confirm: the Qemu internal error did not appear any more, right?

W dniu 15.10.2015 o 08:41, Xiao Guangrong pisze:

Quoted 58 lines · Janusz

Quoted 54 lines

W dniu 15.10.2015 o 06:19, Xiao Guangrong pisze:

Quoted 42 lines

Well, the bug may be not in KVM. When this bug happened, i saw OVMF only checked 1 CPU out, there is the log from OVMF's debug input:

Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCDs
Detect CPU count: 1

So that the startup code has been freed however the APs are still running,
i think that why we saw the vCPUs executed on unexpected address.

After digging into OVMF's code, i noticed that BSP CPU waits for APs for a fixed timer period, however, KVM recent changes require zap all mappings if CR0.CD is changed, that means the APs need more time to startup.

After following changes to OVMF, the bug is completely gone on my side:

UefiCpuPkg/CpuDxe/ApStartup.c +0 -0

@@ -454,7 +454,9 @@ StartApsStackless (
     //
     // Wait 100 milliseconds for APs to arrive at the ApEntryPoint

routine

     //

UefiCpuPkg/CpuDxe/ApStartup.c +1 -1

-  MicroSecondDelay (100 * 1000);
+  MicroSecondDelay (10 * 100 * 1000);
 
     return EFI_SUCCESS;
   }

Quoted 4 lines

Janusz, could you please check this instead? You can switch to your previous kernel to do this test.

Ok, now first time when I started VM I was able to start system successfully. When I turned it off and started it again, it restarted my vm at system boot couple of times. Sometimes I also get very high cpu usage for no reason. Also, I get less fps in GTA 5 than in kernel 4.1, I get something like 30-55, but on 4.1 I get all the time 60 fps. This is my new log: https://bpaste.net/show/61a122ad7fe5

Quoted 1 line

Just confirm: the Qemu internal error did not appear any more, right?

Yes, when I reverted your first patch, switched to -vga std from -vga none and didn't passthrough my GPU (case when I got this internal error), vm started without problem. I even didn't get any VM restarts like with passthrough

Quoted 63 lines

W dniu 15.10.2015 o 08:41, Xiao Guangrong pisze:

Quoted 62 lines · Janusz

Quoted 58 lines

W dniu 15.10.2015 o 06:19, Xiao Guangrong pisze:

Quoted 43 lines

Well, the bug may be not in KVM. When this bug happened, i saw OVMF only checked 1 CPU out, there is the log from OVMF's debug input:

Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCDs
Detect CPU count: 1

So that the startup code has been freed however the APs are still running,
i think that why we saw the vCPUs executed on unexpected address.

After digging into OVMF's code, i noticed that BSP CPU waits for APs for a fixed timer period, however, KVM recent changes require zap all mappings if CR0.CD is changed, that means the APs need more time to startup.

After following changes to OVMF, the bug is completely gone on my side:

UefiCpuPkg/CpuDxe/ApStartup.c +0 -0

@@ -454,7 +454,9 @@ StartApsStackless (
     //
     // Wait 100 milliseconds for APs to arrive at the ApEntryPoint

routine

     //

UefiCpuPkg/CpuDxe/ApStartup.c +1 -1

-  MicroSecondDelay (100 * 1000);
+  MicroSecondDelay (10 * 100 * 1000);
 
     return EFI_SUCCESS;
   }

Quoted 4 lines

Janusz, could you please check this instead? You can switch to your previous kernel to do this test.

Ok, now first time when I started VM I was able to start system successfully. When I turned it off and started it again, it restarted my
vm at system boot couple of times. Sometimes I also get very high cpu usage for no reason. Also, I get less fps in GTA 5 than in kernel 4.1, I
get something like 30-55, but on 4.1 I get all the time 60 fps. This is
my new log: https://bpaste.net/show/61a122ad7fe5

Quoted 6 lines

Quoted 1 line

Just confirm: the Qemu internal error did not appear any more, right?

Yes, when I reverted your first patch, switched to -vga std from -vga none and didn't passthrough my GPU (case when I got this internal error), vm started without problem. I even didn't get any VM restarts like with passthrough

Wow, it seems we have fixed the QEMU internal error now. :)

Recurrently, Paolo has reverted some MTRR patches, was your test based on these reverted patches?

The GPU passthrough issue may be related to vfio (not sure), Alex, do you have any idea?

Laszlo, could you please check the root case is reasonable and fix it in OVMF if it's right?

BTW, OVMF handles #UD with no trace - nothing is killed, and no call trace
in the debug input...

Quoted 62 lines · Janusz

W dniu 15.10.2015 o 08:41, Xiao Guangrong pisze:

Quoted 61 lines · Janusz

Quoted 57 lines

W dniu 15.10.2015 o 06:19, Xiao Guangrong pisze:

Quoted 43 lines

Well, the bug may be not in KVM. When this bug happened, i saw OVMF only checked 1 CPU out, there is the log from OVMF's debug input:

Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCDs
Detect CPU count: 1

So that the startup code has been freed however the APs are still running,
i think that why we saw the vCPUs executed on unexpected address.

After digging into OVMF's code, i noticed that BSP CPU waits for APs for a fixed timer period, however, KVM recent changes require zap all mappings if CR0.CD is changed, that means the APs need more time to startup.

After following changes to OVMF, the bug is completely gone on my side:

UefiCpuPkg/CpuDxe/ApStartup.c +0 -0

@@ -454,7 +454,9 @@ StartApsStackless (
     //
     // Wait 100 milliseconds for APs to arrive at the ApEntryPoint

routine

     //

UefiCpuPkg/CpuDxe/ApStartup.c +1 -1

-  MicroSecondDelay (100 * 1000);
+  MicroSecondDelay (10 * 100 * 1000);
 
     return EFI_SUCCESS;
   }

Quoted 4 lines

Janusz, could you please check this instead? You can switch to your previous kernel to do this test.

Ok, now first time when I started VM I was able to start system successfully. When I turned it off and started it again, it restarted my
vm at system boot couple of times. Sometimes I also get very high cpu usage for no reason. Also, I get less fps in GTA 5 than in kernel 4.1, I
get something like 30-55, but on 4.1 I get all the time 60 fps. This is my new log: https://bpaste.net/show/61a122ad7fe5

Quoted 6 lines

Quoted 1 line

Just confirm: the Qemu internal error did not appear any more, right?

Yes, when I reverted your first patch, switched to -vga std from -vga none and didn't passthrough my GPU (case when I got this internal error), vm started without problem. I even didn't get any VM restarts like with passthrough

Wow, it seems we have fixed the QEMU internal error now. :)

Recurrently, Paolo has reverted some MTRR patches, was your test based on these reverted patches?

The GPU passthrough issue may be related to vfio (not sure), Alex, do you have any idea?

Laszlo, could you please check the root case is reasonable and fix it in OVMF if it's right?

BTW, OVMF handles #UD with no trace - nothing is killed, and no call trace in the debug input...

-----Original Message-----
From: edk2-devel [mailto:[email protected]] On Behalf Of Laszlo Ersek
Sent: Thursday, October 15, 2015 9:19 AM
To: Xiao Guangrong
Cc: [email protected]; Justen, Jordan L; [email protected]; Alex Williamson; Chen Fan; Paolo Bonzini; Wanpeng Li
Subject: Re: [edk2] KVM: MTRR: fix memory type handling if MTRR is completely disabled

CC'ing Jordan and Chen Fan.

Quoted 6 lines · Xiao Guangrong

Quoted 3 lines · Janusz

W dniu 15.10.2015 o 08:41, Xiao Guangrong pisze:

Quoted 2 lines

Quoted 6 lines

Quoted 6 lines

Quoted 6 lines · Janusz

Quoted 5 lines

W dniu 15.10.2015 o 06:19, Xiao Guangrong pisze:

Quoted 4 lines

Well, the bug may be not in KVM. When this bug happened, i saw

OVMF

Quoted 62 lines

Quoted 53 lines

Quoted 53 lines

Quoted 52 lines

Quoted 39 lines

only checked 1 CPU out, there is the log from OVMF's debug input:

Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCDs
Detect CPU count: 1

So that the startup code has been freed however the APs are still running,
i think that why we saw the vCPUs executed on unexpected address.

After digging into OVMF's code, i noticed that BSP CPU waits for APs for a fixed timer period, however, KVM recent changes require zap all mappings if CR0.CD is changed, that means the APs need more time to startup.

After following changes to OVMF, the bug is completely gone on my side:

UefiCpuPkg/CpuDxe/ApStartup.c +0 -0

@@ -454,7 +454,9 @@ StartApsStackless (
     //
     // Wait 100 milliseconds for APs to arrive at the ApEntryPoint

routine

     //

UefiCpuPkg/CpuDxe/ApStartup.c +1 -1

-  MicroSecondDelay (100 * 1000);
+  MicroSecondDelay (10 * 100 * 1000);
 
     return EFI_SUCCESS;
   }

Quoted 4 lines

Janusz, could you please check this instead? You can switch to your previous kernel to do this test.

Ok, now first time when I started VM I was able to start system successfully. When I turned it off and started it again, it restarted my
vm at system boot couple of times. Sometimes I also get very high cpu usage for no reason. Also, I get less fps in GTA 5 than in kernel 4.1, I
get something like 30-55, but on 4.1 I get all the time 60 fps. This is my new log: https://bpaste.net/show/61a122ad7fe5

Quoted 6 lines

Quoted 1 line

Just confirm: the Qemu internal error did not appear any more, right?

Yes, when I reverted your first patch, switched to -vga std from -vga none and didn't passthrough my GPU (case when I got this internal error), vm started without problem. I even didn't get any VM restarts like with passthrough

Wow, it seems we have fixed the QEMU internal error now. :)

Quoted 8 lines

Recurrently, Paolo has reverted some MTRR patches, was your test based on these reverted patches?

The GPU passthrough issue may be related to vfio (not sure), Alex, do you have any idea?

Laszlo, could you please check the root case is reasonable and fix it in OVMF if it's right?

The code that you have found is in edk2's EFI_MP_SERVICES_PROTOCOL implementation -- more closely, its initial CPU counter code --, from edk2 git commit 533263ee5a7f. It is not specific to OVMF -- it is generic edk2 code for Intel processors. (I'm CC'ing Jordan and Chen Fan because they authored the patch in question.)

If VCPUs need more time to rendezvous than written in the code, on recent KVM, then I think we should introduce a new FixedPCD in UefiCpuPkg (practically: a compile time constant) for the timeout. Which is not hard to do.

However, we'll need two things:
- an idea about the concrete rendezvous timeout to set, from OvmfPkg

- a *detailed* explanation / elaboration on your words:

"KVM recent changes require zap all mappings if CR0.CD is changed, that means the APs need more time to startup"

Preferably with references to Linux kernel commits and the Intel SDM, so that n00bs like me can get a fleeting idea. Do you mean that with caching disabled, the APs execute their rendezvous code (from memory) more slowly?

Quoted 2 lines

BTW, OVMF handles #UD with no trace - nothing is killed, and no call trace in the debug input...

There *is* a trace (of any unexpected exception -- at least for the BSP), but unfortunately its location is not intuitive.

The exception handler that is built into OVMF ("UefiCpuPkg/Library/CpuExceptionHandlerLib") is again generic edk2 code, and it prints the trace directly to the serial port, regardless of the fact that OVMF's DebugLib instance logs explicit DEBUGs to the QEMU debug port. (The latter can be directed to the serial port as well, if you build OVMF with -D DEBUG_ON_SERIAL_PORT, but this is not relevant here.)

If you reproduce the issue while looking at the (virtual) serial port of the guest, I trust you will get a register dump.

Thanks!
Laszlo
_______________________________________________
edk2-devel mailing list
[email protected]
https://lists.01.org/mailman/listinfo/edk2-devel

Laszlo,

There is already a PCD for this timeout that is used by CpuMpPei.

gUefiCpuPkgTokenSpaceGuid.PcdCpuApInitTimeOutInMicroSeconds

I noticed that CpuDxe is using a hard coded AP timeout. I think we should just use this same PCD for both the PEI and DXE CPU module and then set it for OVMF to the compatible value.

Mike

Quoted 144 lines

-----Original Message-----
From: edk2-devel [mailto:[email protected]] On Behalf Of Laszlo Ersek
Sent: Thursday, October 15, 2015 9:19 AM
To: Xiao Guangrong
Cc: [email protected]; Justen, Jordan L; [email protected]; Alex Williamson; Chen Fan; Paolo Bonzini; Wanpeng Li
Subject: Re: [edk2] KVM: MTRR: fix memory type handling if MTRR is completely disabled

CC'ing Jordan and Chen Fan.

Quoted 6 lines · Xiao Guangrong

Quoted 3 lines · Janusz

W dniu 15.10.2015 o 08:41, Xiao Guangrong pisze:

Quoted 2 lines

Quoted 6 lines

Quoted 6 lines

Quoted 6 lines · Janusz

Quoted 5 lines

W dniu 15.10.2015 o 06:19, Xiao Guangrong pisze:

Quoted 4 lines

Well, the bug may be not in KVM. When this bug happened, i saw

OVMF

Quoted 62 lines

Quoted 53 lines

Quoted 53 lines

Quoted 52 lines

Quoted 39 lines

only checked 1 CPU out, there is the log from OVMF's debug input:

Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCDs
Detect CPU count: 1

So that the startup code has been freed however the APs are still running,
i think that why we saw the vCPUs executed on unexpected address.

After digging into OVMF's code, i noticed that BSP CPU waits for APs for a fixed timer period, however, KVM recent changes require zap all mappings if CR0.CD is changed, that means the APs need more time to startup.

After following changes to OVMF, the bug is completely gone on my side:

UefiCpuPkg/CpuDxe/ApStartup.c +0 -0

@@ -454,7 +454,9 @@ StartApsStackless (
     //
     // Wait 100 milliseconds for APs to arrive at the ApEntryPoint

routine

     //

UefiCpuPkg/CpuDxe/ApStartup.c +1 -1

-  MicroSecondDelay (100 * 1000);
+  MicroSecondDelay (10 * 100 * 1000);
 
     return EFI_SUCCESS;
   }

Quoted 4 lines

Janusz, could you please check this instead? You can switch to your previous kernel to do this test.

Ok, now first time when I started VM I was able to start system successfully. When I turned it off and started it again, it restarted my
vm at system boot couple of times. Sometimes I also get very high cpu usage for no reason. Also, I get less fps in GTA 5 than in kernel 4.1, I
get something like 30-55, but on 4.1 I get all the time 60 fps. This is my new log: https://bpaste.net/show/61a122ad7fe5

Quoted 6 lines

Quoted 1 line

Just confirm: the Qemu internal error did not appear any more, right?

Yes, when I reverted your first patch, switched to -vga std from -vga none and didn't passthrough my GPU (case when I got this internal error), vm started without problem. I even didn't get any VM restarts like with passthrough

Wow, it seems we have fixed the QEMU internal error now. :)

Quoted 8 lines

Recurrently, Paolo has reverted some MTRR patches, was your test based on these reverted patches?

The GPU passthrough issue may be related to vfio (not sure), Alex, do you have any idea?

Laszlo, could you please check the root case is reasonable and fix it in OVMF if it's right?

The code that you have found is in edk2's EFI_MP_SERVICES_PROTOCOL implementation -- more closely, its initial CPU counter code --, from edk2 git commit 533263ee5a7f. It is not specific to OVMF -- it is generic edk2 code for Intel processors. (I'm CC'ing Jordan and Chen Fan because they authored the patch in question.)

If VCPUs need more time to rendezvous than written in the code, on recent KVM, then I think we should introduce a new FixedPCD in UefiCpuPkg (practically: a compile time constant) for the timeout. Which is not hard to do.

However, we'll need two things:
- an idea about the concrete rendezvous timeout to set, from OvmfPkg

- a *detailed* explanation / elaboration on your words:

"KVM recent changes require zap all mappings if CR0.CD is changed, that means the APs need more time to startup"

Preferably with references to Linux kernel commits and the Intel SDM, so that n00bs like me can get a fleeting idea. Do you mean that with caching disabled, the APs execute their rendezvous code (from memory) more slowly?

Quoted 2 lines

BTW, OVMF handles #UD with no trace - nothing is killed, and no call trace in the debug input...

There *is* a trace (of any unexpected exception -- at least for the BSP), but unfortunately its location is not intuitive.

The exception handler that is built into OVMF ("UefiCpuPkg/Library/CpuExceptionHandlerLib") is again generic edk2 code, and it prints the trace directly to the serial port, regardless of the fact that OVMF's DebugLib instance logs explicit DEBUGs to the QEMU debug port. (The latter can be directed to the serial port as well, if you build OVMF with -D DEBUG_ON_SERIAL_PORT, but this is not relevant here.)

If you reproduce the issue while looking at the (virtual) serial port of the guest, I trust you will get a register dump.

Thanks!
Laszlo
_______________________________________________
edk2-devel mailing list
[email protected]
https://lists.01.org/mailman/listinfo/edk2-devel

Quoted 7 lines

Laszlo,

There is already a PCD for this timeout that is used by CpuMpPei.

gUefiCpuPkgTokenSpaceGuid.PcdCpuApInitTimeOutInMicroSeconds

I noticed that CpuDxe is using a hard coded AP timeout. I think we should just use this same PCD for both the PEI and DXE CPU module and then set it for OVMF to the compatible value.

Perfect, thank you!

(I notice the default in the DEC file is 50000, which is half of what the DXE driver hardcodes.)

Now we only need a recommended (or experimental) value for it, and an explanation why 100*1000 is no longer sufficient on KVM :)

Thanks!
Laszlo

W dniu 15.10.2015 o 20:46, Laszlo Ersek pisze:

Quoted 10 lines · Michael D

Quoted 7 lines

Laszlo,

There is already a PCD for this timeout that is used by CpuMpPei.

gUefiCpuPkgTokenSpaceGuid.PcdCpuApInitTimeOutInMicroSeconds

I noticed that CpuDxe is using a hard coded AP timeout. I think we should just use this same PCD for both the PEI and DXE CPU module and then set it for OVMF to the compatible value.

Perfect, thank you!

Quoted 11 lines

(I notice the default in the DEC file is 50000, which is half of what the DXE driver hardcodes.)

Now we only need a recommended (or experimental) value for it, and an explanation why 100*1000 is no longer sufficient on KVM :)

Thanks!
Laszlo

Laszlo,

I saw that there is already some change in ovmf for MicroSecondDelay
https://github.com/tianocore/edk2/commit/1e410eadd80c328e66868263b3006a274ce81ae0
Is that a fix for it? Because I tried it and it still doesn't work for
me: https://bpaste.net/show/2514b51bf41f
I still get internal error

Hi,

Quoted 24 lines · Janusz

W dniu 15.10.2015 o 20:46, Laszlo Ersek pisze:

Quoted 10 lines · Michael D

Quoted 7 lines

Laszlo,

There is already a PCD for this timeout that is used by CpuMpPei.

gUefiCpuPkgTokenSpaceGuid.PcdCpuApInitTimeOutInMicroSeconds

I noticed that CpuDxe is using a hard coded AP timeout. I think we should just use this same PCD for both the PEI and DXE CPU module and then set it for OVMF to the compatible value.

Perfect, thank you!

Quoted 11 lines

(I notice the default in the DEC file is 50000, which is half of what the DXE driver hardcodes.)

Now we only need a recommended (or experimental) value for it, and an explanation why 100*1000 is no longer sufficient on KVM :)

Thanks!
Laszlo

Laszlo,

Quoted 5 lines

I saw that there is already some change in ovmf for MicroSecondDelay
https://github.com/tianocore/edk2/commit/1e410eadd80c328e66868263b3006a274ce81ae0
Is that a fix for it? Because I tried it and it still doesn't work for
me: https://bpaste.net/show/2514b51bf41f
I still get internal error

I think you guys are now "mature enough OVMF users" to start employing the correct terminology.

"edk2" (also spelled as "EDK II") is: "a modern, feature-rich, cross-platform firmware development environment for the UEFI and PI specifications".

The source tree contains a whole bunch of modules (drivers, applications, libraries), organized into packages.

"OVMF" usually denotes a firmware binary built from one of the OvmfPkg/OvmfPkg*.dsc "platform description files". Think of them as "top level makefiles". The difference between them is the target architecture (there's Ia32, X64, and Ia32X64 -- the last one means that the SEC and PEI phases are 32-bit, whereas the DXE and later phases are 64-bit.) In practice you'll only care about full X64.

Now, each of OvmfPkg/OvmfPkg*.dsc builds the following three kinds of modules into the final binary:
- platform-independent modules from various top-level packages
- platform- (ie. Ia32/X64-) dependent modules from various top-level packages
- modules from under OvmfPkg that are specific to QEMU/KVM (and Xen, if you happen to use OVMF with Xen)

Now, when you reference a commit like 1e410ead above, you can look at the diffstat, and decide if it is OvmfPkg-specific (third category above) or not. Here you see UefiCpuPkg, which happens to be the second category.

The important point is: please do *not* call any and all edk2 patches "OVMF changes", indiscriminately. That's super confusing for people who understand the above distinctions. Which now you do too. :)

Let me add that in edk2, patches that straddle top level packages are generally forbidden -- you can't have a patch that modifies OvmfPkg and UefiCpuPkg at the same time, modulo *very* rare exceptions. If a feature or bugfix needs to touch several top-level packages, the series must be built up carefully in stages.

Knowing all of the above, you can tell that the patch you referenced had only *enabled* OvmfPkg to customize UefiCpuPkg, via "PcdCpuApInitTimeOutInMicroSeconds". But for that customization to occur actually, a small patch for OvmfPkg will be necessary too, in order to set "PcdCpuApInitTimeOutInMicroSeconds" differently from the default.

I plan to send that patch soon. If you'd like to be CC'd, that's great (reporting back with a Tested-by is even better!), but I'll need your real name for that. (Or any name that looks like a real name.)

Thanks!
Laszlo

Quoted 85 lines · Laszlo Ersek

CC'ing Jordan and Chen Fan.

Quoted 82 lines · Xiao Guangrong

Quoted 64 lines · Janusz

W dniu 15.10.2015 o 08:41, Xiao Guangrong pisze:

Quoted 63 lines · Janusz

Quoted 59 lines

W dniu 15.10.2015 o 06:19, Xiao Guangrong pisze:

Quoted 44 lines

Well, the bug may be not in KVM. When this bug happened, i saw OVMF only checked 1 CPU out, there is the log from OVMF's debug input:

Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCD
Flushing GCDs
Detect CPU count: 1

So that the startup code has been freed however the APs are still running,
i think that why we saw the vCPUs executed on unexpected address.

After digging into OVMF's code, i noticed that BSP CPU waits for APs for a fixed timer period, however, KVM recent changes require zap all
mappings if CR0.CD is changed, that means the APs need more time to startup.

After following changes to OVMF, the bug is completely gone on my side:

UefiCpuPkg/CpuDxe/ApStartup.c +0 -0

@@ -454,7 +454,9 @@ StartApsStackless (
      //
      // Wait 100 milliseconds for APs to arrive at the ApEntryPoint

routine

      //

UefiCpuPkg/CpuDxe/ApStartup.c +1 -1

-  MicroSecondDelay (100 * 1000);
+  MicroSecondDelay (10 * 100 * 1000);
 
      return EFI_SUCCESS;
    }

Quoted 4 lines

Janusz, could you please check this instead? You can switch to your previous kernel to do this test.

Ok, now first time when I started VM I was able to start system successfully. When I turned it off and started it again, it restarted my
vm at system boot couple of times. Sometimes I also get very high cpu usage for no reason. Also, I get less fps in GTA 5 than in kernel 4.1, I
get something like 30-55, but on 4.1 I get all the time 60 fps. This is
my new log: https://bpaste.net/show/61a122ad7fe5

Quoted 6 lines

Quoted 1 line

Just confirm: the Qemu internal error did not appear any more, right?

Yes, when I reverted your first patch, switched to -vga std from -vga none and didn't passthrough my GPU (case when I got this internal error), vm started without problem. I even didn't get any VM restarts like with passthrough

Wow, it seems we have fixed the QEMU internal error now. :)

Recurrently, Paolo has reverted some MTRR patches, was your test based on these reverted patches?

The GPU passthrough issue may be related to vfio (not sure), Alex, do you have any idea?

Quoted 8 lines

Quoted 2 lines

Laszlo, could you please check the root case is reasonable and fix it in OVMF if it's right?

The code that you have found is in edk2's EFI_MP_SERVICES_PROTOCOL implementation -- more closely, its initial CPU counter code --, from edk2 git commit 533263ee5a7f. It is not specific to OVMF -- it is generic edk2 code for Intel processors. (I'm CC'ing Jordan and Chen Fan because they authored the patch in question.)

Okay, good to know it, i do not have much knowledge on edk2 and OVMF... :(

Quoted 11 lines

If VCPUs need more time to rendezvous than written in the code, on recent KVM, then I think we should introduce a new FixedPCD in UefiCpuPkg (practically: a compile time constant) for the timeout. Which is not hard to do.

However, we'll need two things:
- an idea about the concrete rendezvous timeout to set, from OvmfPkg

- a *detailed* explanation / elaboration on your words:

Quoted 7 lines

"KVM recent changes require zap all mappings if CR0.CD is changed, that means the APs need more time to startup"

Preferably with references to Linux kernel commits and the Intel SDM, so that n00bs like me can get a fleeting idea. Do you mean that with caching disabled, the APs execute their rendezvous code (from memory) more slowly?

Kernel commit b18d5431acc causes the vCPUs need more time to startup as:
- it zaps all the mappings for the guest memory in EPT or shadow page table, it requires VM-exits to rebuild the mappings for all memory access.

- if there is device passthrough-ed in guest and IOMMU lacks snooping control feature, the memory will become UC after CR0.CD is set to 1.

And a generic factor is, if the guest has more vCPUs then more time is needed. That why the bug is hardly triggered on small vCPUs guest. I guess we need a self-adapting way to handle the case...

Quoted 17 lines

Quoted 5 lines

BTW, OVMF handles #UD with no trace - nothing is killed, and no call trace
in the debug input...

There *is* a trace (of any unexpected exception -- at least for the BSP), but unfortunately its location is not intuitive.

The exception handler that is built into OVMF ("UefiCpuPkg/Library/CpuExceptionHandlerLib") is again generic edk2 code, and it prints the trace directly to the serial port, regardless of the fact that OVMF's DebugLib instance logs explicit DEBUGs to the QEMU debug port. (The latter can be directed to the serial port as well, if you build OVMF with -D DEBUG_ON_SERIAL_PORT, but this is not relevant here.)

Quoted 2 lines

If you reproduce the issue while looking at the (virtual) serial port of the guest, I trust you will get a register dump.

Er... it seems no dump in serial output, i attached it in this mail. The system
continues to run with 1 CPU enabled......

Thanks for your report and analysis, Janusz!

Quoted 26 lines · Janusz

W dniu 18.09.2015 o 12:07, Laszlo Ersek pisze:

Quoted 10 lines · Janusz

Quoted 9 lines

Hello,

I am writting about this patch that was posted by Xiao:
http://www.spinics.net/lists/kvm/msg119044.html and this:
http://www.spinics.net/lists/kvm/msg119045.html
I've tested both kernel 4.2 and 4.3 and problem still exists when I use
OVMF - 100% cpu usage, VM resetting, while it works properly on kernel 4.1

Quoted 3 lines

My last (still current) request remains "please quirk it". See the end of <http://thread.gmane.org/gmane.linux.kernel/1952205/focus=1996025>,
and other messages in that subthread.

when I saw message from Xiao that he posted patch for it and have seen this code in kernel sources (landed in 4.2-rc3) I though that the status is not "please quirk it" anymore

Quoted 9 lines

I haven't been following kernel development, so maybe the quirk has not happened. No clue.

... "VM resetting" looks something different though; I've been under the
impression that the pedantic (=unquirked) MTRR configuration didn't impact other things than speed. Janusz, maybe you could contribute with a host kernel bisection for the VM reset symptom.

Quoted 6 lines

To be more exact - VM is mostly not starting or its starting after long time and then resetting it self at random time (but before system boots) or gets very high cpu usage or sometimes boots without problem (the least possible case scenario). When I start VM with -vga std, not with my gpu passthrough - in most of the time I get this:
http://pastebin.com/raw.php?i=CKrNsueS

It seems the behaviour is different with previous (previously, it can boot
but slowly), right?

The URL cat not be accessed, i do not know it's your web server issue or our networking issue.

Quoted 54 lines

Result of bisect:

git bisect start
# bad: [d770e558e21961ad6cfdf0ff7df0eb5d7d4f0754] Linux 4.2-rc1 git bisect bad d770e558e21961ad6cfdf0ff7df0eb5d7d4f0754
# good: [b953c0d234bc72e8489d3bf51a276c5c4ec85345] Linux 4.1 git bisect good b953c0d234bc72e8489d3bf51a276c5c4ec85345
# good: [4570a37169d4b44d316f40b2ccc681dc93fedc7b] Merge tag 'sound-4.2-rc1' of
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
git bisect good 4570a37169d4b44d316f40b2ccc681dc93fedc7b
# good: [8d7804a2f03dbd34940fcb426450c730adf29dae] Merge tag 'driver-core-4.2-rc1' of
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
git bisect good 8d7804a2f03dbd34940fcb426450c730adf29dae
# bad: [78c10e556ed904d5bfbd71e9cadd8ce8f25d6982] Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
git bisect bad 78c10e556ed904d5bfbd71e9cadd8ce8f25d6982
# good: [623f0e137c0fedb81bbf3d88be4ed300eee163da] Staging: lustre: fix space before and after comma in dt_object.c
git bisect good 623f0e137c0fedb81bbf3d88be4ed300eee163da
# bad: [8c7febe83915332276cab49e89f6580bb963fb9a] Merge tag 'tty-4.2-rc1' of
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
git bisect bad 8c7febe83915332276cab49e89f6580bb963fb9a
# good: [bcf5b92d9bbf0b7683199615f0f184e89fa486bc] staging: rtl8192e:
Remove rt_hi_throughput::ChnkOp
git bisect good bcf5b92d9bbf0b7683199615f0f184e89fa486bc
# good: [71eec4836b834b992e0cefeefc8b85efe4cb185b] drivers: PL011: allow avoiding UART enabling/disabling
git bisect good 71eec4836b834b992e0cefeefc8b85efe4cb185b
# good: [49ef9c850154756cf2fbc50fd3804c44675d4633] staging: comedi:
me4000: rename 'thisboard' variables
git bisect good 49ef9c850154756cf2fbc50fd3804c44675d4633
# good: [2a4462418af771ef9f1f1d1532bcbb8799df842d] tty/serial: kill off set_irq_flags usage
git bisect good 2a4462418af771ef9f1f1d1532bcbb8799df842d
# good: [6d43b0f482561ab421a91ebf59a51192d66cf8a7] Staging: sm750fb:
ddk750_swi2c.c: Insert spaces around operators
git bisect good 6d43b0f482561ab421a91ebf59a51192d66cf8a7
# good: [84e1eb83d0b9e0969a59b6848d718eaf71e98fcb] MAINTAINERS: tty: add serial docs directory
git bisect good 84e1eb83d0b9e0969a59b6848d718eaf71e98fcb
# good: [53a20e9e378ecd52f0afa4b60f8f8c81b6f97c27] staging: wilc1000:
disable driver due to build warnings
git bisect good 53a20e9e378ecd52f0afa4b60f8f8c81b6f97c27
# good: [71206b9f8120eb513c621d4f31906577bb658df3] Doc:
serial-rs485.txt: update RS485 driver interface
git bisect good 71206b9f8120eb513c621d4f31906577bb658df3
# bad: [23908db413eccd77084b09c9b0a4451dfb0524c0] Merge tag 'staging-4.2-rc1' of
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
git bisect bad 23908db413eccd77084b09c9b0a4451dfb0524c0

Quoted 4 lines

# first bad commit: [23908db413eccd77084b09c9b0a4451dfb0524c0] Merge tag
'staging-4.2-rc1' of
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

The bad commit is:
commit 23908db413eccd77084b09c9b0a4451dfb0524c0
Merge: 8d7804a 53a20e9
Author: Linus Torvalds <[email protected]>
Date: Fri Jun 26 15:46:08 2015 -0700

Hard to find which one causes the real issue... but i will try to reproduce
it, could you please share your command line?

Hello,

I am writting about this patch that was posted by Xiao:
http://www.spinics.net/lists/kvm/msg119044.html and this:
http://www.spinics.net/lists/kvm/msg119045.html
I've tested both kernel 4.2 and 4.3 and problem still exists when I use OVMF - 100% cpu usage, VM resetting, while it works properly on kernel 4.1

Quoted 7 lines

Hello,

I am writting about this patch that was posted by Xiao:
http://www.spinics.net/lists/kvm/msg119044.html and this:
http://www.spinics.net/lists/kvm/msg119045.html
I've tested both kernel 4.2 and 4.3 and problem still exists when I use OVMF - 100% cpu usage, VM resetting, while it works properly on kernel 4.1

Is this an Intel or AMD CPU?

Paolo