Re: [PATCH v11 0/7] Support x2APIC mode with TCG accelerator

[Bui Quang Minh]

On 12/28/23 22:44, Bui Quang Minh wrote:
> On 12/26/23 16:21, Michael S. Tsirkin wrote:
> > On Mon, Dec 25, 2023 at 11:40:54PM +0700, Bui Quang Minh wrote:
> > > Hi everyone,
> > >
> > > This series implements x2APIC mode in userspace local APIC and the
> > > RDMSR/WRMSR helper to access x2APIC registers in x2APIC mode. Intel 
> > > iommu
> > > and AMD iommu are adjusted to support x2APIC interrupt remapping. 
> > > With this
> > > series, we can now boot Linux kernel into x2APIC mode with TCG 
> > > accelerator
> > > using either Intel or AMD iommu.
> > >
> > > Testing to boot my own built Linux 6.3.0-rc2, the kernel successfully 
> > > boot
> > > with enabled x2APIC and can enumerate CPU with APIC ID 257
> > >
> > > Using Intel IOMMU
> > >
> > > qemu/build/qemu-system-x86_64 \
> > >    -smp 2,maxcpus=260 \
> > >    -cpu qemu64,x2apic=on \
> > >    -machine q35 \
> > >    -device intel-iommu,intremap=on,eim=on \
> > >    -device 
> > > qemu64-x86_64-cpu,x2apic=on,core-id=257,socket-id=0,thread-id=0 \
> > >    -m 2G \
> > >    -kernel $KERNEL_DIR \
> > >    -append "nokaslr console=ttyS0 root=/dev/sda earlyprintk=serial 
> > > net.ifnames=0" \
> > >    -drive file=$IMAGE_DIR,format=raw \
> > >    -nographic \
> > >    -s
> > >
> > > Using AMD IOMMU
> > >
> > > qemu/build/qemu-system-x86_64 \
> > >    -smp 2,maxcpus=260 \
> > >    -cpu qemu64,x2apic=on \
> > >    -machine q35 \
> > >    -device amd-iommu,intremap=on,xtsup=on \
> > >    -device 
> > > qemu64-x86_64-cpu,x2apic=on,core-id=257,socket-id=0,thread-id=0 \
> > >    -m 2G \
> > >    -kernel $KERNEL_DIR \
> > >    -append "nokaslr console=ttyS0 root=/dev/sda earlyprintk=serial 
> > > net.ifnames=0" \
> > >    -drive file=$IMAGE_DIR,format=raw \
> > >    -nographic \
> > >    -s
> > >
> > > Testing the emulated userspace APIC with kvm-unit-tests, disable test
> > > device with this patch
> >
> > Seems to break build for windows/amd64
> > https://gitlab.com/mstredhat/qemu/-/pipelines/1118886361/failures
>
> I saw the CI test "pages" failed too. On my CI, most of the time, it 
> failed with
>
> $ htags -anT --tree-view=filetree -m qemu_init -t "Welcome to the QEMU 
> sourcecode"
> 00:24
> htags: Negative exec line limit = -8099
>
> It only succeeded once. I could not reproduce locally. Do you have any 
> ideas what the problem is?

I think I briefly understand why pages test fails. Internally, htags 
call global to parse the output of gtags. When executing command, it 
expects the size of argv and env to 20*1024 
(https://github.com/harai/gnu-global/blob/f86ba74d867385353815f8656c4a6cf4029c1f0b/libutil/xargs.c#L92-L105). 
The failed test case only happens when the last commit is patch 7 (test: 
bios-tables-test: add IVRS changed binary) which has a very long commit 
message (around 9000 bytes). By default, Gitlab appends some environment 
variables to the runner and one of them is CI_COMMIT_MESSAGE which 
contains the long commit message. So it exceeds the limit of 20*1024 
bytes and fails.

In my opinion, this failed test is not so critical and seems unrelated 
to the series so I skip this failed test. I will post the new version to 
fix the windows/amd64 build soon.

Thanks,
Quang Minh.