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

["Michael S. Tsirkin" <mst@redhat.com>]

On Sat, Jan 06, 2024 at 11:33:29PM +0700, Bui Quang Minh wrote:
> 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.


Thanks for debugging this!
So I think we should clear CI_COMMIT_MESSAGE when invoking htags, right?


> In my opinion, this failed test is not so critical and seems unrelated to
> the series so I skip this failed test.

Yes ok to ignore. But even better if we also add a workaround.

> I will post the new version to fix
> the windows/amd64 build soon.
> 
> Thanks,
> Quang Minh.