Add -kernel_irqchip=split
./x86-run x86/eventinj.flat
qemu-system-x86_64 -enable-kvm -machine kernel_irqchip=split -cpu host
-device pc-testdev -device isa-debug-exit,iobase=0xf4,iosize=0x4 -vnc
none -serial stdio -device pci-testdev -kernel x86/eventinj.flat
enabling apic
paging enabled
cr0 = 80010011
cr3 = 7fff000
cr4 = 20
Sending vec 33 and 62 and mask one with TPR
irq1 running
irq1 running
After 33/62 TPR test
FAIL: TPR
irq0 running
irq0 running
Both irq1 and irq0 are executing twice.
kvm_entry: vcpu 0
kvm_exit: reason MSR_WRITE rip 0x401f33 info 0 0
kvm_apic: apic_write APIC_EOI = 0x0
kvm_eoi: apicid 0 vector 62
kvm_msr: msr_write 80b = 0x0
kvm_entry: vcpu 0
kvm_exit: reason PENDING_INTERRUPT rip 0x401f35 info 0 0
kvm_userspace_exit: reason KVM_EXIT_IRQ_WINDOW_OPEN (7)
kvm_inj_virq: irq 62
kvm_entry: vcpu 0
kvm_exit: reason IO_INSTRUCTION rip 0x4016ec info 3fd0008 0
From the trace we can see there is an interrupt window exit
after the first interrupt EOI(irq 62), and the same irq(62)
is injected duplicately after the interrupt window.
QEMU does KVM_INTERRUPT(62) ioctl after KVM exits with
KVM_EXIT_IRQ_WINDOW_OPEN, which QEMU requested while the
guest was printing. The printing calls
serial_update_irq() -> qemu_irq_lower() -> qemu_set_irq() ->
gsi_handler() -> qemu_set_irq() -> pic_irq_request() ->
apic_deliver_pic_intr() -> kvm_handle_interrupt()
kvm_handle_interrupt() does
interrupt_request |= CPU_INTERRUPT_HARD
which later calls cpu_get_pic_interrupt() in kvm_arch_pre_run(),
but that function uses stale information from APIC and injects
62 again. If we synchronized the APIC, then the test would #GP,
because there would be no injectable interrupt in LAPIC or PIC,
so pic_read_irq() would return 15, thinking it was spurious.
This patch fix it by don't touch LAPIC if LAPIC is in kernel.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Suggested-by: Radim Krčmář <rkrcmar@redhat.com>
Cc: qemu-stable@nongnu.org
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Message-Id: <1473832464-3478-1-git-send-email-wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
QEMU README
===========
QEMU is a generic and open source machine & userspace emulator and
virtualizer.
QEMU is capable of emulating a complete machine in software without any
need for hardware virtualization support. By using dynamic translation,
it achieves very good performance. QEMU can also integrate with the Xen
and KVM hypervisors to provide emulated hardware while allowing the
hypervisor to manage the CPU. With hypervisor support, QEMU can achieve
near native performance for CPUs. When QEMU emulates CPUs directly it is
capable of running operating systems made for one machine (e.g. an ARMv7
board) on a different machine (e.g. an x86_64 PC board).
QEMU is also capable of providing userspace API virtualization for Linux
and BSD kernel interfaces. This allows binaries compiled against one
architecture ABI (e.g. the Linux PPC64 ABI) to be run on a host using a
different architecture ABI (e.g. the Linux x86_64 ABI). This does not
involve any hardware emulation, simply CPU and syscall emulation.
QEMU aims to fit into a variety of use cases. It can be invoked directly
by users wishing to have full control over its behaviour and settings.
It also aims to facilitate integration into higher level management
layers, by providing a stable command line interface and monitor API.
It is commonly invoked indirectly via the libvirt library when using
open source applications such as oVirt, OpenStack and virt-manager.
QEMU as a whole is released under the GNU General Public License,
version 2. For full licensing details, consult the LICENSE file.
Building
========
QEMU is multi-platform software intended to be buildable on all modern
Linux platforms, OS-X, Win32 (via the Mingw64 toolchain) and a variety
of other UNIX targets. The simple steps to build QEMU are:
mkdir build
cd build
../configure
make
Complete details of the process for building and configuring QEMU for
all supported host platforms can be found in the qemu-tech.html file.
Additional information can also be found online via the QEMU website:
http://qemu-project.org/Hosts/Linux
http://qemu-project.org/Hosts/W32
Submitting patches
==================
The QEMU source code is maintained under the GIT version control system.
git clone git://git.qemu-project.org/qemu.git
When submitting patches, the preferred approach is to use 'git
format-patch' and/or 'git send-email' to format & send the mail to the
qemu-devel@nongnu.org mailing list. All patches submitted must contain
a 'Signed-off-by' line from the author. Patches should follow the
guidelines set out in the HACKING and CODING_STYLE files.
Additional information on submitting patches can be found online via
the QEMU website
http://qemu-project.org/Contribute/SubmitAPatch
http://qemu-project.org/Contribute/TrivialPatches
Bug reporting
=============
The QEMU project uses Launchpad as its primary upstream bug tracker. Bugs
found when running code built from QEMU git or upstream released sources
should be reported via:
https://bugs.launchpad.net/qemu/
If using QEMU via an operating system vendor pre-built binary package, it
is preferable to report bugs to the vendor's own bug tracker first. If
the bug is also known to affect latest upstream code, it can also be
reported via launchpad.
For additional information on bug reporting consult:
http://qemu-project.org/Contribute/ReportABug
Contact
=======
The QEMU community can be contacted in a number of ways, with the two
main methods being email and IRC
- qemu-devel@nongnu.org
http://lists.nongnu.org/mailman/listinfo/qemu-devel
- #qemu on irc.oftc.net
Information on additional methods of contacting the community can be
found online via the QEMU website:
http://qemu-project.org/Contribute/StartHere
-- End