On 3/9/20 7:15 PM, Nitesh Narayan Lal wrote: > There are following issues with the ioapic logical destination mode test: > > - A race condition that is triggered when the interrupt handler > ioapic_isr_86() is called at the same time by multiple vCPUs. Due to this > the g_isr_86 is not correctly incremented. To prevent this a spinlock is > added around ‘g_isr_86++’. > > - On older QEMU versions initial x2APIC ID is not set, that is why > the local APIC IDs of each vCPUs are not configured. Hence the logical > destination mode test fails/hangs. Adding ‘+x2apic’ to the qemu -cpu params > ensures that the local APICs are configured every time, irrespective of the > QEMU version. > > - With ‘-machine kernel_irqchip=split’ included in the ioapic test > test_ioapic_self_reconfigure() always fails and somehow leads to a state where > after submitting IOAPIC fixed delivery - logical destination mode request we > never receive an interrupt back. For now, the physical and logical destination > mode tests are moved above test_ioapic_self_reconfigure(). The above were the reasons which were causing the ioapic logical destination mode test to fail/hang. The previous discussion can be found at: https://lore.kernel.org/kvm/20191205151610.19299-1-thuth@xxxxxxxxxx/ Following is a test run with smp = 4 and -machine kernel_irqchip=split. [root@virtlab420 kvm-unit-tests]# git diff diff --git a/x86/unittests.cfg b/x86/unittests.cfg index d658bc8..348953b 100644 --- a/x86/unittests.cfg +++ b/x86/unittests.cfg @@ -46,7 +46,7 @@ timeout = 30 [ioapic] file = ioapic.flat smp = 4 -extra_params = -cpu qemu64,+x2apic +extra_params = -cpu qemu64,+x2apic -machine kernel_irqchip=split arch = x86_64 [cmpxchg8b] [root@virtlab420 kvm-unit-tests]# ./tests/ioapic BUILD_HEAD=83a3b429 timeout -k 1s --foreground 90s /usr/libexec/qemu-kvm -nodefaults -device pc-testdev -device isa-debug-exit,iobase=0xf4,iosize=0x4 -vnc none -serial stdio -device pci-testdev -machine accel=kvm -kernel /tmp/tmp.cS40xFvt0U -smp 4 -cpu qemu64,+x2apic -machine kernel_irqchip=split # -initrd /tmp/tmp.69rw56TppH enabling apic enabling apic enabling apic enabling apic paging enabled cr0 = 80010011 cr3 = 61d000 cr4 = 20 x2apic enabled PASS: version register read only test PASS: id register only bits [24:27] writable PASS: arbitration register set by id PASS: arbtration register read only PASS: edge triggered intr PASS: level triggered intr PASS: ioapic simultaneous edge interrupts PASS: coalesce simultaneous level interrupts PASS: sequential level interrupts PASS: retriggered level interrupts without masking PASS: masked level interrupt PASS: unmasked level interrupt PASS: masked level interrupt PASS: unmasked level interrupt PASS: retriggered level interrupts with mask PASS: TMR for ioapic edge interrupts (expected false) PASS: TMR for ioapic level interrupts (expected false) PASS: TMR for ioapic level interrupts (expected true) PASS: TMR for ioapic edge interrupts (expected true) PASS: ioapic physical destination mode PASS: ioapic logical destination mode 1012375 iterations before interrupt received PASS: TMR for ioapic edge interrupts (expected false) 832021 iterations before interrupt received PASS: TMR for ioapic level interrupts (expected false) 1009498 iterations before interrupt received PASS: TMR for ioapic level interrupts (expected true) 994532 iterations before interrupt received PASS: TMR for ioapic edge interrupts (expected true) FAIL: Reconfigure self SUMMARY: 26 tests, 1 unexpected failures FAIL ioapic (26 tests, 1 unexpected failures) Please let me know if there are any more suggestions/comments. [...] -- Nitesh
