Seeing a problem in multi hw thread runs where memory mapped pcie device register reads are returning incorrect values using QEMU 4.2
Background == I have a test environment which runs QEMU 4.2 with a plugin that runs two copies of a PCIE device simulator on Ubuntu 18.04/CentOS 7.5 host and with an Ubuntu 18.04 guest. When running with a single QEMU hw thread/CPU using: -cpu kvm64,+lahf_lm -M q35,kernel-irqchip=off -device intel-iommu,intremap=on Our tests run fine. But when running with multiple hw threads/cpu's: 2 cores 1 thread per core (2 hw threads/cpus): -cpu kvm64,+lahf_lm -M q35,kernel-irqchip=off -device intel-iommu,intremap=on -smp 2,sockets=1,cores=2 1 core, t threads per core (2 hw threads/cpus) -cpu kvm64,+lahf_lm -M q35,kernel-irqchip=off -device intel-iommu,intremap=on -smp 2,sockets=1,cores=1 2 cores, 2 threads per core (4 hw threads/cpus): -cpu kvm64,+lahf_lm -M q35,kernel-irqchip=off -device intel-iommu,intremap=on -smp 4,sockets=1,cores=2 The values retuned are correct all the way up the call stack and in KVM_EXIT_MMIO in kvm_cpu_exec (qemu-4.2.0/accel/kvm/kvm-all.c:2365) but the value returned to the device driver which initiated the read is 0. I'm currently testing this issue on Ubuntu 18.04.4 LTS Kernel: 4.15.0-108-generic KVM Version: 1:2.11+dfsg-1ubuntu7.28 And: CentOS: 7.5.1804 Kernel 4.14.78-7.x86_64 KVM Version : 1.5.3 Seeing the same issues in both cases. Questions = I have the following questions: Is anyone else running QEMU 4.2 in multi hw thread/cpu mode? Is anyone getting incorrect reads from memory mapped device registers when running in this mode? Does anyone have any pointers on how best to debug the flow from KVM_EXIT_MMIO back to the device driver running on the guest
RE: Seeing a problem in multi cpu runs where memory mapped pcie device register reads are returning incorrect values
From: Mark Wood-Patrick Sent: Wednesday, July 1, 2020 11:26 AM To: qemu-devel@nongnu.org Cc: Mark Wood-Patrick Subject: Seeing a problem in multi cpu runs where memory mapped pcie device register reads are returning incorrect values Background I have a test environment which runs QEMU 4.2 with a plugin that runs two copies of a PCIE device simulator on a CentOS 7.5 host with an Ubuntu 18.04 guest. When running with a single QEMU CPU using: -cpu kvm64,+lahf_lm -M q35,kernel-irqchip=off -device intel-iommu,intremap=on Our tests run fine. But when running with multiple cpu's: -cpu kvm64,+lahf_lm -M q35,kernel-irqchip=off -device intel-iommu,intremap=on -smp 2,sockets=1,cores=2 The values retuned are correct all the way up the call stack and in KVM_EXIT_MMIO in kvm_cpu_exec (qemu-4.2.0/accel/kvm/kvm-all.c:2365) but the value returned to the device driver which initiated the read is 0. Question Is anyone else running QEMU 4.2 in multi cpu mode? Is anyone getting incorrect reads from memory mapped device registers when running in this mode? I would appreciate any pointers on how best to debug the flow from KVM_EXIT_MMIO back to the device driver running on the guest
Seeing a problem in multi cpu runs where memory mapped pcie device register reads are returning incorrect values
Background I have a test environment which runs QEMU 4.2 with a plugin that runs two copies of a PCIE device simulator on a CentOS 7.5 host with an Ubuntu 18.04 guest. When running with a single QEMU CPU using: -cpu kvm64,+lahf_lm -M q35,kernel-irqchip=off -device intel-iommu,intremap=on Our tests run fine. But when running with multiple cpu's: -cpu kvm64,+lahf_lm -M q35,kernel-irqchip=off -device intel-iommu,intremap=on -smp 2,sockets=1,cores=2 The values retuned are correct all the way up the call stack and in KVM_EXIT_MMIO in kvm_cpu_exec (qemu-4.2.0/accel/kvm/kvm-all.c:2365) but the value returned to the device driver which initiated the read is 0. Question Is anyone else running QEMU 4.2 in multi cpu mode? Is anyone getting incorrect reads from memory mapped device registers when running in this mode? I would appreciate any pointers on how best to debug the flow from KVM_EXIT_MMIO back to the device driver running on the guest
[Qemu-devel] [Bug 1298442] [NEW] build problem in qemu-2.0.0-rc0 No rule to make target `trace/generated-events.h'
Public bug reported: With qemu-2.0.0-rc0 on CentOS release 5.7 (Final) I get make: *** No rule to make target `trace/generated-events.h', needed by `Makefile'. Stop. ** Affects: qemu Importance: Undecided Status: New -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1298442 Title: build problem in qemu-2.0.0-rc0 No rule to make target `trace /generated-events.h' Status in QEMU: New Bug description: With qemu-2.0.0-rc0 on CentOS release 5.7 (Final) I get make: *** No rule to make target `trace/generated-events.h', needed by `Makefile'. Stop. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1298442/+subscriptions
