------- Comment From boris.m...@de.ibm.com 2022-11-08 05:32 EDT------- Fix is upstream available: Upstream-ID: c3f0e5fd2d33d80c5a5a8b5e5d2bab2841709cc8 Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c3f0e5fd2d33d80c5a5a8b5e5d2bab2841709cc8
-- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1995941 Title: [UBUNTU 20.04] KVM: PV: ext call delivered twice when receiver in PSW wait Status in linux package in Ubuntu: New Bug description: Description: KVM: PV: ext call delivered twice when receiver in PSW wait Symptom: In a secure execution guest, the external interrupt for the SIGP external call order is delivered twice to a VCPU even though it was only sent once. Problem: Under PV, external call interrupts are delivered by the SIGP interpretation facility, without KVM's involvement. But, if the receiving CPU is in enabled wait, KVM needs to wake the receiving CPU such that the interrupt can be delivered. Hence, in this case, the SIGP external call order causes an interception. In response, KVM only needs to wake the receiving VCPU. Interrupt delivery is then handled by the SIGP interpretation facility. KVM wrongfuly assumed it also needs to request injection for the external call interrupt after the respective intercept, causing the interrupt to be delivered twice: once through the SIGP interpretation facility and once through the interrupt injection control by KVM. Solution: Add appropriate special handling for 108 external call intercepts. Reproduction: 0. Apply kvm-unit-test submitted upstream ("[kvm-unit-tests PATCH v1 0/4] s390x: add tests for SIGP call orders in enabled wait"). 1. Run the smp_PV kvm-unit-test: ./run_tests.sh smp_PV 2. Check logs/smp_PV.log. If system is affected, the following line can be found: ABORT: smp: psw wait: ecall: Unexpected external call \ interrupt (code 0x1202): on cpu 1 at 0x11958 If the system is not affected, the line should look like this: PASS: smp: psw wait: ecall: received Preventive: yes Author: Nico Boehr <n...@linux.ibm.com> Component: kernel To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1995941/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
