** Description changed:
- Issue found on B-ibm-gt-4.15.0-1116.127
+ [Impact]
+ rdpru test in ubuntu_kvm_unit_tests is to check if the RDPRU instruction can
be intercepted by the Hypervisor.
+
+ RDPRU is one of the new instruction set extensions of AMD "Zen 2" CPUs
+ that is for reading a processor register that is typically limited to
+ privilege level zero. RDPRU allows for reading select registers at any
+ privilege level. With Linux 5.5, the RDPRU presence will be advertised
+ by the CPU features.
+
+ Without this patchset, the rdpru test will fail on our AMD Zen 2 system
+ "riccioli"
+
+ [Fix]
+ * 9d40b85b x86/cpufeatures: Add feature bit RDPRU on AMD
+ * 0cb8410b kvm: svm: Intercept RDPRU
+
+ We have these patches in newer releases already, only Bionic 4.15
+ require this fix. And they can be cherry-picked without any conflict.
+
+ [Test]
+ With the patched kernel, this rdpru test will pass on the target AMD Zen 2
system.
+
+ And the rdpru flag will be available in cpuinfo:
+ flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat
pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm
constant_tsc rep_good nopl xtopology nonstop_tsc cpuid extd_apicid aperfmperf
pni pclmulqdq monitor ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt aes
xsave avx f16c rdrand lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a
misalignsse 3dnowprefetch osvw ibs skinit wdt tce topoext perfctr_core
perfctr_nb bpext perfctr_llc mwaitx cpb cat_l3 cdp_l3 invpcid_single hw_pstate
ssbd ibrs ibpb stibp vmmcall fsgsbase bmi1 avx2 smep bmi2 erms invpcid cqm
rdt_a rdseed adx smap clflushopt clwb sha_ni xsaveopt xsavec xgetbv1 xsaves
cqm_llc cqm_occup_llc cqm_mbm_total cqm_mbm_local clzero irperf xsaveerptr
rdpru arat npt lbrv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid
decodeassists pausefilter pfthreshold v_vmsave_vmload vgif umip pku ospke vaes
vpclmulqdq rdpid overflow_recov succor smca
+ bugs : sysret_ss_attrs spectre_v1 spectre_v2 spec_store_bypass
+
+ $ sudo ./rdpru
+ BUILD_HEAD=16647354
+ timeout -k 1s --foreground 90s /usr/bin/qemu-system-x86_64 --no-reboot
-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.syc17ecDpN -smp 1 -cpu max # -initrd /tmp/tmp.poLG53JqrJ
+ enabling apic
+ PASS: RDPRU raises #UD
+ SUMMARY: 1 tests
+ PASS rdpru (1 tests)
+
+ [Where problems could occur]
+ This patchset will add a new feature bit RDPRU, the impact should be small as
it's still up to user-space for making use of it.
+
+ [Original Bug Report]
+ Issue found on B-ibm-gt-4.15.0-1116.127
This can be reproduced with B-4.15.0-175 as well.
This failure is only visible on this node.
Running
'/home/ubuntu/autotest/client/tmp/ubuntu_kvm_unit_tests/src/kvm-unit-tests/tests/rdpru'
BUILD_HEAD=16647354
timeout -k 1s --foreground 90s /usr/bin/qemu-system-x86_64 --no-reboot
-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.qGIR5tvTw1 -smp 1 -cpu max # -initrd /tmp/tmp.8JuYRCFRUi
enabling apic
FAIL: RDPRU raises #UD
SUMMARY: 1 tests, 1 unexpected failures
FAIL rdpru (1 tests, 1 unexpected failures)
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https://bugs.launchpad.net/bugs/1968681
Title:
rdpru in ubuntu_kvm_unit_tests failed on B-4.15 node riccioli with
FAIL: RDPRU raises #UD
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