This series add support for SPE(Statistical Profiling Extension)[1] in KVM guest. It's based on Andrew Murray's kernel KVM patches V2[2], and has been tested to ensure that guest can use SPE with valid data. E.g.
In host: $ ./qemu-system-aarch64 \ -cpu host -M virt,accel=kvm,gic-version=3 -nographic -m 2048M \ -kernel ./Image-new \ -initrd /boot/initrd.img-5.6.0-rc2+ \ -append "root=/dev/vda rw console=ttyAMA0" -nodefaults -serial stdio\ -drive if=none,file=./xenial.rootfs.ext4,id=hd0,format=raw \ -device virtio-blk-device,drive=hd0 \ In guest: $ perf record -e arm_spe/ts_enable=1,pa_enable=1,pct_enable=1/ \ dd if=/dev/zero of=/dev/null count=1000 $ perf report --dump-raw-trace > spe_buf.txt The spe_buf.txt should contain similar data as below: . ... ARM SPE data: size 135944 bytes . 00000000: b0 f4 d3 29 10 00 80 ff a0 PC 0xff80001029d3f4 el1 ns=1 . 00000009: 99 0b 00 LAT 11 ISSUE . 0000000c: 98 0d 00 LAT 13 TOT . 0000000f: 52 16 00 EV RETIRED L1D-ACCESS TLB-ACCESS . 00000012: 49 00 LD . 00000014: b2 d0 40 d8 70 00 00 ff 00 VA 0xff000070d840d0 . 0000001d: 9a 01 00 LAT 1 XLAT . 00000020: 00 00 00 PAD . 00000023: 71 a5 1f b3 20 14 00 00 00 TS 86447955877 . 0000002c: b0 7c f9 29 10 00 80 ff a0 PC 0xff80001029f97c el1 ns=1 . 00000035: 99 02 00 LAT 2 ISSUE . 00000038: 98 03 00 LAT 3 TOT . 0000003b: 52 02 00 EV RETIRED . 0000003e: 48 00 INSN-OTHER . 00000040: 00 00 00 PAD . 00000043: 71 ef 1f b3 20 14 00 00 00 TS 86447955951 . 0000004c: b0 f0 e9 29 10 00 80 ff a0 PC 0xff80001029e9f0 el1 ns=1 . 00000055: 99 02 00 LAT 2 ISSUE . 00000058: 98 03 00 LAT 3 TOT . 0000005b: 52 02 00 EV RETIRED If you want to disable the vSPE support, you can use the 'spe=off' cpu property: ./qemu-system-aarch64 \ -cpu host,spe=off -M virt,accel=kvm,gic-version=3 -nographic -m 2048M \ -kernel ./Image-new \ -initrd /boot/initrd.img-5.6.0-rc2+ \ -append "root=/dev/vda rw console=ttyAMA0" -nodefaults -serial stdio\ -drive if=none,file=./xenial.rootfs.ext4,id=hd0,format=raw \ -device virtio-blk-device,drive=hd0 \ Note: (1) Since the kernel patches are still under review, some of the macros in the header files may be changed after merging. We may need to update them accordingly. (2) These patches only add vSPE support in KVM mode, for TCG mode, I'm not sure whether we need to support it. (3) Just followed the 'pmu' property, we only allow this feature to be removed from CPUs which enable it by default. But since the SPE is an optional feature extension for Armv8.2, I think a better way may be to disable it by default, and only enable it when the host cpu do have the feature. [1]https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/ posts/statistical-profiling-extension-for-armv8-a [2]https://www.spinics.net/lists/arm-kernel/msg776228.html Haibo Xu (7): update Linux headers with new vSPE macros target/arm/kvm: spe: Add helper to detect SPE when using KVM target/arm/cpu: spe: Add an option to turn on/off vSPE support target/arm/kvm: spe: Unify device attr operatioin helper target/arm/kvm: spe: Add device init and set_irq operations hw/arm/virt: spe: Add SPE fdt binding for virt machine target/arm/cpu: spe: Enable spe to work with host cpu hw/arm/virt-acpi-build.c | 3 +++ hw/arm/virt.c | 42 ++++++++++++++++++++++++++++++ include/hw/acpi/acpi-defs.h | 1 + include/hw/arm/virt.h | 1 + linux-headers/asm-arm64/kvm.h | 4 +++ linux-headers/linux/kvm.h | 2 ++ target/arm/cpu.c | 34 +++++++++++++++++++++++++ target/arm/cpu.h | 5 ++++ target/arm/kvm.c | 11 ++++++++ target/arm/kvm64.c | 48 ++++++++++++++++++++++++++++++++--- target/arm/kvm_arm.h | 18 +++++++++++++ 11 files changed, 166 insertions(+), 3 deletions(-) -- 2.17.1