On Mon, 31 Aug 2020 at 15:56, Auger Eric <eric.au...@redhat.com> wrote: > > Hi Haibo, > > On 8/7/20 10:10 AM, Haibo Xu wrote: > > 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. > to be more explicit one needs to replace on the kernel 5.5-rc2 based series > > -#define KVM_CAP_ARM_SPE_V1 179 > +#define KVM_CAP_ARM_SPE_V1 184 > > I got misleaded ;-) > > + Andrew in CC as he contributed the kernel part. > > For information, I have been working on a kvm unit test series for > testing SPE. I will send an RFC, most probably this week. At the moment > I still face some weirdness such as some unexpected Service state in the > syndrome register. Anyway I will share the existing code so that we can > discuss the issues. > > Are there any plans to respin the kernel series > > Thanks > > Eric >
Hi Eric, Thanks for elaborating on the above macro definition! The next version of the kernel series are supposed to be sent out in mid-September, and it should not change so much except for some macro definitions. Regards, Haibo > > (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(-) > > >
