# git rev-parse -q --verify 3c25ab35fbc8526ac0c9b298e8a78e7ad7a55479^{commit} 3c25ab35fbc8526ac0c9b298e8a78e7ad7a55479 already have revision, skipping fetch # git checkout -q -f -B kisskb 3c25ab35fbc8526ac0c9b298e8a78e7ad7a55479 # git clean -qxdf # < git log -1 # commit 3c25ab35fbc8526ac0c9b298e8a78e7ad7a55479 # Author: Suraj Jitindar Singh # Date: Thu Jun 20 11:46:51 2019 +1000 # # KVM: PPC: Book3S HV: Clear pending decrementer exceptions on nested guest entry # # If we enter an L1 guest with a pending decrementer exception then this # is cleared on guest exit if the guest has writtien a positive value # into the decrementer (indicating that it handled the decrementer # exception) since there is no other way to detect that the guest has # handled the pending exception and that it should be dequeued. In the # event that the L1 guest tries to run a nested (L2) guest immediately # after this and the L2 guest decrementer is negative (which is loaded # by L1 before making the H_ENTER_NESTED hcall), then the pending # decrementer exception isn't cleared and the L2 entry is blocked since # L1 has a pending exception, even though L1 may have already handled # the exception and written a positive value for it's decrementer. This # results in a loop of L1 trying to enter the L2 guest and L0 blocking # the entry since L1 has an interrupt pending with the outcome being # that L2 never gets to run and hangs. # # Fix this by clearing any pending decrementer exceptions when L1 makes # the H_ENTER_NESTED hcall since it won't do this if it's decrementer # has gone negative, and anyway it's decrementer has been communicated # to L0 in the hdec_expires field and L0 will return control to L1 when # this goes negative by delivering an H_DECREMENTER exception. # # Fixes: 95a6432ce903 ("KVM: PPC: Book3S HV: Streamlined guest entry/exit path on P9 for radix guests") # Cc: stable@vger.kernel.org # v4.20+ # Signed-off-by: Suraj Jitindar Singh # Signed-off-by: Michael Ellerman # < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version # < git log --format=%s --max-count=1 3c25ab35fbc8526ac0c9b298e8a78e7ad7a55479 # < make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-next_mpc86xx_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- mpc86xx_defconfig # make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-next_mpc86xx_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- /kisskb/src/kernel/futex.c: In function 'do_futex': /kisskb/src/kernel/futex.c:1658:17: warning: 'oldval' may be used uninitialized in this function [-Wmaybe-uninitialized] return oldval == cmparg; ^ /kisskb/src/kernel/futex.c:1633:6: note: 'oldval' was declared here int oldval, ret; ^ /kisskb/src/arch/powerpc/boot/dts/fsl/mvme7100.dts:140.22-142.4: Warning (pci_bridge): /pcie@f1008000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8641si-post.dtsi:97.7-122.3 /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8641si-post.dtsi:107.9-121.4: Warning (pci_bridge): /pcie@f1008000/pcie@0: missing ranges for PCI bridge (or not a bridge) /kisskb/src/arch/powerpc/boot/dts/fsl/mvme7100.dts:144.22-146.4: Warning (pci_bridge): /pcie@f1009000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8641si-post.dtsi:124.7-149.3 /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8641si-post.dtsi:134.9-148.4: Warning (pci_bridge): /pcie@f1009000/pcie@0: missing ranges for PCI bridge (or not a bridge) arch/powerpc/boot/dts/fsl/mvme7100.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' /kisskb/src/arch/powerpc/boot/dts/fsl/mvme7100.dts:35.11-37.6: Warning (i2c_bus_reg): /soc@f1000000/i2c@3000/rtc@68: missing or empty reg property INFO: Uncompressed kernel (size 0xa4b0dc) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xb00000) Image Name: Linux-5.2.0-rc2-g3c25ab35fbc8 Created: Fri Jun 21 01:30:58 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5081560 Bytes = 4962.46 KiB = 4.85 MiB Load Address: 00000000 Entry Point: 00000000 Completed OK # rm -rf /kisskb/build/powerpc-next_mpc86xx_defconfig_powerpc-gcc5 # Build took: 0:01:03.424341