# 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/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-gcc --version # < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-ld --version # < git log --format=%s --max-count=1 3c25ab35fbc8526ac0c9b298e8a78e7ad7a55479 # < make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-next_pmac32_defconfig+kexec_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- pmac32_defconfig # Added to kconfig configs/2006/11/29/pmac32_defconfigkexec # yes \n | make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-next_pmac32_defconfig+kexec_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- oldconfig yes: standard output: Broken pipe # make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-next_pmac32_defconfig+kexec_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- /kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl': /kisskb/src/kernel/printk/printk.c:194:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/proc/inode.c: In function 'proc_reg_open': /kisskb/src/include/linux/list.h:65:12: warning: 'pdeo' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/proc/inode.c:331:21: note: 'pdeo' was declared here /kisskb/src/drivers/base/regmap/regmap.c: In function 'regmap_raw_read': /kisskb/src/drivers/base/regmap/regmap.c:2589:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/base/regmap/regmap.c: In function '_regmap_raw_write': /kisskb/src/drivers/base/regmap/regmap.c:1850:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/sound/ppc/awacs.c: In function 'snd_pmac_awacs_init': /kisskb/src/include/sound/control.h:223:2: warning: 'speaker_vol' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/sound/ppc/awacs.c:886:36: note: 'speaker_vol' was declared here /kisskb/src/fs/nfsd/nfs4xdr.c: In function 'nfsd4_encode_components_esc': /kisskb/src/fs/nfsd/nfs4xdr.c:2077:9: warning: 'str' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/tty/serial/8250/8250_core.c: In function 'univ8250_release_irq': /kisskb/src/drivers/tty/serial/8250/8250_core.c:247:18: warning: 'i' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/tty/serial/8250/8250_core.c:227:19: note: 'i' was declared here /kisskb/src/fs/udf/unicode.c: In function 'udf_name_conv_char': /kisskb/src/fs/udf/unicode.c:132:8: warning: 'c' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/kernel/futex.c: In function 'do_futex': /kisskb/src/kernel/futex.c:1658:3: warning: 'oldval' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/kernel/futex.c:1633:6: note: 'oldval' was declared here /kisskb/src/drivers/net/wireless/broadcom/b43/phy_n.c: In function 'b43_nphy_rf_ctl_override_rev7': /kisskb/src/drivers/net/wireless/broadcom/b43/phy_n.c:190:21: warning: 'val_addr' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/net/tun.c: In function 'tun_get_user': /kisskb/src/drivers/net/tun.c:1851:30: warning: 'copylen' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/net/tun.c:1764:46: warning: 'linear' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/mac80211/mlme.c: In function 'ieee80211_rx_mgmt_beacon': /kisskb/src/net/mac80211/mlme.c:1578:3: warning: 'pwr_level_cisco' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/mac80211/mlme.c:1535:6: note: 'pwr_level_cisco' was declared here INFO: Uncompressed kernel (size 0x92a3fc) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xa00000) Completed OK # rm -rf /kisskb/build/powerpc-next_pmac32_defconfig+kexec_powerpc-gcc4.6 # Build took: 0:00:46.423300