On Sat, 11 Jan 2020 at 15:49, Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > From: Marc Zyngier <marc.zyngier@xxxxxxx> > > commit d3ec3a08fa700c8b46abb137dce4e2514a6f9668 upstream. > > In order to workaround the TX2-219 erratum, it is necessary to trap > TTBRx_EL1 accesses to EL2. This is done by setting HCR_EL2.TVM on > guest entry, which has the side effect of trapping all the other > VM-related sysregs as well. > > To minimize the overhead, a fast path is used so that we don't > have to go all the way back to the main sysreg handling code, > unless the rest of the hypervisor expects to see these accesses. > > Cc: <stable@xxxxxxxxxxxxxxx> > Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> > Signed-off-by: Will Deacon <will@xxxxxxxxxx> > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> On stable-rc 4.19 all arm64 builds failed due to this error, arch/arm64/kvm/hyp/switch.c: In function 'handle_tx2_tvm': arch/arm64/kvm/hyp/switch.c:438:2: error: implicit declaration of function '__kvm_skip_instr'; did you mean 'kvm_skip_instr'? [-Werror=implicit-function-declaration] __kvm_skip_instr(vcpu); ^~~~~~~~~~~~~~~~ kvm_skip_instr cc1: some warnings being treated as errors scripts/Makefile.build:303: recipe for target 'arch/arm64/kvm/hyp/switch.o' failed Full build log, https://ci.linaro.org/view/lkft/job/openembedded-lkft-linux-stable-rc-4.19/DISTRO=lkft,MACHINE=hikey,label=docker-lkft/413/consoleText -- Linaro LKFT https://lkft.linaro.org
