arm_smccc_1_1_hvc() only adds write contraints for x0-3 in the inline assembly for the HVC instruction so make sure those are the only registers that change when __do_hyp_init is called. Tested-by: David Brazdil <dbrazdil@xxxxxxxxxx> Signed-off-by: Andrew Scull <ascull@xxxxxxxxxx> --- arch/arm64/kvm/hyp/nvhe/hyp-init.S | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-init.S b/arch/arm64/kvm/hyp/nvhe/hyp-init.S index b3915ccb23b0..3df583ad12af 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-init.S +++ b/arch/arm64/kvm/hyp/nvhe/hyp-init.S @@ -47,6 +47,8 @@ __invalid: b . /* + * Only uses x0..x3 so as to not clobber callee-saved SMCCC registers. + * * x0: SMCCC function ID * x1: struct kvm_nvhe_init_params PA */ @@ -63,9 +65,9 @@ __do_hyp_init: eret 1: mov x0, x1 - mov x4, lr - bl ___kvm_hyp_init - mov lr, x4 + mov x3, lr + bl ___kvm_hyp_init // Clobbers x0..x2 + mov lr, x3 /* Hello, World! */ mov x0, #SMCCC_RET_SUCCESS @@ -75,8 +77,8 @@ SYM_CODE_END(__kvm_hyp_init) /* * Initialize the hypervisor in EL2. * - * Only uses x0..x3 so as to not clobber callee-saved SMCCC registers - * and leave x4 for the caller. + * Only uses x0..x2 so as to not clobber callee-saved SMCCC registers + * and leave x3 for the caller. * * x0: struct kvm_nvhe_init_params PA */ @@ -105,9 +107,9 @@ alternative_else_nop_endif /* * Set the PS bits in TCR_EL2. */ - ldr x1, [x0, #NVHE_INIT_TCR_EL2] - tcr_compute_pa_size x1, #TCR_EL2_PS_SHIFT, x2, x3 - msr tcr_el2, x1 + ldr x0, [x0, #NVHE_INIT_TCR_EL2] + tcr_compute_pa_size x0, #TCR_EL2_PS_SHIFT, x1, x2 + msr tcr_el2, x0 isb @@ -186,7 +188,7 @@ SYM_CODE_START_LOCAL(__kvm_hyp_init_cpu) /* Enable MMU, set vectors and stack. */ mov x0, x28 - bl ___kvm_hyp_init // Clobbers x0..x3 + bl ___kvm_hyp_init // Clobbers x0..x2 /* Leave idmap. */ mov x0, x29 -- 2.30.0.280.ga3ce27912f-goog _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
