When nVHE hyp starts interception host's PSCI CPU_ON SMCs, it will need to install KVM on the newly booted CPU before returning to the host. Add an entry point which expects the same kvm_nvhe_init_params struct as the __kvm_hyp_init HVC in the CPU_ON context argument (x0).
The entry point initializes EL2 state with the same init_el2_state macro used by the kernel's entry point. It then initializes KVM using the same helper function used in the __kvm_hyp_init HVC. When done, the entry point branches to a function provided in the init params. Signed-off-by: David Brazdil <[email protected]> --- arch/arm64/include/asm/kvm_asm.h | 1 + arch/arm64/kernel/asm-offsets.c | 1 + arch/arm64/kvm/hyp/nvhe/hyp-init.S | 30 ++++++++++++++++++++++++++++++ 3 files changed, 32 insertions(+) diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index 893327d1e449..efb4872bb29f 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h @@ -155,6 +155,7 @@ struct kvm_nvhe_init_params { unsigned long tpidr_el2; unsigned long hyp_stack_ptr; unsigned long vector_ptr; + unsigned long psci_cpu_entry_fn; }; /* Translate a kernel address @ptr into its equivalent linear mapping */ diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index 0cbb86135c7c..ffc84e68ad97 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -114,6 +114,7 @@ int main(void) DEFINE(NVHE_INIT_TPIDR_EL2, offsetof(struct kvm_nvhe_init_params, tpidr_el2)); DEFINE(NVHE_INIT_STACK_PTR, offsetof(struct kvm_nvhe_init_params, hyp_stack_ptr)); DEFINE(NVHE_INIT_VECTOR_PTR, offsetof(struct kvm_nvhe_init_params, vector_ptr)); + DEFINE(NVHE_INIT_PSCI_CPU_ENTRY_FN, offsetof(struct kvm_nvhe_init_params, psci_cpu_entry_fn)); #endif #ifdef CONFIG_CPU_PM DEFINE(CPU_CTX_SP, offsetof(struct cpu_suspend_ctx, sp)); diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-init.S b/arch/arm64/kvm/hyp/nvhe/hyp-init.S index 1697d25756e9..f999a35b2c8c 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-init.S +++ b/arch/arm64/kvm/hyp/nvhe/hyp-init.S @@ -6,6 +6,7 @@ #include <linux/arm-smccc.h> #include <linux/linkage.h> +#include <linux/irqchip/arm-gic-v3.h> #include <asm/alternative.h> #include <asm/assembler.h> @@ -159,6 +160,35 @@ alternative_else_nop_endif ret SYM_CODE_END(___kvm_hyp_init) +SYM_CODE_START(__kvm_hyp_cpu_entry) + msr SPsel, #1 // We want to use SP_EL{1,2} + + /* + * Check that the core was booted in EL2. Loop indefinitely if not + * because it cannot be safely given to the host without installing KVM. + */ + mrs x1, CurrentEL + cmp x1, #CurrentEL_EL2 + b.ne . + + /* Initialize EL2 CPU state to sane values. */ + mov x29, x0 + init_el2_state nvhe + mov x0, x29 + + /* + * Load hyp VA of C entry function. Must do so before switching on the + * MMU because the struct pointer is PA and not identity-mapped in hyp. + */ + ldr x29, [x0, #NVHE_INIT_PSCI_CPU_ENTRY_FN] + + /* Enable MMU, set vectors and stack. */ + bl ___kvm_hyp_init + + /* Leave idmap. */ + br x29 +SYM_CODE_END(__kvm_hyp_cpu_entry) + SYM_CODE_START(__kvm_handle_stub_hvc) cmp x0, #HVC_SOFT_RESTART b.ne 1f -- 2.29.2.222.g5d2a92d10f8-goog
