Add helpers so that guest hypervisors can run nested guests. SP_EL1 save/restore is added to allow nested guests to use a stack.
Signed-off-by: Wei-Lin Chang <[email protected]> --- .../selftests/kvm/include/arm64/nested.h | 17 +++++++ tools/testing/selftests/kvm/lib/arm64/entry.S | 5 ++ .../testing/selftests/kvm/lib/arm64/nested.c | 46 +++++++++++++++++++ 3 files changed, 68 insertions(+) diff --git a/tools/testing/selftests/kvm/include/arm64/nested.h b/tools/testing/selftests/kvm/include/arm64/nested.h index 86d931facacb..30e626e427da 100644 --- a/tools/testing/selftests/kvm/include/arm64/nested.h +++ b/tools/testing/selftests/kvm/include/arm64/nested.h @@ -21,8 +21,17 @@ extern char hyp_vectors[]; +enum vcpu_sysreg { + __INVALID_SYSREG__, /* 0 is reserved as an invalid value */ + + SP_EL1, + + NR_SYS_REGS +}; + struct cpu_context { struct user_pt_regs regs; /* sp = sp_el0 */ + u64 sys_regs[NR_SYS_REGS]; }; struct vcpu { @@ -37,9 +46,17 @@ struct hyp_data { struct cpu_context hyp_context; }; +void prepare_hyp(void); +void init_vcpu(struct vcpu *vcpu, gpa_t l2_pc, gpa_t l2_stack_top); +int run_l2(struct vcpu *vcpu, struct hyp_data *hyp_data); + +void do_hvc(void); u64 __guest_enter(struct vcpu *vcpu, struct cpu_context *hyp_context); void __hyp_exception(u64 type); +void __sysreg_save_el1_state(struct cpu_context *ctxt); +void __sysreg_restore_el1_state(struct cpu_context *ctxt); + #endif /* !__ASSEMBLER__ */ #endif /* SELFTEST_KVM_NESTED_H */ diff --git a/tools/testing/selftests/kvm/lib/arm64/entry.S b/tools/testing/selftests/kvm/lib/arm64/entry.S index 33bedf5e7fb2..df3af3463c6c 100644 --- a/tools/testing/selftests/kvm/lib/arm64/entry.S +++ b/tools/testing/selftests/kvm/lib/arm64/entry.S @@ -3,6 +3,11 @@ * adapted from arch/arm64/kvm/hyp/entry.S */ + .globl do_hvc + do_hvc: + hvc #0 + ret + /* * Manually define these for now */ diff --git a/tools/testing/selftests/kvm/lib/arm64/nested.c b/tools/testing/selftests/kvm/lib/arm64/nested.c index 06ddaab2436f..f6c24beb01d0 100644 --- a/tools/testing/selftests/kvm/lib/arm64/nested.c +++ b/tools/testing/selftests/kvm/lib/arm64/nested.c @@ -4,7 +4,53 @@ */ #include "nested.h" +#include "processor.h" #include "test_util.h" +#include <asm/sysreg.h> + +void prepare_hyp(void) +{ + write_sysreg(HCR_EL2_E2H | HCR_EL2_RW, hcr_el2); + write_sysreg(hyp_vectors, vbar_el2); + isb(); +} + +void init_vcpu(struct vcpu *vcpu, gpa_t l2_pc, gpa_t l2_stack_top) +{ + memset(vcpu, 0, sizeof(*vcpu)); + vcpu->context.regs.pc = l2_pc; + vcpu->context.regs.pstate = PSR_MODE_EL1h | PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT; + vcpu->context.sys_regs[SP_EL1] = l2_stack_top; +} + +void __sysreg_save_el1_state(struct cpu_context *ctxt) +{ + ctxt->sys_regs[SP_EL1] = read_sysreg(sp_el1); +} + +void __sysreg_restore_el1_state(struct cpu_context *ctxt) +{ + write_sysreg(ctxt->sys_regs[SP_EL1], sp_el1); +} + +int run_l2(struct vcpu *vcpu, struct hyp_data *hyp_data) +{ + u64 ret; + + __sysreg_restore_el1_state(&vcpu->context); + + write_sysreg(vcpu->context.regs.pstate, spsr_el2); + write_sysreg(vcpu->context.regs.pc, elr_el2); + + ret = __guest_enter(vcpu, &hyp_data->hyp_context); + + vcpu->context.regs.pc = read_sysreg(elr_el2); + vcpu->context.regs.pstate = read_sysreg(spsr_el2); + + __sysreg_save_el1_state(&vcpu->context); + + return ret; +} void __hyp_exception(u64 type) { -- 2.43.0
