Let's define a new stub hypercall that resets the HYP configuration to its default: hyp-stub vectors, and MMU disabled. Of course, for the hyp-stub itself, this is a trivial no-op. Hypervisors will have a bit more work to do. Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> --- arch/arm64/include/asm/virt.h | 8 ++++++++ arch/arm64/kernel/hyp-stub.S | 13 ++++++++++++- 2 files changed, 20 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h index 439f6b5d31f6..6d085a4d6cf1 100644 --- a/arch/arm64/include/asm/virt.h +++ b/arch/arm64/include/asm/virt.h @@ -39,6 +39,14 @@ */ #define HVC_SOFT_RESTART 2 +/* + * HVC_RESET_VECTORS - Restore the vectors to the original HYP stubs + */ +#define HVC_RESET_VECTORS 3 + +/* Max number of HYP stub hypercalls */ +#define HVC_STUB_HCALL_NR 4 + #define BOOT_CPU_MODE_EL1 (0xe11) #define BOOT_CPU_MODE_EL2 (0xe12) diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S index d3b5f75e652e..a162182d5662 100644 --- a/arch/arm64/kernel/hyp-stub.S +++ b/arch/arm64/kernel/hyp-stub.S @@ -79,8 +79,11 @@ el1_sync: mov x1, x3 br x4 // no return +3: cmp x0, #HVC_RESET_VECTORS + beq 9f // Nothing to reset! + /* Someone called kvm_call_hyp() against the hyp-stub... */ -3: mov x0, #ARM_EXCEPTION_HYP_GONE + mov x0, #ARM_EXCEPTION_HYP_GONE 9: eret ENDPROC(el1_sync) @@ -137,3 +140,11 @@ ENTRY(__hyp_set_vectors) ldr lr, [sp], #16 ret ENDPROC(__hyp_set_vectors) + +ENTRY(__hyp_reset_vectors) + str lr, [sp, #-16]! + mov x0, #HVC_RESET_VECTORS + hvc #0 + ldr lr, [sp], #16 + ret +ENDPROC(__hyp_reset_vectors) -- 2.11.0
