[PATCH v5 7/8] KVM: arm64: Trap access to pVM restricted features
From: Fuad Tabba <hidden>
Date: 2021-08-27 10:19:50
Also in:
kvm, kvmarm
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
Trap accesses to restricted features for VMs running in protected mode. Access to feature registers are emulated, and only supported features are exposed to protected VMs. Accesses to restricted registers as well as restricted instructions are trapped, and an undefined exception is injected into the protected guests, i.e., with EC = 0x0 (unknown reason). This EC is the one used, according to the Arm Architecture Reference Manual, for unallocated or undefined system registers or instructions. Only affects the functionality of protected VMs. Otherwise, should not affect non-protected VMs when KVM is running in protected mode. Signed-off-by: Fuad Tabba <redacted> --- arch/arm64/kvm/hyp/nvhe/switch.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index 41f05bf88f61..fe0c3833ec66 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c@@ -171,8 +171,23 @@ static const exit_handler_fn hyp_exit_handlers[] = { [ESR_ELx_EC_PAC] = kvm_hyp_handle_ptrauth, }; +static const exit_handler_fn pvm_exit_handlers[] = { + [0 ... ESR_ELx_EC_MAX] = NULL, + [ESR_ELx_EC_CP15_32] = kvm_hyp_handle_cp15, + [ESR_ELx_EC_CP15_64] = kvm_hyp_handle_cp15, + [ESR_ELx_EC_SYS64] = kvm_handle_pvm_sys64, + [ESR_ELx_EC_SVE] = kvm_handle_pvm_restricted, + [ESR_ELx_EC_FP_ASIMD] = kvm_handle_pvm_fpsimd, + [ESR_ELx_EC_IABT_LOW] = kvm_hyp_handle_iabt_low, + [ESR_ELx_EC_DABT_LOW] = kvm_hyp_handle_dabt_low, + [ESR_ELx_EC_PAC] = kvm_hyp_handle_ptrauth, +}; + const exit_handler_fn *kvm_get_exit_handler_array(struct kvm *kvm) { + if (unlikely(kvm_vm_is_protected(kvm))) + return pvm_exit_handlers; + return hyp_exit_handlers; }
--
2.33.0.259.gc128427fd7-goog
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