From: Bibo Mao Date: Mon, 13 Jan 2025 13:37:17 +0000 (+0800) Subject: LoongArch: KVM: Add hypercall service support for usermode VMM X-Git-Tag: v6.14-rc1~94^2~10^2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=2737dee1067c2fc02256b2b15dab158c5e840568;p=thirdparty%2Fkernel%2Flinux.git LoongArch: KVM: Add hypercall service support for usermode VMM Some VMMs provides special hypercall service in usermode, KVM should not handle the usermode hypercall service, thus pass it to usermode, let the usermode VMM handle it. Here a new code KVM_HCALL_CODE_USER_SERVICE is added for the user-mode hypercall service, KVM lets all six registers visible to usermode VMM. Signed-off-by: Bibo Mao Signed-off-by: Huacai Chen --- diff --git a/arch/loongarch/include/asm/kvm_host.h b/arch/loongarch/include/asm/kvm_host.h index 7b8367c39da85..590982cd986ec 100644 --- a/arch/loongarch/include/asm/kvm_host.h +++ b/arch/loongarch/include/asm/kvm_host.h @@ -162,6 +162,7 @@ enum emulation_result { #define LOONGARCH_PV_FEAT_UPDATED BIT_ULL(63) #define LOONGARCH_PV_FEAT_MASK (BIT(KVM_FEATURE_IPI) | \ BIT(KVM_FEATURE_STEAL_TIME) | \ + BIT(KVM_FEATURE_USER_HCALL) | \ BIT(KVM_FEATURE_VIRT_EXTIOI)) struct kvm_vcpu_arch { diff --git a/arch/loongarch/include/asm/kvm_para.h b/arch/loongarch/include/asm/kvm_para.h index c4e84227280dc..3e4b397f423f4 100644 --- a/arch/loongarch/include/asm/kvm_para.h +++ b/arch/loongarch/include/asm/kvm_para.h @@ -13,6 +13,7 @@ #define KVM_HCALL_CODE_SERVICE 0 #define KVM_HCALL_CODE_SWDBG 1 +#define KVM_HCALL_CODE_USER_SERVICE 2 #define KVM_HCALL_SERVICE HYPERCALL_ENCODE(HYPERVISOR_KVM, KVM_HCALL_CODE_SERVICE) #define KVM_HCALL_FUNC_IPI 1 @@ -20,6 +21,8 @@ #define KVM_HCALL_SWDBG HYPERCALL_ENCODE(HYPERVISOR_KVM, KVM_HCALL_CODE_SWDBG) +#define KVM_HCALL_USER_SERVICE HYPERCALL_ENCODE(HYPERVISOR_KVM, KVM_HCALL_CODE_USER_SERVICE) + /* * LoongArch hypercall return code */ diff --git a/arch/loongarch/include/asm/kvm_vcpu.h b/arch/loongarch/include/asm/kvm_vcpu.h index d7e8f7d50ee0c..2c349f961bfbc 100644 --- a/arch/loongarch/include/asm/kvm_vcpu.h +++ b/arch/loongarch/include/asm/kvm_vcpu.h @@ -43,6 +43,7 @@ int kvm_emu_mmio_read(struct kvm_vcpu *vcpu, larch_inst inst); int kvm_emu_mmio_write(struct kvm_vcpu *vcpu, larch_inst inst); int kvm_complete_mmio_read(struct kvm_vcpu *vcpu, struct kvm_run *run); int kvm_complete_iocsr_read(struct kvm_vcpu *vcpu, struct kvm_run *run); +int kvm_complete_user_service(struct kvm_vcpu *vcpu, struct kvm_run *run); int kvm_emu_idle(struct kvm_vcpu *vcpu); int kvm_pending_timer(struct kvm_vcpu *vcpu); int kvm_handle_fault(struct kvm_vcpu *vcpu, int fault); diff --git a/arch/loongarch/include/uapi/asm/kvm_para.h b/arch/loongarch/include/uapi/asm/kvm_para.h index b0604aa9b4bbd..76d802ef01ce3 100644 --- a/arch/loongarch/include/uapi/asm/kvm_para.h +++ b/arch/loongarch/include/uapi/asm/kvm_para.h @@ -17,5 +17,6 @@ #define KVM_FEATURE_STEAL_TIME 2 /* BIT 24 - 31 are features configurable by user space vmm */ #define KVM_FEATURE_VIRT_EXTIOI 24 +#define KVM_FEATURE_USER_HCALL 25 #endif /* _UAPI_ASM_KVM_PARA_H */ diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c index a7893bd01e732..c1e8ec5b941b2 100644 --- a/arch/loongarch/kvm/exit.c +++ b/arch/loongarch/kvm/exit.c @@ -709,6 +709,14 @@ static int kvm_handle_write_fault(struct kvm_vcpu *vcpu) return kvm_handle_rdwr_fault(vcpu, true); } +int kvm_complete_user_service(struct kvm_vcpu *vcpu, struct kvm_run *run) +{ + update_pc(&vcpu->arch); + kvm_write_reg(vcpu, LOONGARCH_GPR_A0, run->hypercall.ret); + + return 0; +} + /** * kvm_handle_fpu_disabled() - Guest used fpu however it is disabled at host * @vcpu: Virtual CPU context. @@ -873,6 +881,28 @@ static int kvm_handle_hypercall(struct kvm_vcpu *vcpu) vcpu->stat.hypercall_exits++; kvm_handle_service(vcpu); break; + case KVM_HCALL_USER_SERVICE: + if (!kvm_guest_has_pv_feature(vcpu, KVM_FEATURE_USER_HCALL)) { + kvm_write_reg(vcpu, LOONGARCH_GPR_A0, KVM_HCALL_INVALID_CODE); + break; + } + + vcpu->stat.hypercall_exits++; + vcpu->run->exit_reason = KVM_EXIT_HYPERCALL; + vcpu->run->hypercall.nr = KVM_HCALL_USER_SERVICE; + vcpu->run->hypercall.args[0] = kvm_read_reg(vcpu, LOONGARCH_GPR_A0); + vcpu->run->hypercall.args[1] = kvm_read_reg(vcpu, LOONGARCH_GPR_A1); + vcpu->run->hypercall.args[2] = kvm_read_reg(vcpu, LOONGARCH_GPR_A2); + vcpu->run->hypercall.args[3] = kvm_read_reg(vcpu, LOONGARCH_GPR_A3); + vcpu->run->hypercall.args[4] = kvm_read_reg(vcpu, LOONGARCH_GPR_A4); + vcpu->run->hypercall.args[5] = kvm_read_reg(vcpu, LOONGARCH_GPR_A5); + vcpu->run->hypercall.flags = 0; + /* + * Set invalid return value by default, let user-mode VMM modify it. + */ + vcpu->run->hypercall.ret = KVM_HCALL_INVALID_CODE; + ret = RESUME_HOST; + break; case KVM_HCALL_SWDBG: /* KVM_HCALL_SWDBG only in effective when SW_BP is enabled */ if (vcpu->guest_debug & KVM_GUESTDBG_SW_BP_MASK) { diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c index d18a4a2704150..fb72095c8077e 100644 --- a/arch/loongarch/kvm/vcpu.c +++ b/arch/loongarch/kvm/vcpu.c @@ -1732,9 +1732,14 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) vcpu->mmio_needed = 0; } - if (run->exit_reason == KVM_EXIT_LOONGARCH_IOCSR) { + switch (run->exit_reason) { + case KVM_EXIT_HYPERCALL: + kvm_complete_user_service(vcpu, run); + break; + case KVM_EXIT_LOONGARCH_IOCSR: if (!run->iocsr_io.is_write) kvm_complete_iocsr_read(vcpu, run); + break; } if (!vcpu->wants_to_run)