From 372631bb62d3791f0122a67f5a3e959a4d99bebd Mon Sep 17 00:00:00 2001 From: Bibo Mao Date: Mon, 6 May 2024 22:00:46 +0800 Subject: LoongArch: KVM: Add hypercall instruction emulation On LoongArch system, there is a hypercall instruction special for virtualization. When system executes this instruction on host side, there is an illegal instruction exception reported, however it will trap into host when it is executed in VM mode. When hypercall is emulated, A0 register is set with value KVM_HCALL_INVALID_CODE, rather than inject EXCCODE_INE invalid instruction exception. So VM can continue to executing the next code. Signed-off-by: Bibo Mao Signed-off-by: Huacai Chen --- arch/loongarch/include/asm/Kbuild | 1 - arch/loongarch/include/asm/kvm_para.h | 27 +++++++++++++++++++++++++++ arch/loongarch/kvm/exit.c | 11 +++++++++++ 3 files changed, 38 insertions(+), 1 deletion(-) create mode 100644 arch/loongarch/include/asm/kvm_para.h diff --git a/arch/loongarch/include/asm/Kbuild b/arch/loongarch/include/asm/Kbuild index 2dbec7853ae8..c862672ed953 100644 --- a/arch/loongarch/include/asm/Kbuild +++ b/arch/loongarch/include/asm/Kbuild @@ -26,4 +26,3 @@ generic-y += poll.h generic-y += param.h generic-y += posix_types.h generic-y += resource.h -generic-y += kvm_para.h diff --git a/arch/loongarch/include/asm/kvm_para.h b/arch/loongarch/include/asm/kvm_para.h new file mode 100644 index 000000000000..7f21de5c1632 --- /dev/null +++ b/arch/loongarch/include/asm/kvm_para.h @@ -0,0 +1,27 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_LOONGARCH_KVM_PARA_H +#define _ASM_LOONGARCH_KVM_PARA_H + +/* + * LoongArch hypercall return code + */ +#define KVM_HCALL_SUCCESS 0 +#define KVM_HCALL_INVALID_CODE -1UL +#define KVM_HCALL_INVALID_PARAMETER -2UL + +static inline unsigned int kvm_arch_para_features(void) +{ + return 0; +} + +static inline unsigned int kvm_arch_para_hints(void) +{ + return 0; +} + +static inline bool kvm_check_and_clear_guest_paused(void) +{ + return false; +} + +#endif /* _ASM_LOONGARCH_KVM_PARA_H */ diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c index ed1d89d53e2e..f368673db395 100644 --- a/arch/loongarch/kvm/exit.c +++ b/arch/loongarch/kvm/exit.c @@ -685,6 +685,16 @@ static int kvm_handle_lasx_disabled(struct kvm_vcpu *vcpu) return RESUME_GUEST; } +static int kvm_handle_hypercall(struct kvm_vcpu *vcpu) +{ + update_pc(&vcpu->arch); + + /* Treat it as noop intruction, only set return value */ + vcpu->arch.gprs[LOONGARCH_GPR_A0] = KVM_HCALL_INVALID_CODE; + + return RESUME_GUEST; +} + /* * LoongArch KVM callback handling for unimplemented guest exiting */ @@ -716,6 +726,7 @@ static exit_handle_fn kvm_fault_tables[EXCCODE_INT_START] = { [EXCCODE_LSXDIS] = kvm_handle_lsx_disabled, [EXCCODE_LASXDIS] = kvm_handle_lasx_disabled, [EXCCODE_GSPR] = kvm_handle_gspr, + [EXCCODE_HVC] = kvm_handle_hypercall, }; int kvm_handle_fault(struct kvm_vcpu *vcpu, int fault) -- cgit v1.2.3