Messages in this thread | | | Subject | Re: [PATCH v8 2/6] LoongArch: KVM: Add hypercall instruction emulation support | From | maobibo <> | Date | Mon, 6 May 2024 10:41:02 +0800 |
| |
On 2024/5/6 上午9:54, Huacai Chen wrote: > Hi, Bibo, > > On Sun, Apr 28, 2024 at 6:05 PM Bibo Mao <maobibo@loongson.cn> wrote: >> >> On LoongArch system, there is hypercall instruction special for >> virtualization. When system executes this instruction on host side, >> there is 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 <maobibo@loongson.cn> >> --- >> arch/loongarch/include/asm/Kbuild | 1 - >> arch/loongarch/include/asm/kvm_para.h | 26 ++++++++++++++++++++++++++ >> arch/loongarch/include/uapi/asm/Kbuild | 2 -- >> arch/loongarch/kvm/exit.c | 10 ++++++++++ >> 4 files changed, 36 insertions(+), 3 deletions(-) >> create mode 100644 arch/loongarch/include/asm/kvm_para.h >> delete mode 100644 arch/loongarch/include/uapi/asm/Kbuild >> >> 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..d48f993ae206 >> --- /dev/null >> +++ b/arch/loongarch/include/asm/kvm_para.h >> @@ -0,0 +1,26 @@ >> +/* 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_STATUS_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/include/uapi/asm/Kbuild b/arch/loongarch/include/uapi/asm/Kbuild >> deleted file mode 100644 >> index 4aa680ca2e5f..000000000000 >> --- a/arch/loongarch/include/uapi/asm/Kbuild >> +++ /dev/null >> @@ -1,2 +0,0 @@ >> -# SPDX-License-Identifier: GPL-2.0 >> -generic-y += kvm_para.h > This file shouldn't be removed. yes, uapi kvm_param.h is needed for Loongarch, and there will be problem if it is removed. And it should kept unchanged.
Regards Bibo Mao > > Huacai > >> diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c >> index ed1d89d53e2e..923bbca9bd22 100644 >> --- a/arch/loongarch/kvm/exit.c >> +++ b/arch/loongarch/kvm/exit.c >> @@ -685,6 +685,15 @@ 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 +725,7 @@ 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) >> -- >> 2.39.3 >> >>
| |