Huacai, On 2024/7/6 上午11:00, Huacai Chen wrote:
By my understanding, macro vcpu_is_preempted() is used together with pv spinlock, and pv spinlock depends on pv stealtime. So I think preempted flag is not part of pv stealtime, it is part of pv spinlock.Hi, Bibo, On Fri, May 24, 2024 at 3:38 PM Bibo Mao <maobibo@xxxxxxxxxxx> wrote:Steal time feature is added here in kvm side, VM can search supported features provided by KVM hypervisor, feature KVM_FEATURE_STEAL_TIME is added here. Like x86, steal time structure is saved in guest memory, one hypercall function KVM_HCALL_FUNC_NOTIFY is added to notify KVM to enable the feature. One cpu attr ioctl command KVM_LOONGARCH_VCPU_PVTIME_CTRL is added to save and restore base address of steal time structure when VM is migrated. Signed-off-by: Bibo Mao <maobibo@xxxxxxxxxxx> --- arch/loongarch/include/asm/kvm_host.h | 7 ++ arch/loongarch/include/asm/kvm_para.h | 10 ++ arch/loongarch/include/asm/kvm_vcpu.h | 4 + arch/loongarch/include/asm/loongarch.h | 1 + arch/loongarch/include/uapi/asm/kvm.h | 4 + arch/loongarch/kvm/Kconfig | 1 + arch/loongarch/kvm/exit.c | 38 +++++++- arch/loongarch/kvm/vcpu.c | 124 +++++++++++++++++++++++++ 8 files changed, 187 insertions(+), 2 deletions(-) diff --git a/arch/loongarch/include/asm/kvm_host.h b/arch/loongarch/include/asm/kvm_host.h index c87b6ea0ec47..2eb2f7572023 100644 --- a/arch/loongarch/include/asm/kvm_host.h +++ b/arch/loongarch/include/asm/kvm_host.h @@ -30,6 +30,7 @@ #define KVM_PRIVATE_MEM_SLOTS 0 #define KVM_HALT_POLL_NS_DEFAULT 500000 +#define KVM_REQ_STEAL_UPDATE KVM_ARCH_REQ(1) #define KVM_GUESTDBG_SW_BP_MASK \ (KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP) @@ -201,6 +202,12 @@ struct kvm_vcpu_arch { struct kvm_mp_state mp_state; /* cpucfg */ u32 cpucfg[KVM_MAX_CPUCFG_REGS]; + /* paravirt steal time */ + struct { + u64 guest_addr; + u64 last_steal; + struct gfn_to_hva_cache cache; + } st; }; static inline unsigned long readl_sw_gcsr(struct loongarch_csrs *csr, int reg) diff --git a/arch/loongarch/include/asm/kvm_para.h b/arch/loongarch/include/asm/kvm_para.h index 4ba2312e5f8c..a9ba8185d4af 100644 --- a/arch/loongarch/include/asm/kvm_para.h +++ b/arch/loongarch/include/asm/kvm_para.h @@ -14,6 +14,7 @@ #define KVM_HCALL_SERVICE HYPERCALL_ENCODE(HYPERVISOR_KVM, KVM_HCALL_CODE_SERVICE) #define KVM_HCALL_FUNC_IPI 1 +#define KVM_HCALL_FUNC_NOTIFY 2 #define KVM_HCALL_SWDBG HYPERCALL_ENCODE(HYPERVISOR_KVM, KVM_HCALL_CODE_SWDBG) @@ -24,6 +25,15 @@ #define KVM_HCALL_INVALID_CODE -1UL #define KVM_HCALL_INVALID_PARAMETER -2UL +#define KVM_STEAL_PHYS_VALID BIT_ULL(0) +#define KVM_STEAL_PHYS_MASK GENMASK_ULL(63, 6) +struct kvm_steal_time { + __u64 steal; + __u32 version; + __u32 flags;I found that x86 has a preempted field here, in our internal repo the LoongArch version also has this field. Moreover, kvm_steal_time_set_preempted() and kvm_steal_time_clear_preempted() seems needed.
We are going to add preempted field if pv spinlock is added.
+ __u32 pad[12]; +}; + /* * Hypercall interface for KVM hypervisor * diff --git a/arch/loongarch/include/asm/kvm_vcpu.h b/arch/loongarch/include/asm/kvm_vcpu.h index 590a92cb5416..d7e51300a89f 100644 --- a/arch/loongarch/include/asm/kvm_vcpu.h +++ b/arch/loongarch/include/asm/kvm_vcpu.h @@ -120,4 +120,8 @@ static inline void kvm_write_reg(struct kvm_vcpu *vcpu, int num, unsigned long v vcpu->arch.gprs[num] = val; } +static inline bool kvm_pvtime_supported(void) +{ + return !!sched_info_on(); +} #endif /* __ASM_LOONGARCH_KVM_VCPU_H__ */ diff --git a/arch/loongarch/include/asm/loongarch.h b/arch/loongarch/include/asm/loongarch.h index eb09adda54b7..7a4633ef284b 100644 --- a/arch/loongarch/include/asm/loongarch.h +++ b/arch/loongarch/include/asm/loongarch.h @@ -169,6 +169,7 @@ #define KVM_SIGNATURE "KVM\0" #define CPUCFG_KVM_FEATURE (CPUCFG_KVM_BASE + 4) #define KVM_FEATURE_IPI BIT(1) +#define KVM_FEATURE_STEAL_TIME BIT(2) #ifndef __ASSEMBLY__ diff --git a/arch/loongarch/include/uapi/asm/kvm.h b/arch/loongarch/include/uapi/asm/kvm.h index f9abef382317..ddc5cab0ffd0 100644 --- a/arch/loongarch/include/uapi/asm/kvm.h +++ b/arch/loongarch/include/uapi/asm/kvm.h @@ -81,7 +81,11 @@ struct kvm_fpu { #define LOONGARCH_REG_64(TYPE, REG) (TYPE | KVM_REG_SIZE_U64 | (REG << LOONGARCH_REG_SHIFT)) #define KVM_IOC_CSRID(REG) LOONGARCH_REG_64(KVM_REG_LOONGARCH_CSR, REG) #define KVM_IOC_CPUCFG(REG) LOONGARCH_REG_64(KVM_REG_LOONGARCH_CPUCFG, REG) + +/* Device Control API on vcpu fd */ #define KVM_LOONGARCH_VCPU_CPUCFG 0 +#define KVM_LOONGARCH_VCPU_PVTIME_CTRL 1 +#define KVM_LOONGARCH_VCPU_PVTIME_GPA 0 struct kvm_debug_exit_arch { }; diff --git a/arch/loongarch/kvm/Kconfig b/arch/loongarch/kvm/Kconfig index c4ef2b4d9797..248744b4d086 100644 --- a/arch/loongarch/kvm/Kconfig +++ b/arch/loongarch/kvm/Kconfig @@ -29,6 +29,7 @@ config KVM select KVM_MMIO select HAVE_KVM_READONLY_MEM select KVM_XFER_TO_GUEST_WORK + select SCHED_INFO help Support hosting virtualized guest machines using hardware virtualization extensions. You will need diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c index c86e099af5ca..e2abd97fb13f 100644 --- a/arch/loongarch/kvm/exit.c +++ b/arch/loongarch/kvm/exit.c @@ -24,7 +24,7 @@ static int kvm_emu_cpucfg(struct kvm_vcpu *vcpu, larch_inst inst) { int rd, rj; - unsigned int index; + unsigned int index, ret; if (inst.reg2_format.opcode != cpucfg_op) return EMULATE_FAIL; @@ -50,7 +50,10 @@ static int kvm_emu_cpucfg(struct kvm_vcpu *vcpu, larch_inst inst) vcpu->arch.gprs[rd] = *(unsigned int *)KVM_SIGNATURE; break; case CPUCFG_KVM_FEATURE: - vcpu->arch.gprs[rd] = KVM_FEATURE_IPI; + ret = KVM_FEATURE_IPI; + if (sched_info_on())What about replacing it with your helper function kvm_pvtime_supported()?
Sure, will replace it with helper function kvm_pvtime_supported(). Regards Bibo Mao
Huacai+ ret |= KVM_FEATURE_STEAL_TIME; + vcpu->arch.gprs[rd] = ret; break; default: vcpu->arch.gprs[rd] = 0; @@ -687,6 +690,34 @@ static int kvm_handle_fpu_disabled(struct kvm_vcpu *vcpu) return RESUME_GUEST; } +static long kvm_save_notify(struct kvm_vcpu *vcpu) +{ + unsigned long id, data; + + id = kvm_read_reg(vcpu, LOONGARCH_GPR_A1); + data = kvm_read_reg(vcpu, LOONGARCH_GPR_A2); + switch (id) { + case KVM_FEATURE_STEAL_TIME: + if (!kvm_pvtime_supported()) + return KVM_HCALL_INVALID_CODE; + + if (data & ~(KVM_STEAL_PHYS_MASK | KVM_STEAL_PHYS_VALID)) + return KVM_HCALL_INVALID_PARAMETER; + + vcpu->arch.st.guest_addr = data; + if (!(data & KVM_STEAL_PHYS_VALID)) + break; + + vcpu->arch.st.last_steal = current->sched_info.run_delay; + kvm_make_request(KVM_REQ_STEAL_UPDATE, vcpu); + break; + default: + break; + }; + + return 0; +}; + /* * kvm_handle_lsx_disabled() - Guest used LSX while disabled in root. * @vcpu: Virtual CPU context. @@ -758,6 +789,9 @@ static void kvm_handle_service(struct kvm_vcpu *vcpu) kvm_send_pv_ipi(vcpu); ret = KVM_HCALL_SUCCESS; break; + case KVM_HCALL_FUNC_NOTIFY: + ret = kvm_save_notify(vcpu); + break; default: ret = KVM_HCALL_INVALID_CODE; break; diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c index 9e8030d45129..382796f1d3e6 100644 --- a/arch/loongarch/kvm/vcpu.c +++ b/arch/loongarch/kvm/vcpu.c @@ -31,6 +31,117 @@ const struct kvm_stats_header kvm_vcpu_stats_header = { sizeof(kvm_vcpu_stats_desc), }; +static void kvm_update_stolen_time(struct kvm_vcpu *vcpu) +{ + struct kvm_steal_time __user *st; + struct gfn_to_hva_cache *ghc; + struct kvm_memslots *slots; + gpa_t gpa; + u64 steal; + u32 version; + + ghc = &vcpu->arch.st.cache; + gpa = vcpu->arch.st.guest_addr; + if (!(gpa & KVM_STEAL_PHYS_VALID)) + return; + + gpa &= KVM_STEAL_PHYS_MASK; + slots = kvm_memslots(vcpu->kvm); + if (slots->generation != ghc->generation || gpa != ghc->gpa) { + if (kvm_gfn_to_hva_cache_init(vcpu->kvm, ghc, gpa, + sizeof(*st))) { + ghc->gpa = INVALID_GPA; + return; + } + } + + st = (struct kvm_steal_time __user *)ghc->hva; + unsafe_get_user(version, &st->version, out); + if (version & 1) + version += 1; + version += 1; + unsafe_put_user(version, &st->version, out); + smp_wmb(); + + unsafe_get_user(steal, &st->steal, out); + steal += current->sched_info.run_delay - + vcpu->arch.st.last_steal; + vcpu->arch.st.last_steal = current->sched_info.run_delay; + unsafe_put_user(steal, &st->steal, out); + + smp_wmb(); + version += 1; + unsafe_put_user(version, &st->version, out); +out: + mark_page_dirty_in_slot(vcpu->kvm, ghc->memslot, gpa_to_gfn(ghc->gpa)); +} + +static int kvm_loongarch_pvtime_has_attr(struct kvm_vcpu *vcpu, + struct kvm_device_attr *attr) +{ + if (!kvm_pvtime_supported() || + attr->attr != KVM_LOONGARCH_VCPU_PVTIME_GPA) + return -ENXIO; + + return 0; +} + +static int kvm_loongarch_pvtime_get_attr(struct kvm_vcpu *vcpu, + struct kvm_device_attr *attr) +{ + u64 __user *user = (u64 __user *)attr->addr; + u64 gpa; + + if (!kvm_pvtime_supported() || + attr->attr != KVM_LOONGARCH_VCPU_PVTIME_GPA) + return -ENXIO; + + gpa = vcpu->arch.st.guest_addr; + if (put_user(gpa, user)) + return -EFAULT; + + return 0; +} + +static int kvm_loongarch_pvtime_set_attr(struct kvm_vcpu *vcpu, + struct kvm_device_attr *attr) +{ + u64 __user *user = (u64 __user *)attr->addr; + struct kvm *kvm = vcpu->kvm; + u64 gpa; + int ret = 0; + int idx; + + if (!kvm_pvtime_supported() || + attr->attr != KVM_LOONGARCH_VCPU_PVTIME_GPA) + return -ENXIO; + + if (get_user(gpa, user)) + return -EFAULT; + + if (gpa & ~(KVM_STEAL_PHYS_MASK | KVM_STEAL_PHYS_VALID)) + return -EINVAL; + + if (!(gpa & KVM_STEAL_PHYS_VALID)) { + vcpu->arch.st.guest_addr = gpa; + return 0; + } + + /* Check the address is in a valid memslot */ + idx = srcu_read_lock(&kvm->srcu); + if (kvm_is_error_hva(gfn_to_hva(kvm, gpa >> PAGE_SHIFT))) + ret = -EINVAL; + srcu_read_unlock(&kvm->srcu, idx); + + if (!ret) { + vcpu->arch.st.guest_addr = gpa; + vcpu->arch.st.last_steal = current->sched_info.run_delay; + kvm_make_request(KVM_REQ_STEAL_UPDATE, vcpu); + } + + return ret; +} + /* * kvm_check_requests - check and handle pending vCPU requests * @@ -48,6 +159,9 @@ static int kvm_check_requests(struct kvm_vcpu *vcpu) if (kvm_dirty_ring_check_request(vcpu)) return RESUME_HOST; + if (kvm_check_request(KVM_REQ_STEAL_UPDATE, vcpu)) + kvm_update_stolen_time(vcpu); + return RESUME_GUEST; } @@ -671,6 +785,9 @@ static int kvm_loongarch_vcpu_has_attr(struct kvm_vcpu *vcpu, case KVM_LOONGARCH_VCPU_CPUCFG: ret = kvm_loongarch_cpucfg_has_attr(vcpu, attr); break; + case KVM_LOONGARCH_VCPU_PVTIME_CTRL: + ret = kvm_loongarch_pvtime_has_attr(vcpu, attr); + break; default: break; } @@ -703,6 +820,9 @@ static int kvm_loongarch_vcpu_get_attr(struct kvm_vcpu *vcpu, case KVM_LOONGARCH_VCPU_CPUCFG: ret = kvm_loongarch_get_cpucfg_attr(vcpu, attr); break; + case KVM_LOONGARCH_VCPU_PVTIME_CTRL: + ret = kvm_loongarch_pvtime_get_attr(vcpu, attr); + break; default: break; } @@ -725,6 +845,9 @@ static int kvm_loongarch_vcpu_set_attr(struct kvm_vcpu *vcpu, case KVM_LOONGARCH_VCPU_CPUCFG: ret = kvm_loongarch_cpucfg_set_attr(vcpu, attr); break; + case KVM_LOONGARCH_VCPU_PVTIME_CTRL: + ret = kvm_loongarch_pvtime_set_attr(vcpu, attr); + break; default: break; } @@ -1084,6 +1207,7 @@ static int _kvm_vcpu_load(struct kvm_vcpu *vcpu, int cpu) /* Control guest page CCA attribute */ change_csr_gcfg(CSR_GCFG_MATC_MASK, CSR_GCFG_MATC_ROOT); + kvm_make_request(KVM_REQ_STEAL_UPDATE, vcpu); /* Don't bother restoring registers multiple times unless necessary */ if (vcpu->arch.aux_inuse & KVM_LARCH_HWCSR_USABLE) -- 2.39.3
