| Message ID | 1523309796-36423-3-git-send-email-gengdongjiu@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Dongjiu Geng, On 09/04/18 22:36, Dongjiu Geng wrote: > This new IOCTL exports user-invisible states related to SError. > Together with appropriate user space changes, it can inject > SError with specified syndrome to guest by setup kvm_vcpu_events > value. > Also it can support live migration. Could you explain what user-space is expected to do for this? (this is also relevant for snapshot-ing/suspending VMs) It's probably worth noting that this solves an existing problem: KVM may make an SError pending, but user-space has no way to discover/migrate this. > diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt > index 8a3d708..45719b4 100644 > --- a/Documentation/virtual/kvm/api.txt > +++ b/Documentation/virtual/kvm/api.txt > @@ -819,11 +819,13 @@ struct kvm_clock_data { > > Capability: KVM_CAP_VCPU_EVENTS > Extended by: KVM_CAP_INTR_SHADOW > -Architectures: x86 > +Architectures: x86, arm, arm64 > Type: vm ioctl > Parameters: struct kvm_vcpu_event (out) > Returns: 0 on success, -1 on error > > +X86: > + > Gets currently pending exceptions, interrupts, and NMIs as well as related > states of the vcpu. > > @@ -865,15 +867,31 @@ Only two fields are defined in the flags field: > - KVM_VCPUEVENT_VALID_SMM may be set in the flags field to signal that > smi contains a valid state. > > +ARM, ARM64: > + > +Gets currently pending SError exceptions as well as related states of the vcpu. > + > +struct kvm_vcpu_events { > + struct { > + __u8 serror_pending; > + __u8 serror_has_esr; > + /* Align it to 4 bytes */ > + __u8 pad[2]; > + __u64 serror_esr; > + } exception; > +}; > + I'm not convinced we should change this struct from the layout/size x86 has. Its confusing for the documentation, is this API call really the same on all architectures? What if we want to add some future interrupt, NMI or related state? We've found ourselves needing to add this API, it seems odd to remove its other uses on x86. We can't put them back in the future. Having a different layout would force user-space to ifdef/duplicate any code that accesses this between architectures. The compiler will want that __u64 to be naturally aligned to 8-bytes, so your 4-byte padding still causes some secret compiler-padding to be inserted. Different versions of the compiler may put it in different places. > 4.32 KVM_SET_VCPU_EVENTS > > Capability: KVM_CAP_VCPU_EVENTS > Extended by: KVM_CAP_INTR_SHADOW > -Architectures: x86 > +Architectures: x86, arm, arm64 > Type: vm ioctl > Parameters: struct kvm_vcpu_event (in) > Returns: 0 on success, -1 on error > > +X86: > + > Set pending exceptions, interrupts, and NMIs as well as related states of the > vcpu. > > @@ -894,6 +912,12 @@ shall be written into the VCPU. > > KVM_VCPUEVENT_VALID_SMM can only be set if KVM_CAP_X86_SMM is available. > > +ARM, ARM64: > + > +Set pending SError exceptions as well as related states of the vcpu. > + > +See KVM_GET_VCPU_EVENTS for the data structure. > + > > 4.33 KVM_GET_DEBUGREGS > > diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h > index 9abbf30..855cc9a 100644 > --- a/arch/arm64/include/uapi/asm/kvm.h > +++ b/arch/arm64/include/uapi/asm/kvm.h > @@ -39,6 +39,7 @@ > #define __KVM_HAVE_GUEST_DEBUG > #define __KVM_HAVE_IRQ_LINE > #define __KVM_HAVE_READONLY_MEM > +#define __KVM_HAVE_VCPU_EVENTS > > #define KVM_COALESCED_MMIO_PAGE_OFFSET 1 > > @@ -153,6 +154,17 @@ struct kvm_sync_regs { > struct kvm_arch_memory_slot { > }; > > +/* for KVM_GET/SET_VCPU_EVENTS */ > +struct kvm_vcpu_events { > + struct { > + __u8 serror_pending; > + __u8 serror_has_esr; > + /* Align it to 4 bytes */ > + __u8 pad[2]; (padding noted above) > + __u64 serror_esr; > + } exception; > +}; > + > /* If you need to interpret the index values, here is the key: */ > #define KVM_REG_ARM_COPROC_MASK 0x000000000FFF0000 > #define KVM_REG_ARM_COPROC_SHIFT 16 > diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c > index 5c7f657..42e1222 100644 > --- a/arch/arm64/kvm/guest.c > +++ b/arch/arm64/kvm/guest.c > @@ -277,6 +277,37 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu, > return -EINVAL; > } > > +int kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu, > + struct kvm_vcpu_events *events) > +{ > + events->exception.serror_pending = (vcpu_get_hcr(vcpu) & HCR_VSE); > + events->exception.serror_has_esr = > + cpus_have_const_cap(ARM64_HAS_RAS_EXTN) && > + (!!vcpu_get_vsesr(vcpu)); > + events->exception.serror_esr = vcpu_get_vsesr(vcpu); This will return a stale ESR even if nothing is pending. On systems without the RAS extensions it will return 'ESR_ELx_ISV' if kvm_inject_vabt() has ever been called for this CPU. Could we hide this behind (pending && has_esr), setting it to 0 otherwise. This is just to avoid exposing the stale value. > + > + return 0; > +} > +int kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu, > + struct kvm_vcpu_events *events) > +{ > + bool injected = events->exception.serror_pending; > + bool has_esr = events->exception.serror_has_esr; > + > + if (injected && has_esr) { > + if (!cpus_have_const_cap(ARM64_HAS_RAS_EXTN)) > + return -EINVAL; > + > + kvm_set_sei_esr(vcpu, events->exception.serror_esr); > + > + } else if (injected) { > + kvm_inject_vabt(vcpu); Nit: looks like 'injected' is misnamed. > + } > + > + return 0; > +} > + > int __attribute_const__ kvm_target_cpu(void) > { > unsigned long implementor = read_cpuid_implementor(); > diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c > index 38c8a64..20e919a 100644 > --- a/arch/arm64/kvm/reset.c > +++ b/arch/arm64/kvm/reset.c > @@ -82,6 +82,7 @@ int kvm_arch_dev_ioctl_check_extension(struct kvm *kvm, long ext) > break; > case KVM_CAP_SET_GUEST_DEBUG: > case KVM_CAP_VCPU_ATTRIBUTES: > + case KVM_CAP_VCPU_EVENTS: > r = 1; > break; > default: > diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c > index 7e3941f..945655d 100644 > --- a/virt/kvm/arm/arm.c > +++ b/virt/kvm/arm/arm.c > @@ -1051,6 +1051,27 @@ long kvm_arch_vcpu_ioctl(struct file *filp, > return -EFAULT; > return kvm_arm_vcpu_has_attr(vcpu, &attr); > } > + case KVM_GET_VCPU_EVENTS: { > + struct kvm_vcpu_events events; > + > + memset(&events, 0, sizeof(struct kvm_vcpu_events)); sizeof(events) is the normal style here, it means if someone changes event's type we don't get any surprises... > + if (kvm_arm_vcpu_get_events(vcpu, &events)) > + return -EINVAL; > + > + if (copy_to_user(argp, &events, sizeof(struct kvm_vcpu_events))) sizeof(events) > + return -EFAULT; > + > + return 0; > + } > + case KVM_SET_VCPU_EVENTS: { > + struct kvm_vcpu_events events; > + > + if (copy_from_user(&events, argp, > + sizeof(struct kvm_vcpu_events))) > + return -EFAULT; > + > + return kvm_arm_vcpu_set_events(vcpu, &events); > + } > default: > return -EINVAL; > } > Despite KVM_CAP_VCPU_EVENTS not being advertised on 32bit, any attempt to call it will still end up in here, but will always fail as the {g,s}et_events() calls always return -EINVAL. I don't think this will cause us any problems. Thanks, James
Hi James, Thanks for the comments. 2018-04-10 22:15 GMT+08:00, James Morse <james.morse@arm.com>: > Hi Dongjiu Geng, > > On 09/04/18 22:36, Dongjiu Geng wrote: >> This new IOCTL exports user-invisible states related to SError. >> Together with appropriate user space changes, it can inject >> SError with specified syndrome to guest by setup kvm_vcpu_events >> value. > >> Also it can support live migration. > > Could you explain what user-space is expected to do for this? > (this is also relevant for snapshot-ing/suspending VMs) Ok. > > It's probably worth noting that this solves an existing problem: KVM may > make an > SError pending, but user-space has no way to discover/migrate this. if KVM make an SError pending, when user-space do migration, it get the kvm_vcpu_events through KVM_GET_VCPU_EVENTS, then can find that pending status. What are the things you're worried about? > > >> diff --git a/Documentation/virtual/kvm/api.txt >> b/Documentation/virtual/kvm/api.txt >> index 8a3d708..45719b4 100644 >> --- a/Documentation/virtual/kvm/api.txt >> +++ b/Documentation/virtual/kvm/api.txt >> @@ -819,11 +819,13 @@ struct kvm_clock_data { >> >> Capability: KVM_CAP_VCPU_EVENTS >> Extended by: KVM_CAP_INTR_SHADOW >> -Architectures: x86 >> +Architectures: x86, arm, arm64 >> Type: vm ioctl >> Parameters: struct kvm_vcpu_event (out) >> Returns: 0 on success, -1 on error >> >> +X86: >> + >> Gets currently pending exceptions, interrupts, and NMIs as well as >> related >> states of the vcpu. >> >> @@ -865,15 +867,31 @@ Only two fields are defined in the flags field: >> - KVM_VCPUEVENT_VALID_SMM may be set in the flags field to signal that >> smi contains a valid state. >> >> +ARM, ARM64: >> + >> +Gets currently pending SError exceptions as well as related states of the >> vcpu. >> + >> +struct kvm_vcpu_events { >> + struct { >> + __u8 serror_pending; >> + __u8 serror_has_esr; >> + /* Align it to 4 bytes */ >> + __u8 pad[2]; >> + __u64 serror_esr; >> + } exception; >> +}; >> + > > I'm not convinced we should change this struct from the layout/size x86 has. > Its > confusing for the documentation, is this API call really the same on all > architectures? > > What if we want to add some future interrupt, NMI or related state? We've > found > ourselves needing to add this API, it seems odd to remove its other uses on > x86. > We can't put them back in the future. > > Having a different layout would force user-space to ifdef/duplicate any > code > that accesses this between architectures. In x86 and arm64 user space code, the handling logic of KVM_GET/SET_VCPU_EVENTS is in different ARCH folder, maybe it is not necessary to share the handling code in the user space. > > > > The compiler will want that __u64 to be naturally aligned to 8-bytes, so > your > 4-byte padding still causes some secret compiler-padding to be inserted. > Different versions of the compiler may put it in different places. > > >> 4.32 KVM_SET_VCPU_EVENTS >> >> Capability: KVM_CAP_VCPU_EVENTS >> Extended by: KVM_CAP_INTR_SHADOW >> -Architectures: x86 >> +Architectures: x86, arm, arm64 >> Type: vm ioctl >> Parameters: struct kvm_vcpu_event (in) >> Returns: 0 on success, -1 on error >> >> +X86: >> + >> Set pending exceptions, interrupts, and NMIs as well as related states of >> the >> vcpu. >> >> @@ -894,6 +912,12 @@ shall be written into the VCPU. >> >> KVM_VCPUEVENT_VALID_SMM can only be set if KVM_CAP_X86_SMM is available. >> >> +ARM, ARM64: >> + >> +Set pending SError exceptions as well as related states of the vcpu. >> + >> +See KVM_GET_VCPU_EVENTS for the data structure. >> + >> >> 4.33 KVM_GET_DEBUGREGS >> > > >> diff --git a/arch/arm64/include/uapi/asm/kvm.h >> b/arch/arm64/include/uapi/asm/kvm.h >> index 9abbf30..855cc9a 100644 >> --- a/arch/arm64/include/uapi/asm/kvm.h >> +++ b/arch/arm64/include/uapi/asm/kvm.h >> @@ -39,6 +39,7 @@ >> #define __KVM_HAVE_GUEST_DEBUG >> #define __KVM_HAVE_IRQ_LINE >> #define __KVM_HAVE_READONLY_MEM >> +#define __KVM_HAVE_VCPU_EVENTS >> >> #define KVM_COALESCED_MMIO_PAGE_OFFSET 1 >> >> @@ -153,6 +154,17 @@ struct kvm_sync_regs { >> struct kvm_arch_memory_slot { >> }; >> >> +/* for KVM_GET/SET_VCPU_EVENTS */ >> +struct kvm_vcpu_events { >> + struct { >> + __u8 serror_pending; >> + __u8 serror_has_esr; > >> + /* Align it to 4 bytes */ >> + __u8 pad[2]; > > (padding noted above) > > >> + __u64 serror_esr; >> + } exception; >> +}; >> + >> /* If you need to interpret the index values, here is the key: */ >> #define KVM_REG_ARM_COPROC_MASK 0x000000000FFF0000 >> #define KVM_REG_ARM_COPROC_SHIFT 16 > > >> diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c >> index 5c7f657..42e1222 100644 >> --- a/arch/arm64/kvm/guest.c >> +++ b/arch/arm64/kvm/guest.c >> @@ -277,6 +277,37 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu >> *vcpu, >> return -EINVAL; >> } >> >> +int kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu, >> + struct kvm_vcpu_events *events) >> +{ >> + events->exception.serror_pending = (vcpu_get_hcr(vcpu) & HCR_VSE); >> + events->exception.serror_has_esr = >> + cpus_have_const_cap(ARM64_HAS_RAS_EXTN) && >> + (!!vcpu_get_vsesr(vcpu)); > >> + events->exception.serror_esr = vcpu_get_vsesr(vcpu); > > This will return a stale ESR even if nothing is pending. On systems without > the > RAS extensions it will return 'ESR_ELx_ISV' if kvm_inject_vabt() has ever > been > called for this CPU. > > Could we hide this behind (pending && has_esr), setting it to 0 otherwise. > This > is just to avoid exposing the stale value. Exactly, it is indeed. > > >> + >> + return 0; >> +} > >> +int kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu, >> + struct kvm_vcpu_events *events) >> +{ >> + bool injected = events->exception.serror_pending; >> + bool has_esr = events->exception.serror_has_esr; >> + >> + if (injected && has_esr) { >> + if (!cpus_have_const_cap(ARM64_HAS_RAS_EXTN)) >> + return -EINVAL; >> + >> + kvm_set_sei_esr(vcpu, events->exception.serror_esr); >> + >> + } else if (injected) { >> + kvm_inject_vabt(vcpu); > > Nit: looks like 'injected' is misnamed. "injected" change to "pending"? > > >> + } >> + >> + return 0; >> +} >> + >> int __attribute_const__ kvm_target_cpu(void) >> { >> unsigned long implementor = read_cpuid_implementor(); > > >> diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c >> index 38c8a64..20e919a 100644 >> --- a/arch/arm64/kvm/reset.c >> +++ b/arch/arm64/kvm/reset.c >> @@ -82,6 +82,7 @@ int kvm_arch_dev_ioctl_check_extension(struct kvm *kvm, >> long ext) >> break; >> case KVM_CAP_SET_GUEST_DEBUG: >> case KVM_CAP_VCPU_ATTRIBUTES: >> + case KVM_CAP_VCPU_EVENTS: >> r = 1; >> break; >> default: > >> diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c >> index 7e3941f..945655d 100644 >> --- a/virt/kvm/arm/arm.c >> +++ b/virt/kvm/arm/arm.c >> @@ -1051,6 +1051,27 @@ long kvm_arch_vcpu_ioctl(struct file *filp, >> return -EFAULT; >> return kvm_arm_vcpu_has_attr(vcpu, &attr); >> } >> + case KVM_GET_VCPU_EVENTS: { >> + struct kvm_vcpu_events events; >> + >> + memset(&events, 0, sizeof(struct kvm_vcpu_events)); > > sizeof(events) is the normal style here, it means if someone changes > event's > type we don't get any surprises... Ok, thanks > > >> + if (kvm_arm_vcpu_get_events(vcpu, &events)) >> + return -EINVAL; >> + >> + if (copy_to_user(argp, &events, sizeof(struct kvm_vcpu_events))) > > sizeof(events) thanks > > >> + return -EFAULT; >> + >> + return 0; >> + } >> + case KVM_SET_VCPU_EVENTS: { >> + struct kvm_vcpu_events events; >> + >> + if (copy_from_user(&events, argp, >> + sizeof(struct kvm_vcpu_events))) >> + return -EFAULT; >> + >> + return kvm_arm_vcpu_set_events(vcpu, &events); >> + } >> default: >> return -EINVAL; >> } >> > > Despite KVM_CAP_VCPU_EVENTS not being advertised on 32bit, any attempt to > call > it will still end up in here, but will always fail as the {g,s}et_events() > calls > always return -EINVAL. I don't think this will cause us any problems. What are the things you're worried about? > > > Thanks, > > James > _______________________________________________ > kvmarm mailing list > kvmarm@lists.cs.columbia.edu > https://lists.cs.columbia.edu/mailman/listinfo/kvmarm >
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 8a3d708..45719b4 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -819,11 +819,13 @@ struct kvm_clock_data { Capability: KVM_CAP_VCPU_EVENTS Extended by: KVM_CAP_INTR_SHADOW -Architectures: x86 +Architectures: x86, arm, arm64 Type: vm ioctl Parameters: struct kvm_vcpu_event (out) Returns: 0 on success, -1 on error +X86: + Gets currently pending exceptions, interrupts, and NMIs as well as related states of the vcpu. @@ -865,15 +867,31 @@ Only two fields are defined in the flags field: - KVM_VCPUEVENT_VALID_SMM may be set in the flags field to signal that smi contains a valid state. +ARM, ARM64: + +Gets currently pending SError exceptions as well as related states of the vcpu. + +struct kvm_vcpu_events { + struct { + __u8 serror_pending; + __u8 serror_has_esr; + /* Align it to 4 bytes */ + __u8 pad[2]; + __u64 serror_esr; + } exception; +}; + 4.32 KVM_SET_VCPU_EVENTS Capability: KVM_CAP_VCPU_EVENTS Extended by: KVM_CAP_INTR_SHADOW -Architectures: x86 +Architectures: x86, arm, arm64 Type: vm ioctl Parameters: struct kvm_vcpu_event (in) Returns: 0 on success, -1 on error +X86: + Set pending exceptions, interrupts, and NMIs as well as related states of the vcpu. @@ -894,6 +912,12 @@ shall be written into the VCPU. KVM_VCPUEVENT_VALID_SMM can only be set if KVM_CAP_X86_SMM is available. +ARM, ARM64: + +Set pending SError exceptions as well as related states of the vcpu. + +See KVM_GET_VCPU_EVENTS for the data structure. + 4.33 KVM_GET_DEBUGREGS diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index ef54013..d81621e 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -211,6 +211,12 @@ struct kvm_vcpu_stat { int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *indices); int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg); int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg); +int kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu, + struct kvm_vcpu_events *events); + +int kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu, + struct kvm_vcpu_events *events); + unsigned long kvm_call_hyp(void *hypfn, ...); void force_vm_exit(const cpumask_t *mask); diff --git a/arch/arm/kvm/guest.c b/arch/arm/kvm/guest.c index 1e0784e..39f895d 100644 --- a/arch/arm/kvm/guest.c +++ b/arch/arm/kvm/guest.c @@ -248,6 +248,18 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu, return -EINVAL; } +int kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu, + struct kvm_vcpu_events *events) +{ + return -EINVAL; +} + +int kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu, + struct kvm_vcpu_events *events) +{ + return -EINVAL; +} + int __attribute_const__ kvm_target_cpu(void) { switch (read_cpuid_part()) { diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h index 413dc82..3294885 100644 --- a/arch/arm64/include/asm/kvm_emulate.h +++ b/arch/arm64/include/asm/kvm_emulate.h @@ -71,6 +71,11 @@ static inline void vcpu_set_hcr(struct kvm_vcpu *vcpu, unsigned long hcr) vcpu->arch.hcr_el2 = hcr; } +static inline unsigned long vcpu_get_vsesr(struct kvm_vcpu *vcpu) +{ + return vcpu->arch.vsesr_el2; +} + static inline void vcpu_set_vsesr(struct kvm_vcpu *vcpu, u64 vsesr) { vcpu->arch.vsesr_el2 = vsesr; diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index a73f63a..1125540 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -326,6 +326,11 @@ struct kvm_vcpu_stat { int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *indices); int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg); int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg); +int kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu, + struct kvm_vcpu_events *events); + +int kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu, + struct kvm_vcpu_events *events); #define KVM_ARCH_WANT_MMU_NOTIFIER int kvm_unmap_hva(struct kvm *kvm, unsigned long hva); @@ -354,6 +359,8 @@ void handle_exit_early(struct kvm_vcpu *vcpu, struct kvm_run *run, int kvm_perf_init(void); int kvm_perf_teardown(void); +void kvm_set_sei_esr(struct kvm_vcpu *vcpu, u64 syndrome); + struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr); static inline void __cpu_init_hyp_mode(phys_addr_t pgd_ptr, diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h index 9abbf30..855cc9a 100644 --- a/arch/arm64/include/uapi/asm/kvm.h +++ b/arch/arm64/include/uapi/asm/kvm.h @@ -39,6 +39,7 @@ #define __KVM_HAVE_GUEST_DEBUG #define __KVM_HAVE_IRQ_LINE #define __KVM_HAVE_READONLY_MEM +#define __KVM_HAVE_VCPU_EVENTS #define KVM_COALESCED_MMIO_PAGE_OFFSET 1 @@ -153,6 +154,17 @@ struct kvm_sync_regs { struct kvm_arch_memory_slot { }; +/* for KVM_GET/SET_VCPU_EVENTS */ +struct kvm_vcpu_events { + struct { + __u8 serror_pending; + __u8 serror_has_esr; + /* Align it to 4 bytes */ + __u8 pad[2]; + __u64 serror_esr; + } exception; +}; + /* If you need to interpret the index values, here is the key: */ #define KVM_REG_ARM_COPROC_MASK 0x000000000FFF0000 #define KVM_REG_ARM_COPROC_SHIFT 16 diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c index 5c7f657..42e1222 100644 --- a/arch/arm64/kvm/guest.c +++ b/arch/arm64/kvm/guest.c @@ -277,6 +277,37 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu, return -EINVAL; } +int kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu, + struct kvm_vcpu_events *events) +{ + events->exception.serror_pending = (vcpu_get_hcr(vcpu) & HCR_VSE); + events->exception.serror_has_esr = + cpus_have_const_cap(ARM64_HAS_RAS_EXTN) && + (!!vcpu_get_vsesr(vcpu)); + events->exception.serror_esr = vcpu_get_vsesr(vcpu); + + return 0; +} + +int kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu, + struct kvm_vcpu_events *events) +{ + bool injected = events->exception.serror_pending; + bool has_esr = events->exception.serror_has_esr; + + if (injected && has_esr) { + if (!cpus_have_const_cap(ARM64_HAS_RAS_EXTN)) + return -EINVAL; + + kvm_set_sei_esr(vcpu, events->exception.serror_esr); + + } else if (injected) { + kvm_inject_vabt(vcpu); + } + + return 0; +} + int __attribute_const__ kvm_target_cpu(void) { unsigned long implementor = read_cpuid_implementor(); diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c index 60666a0..aa0358a 100644 --- a/arch/arm64/kvm/inject_fault.c +++ b/arch/arm64/kvm/inject_fault.c @@ -166,7 +166,7 @@ void kvm_inject_undefined(struct kvm_vcpu *vcpu) static void pend_guest_serror(struct kvm_vcpu *vcpu, u64 esr) { - vcpu_set_vsesr(vcpu, esr); + vcpu_set_vsesr(vcpu, esr & ESR_ELx_ISS_MASK); vcpu_set_hcr(vcpu, vcpu_get_hcr(vcpu) | HCR_VSE); } @@ -186,3 +186,8 @@ void kvm_inject_vabt(struct kvm_vcpu *vcpu) { pend_guest_serror(vcpu, ESR_ELx_ISV); } + +void kvm_set_sei_esr(struct kvm_vcpu *vcpu, u64 syndrome) +{ + pend_guest_serror(vcpu, syndrome); +} diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index 38c8a64..20e919a 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -82,6 +82,7 @@ int kvm_arch_dev_ioctl_check_extension(struct kvm *kvm, long ext) break; case KVM_CAP_SET_GUEST_DEBUG: case KVM_CAP_VCPU_ATTRIBUTES: + case KVM_CAP_VCPU_EVENTS: r = 1; break; default: diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index 7e3941f..945655d 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -1051,6 +1051,27 @@ long kvm_arch_vcpu_ioctl(struct file *filp, return -EFAULT; return kvm_arm_vcpu_has_attr(vcpu, &attr); } + case KVM_GET_VCPU_EVENTS: { + struct kvm_vcpu_events events; + + memset(&events, 0, sizeof(struct kvm_vcpu_events)); + if (kvm_arm_vcpu_get_events(vcpu, &events)) + return -EINVAL; + + if (copy_to_user(argp, &events, sizeof(struct kvm_vcpu_events))) + return -EFAULT; + + return 0; + } + case KVM_SET_VCPU_EVENTS: { + struct kvm_vcpu_events events; + + if (copy_from_user(&events, argp, + sizeof(struct kvm_vcpu_events))) + return -EFAULT; + + return kvm_arm_vcpu_set_events(vcpu, &events); + } default: return -EINVAL; }
This new IOCTL exports user-invisible states related to SError. Together with appropriate user space changes, it can inject SError with specified syndrome to guest by setup kvm_vcpu_events value. Also it can support live migration. Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com> Change since V10: Address James's comments, thanks James 1. Merge the helper function with the user. 2. Move the ISS_MASK into pend_guest_serror() to clear top bits 3. Make kvm_vcpu_events struct align to 4 bytes 4. Add something check in the kvm_arm_vcpu_set_events() 5. Check kvm_arm_vcpu_get/set_events()'s return value. 6. Initialise kvm_vcpu_events to 0 so that padding transferred to user-space doesn't contain kernel stack. --- Documentation/virtual/kvm/api.txt | 28 ++++++++++++++++++++++++++-- arch/arm/include/asm/kvm_host.h | 6 ++++++ arch/arm/kvm/guest.c | 12 ++++++++++++ arch/arm64/include/asm/kvm_emulate.h | 5 +++++ arch/arm64/include/asm/kvm_host.h | 7 +++++++ arch/arm64/include/uapi/asm/kvm.h | 12 ++++++++++++ arch/arm64/kvm/guest.c | 31 +++++++++++++++++++++++++++++++ arch/arm64/kvm/inject_fault.c | 7 ++++++- arch/arm64/kvm/reset.c | 1 + virt/kvm/arm/arm.c | 21 +++++++++++++++++++++ 10 files changed, 127 insertions(+), 3 deletions(-)