| Message ID | 20210310003024.2026253-3-jingzhangos@google.com |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | [RFC,1/4] KVM: stats: Separate statistics name strings from debugfs code | expand |
On Wed, 10 Mar 2021 00:30:22 +0000, Jing Zhang <jingzhangos@google.com> wrote: > > Define ioctl commands for VM/vCPU aggregated statistics data retrieval > in binary format and update corresponding API documentation. > > The capability and ioctl are not enabled for now. > No functional change intended. > > Signed-off-by: Jing Zhang <jingzhangos@google.com> > --- > Documentation/virt/kvm/api.rst | 79 ++++++++++++++++++++++++++++++++++ > include/linux/kvm_host.h | 1 - > include/uapi/linux/kvm.h | 60 ++++++++++++++++++++++++++ > 3 files changed, 139 insertions(+), 1 deletion(-) > > diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst > index 1a2b5210cdbf..aa4b5270c966 100644 > --- a/Documentation/virt/kvm/api.rst > +++ b/Documentation/virt/kvm/api.rst > @@ -4938,6 +4938,76 @@ see KVM_XEN_VCPU_SET_ATTR above. > The KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST type may not be used > with the KVM_XEN_VCPU_GET_ATTR ioctl. > > +4.131 KVM_STATS_GET_INFO > +------------------------ > + > +:Capability: KVM_CAP_STATS_BINARY_FORM > +:Architectures: all > +:Type: vm ioctl, vcpu ioctl > +:Parameters: struct kvm_stats_info (out) > +:Returns: 0 on success, < 0 on error Missing description of the errors (this is throughout the document). > + > +:: > + > + struct kvm_stats_info { > + __u32 num_stats; > + }; > + > +This ioctl is used to get the information about VM or vCPU statistics data. > +The number of statistics data would be returned in field num_stats in > +struct kvm_stats_info. This ioctl only needs to be called once on running > +VMs on the same architecture. Is this allowed to be variable across VMs? Or is that a constant for a given host system boot? Given that this returns a single field, is there any value in copying this structure across? Could it be returned by the ioctl itself instead, at the expense of only being a 31bit value? > + > +4.132 KVM_STATS_GET_NAMES > +------------------------- > + > +:Capability: KVM_CAP_STATS_BINARY_FORM > +:Architectures: all > +:Type: vm ioctl, vcpu ioctl > +:Parameters: struct kvm_stats_names (in/out) > +:Returns: 0 on success, < 0 on error > + > +:: > + > + #define KVM_STATS_NAME_LEN 32 > + struct kvm_stats_names { > + __u32 size; > + __u8 names[0]; > + }; > + > +This ioctl is used to get the string names of all the statistics data for VM > +or vCPU. Users must use KVM_STATS_GET_INFO to find the number of statistics. > +They must allocate a buffer of the size num_stats * KVM_STATS_NAME_LEN > +immediately following struct kvm_stats_names. The size field of kvm_stats_name > +must contain the buffer size as an input. What is the unit for the buffer size? bytes? or number of "names"? > +The buffer can be treated like a string array, each name string is null-padded > +to a size of KVM_STATS_NAME_LEN; Is this allowed to query fewer strings than described by kvm_stats_info? If it isn't, I question the need for the "size" field. Either there is enough space in the buffer passed by userspace, or -EFAULT is returned. > +This ioclt only needs to be called once on running VMs on the same architecture. Same question about the immutability of these names. > + > +4.133 KVM_STATS_GET_DATA > +------------------------- > + > +:Capability: KVM_CAP_STATS_BINARY_FORM > +:Architectures: all > +:Type: vm ioctl, vcpu ioctl > +:Parameters: struct kvm_stats_data (in/out) > +:Returns: 0 on success, < 0 on error > + > +:: > + > + struct kvm_stats_data { > + __u32 size; Same question about the actual need for this field. > + __u64 data[0]; So userspace always sees a 64bit quantify per stat. My earlier comment about the ulong/u64 discrepancy stands! ;-) > + }; > + > +This ioctl is used to get the aggregated statistics data for VM or vCPU. > +Users must use KVM_STATS_GET_INFO to find the number of statistics. > +They must allocate a buffer of the appropriate size num_stats * sizeof(data[0]) > +immediately following struct kvm_stats_data. The size field of kvm_stats_data > +must contain the buffer size as an input. > +The data buffer 1-1 maps to name strings buffer in sequential order. > +This ioctl is usually called periodically to pull statistics data. Is there any provision to reset the counters on read? > + > 5. The kvm_run structure > ======================== > > @@ -6721,3 +6791,12 @@ vcpu_info is set. > The KVM_XEN_HVM_CONFIG_RUNSTATE flag indicates that the runstate-related > features KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR/_CURRENT/_DATA/_ADJUST are > supported by the KVM_XEN_VCPU_SET_ATTR/KVM_XEN_VCPU_GET_ATTR ioctls. > + > +8.31 KVM_CAP_STATS_BINARY_FORM > +------------------------------ > + > +:Architectures: all > + > +This capability indicates that KVM supports retrieving aggregated statistics > +data in binary format with corresponding VM/VCPU ioctl KVM_STATS_GET_INFO, > +KVM_STATS_GET_NAMES and KVM_STATS_GET_DATA. nit: for ease of reviewing, consider splitting the documentation in a separate patch. > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h > index 1ea297458306..f2dabf457717 100644 > --- a/include/linux/kvm_host.h > +++ b/include/linux/kvm_host.h > @@ -1164,7 +1164,6 @@ static inline bool kvm_is_error_gpa(struct kvm *kvm, gpa_t gpa) > > #define VM_STAT_COUNT (sizeof(struct kvm_vm_stat)/sizeof(ulong)) > #define VCPU_STAT_COUNT (sizeof(struct kvm_vcpu_stat)/sizeof(u64)) > -#define KVM_STATS_NAME_LEN 32 > > /* Make sure it is synced with fields in struct kvm_vm_stat. */ > extern const char kvm_vm_stat_strings[][KVM_STATS_NAME_LEN]; > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > index f6afee209620..ad185d4c5e42 100644 > --- a/include/uapi/linux/kvm.h > +++ b/include/uapi/linux/kvm.h > @@ -1078,6 +1078,7 @@ struct kvm_ppc_resize_hpt { > #define KVM_CAP_DIRTY_LOG_RING 192 > #define KVM_CAP_X86_BUS_LOCK_EXIT 193 > #define KVM_CAP_PPC_DAWR1 194 > +#define KVM_CAP_STATS_BINARY_FORM 195 > > #ifdef KVM_CAP_IRQ_ROUTING > > @@ -1853,4 +1854,63 @@ struct kvm_dirty_gfn { > #define KVM_BUS_LOCK_DETECTION_OFF (1 << 0) > #define KVM_BUS_LOCK_DETECTION_EXIT (1 << 1) > > +/* Available with KVM_CAP_STATS_BINARY_FORM */ > + > +#define KVM_STATS_NAME_LEN 32 > + > +/** > + * struct kvm_stats_info - statistics information > + * > + * Used as parameter for ioctl %KVM_STATS_GET_INFO. > + * > + * @num_stats: On return, the number of statistics data of vm or vcpu. > + * > + */ > +struct kvm_stats_info { > + __u32 num_stats; > +}; > + > +/** > + * struct kvm_stats_names - string list of statistics names > + * > + * Used as parameter for ioctl %KVM_STATS_GET_NAMES. > + * > + * @size: Input from user, indicating the size of buffer after the struture. > + * @names: Buffer of name string list for vm or vcpu. Each string is > + * null-padded to a size of %KVM_STATS_NAME_LEN. > + * > + * Users must use %KVM_STATS_GET_INFO to find the number of > + * statistics. They must allocate a buffer of the appropriate > + * size (>= &struct kvm_stats_info @num_stats * %KVM_STATS_NAME_LEN) > + * immediately following this struture. > + */ > +struct kvm_stats_names { > + __u32 size; > + __u8 names[0]; > +}; > + > +/** > + * struct kvm_stats_data - statistics data array > + * > + * Used as parameter for ioctl %KVM_STATS_GET_DATA. > + * > + * @size: Input from user, indicating the size of buffer after the struture. > + * @data: Buffer of statistics data for vm or vcpu. > + * > + * Users must use %KVM_STATS_GET_INFO to find the number of > + * statistics. They must allocate a buffer of the appropriate > + * size (>= &struct kvm_stats_info @num_stats * sizeof(@data[0]) > + * immediately following this structure. > + * &struct kvm_stats_names @names 1-1 maps to &structkvm_stats_data > + * @data in sequential order. > + */ > +struct kvm_stats_data { > + __u32 size; > + __u64 data[0]; > +}; > + > +#define KVM_STATS_GET_INFO _IOR(KVMIO, 0xcc, struct kvm_stats_info) > +#define KVM_STATS_GET_NAMES _IOR(KVMIO, 0xcd, struct kvm_stats_names) > +#define KVM_STATS_GET_DATA _IOR(KVMIO, 0xce, struct kvm_stats_data) > + > #endif /* __LINUX_KVM_H */ > -- > 2.30.1.766.gb4fecdf3b7-goog > > Thanks, M.
Hi Marc, On Wed, Mar 10, 2021 at 8:58 AM Marc Zyngier <maz@kernel.org> wrote: > > On Wed, 10 Mar 2021 00:30:22 +0000, > Jing Zhang <jingzhangos@google.com> wrote: > > > > Define ioctl commands for VM/vCPU aggregated statistics data retrieval > > in binary format and update corresponding API documentation. > > > > The capability and ioctl are not enabled for now. > > No functional change intended. > > > > Signed-off-by: Jing Zhang <jingzhangos@google.com> > > --- > > Documentation/virt/kvm/api.rst | 79 ++++++++++++++++++++++++++++++++++ > > include/linux/kvm_host.h | 1 - > > include/uapi/linux/kvm.h | 60 ++++++++++++++++++++++++++ > > 3 files changed, 139 insertions(+), 1 deletion(-) > > > > diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst > > index 1a2b5210cdbf..aa4b5270c966 100644 > > --- a/Documentation/virt/kvm/api.rst > > +++ b/Documentation/virt/kvm/api.rst > > @@ -4938,6 +4938,76 @@ see KVM_XEN_VCPU_SET_ATTR above. > > The KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST type may not be used > > with the KVM_XEN_VCPU_GET_ATTR ioctl. > > > > +4.131 KVM_STATS_GET_INFO > > +------------------------ > > + > > +:Capability: KVM_CAP_STATS_BINARY_FORM > > +:Architectures: all > > +:Type: vm ioctl, vcpu ioctl > > +:Parameters: struct kvm_stats_info (out) > > +:Returns: 0 on success, < 0 on error > > > Missing description of the errors (this is throughout the document). Will add errors description. > > > + > > +:: > > + > > + struct kvm_stats_info { > > + __u32 num_stats; > > + }; > > + > > +This ioctl is used to get the information about VM or vCPU statistics data. > > +The number of statistics data would be returned in field num_stats in > > +struct kvm_stats_info. This ioctl only needs to be called once on running > > +VMs on the same architecture. > > Is this allowed to be variable across VMs? Or is that a constant for a > given host system boot? It is a constant for a given host system boot. > > Given that this returns a single field, is there any value in copying > this structure across? Could it be returned by the ioctl itself > instead, at the expense of only being a 31bit value? It is done in this way for potential information we need in the future. One candidate is the length of stats names. I am considering to return the length of name string in this info structure instead of as a constant exported by uapi, which would be more flexible and put no limit on the length of stats names. > > > + > > +4.132 KVM_STATS_GET_NAMES > > +------------------------- > > + > > +:Capability: KVM_CAP_STATS_BINARY_FORM > > +:Architectures: all > > +:Type: vm ioctl, vcpu ioctl > > +:Parameters: struct kvm_stats_names (in/out) > > +:Returns: 0 on success, < 0 on error > > + > > +:: > > + > > + #define KVM_STATS_NAME_LEN 32 > > + struct kvm_stats_names { > > + __u32 size; > > + __u8 names[0]; > > + }; > > + > > +This ioctl is used to get the string names of all the statistics data for VM > > +or vCPU. Users must use KVM_STATS_GET_INFO to find the number of statistics. > > +They must allocate a buffer of the size num_stats * KVM_STATS_NAME_LEN > > +immediately following struct kvm_stats_names. The size field of kvm_stats_name > > +must contain the buffer size as an input. > > What is the unit for the buffer size? bytes? or number of "names"? The unit for the buffer size is bytes. Will clearly indicate the unit. > > > +The buffer can be treated like a string array, each name string is null-padded > > +to a size of KVM_STATS_NAME_LEN; > > Is this allowed to query fewer strings than described by > kvm_stats_info? If it isn't, I question the need for the "size" > field. Either there is enough space in the buffer passed by userspace, > or -EFAULT is returned. It isn't. Will remove the size field. > > > +This ioclt only needs to be called once on running VMs on the same architecture. > > Same question about the immutability of these names. The names are immutable for a given system boot. > > > + > > +4.133 KVM_STATS_GET_DATA > > +------------------------- > > + > > +:Capability: KVM_CAP_STATS_BINARY_FORM > > +:Architectures: all > > +:Type: vm ioctl, vcpu ioctl > > +:Parameters: struct kvm_stats_data (in/out) > > +:Returns: 0 on success, < 0 on error > > + > > +:: > > + > > + struct kvm_stats_data { > > + __u32 size; > > Same question about the actual need for this field. Will remove size field. > > > + __u64 data[0]; > > So userspace always sees a 64bit quantify per stat. My earlier comment > about the ulong/u64 discrepancy stands! ;-) Yes, userspace always sees a 64 bit, but the ulong in KVM would be 64bit or 32bit. > > > + }; > > + > > +This ioctl is used to get the aggregated statistics data for VM or vCPU. > > +Users must use KVM_STATS_GET_INFO to find the number of statistics. > > +They must allocate a buffer of the appropriate size num_stats * sizeof(data[0]) > > +immediately following struct kvm_stats_data. The size field of kvm_stats_data > > +must contain the buffer size as an input. > > +The data buffer 1-1 maps to name strings buffer in sequential order. > > +This ioctl is usually called periodically to pull statistics data. > > Is there any provision to reset the counters on read? Nope. > > > + > > 5. The kvm_run structure > > ======================== > > > > @@ -6721,3 +6791,12 @@ vcpu_info is set. > > The KVM_XEN_HVM_CONFIG_RUNSTATE flag indicates that the runstate-related > > features KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR/_CURRENT/_DATA/_ADJUST are > > supported by the KVM_XEN_VCPU_SET_ATTR/KVM_XEN_VCPU_GET_ATTR ioctls. > > + > > +8.31 KVM_CAP_STATS_BINARY_FORM > > +------------------------------ > > + > > +:Architectures: all > > + > > +This capability indicates that KVM supports retrieving aggregated statistics > > +data in binary format with corresponding VM/VCPU ioctl KVM_STATS_GET_INFO, > > +KVM_STATS_GET_NAMES and KVM_STATS_GET_DATA. > > nit: for ease of reviewing, consider splitting the documentation in a > separate patch. Will do. > > > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h > > index 1ea297458306..f2dabf457717 100644 > > --- a/include/linux/kvm_host.h > > +++ b/include/linux/kvm_host.h > > @@ -1164,7 +1164,6 @@ static inline bool kvm_is_error_gpa(struct kvm *kvm, gpa_t gpa) > > > > #define VM_STAT_COUNT (sizeof(struct kvm_vm_stat)/sizeof(ulong)) > > #define VCPU_STAT_COUNT (sizeof(struct kvm_vcpu_stat)/sizeof(u64)) > > -#define KVM_STATS_NAME_LEN 32 > > > > /* Make sure it is synced with fields in struct kvm_vm_stat. */ > > extern const char kvm_vm_stat_strings[][KVM_STATS_NAME_LEN]; > > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > > index f6afee209620..ad185d4c5e42 100644 > > --- a/include/uapi/linux/kvm.h > > +++ b/include/uapi/linux/kvm.h > > @@ -1078,6 +1078,7 @@ struct kvm_ppc_resize_hpt { > > #define KVM_CAP_DIRTY_LOG_RING 192 > > #define KVM_CAP_X86_BUS_LOCK_EXIT 193 > > #define KVM_CAP_PPC_DAWR1 194 > > +#define KVM_CAP_STATS_BINARY_FORM 195 > > > > #ifdef KVM_CAP_IRQ_ROUTING > > > > @@ -1853,4 +1854,63 @@ struct kvm_dirty_gfn { > > #define KVM_BUS_LOCK_DETECTION_OFF (1 << 0) > > #define KVM_BUS_LOCK_DETECTION_EXIT (1 << 1) > > > > +/* Available with KVM_CAP_STATS_BINARY_FORM */ > > + > > +#define KVM_STATS_NAME_LEN 32 > > + > > +/** > > + * struct kvm_stats_info - statistics information > > + * > > + * Used as parameter for ioctl %KVM_STATS_GET_INFO. > > + * > > + * @num_stats: On return, the number of statistics data of vm or vcpu. > > + * > > + */ > > +struct kvm_stats_info { > > + __u32 num_stats; > > +}; > > + > > +/** > > + * struct kvm_stats_names - string list of statistics names > > + * > > + * Used as parameter for ioctl %KVM_STATS_GET_NAMES. > > + * > > + * @size: Input from user, indicating the size of buffer after the struture. > > + * @names: Buffer of name string list for vm or vcpu. Each string is > > + * null-padded to a size of %KVM_STATS_NAME_LEN. > > + * > > + * Users must use %KVM_STATS_GET_INFO to find the number of > > + * statistics. They must allocate a buffer of the appropriate > > + * size (>= &struct kvm_stats_info @num_stats * %KVM_STATS_NAME_LEN) > > + * immediately following this struture. > > + */ > > +struct kvm_stats_names { > > + __u32 size; > > + __u8 names[0]; > > +}; > > + > > +/** > > + * struct kvm_stats_data - statistics data array > > + * > > + * Used as parameter for ioctl %KVM_STATS_GET_DATA. > > + * > > + * @size: Input from user, indicating the size of buffer after the struture. > > + * @data: Buffer of statistics data for vm or vcpu. > > + * > > + * Users must use %KVM_STATS_GET_INFO to find the number of > > + * statistics. They must allocate a buffer of the appropriate > > + * size (>= &struct kvm_stats_info @num_stats * sizeof(@data[0]) > > + * immediately following this structure. > > + * &struct kvm_stats_names @names 1-1 maps to &structkvm_stats_data > > + * @data in sequential order. > > + */ > > +struct kvm_stats_data { > > + __u32 size; > > + __u64 data[0]; > > +}; > > + > > +#define KVM_STATS_GET_INFO _IOR(KVMIO, 0xcc, struct kvm_stats_info) > > +#define KVM_STATS_GET_NAMES _IOR(KVMIO, 0xcd, struct kvm_stats_names) > > +#define KVM_STATS_GET_DATA _IOR(KVMIO, 0xce, struct kvm_stats_data) > > + > > #endif /* __LINUX_KVM_H */ > > -- > > 2.30.1.766.gb4fecdf3b7-goog > > > > > > Thanks, > > M. > > -- > Without deviation from the norm, progress is not possible. Thanks, Jing
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 1a2b5210cdbf..aa4b5270c966 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -4938,6 +4938,76 @@ see KVM_XEN_VCPU_SET_ATTR above. The KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST type may not be used with the KVM_XEN_VCPU_GET_ATTR ioctl. +4.131 KVM_STATS_GET_INFO +------------------------ + +:Capability: KVM_CAP_STATS_BINARY_FORM +:Architectures: all +:Type: vm ioctl, vcpu ioctl +:Parameters: struct kvm_stats_info (out) +:Returns: 0 on success, < 0 on error + +:: + + struct kvm_stats_info { + __u32 num_stats; + }; + +This ioctl is used to get the information about VM or vCPU statistics data. +The number of statistics data would be returned in field num_stats in +struct kvm_stats_info. This ioctl only needs to be called once on running +VMs on the same architecture. + +4.132 KVM_STATS_GET_NAMES +------------------------- + +:Capability: KVM_CAP_STATS_BINARY_FORM +:Architectures: all +:Type: vm ioctl, vcpu ioctl +:Parameters: struct kvm_stats_names (in/out) +:Returns: 0 on success, < 0 on error + +:: + + #define KVM_STATS_NAME_LEN 32 + struct kvm_stats_names { + __u32 size; + __u8 names[0]; + }; + +This ioctl is used to get the string names of all the statistics data for VM +or vCPU. Users must use KVM_STATS_GET_INFO to find the number of statistics. +They must allocate a buffer of the size num_stats * KVM_STATS_NAME_LEN +immediately following struct kvm_stats_names. The size field of kvm_stats_name +must contain the buffer size as an input. +The buffer can be treated like a string array, each name string is null-padded +to a size of KVM_STATS_NAME_LEN; +This ioclt only needs to be called once on running VMs on the same architecture. + +4.133 KVM_STATS_GET_DATA +------------------------- + +:Capability: KVM_CAP_STATS_BINARY_FORM +:Architectures: all +:Type: vm ioctl, vcpu ioctl +:Parameters: struct kvm_stats_data (in/out) +:Returns: 0 on success, < 0 on error + +:: + + struct kvm_stats_data { + __u32 size; + __u64 data[0]; + }; + +This ioctl is used to get the aggregated statistics data for VM or vCPU. +Users must use KVM_STATS_GET_INFO to find the number of statistics. +They must allocate a buffer of the appropriate size num_stats * sizeof(data[0]) +immediately following struct kvm_stats_data. The size field of kvm_stats_data +must contain the buffer size as an input. +The data buffer 1-1 maps to name strings buffer in sequential order. +This ioctl is usually called periodically to pull statistics data. + 5. The kvm_run structure ======================== @@ -6721,3 +6791,12 @@ vcpu_info is set. The KVM_XEN_HVM_CONFIG_RUNSTATE flag indicates that the runstate-related features KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR/_CURRENT/_DATA/_ADJUST are supported by the KVM_XEN_VCPU_SET_ATTR/KVM_XEN_VCPU_GET_ATTR ioctls. + +8.31 KVM_CAP_STATS_BINARY_FORM +------------------------------ + +:Architectures: all + +This capability indicates that KVM supports retrieving aggregated statistics +data in binary format with corresponding VM/VCPU ioctl KVM_STATS_GET_INFO, +KVM_STATS_GET_NAMES and KVM_STATS_GET_DATA. diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 1ea297458306..f2dabf457717 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1164,7 +1164,6 @@ static inline bool kvm_is_error_gpa(struct kvm *kvm, gpa_t gpa) #define VM_STAT_COUNT (sizeof(struct kvm_vm_stat)/sizeof(ulong)) #define VCPU_STAT_COUNT (sizeof(struct kvm_vcpu_stat)/sizeof(u64)) -#define KVM_STATS_NAME_LEN 32 /* Make sure it is synced with fields in struct kvm_vm_stat. */ extern const char kvm_vm_stat_strings[][KVM_STATS_NAME_LEN]; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index f6afee209620..ad185d4c5e42 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1078,6 +1078,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_DIRTY_LOG_RING 192 #define KVM_CAP_X86_BUS_LOCK_EXIT 193 #define KVM_CAP_PPC_DAWR1 194 +#define KVM_CAP_STATS_BINARY_FORM 195 #ifdef KVM_CAP_IRQ_ROUTING @@ -1853,4 +1854,63 @@ struct kvm_dirty_gfn { #define KVM_BUS_LOCK_DETECTION_OFF (1 << 0) #define KVM_BUS_LOCK_DETECTION_EXIT (1 << 1) +/* Available with KVM_CAP_STATS_BINARY_FORM */ + +#define KVM_STATS_NAME_LEN 32 + +/** + * struct kvm_stats_info - statistics information + * + * Used as parameter for ioctl %KVM_STATS_GET_INFO. + * + * @num_stats: On return, the number of statistics data of vm or vcpu. + * + */ +struct kvm_stats_info { + __u32 num_stats; +}; + +/** + * struct kvm_stats_names - string list of statistics names + * + * Used as parameter for ioctl %KVM_STATS_GET_NAMES. + * + * @size: Input from user, indicating the size of buffer after the struture. + * @names: Buffer of name string list for vm or vcpu. Each string is + * null-padded to a size of %KVM_STATS_NAME_LEN. + * + * Users must use %KVM_STATS_GET_INFO to find the number of + * statistics. They must allocate a buffer of the appropriate + * size (>= &struct kvm_stats_info @num_stats * %KVM_STATS_NAME_LEN) + * immediately following this struture. + */ +struct kvm_stats_names { + __u32 size; + __u8 names[0]; +}; + +/** + * struct kvm_stats_data - statistics data array + * + * Used as parameter for ioctl %KVM_STATS_GET_DATA. + * + * @size: Input from user, indicating the size of buffer after the struture. + * @data: Buffer of statistics data for vm or vcpu. + * + * Users must use %KVM_STATS_GET_INFO to find the number of + * statistics. They must allocate a buffer of the appropriate + * size (>= &struct kvm_stats_info @num_stats * sizeof(@data[0]) + * immediately following this structure. + * &struct kvm_stats_names @names 1-1 maps to &structkvm_stats_data + * @data in sequential order. + */ +struct kvm_stats_data { + __u32 size; + __u64 data[0]; +}; + +#define KVM_STATS_GET_INFO _IOR(KVMIO, 0xcc, struct kvm_stats_info) +#define KVM_STATS_GET_NAMES _IOR(KVMIO, 0xcd, struct kvm_stats_names) +#define KVM_STATS_GET_DATA _IOR(KVMIO, 0xce, struct kvm_stats_data) + #endif /* __LINUX_KVM_H */
Define ioctl commands for VM/vCPU aggregated statistics data retrieval in binary format and update corresponding API documentation. The capability and ioctl are not enabled for now. No functional change intended. Signed-off-by: Jing Zhang <jingzhangos@google.com> --- Documentation/virt/kvm/api.rst | 79 ++++++++++++++++++++++++++++++++++ include/linux/kvm_host.h | 1 - include/uapi/linux/kvm.h | 60 ++++++++++++++++++++++++++ 3 files changed, 139 insertions(+), 1 deletion(-)