From f91bc8f61abf0e1d23108ae9871c60d7612a09b2 Mon Sep 17 00:00:00 2001 From: Magnus Kulke Date: Thu, 6 Nov 2025 14:13:31 -0800 Subject: mshv: Allow mappings that overlap in uaddr Currently the MSHV driver rejects mappings that would overlap in userspace. Some VMMs require the same memory to be mapped to different parts of the guest's address space, and so working around this restriction is difficult. The hypervisor itself doesn't prohibit mappings that overlap in uaddr, (really in SPA; system physical addresses), so supporting this in the driver doesn't require any extra work: only the checks need to be removed. Since no userspace code until now has been able to overlap regions in userspace, relaxing this constraint can't break any existing code. Signed-off-by: Magnus Kulke Signed-off-by: Nuno Das Neves Reviewed-by: Michael Kelley Signed-off-by: Wei Liu --- include/uapi/linux/mshv.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/mshv.h b/include/uapi/linux/mshv.h index 876bfe4e4227..374f75e198bc 100644 --- a/include/uapi/linux/mshv.h +++ b/include/uapi/linux/mshv.h @@ -89,7 +89,7 @@ enum { * @rsvd: MBZ * * Map or unmap a region of userspace memory to Guest Physical Addresses (GPA). - * Mappings can't overlap in GPA space or userspace. + * Mappings can't overlap in GPA space. * To unmap, these fields must match an existing mapping. */ struct mshv_user_mem_region { -- cgit v1.2.3 From c91fe5f162f278d4aa960d06d2dbc42f9857593a Mon Sep 17 00:00:00 2001 From: Muminul Islam Date: Thu, 13 Nov 2025 11:45:33 -0800 Subject: mshv: Extend create partition ioctl to support cpu features The existing mshv create partition ioctl does not provide a way to specify which cpu features are enabled in the guest. Instead, it attempts to enable all features and those that are not supported are silently disabled by the hypervisor. This was done to reduce unnecessary complexity and is sufficient for many cases. However, new scenarios require fine-grained control over these features. Define a new mshv_create_partition_v2 structure which supports passing the disabled processor and xsave feature bits through to the create partition hypercall directly. Introduce a new flag MSHV_PT_BIT_CPU_AND_XSAVE_FEATURES which enables the new structure. If unset, the original mshv_create_partition struct is used, with the old behavior of enabling all features. Co-developed-by: Jinank Jain Signed-off-by: Jinank Jain Signed-off-by: Muminul Islam Signed-off-by: Nuno Das Neves Reviewed-by: Michael Kelley Signed-off-by: Wei Liu --- include/uapi/linux/mshv.h | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/mshv.h b/include/uapi/linux/mshv.h index 374f75e198bc..b645d17cc531 100644 --- a/include/uapi/linux/mshv.h +++ b/include/uapi/linux/mshv.h @@ -26,6 +26,7 @@ enum { MSHV_PT_BIT_LAPIC, MSHV_PT_BIT_X2APIC, MSHV_PT_BIT_GPA_SUPER_PAGES, + MSHV_PT_BIT_CPU_AND_XSAVE_FEATURES, MSHV_PT_BIT_COUNT, }; @@ -41,6 +42,8 @@ enum { * @pt_flags: Bitmask of 1 << MSHV_PT_BIT_* * @pt_isolation: MSHV_PT_ISOLATION_* * + * This is the initial/v1 version for backward compatibility. + * * Returns a file descriptor to act as a handle to a guest partition. * At this point the partition is not yet initialized in the hypervisor. * Some operations must be done with the partition in this state, e.g. setting @@ -52,6 +55,37 @@ struct mshv_create_partition { __u64 pt_isolation; }; +#define MSHV_NUM_CPU_FEATURES_BANKS 2 + +/** + * struct mshv_create_partition_v2 + * + * This is extended version of the above initial MSHV_CREATE_PARTITION + * ioctl and allows for following additional parameters: + * + * @pt_num_cpu_fbanks: Must be set to MSHV_NUM_CPU_FEATURES_BANKS. + * @pt_cpu_fbanks: Disabled processor feature banks array. + * @pt_disabled_xsave: Disabled xsave feature bits. + * + * pt_cpu_fbanks and pt_disabled_xsave are passed through as-is to the create + * partition hypercall. + * + * Returns : same as above original mshv_create_partition + */ +struct mshv_create_partition_v2 { + __u64 pt_flags; + __u64 pt_isolation; + __u16 pt_num_cpu_fbanks; + __u8 pt_rsvd[6]; /* MBZ */ + __u64 pt_cpu_fbanks[MSHV_NUM_CPU_FEATURES_BANKS]; + __u64 pt_rsvd1[2]; /* MBZ */ +#if defined(__x86_64__) + __u64 pt_disabled_xsave; +#else + __u64 pt_rsvd2; /* MBZ */ +#endif +} __packed; + /* /dev/mshv */ #define MSHV_CREATE_PARTITION _IOW(MSHV_IOCTL, 0x00, struct mshv_create_partition) -- cgit v1.2.3 From 7bfe3b8ea6e30437e01fcb8e4f56ef6e4d986d0f Mon Sep 17 00:00:00 2001 From: Naman Jain Date: Thu, 13 Nov 2025 04:41:49 +0000 Subject: Drivers: hv: Introduce mshv_vtl driver Provide an interface for Virtual Machine Monitor like OpenVMM and its use as OpenHCL paravisor to control VTL0 (Virtual trust Level). Expose devices and support IOCTLs for features like VTL creation, VTL0 memory management, context switch, making hypercalls, mapping VTL0 address space to VTL2 userspace, getting new VMBus messages and channel events in VTL2 etc. Co-developed-by: Roman Kisel Signed-off-by: Roman Kisel Co-developed-by: Saurabh Sengar Signed-off-by: Saurabh Sengar Reviewed-by: Michael Kelley Signed-off-by: Naman Jain Signed-off-by: Wei Liu --- include/uapi/linux/mshv.h | 80 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/mshv.h b/include/uapi/linux/mshv.h index b645d17cc531..dee3ece28ce5 100644 --- a/include/uapi/linux/mshv.h +++ b/include/uapi/linux/mshv.h @@ -322,4 +322,84 @@ struct mshv_get_set_vp_state { * #define MSHV_ROOT_HVCALL _IOWR(MSHV_IOCTL, 0x07, struct mshv_root_hvcall) */ +/* Structure definitions, macros and IOCTLs for mshv_vtl */ + +#define MSHV_CAP_CORE_API_STABLE 0x0 +#define MSHV_CAP_REGISTER_PAGE 0x1 +#define MSHV_CAP_VTL_RETURN_ACTION 0x2 +#define MSHV_CAP_DR6_SHARED 0x3 +#define MSHV_MAX_RUN_MSG_SIZE 256 + +struct mshv_vp_registers { + __u32 count; /* supports only 1 register at a time */ + __u32 reserved; /* Reserved for alignment or future use */ + __u64 regs_ptr; /* pointer to struct hv_register_assoc */ +}; + +struct mshv_vtl_set_eventfd { + __s32 fd; + __u32 flag; +}; + +struct mshv_vtl_signal_event { + __u32 connection_id; + __u32 flag; +}; + +struct mshv_vtl_sint_post_msg { + __u64 message_type; + __u32 connection_id; + __u32 payload_size; /* Must not exceed HV_MESSAGE_PAYLOAD_BYTE_COUNT */ + __u64 payload_ptr; /* pointer to message payload (bytes) */ +}; + +struct mshv_vtl_ram_disposition { + __u64 start_pfn; + __u64 last_pfn; +}; + +struct mshv_vtl_set_poll_file { + __u32 cpu; + __u32 fd; +}; + +struct mshv_vtl_hvcall_setup { + __u64 bitmap_array_size; /* stores number of bytes */ + __u64 allow_bitmap_ptr; +}; + +struct mshv_vtl_hvcall { + __u64 control; /* Hypercall control code */ + __u64 input_size; /* Size of the input data */ + __u64 input_ptr; /* Pointer to the input struct */ + __u64 status; /* Status of the hypercall (output) */ + __u64 output_size; /* Size of the output data */ + __u64 output_ptr; /* Pointer to the output struct */ +}; + +struct mshv_sint_mask { + __u8 mask; + __u8 reserved[7]; +}; + +/* /dev/mshv device IOCTL */ +#define MSHV_CHECK_EXTENSION _IOW(MSHV_IOCTL, 0x00, __u32) + +/* vtl device */ +#define MSHV_CREATE_VTL _IOR(MSHV_IOCTL, 0x1D, char) +#define MSHV_ADD_VTL0_MEMORY _IOW(MSHV_IOCTL, 0x21, struct mshv_vtl_ram_disposition) +#define MSHV_SET_POLL_FILE _IOW(MSHV_IOCTL, 0x25, struct mshv_vtl_set_poll_file) +#define MSHV_RETURN_TO_LOWER_VTL _IO(MSHV_IOCTL, 0x27) +#define MSHV_GET_VP_REGISTERS _IOWR(MSHV_IOCTL, 0x05, struct mshv_vp_registers) +#define MSHV_SET_VP_REGISTERS _IOW(MSHV_IOCTL, 0x06, struct mshv_vp_registers) + +/* VMBus device IOCTLs */ +#define MSHV_SINT_SIGNAL_EVENT _IOW(MSHV_IOCTL, 0x22, struct mshv_vtl_signal_event) +#define MSHV_SINT_POST_MESSAGE _IOW(MSHV_IOCTL, 0x23, struct mshv_vtl_sint_post_msg) +#define MSHV_SINT_SET_EVENTFD _IOW(MSHV_IOCTL, 0x24, struct mshv_vtl_set_eventfd) +#define MSHV_SINT_PAUSE_MESSAGE_STREAM _IOW(MSHV_IOCTL, 0x25, struct mshv_sint_mask) + +/* hv_hvcall device */ +#define MSHV_HVCALL_SETUP _IOW(MSHV_IOCTL, 0x1E, struct mshv_vtl_hvcall_setup) +#define MSHV_HVCALL _IOWR(MSHV_IOCTL, 0x1F, struct mshv_vtl_hvcall) #endif -- cgit v1.2.3