Re: [PATCH 3/6] include/hw/hyperv: add hv_vp_register_page struct definition

[Magnus Kulke <magnuskulke@linux.microsoft.com>]

On Tue, Apr 28, 2026 at 04:50:50PM +0300, Doru Blânzeanu wrote:
> Define the `hv_vp_register_page` structure that the linux kernel uses
> to allow access to vcpu registers.
> 
> This structure is going to be used in later patches to access vcpu
> registers.
> 
> Signed-off-by: Doru Blânzeanu <dblanzeanu@linux.microsoft.com>
> ---
>  include/hw/hyperv/hvgdk_mini.h | 103 +++++++++++++++++++++++++++++++++
>  1 file changed, 103 insertions(+)
> 
> diff --git a/include/hw/hyperv/hvgdk_mini.h b/include/hw/hyperv/hvgdk_mini.h

In the kernel and the mshv crates the definitions are in hvhdk.h. We
probably want to put it into the same header in QEMU to avoid confusion.

> index c3a8f33280..07e322865a 100644
> --- a/include/hw/hyperv/hvgdk_mini.h
> +++ b/include/hw/hyperv/hvgdk_mini.h
> @@ -474,6 +474,109 @@ struct hv_input_assert_virtual_interrupt {
>      uint16_t rsvd_z1;
>  } QEMU_PACKED;
>  
> +/* Flags for dirty mask of hv_vp_register_page */
> +enum hv_x64_register_class_type {
> +    HV_X64_REGISTER_CLASS_GENERAL = 0,
> +    HV_X64_REGISTER_CLASS_IP = 1,
> +    HV_X64_REGISTER_CLASS_XMM = 2,
> +    HV_X64_REGISTER_CLASS_SEGMENT = 3,
> +    HV_X64_REGISTER_CLASS_FLAGS = 4,
> +};
> +
> +#define HV_VP_REGISTER_PAGE_MAX_VECTOR_COUNT  7
> +
> +union hv_vp_register_page_interrupt_vectors {
> +    uint64_t as_uint64;
> +    struct {
> +        uint8_t vector_count;
> +        uint8_t vector[HV_VP_REGISTER_PAGE_MAX_VECTOR_COUNT];
> +    };
> +};
> +
> +struct hv_vp_register_page {
> +    uint16_t version;
> +    uint8_t isvalid;
> +    uint8_t rsvdz;
> +    uint32_t dirty;
> +
> +    union {
> +        struct {
> +            /* General purpose registers (HV_X64_REGISTER_CLASS_GENERAL) */
> +            union {
> +                struct {
> +                    uint64_t rax;
> +                    uint64_t rcx;
> +                    uint64_t rdx;
> +                    uint64_t rbx;
> +                    uint64_t rsp;
> +                    uint64_t rbp;
> +                    uint64_t rsi;
> +                    uint64_t rdi;
> +                    uint64_t r8;
> +                    uint64_t r9;
> +                    uint64_t r10;
> +                    uint64_t r11;
> +                    uint64_t r12;
> +                    uint64_t r13;
> +                    uint64_t r14;
> +                    uint64_t r15;
> +                } QEMU_PACKED;
> +
> +                uint64_t gp_registers[16];
> +            };
> +            /* Instruction pointer (HV_X64_REGISTER_CLASS_IP) */
> +            uint64_t rip;
> +            /* Flags (HV_X64_REGISTER_CLASS_FLAGS) */
> +            uint64_t rflags;
> +        } QEMU_PACKED;
> +
> +        uint64_t registers[18];
> +    };
> +    uint8_t reserved[8];
> +    /* Volatile XMM registers (HV_X64_REGISTER_CLASS_XMM) */
> +    union {
> +        struct {
> +            struct hv_u128 xmm0;
> +            struct hv_u128 xmm1;
> +            struct hv_u128 xmm2;
> +            struct hv_u128 xmm3;
> +            struct hv_u128 xmm4;
> +            struct hv_u128 xmm5;
> +        } QEMU_PACKED;
> +
> +        struct hv_u128 xmm_registers[6];
> +    };
> +    /* Segment registers (HV_X64_REGISTER_CLASS_SEGMENT) */
> +    union {
> +        struct {
> +            struct hv_x64_segment_register es;
> +            struct hv_x64_segment_register cs;
> +            struct hv_x64_segment_register ss;
> +            struct hv_x64_segment_register ds;
> +            struct hv_x64_segment_register fs;
> +            struct hv_x64_segment_register gs;
> +        } QEMU_PACKED;
> +
> +        struct hv_x64_segment_register segment_registers[6];
> +    };
> +    /* Misc. control registers (cannot be set via this interface) */
> +    uint64_t cr0;
> +    uint64_t cr3;
> +    uint64_t cr4;
> +    uint64_t cr8;
> +    uint64_t efer;
> +    uint64_t dr7;
> +    union hv_x64_pending_interruption_register pending_interruption;
> +    union hv_x64_interrupt_state_register interrupt_state;
> +    uint64_t instruction_emulation_hints;
> +    uint64_t xfem;
> +
> +    uint8_t reserved1[0x100];
> +
> +    /* Interrupts injected as part of HvCallDispatchVp. */
> +    union hv_vp_register_page_interrupt_vectors interrupt_vectors;
> +} QEMU_PACKED;
> +
>  /* /dev/mshv */
>  #define MSHV_CREATE_PARTITION   _IOW(MSHV_IOCTL, 0x00, struct mshv_create_partition)
>  #define MSHV_CREATE_VP          _IOW(MSHV_IOCTL, 0x01, struct mshv_create_vp)
> -- 
> 2.53.0