RE: [RFC PATCH 10/18] virt/mshv: get and set vcpu registers ioctls

From: Michael Kelley
Date: Mon Feb 08 2021 - 15:59:00 EST

From: Nuno Das Neves <nunodasneves@xxxxxxxxxxxxxxxxxxx> Sent: Friday, November 20, 2020 4:30 PM
>
> Add ioctls for getting and setting virtual processor registers.
>
> Co-developed-by: Lillian Grassin-Drake <ligrassi@xxxxxxxxxxxxx>
> Signed-off-by: Lillian Grassin-Drake <ligrassi@xxxxxxxxxxxxx>
> Signed-off-by: Nuno Das Neves <nunodasneves@xxxxxxxxxxxxxxxxxxx>
> ---
> Documentation/virt/mshv/api.rst | 11 +
> arch/x86/include/uapi/asm/hyperv-tlfs.h | 601 ++++++++++++++++++++++++
> include/asm-generic/hyperv-tlfs.h | 65 +--
> include/linux/mshv.h | 1 +
> include/uapi/linux/mshv.h | 12 +
> virt/mshv/mshv_main.c | 258 +++++++++-
> 6 files changed, 903 insertions(+), 45 deletions(-)
>
> diff --git a/Documentation/virt/mshv/api.rst b/Documentation/virt/mshv/api.rst
> index f997f49f8690..20a626ac02d4 100644
> --- a/Documentation/virt/mshv/api.rst
> +++ b/Documentation/virt/mshv/api.rst
> @@ -96,3 +96,14 @@ is backed by physical memory.
> Create a virtual processor in a guest partition, returning a file descriptor to
> represent the vp and perform ioctls on.
>
> +3.5 MSHV_GET_VP_REGISTERS and MSHV_SET_VP_REGISTERS
> +---------------------------------------------------
> +:Type: vp ioctl
> +:Parameters: struct mshv_vp_registers
> +:Returns: 0 on success
> +
> +Get/set vp registers. See asm/hyperv-tlfs.h for the complete set of registers.
> +Includes general purpose platform registers, MSRs, and virtual registers that
> +are part of Microsoft Hypervisor platform and not directly exposed to the guest.
> +
> +
> diff --git a/arch/x86/include/uapi/asm/hyperv-tlfs.h b/arch/x86/include/uapi/asm/hyperv-
> tlfs.h
> index 72150c25ffe6..2ff655962738 100644
> --- a/arch/x86/include/uapi/asm/hyperv-tlfs.h
> +++ b/arch/x86/include/uapi/asm/hyperv-tlfs.h
> @@ -121,4 +121,605 @@ struct hv_partition_creation_properties {
> disabled_processor_xsave_features;
> };
>
> +enum hv_register_name {
> + /* Suspend Registers */
> + HV_REGISTER_EXPLICIT_SUSPEND = 0x00000000,
> + HV_REGISTER_INTERCEPT_SUSPEND = 0x00000001,
> + HV_REGISTER_INSTRUCTION_EMULATION_HINTS = 0x00000002,
> + HV_REGISTER_DISPATCH_SUSPEND = 0x00000003,
> + HV_REGISTER_INTERNAL_ACTIVITY_STATE = 0x00000004,
> +
> + /* Version */
> + HV_REGISTER_HYPERVISOR_VERSION = 0x00000100, /* 128-bit result same as CPUID 0x40000002 */
> +
> + /* Feature Access (registers are 128 bits) - same as CPUID 0x40000003 - 0x4000000B */
> + HV_REGISTER_PRIVILEGES_AND_FEATURES_INFO = 0x00000200,
> + HV_REGISTER_FEATURES_INFO = 0x00000201,
> + HV_REGISTER_IMPLEMENTATION_LIMITS_INFO = 0x00000202,
> + HV_REGISTER_HARDWARE_FEATURES_INFO = 0x00000203,
> + HV_REGISTER_CPU_MANAGEMENT_FEATURES_INFO = 0x00000204,
> + HV_REGISTER_SVM_FEATURES_INFO = 0x00000205,
> + HV_REGISTER_SKIP_LEVEL_FEATURES_INFO = 0x00000206,
> + HV_REGISTER_NESTED_VIRT_FEATURES_INFO = 0x00000207,
> + HV_REGISTER_IPT_FEATURES_INFO = 0x00000208,
> +
> + /* Guest Crash Registers */
> + HV_REGISTER_GUEST_CRASH_P0 = 0x00000210,
> + HV_REGISTER_GUEST_CRASH_P1 = 0x00000211,
> + HV_REGISTER_GUEST_CRASH_P2 = 0x00000212,
> + HV_REGISTER_GUEST_CRASH_P3 = 0x00000213,
> + HV_REGISTER_GUEST_CRASH_P4 = 0x00000214,
> + HV_REGISTER_GUEST_CRASH_CTL = 0x00000215,
> +
> + /* Power State Configuration */
> + HV_REGISTER_POWER_STATE_CONFIG_C1 = 0x00000220,
> + HV_REGISTER_POWER_STATE_TRIGGER_C1 = 0x00000221,
> + HV_REGISTER_POWER_STATE_CONFIG_C2 = 0x00000222,
> + HV_REGISTER_POWER_STATE_TRIGGER_C2 = 0x00000223,
> + HV_REGISTER_POWER_STATE_CONFIG_C3 = 0x00000224,
> + HV_REGISTER_POWER_STATE_TRIGGER_C3 = 0x00000225,
> +
> + /* Frequency Registers */
> + HV_REGISTER_PROCESSOR_CLOCK_FREQUENCY = 0x00000240,
> + HV_REGISTER_INTERRUPT_CLOCK_FREQUENCY = 0x00000241,
> +
> + /* Idle Register */
> + HV_REGISTER_GUEST_IDLE = 0x00000250,
> +
> + /* Guest Debug */
> + HV_REGISTER_DEBUG_DEVICE_OPTIONS = 0x00000260,
> +
> + /* Memory Zeroing Conrol Register */
> + HV_REGISTER_MEMORY_ZEROING_CONTROL = 0x00000270,
> +
> + /* Pending Event Register */
> + HV_REGISTER_PENDING_EVENT0 = 0x00010004,
> + HV_REGISTER_PENDING_EVENT1 = 0x00010005,
> +
> + /* Misc */
> + HV_REGISTER_VP_RUNTIME = 0x00090000,
> + HV_REGISTER_GUEST_OS_ID = 0x00090002,
> + HV_REGISTER_VP_INDEX = 0x00090003,
> + HV_REGISTER_TIME_REF_COUNT = 0x00090004,
> + HV_REGISTER_CPU_MANAGEMENT_VERSION = 0x00090007,
> + HV_REGISTER_VP_ASSIST_PAGE = 0x00090013,
> + HV_REGISTER_VP_ROOT_SIGNAL_COUNT = 0x00090014,
> + HV_REGISTER_REFERENCE_TSC = 0x00090017,
> +
> + /* Performance statistics Registers */
> + HV_REGISTER_STATS_PARTITION_RETAIL = 0x00090020,
> + HV_REGISTER_STATS_PARTITION_INTERNAL = 0x00090021,
> + HV_REGISTER_STATS_VP_RETAIL = 0x00090022,
> + HV_REGISTER_STATS_VP_INTERNAL = 0x00090023,
> +
> + HV_REGISTER_NESTED_VP_INDEX = 0x00091003,
> +
> + /* Hypervisor-defined Registers (Synic) */
> + HV_REGISTER_SINT0 = 0x000A0000,
> + HV_REGISTER_SINT1 = 0x000A0001,
> + HV_REGISTER_SINT2 = 0x000A0002,
> + HV_REGISTER_SINT3 = 0x000A0003,
> + HV_REGISTER_SINT4 = 0x000A0004,
> + HV_REGISTER_SINT5 = 0x000A0005,
> + HV_REGISTER_SINT6 = 0x000A0006,
> + HV_REGISTER_SINT7 = 0x000A0007,
> + HV_REGISTER_SINT8 = 0x000A0008,
> + HV_REGISTER_SINT9 = 0x000A0009,
> + HV_REGISTER_SINT10 = 0x000A000A,
> + HV_REGISTER_SINT11 = 0x000A000B,
> + HV_REGISTER_SINT12 = 0x000A000C,
> + HV_REGISTER_SINT13 = 0x000A000D,
> + HV_REGISTER_SINT14 = 0x000A000E,
> + HV_REGISTER_SINT15 = 0x000A000F,
> + HV_REGISTER_SCONTROL = 0x000A0010,
> + HV_REGISTER_SVERSION = 0x000A0011,
> + HV_REGISTER_SIFP = 0x000A0012,
> + HV_REGISTER_SIPP = 0x000A0013,
> + HV_REGISTER_EOM = 0x000A0014,
> + HV_REGISTER_SIRBP = 0x000A0015,
> +
> + HV_REGISTER_NESTED_SINT0 = 0x000A1000,
> + HV_REGISTER_NESTED_SINT1 = 0x000A1001,
> + HV_REGISTER_NESTED_SINT2 = 0x000A1002,
> + HV_REGISTER_NESTED_SINT3 = 0x000A1003,
> + HV_REGISTER_NESTED_SINT4 = 0x000A1004,
> + HV_REGISTER_NESTED_SINT5 = 0x000A1005,
> + HV_REGISTER_NESTED_SINT6 = 0x000A1006,
> + HV_REGISTER_NESTED_SINT7 = 0x000A1007,
> + HV_REGISTER_NESTED_SINT8 = 0x000A1008,
> + HV_REGISTER_NESTED_SINT9 = 0x000A1009,
> + HV_REGISTER_NESTED_SINT10 = 0x000A100A,
> + HV_REGISTER_NESTED_SINT11 = 0x000A100B,
> + HV_REGISTER_NESTED_SINT12 = 0x000A100C,
> + HV_REGISTER_NESTED_SINT13 = 0x000A100D,
> + HV_REGISTER_NESTED_SINT14 = 0x000A100E,
> + HV_REGISTER_NESTED_SINT15 = 0x000A100F,
> + HV_REGISTER_NESTED_SCONTROL = 0x000A1010,
> + HV_REGISTER_NESTED_SVERSION = 0x000A1011,
> + HV_REGISTER_NESTED_SIFP = 0x000A1012,
> + HV_REGISTER_NESTED_SIPP = 0x000A1013,
> + HV_REGISTER_NESTED_EOM = 0x000A1014,
> + HV_REGISTER_NESTED_SIRBP = 0x000a1015,
> +
> +
> + /* Hypervisor-defined Registers (Synthetic Timers) */
> + HV_REGISTER_STIMER0_CONFIG = 0x000B0000,
> + HV_REGISTER_STIMER0_COUNT = 0x000B0001,
> + HV_REGISTER_STIMER1_CONFIG = 0x000B0002,
> + HV_REGISTER_STIMER1_COUNT = 0x000B0003,
> + HV_REGISTER_STIMER2_CONFIG = 0x000B0004,
> + HV_REGISTER_STIMER2_COUNT = 0x000B0005,
> + HV_REGISTER_STIMER3_CONFIG = 0x000B0006,
> + HV_REGISTER_STIMER3_COUNT = 0x000B0007,
> + HV_REGISTER_STIME_UNHALTED_TIMER_CONFIG = 0x000B0100,
> + HV_REGISTER_STIME_UNHALTED_TIMER_COUNT = 0x000b0101,
> +
> + /* Synthetic VSM registers */
> +
> + /* 0x000D0000-1 are available for future use. */
> + HV_REGISTER_VSM_CODE_PAGE_OFFSETS = 0x000D0002,
> + HV_REGISTER_VSM_VP_STATUS = 0x000D0003,
> + HV_REGISTER_VSM_PARTITION_STATUS = 0x000D0004,
> + HV_REGISTER_VSM_VINA = 0x000D0005,
> + HV_REGISTER_VSM_CAPABILITIES = 0x000D0006,
> + HV_REGISTER_VSM_PARTITION_CONFIG = 0x000D0007,
> +
> + HV_REGISTER_VSM_VP_SECURE_CONFIG_VTL0 = 0x000D0010,
> + HV_REGISTER_VSM_VP_SECURE_CONFIG_VTL1 = 0x000D0011,
> + HV_REGISTER_VSM_VP_SECURE_CONFIG_VTL2 = 0x000D0012,
> + HV_REGISTER_VSM_VP_SECURE_CONFIG_VTL3 = 0x000D0013,
> + HV_REGISTER_VSM_VP_SECURE_CONFIG_VTL4 = 0x000D0014,
> + HV_REGISTER_VSM_VP_SECURE_CONFIG_VTL5 = 0x000D0015,
> + HV_REGISTER_VSM_VP_SECURE_CONFIG_VTL6 = 0x000D0016,
> + HV_REGISTER_VSM_VP_SECURE_CONFIG_VTL7 = 0x000D0017,
> + HV_REGISTER_VSM_VP_SECURE_CONFIG_VTL8 = 0x000D0018,
> + HV_REGISTER_VSM_VP_SECURE_CONFIG_VTL9 = 0x000D0019,
> + HV_REGISTER_VSM_VP_SECURE_CONFIG_VTL10 = 0x000D001A,
> + HV_REGISTER_VSM_VP_SECURE_CONFIG_VTL11 = 0x000D001B,
> + HV_REGISTER_VSM_VP_SECURE_CONFIG_VTL12 = 0x000D001C,
> + HV_REGISTER_VSM_VP_SECURE_CONFIG_VTL13 = 0x000D001D,
> + HV_REGISTER_VSM_VP_SECURE_CONFIG_VTL14 = 0x000D001E,
> +
> + HV_REGISTER_VSM_VP_WAIT_FOR_TLB_LOCK = 0x000D0020,
> +
> + HV_REGISTER_ISOLATION_CAPABILITIES = 0x000D0100,
> +
> + /* Pending Interruption Register */
> + HV_REGISTER_PENDING_INTERRUPTION = 0x00010002,
> +
> + /* Interrupt State register */
> + HV_REGISTER_INTERRUPT_STATE = 0x00010003,
> +
> + /* Interruptible notification register */
> + HV_X64_REGISTER_DELIVERABILITY_NOTIFICATIONS = 0x00010006,
> +
> + /* X64 User-Mode Registers */
> + HV_X64_REGISTER_RAX = 0x00020000,
> + HV_X64_REGISTER_RCX = 0x00020001,
> + HV_X64_REGISTER_RDX = 0x00020002,
> + HV_X64_REGISTER_RBX = 0x00020003,
> + HV_X64_REGISTER_RSP = 0x00020004,
> + HV_X64_REGISTER_RBP = 0x00020005,
> + HV_X64_REGISTER_RSI = 0x00020006,
> + HV_X64_REGISTER_RDI = 0x00020007,
> + HV_X64_REGISTER_R8 = 0x00020008,
> + HV_X64_REGISTER_R9 = 0x00020009,
> + HV_X64_REGISTER_R10 = 0x0002000A,
> + HV_X64_REGISTER_R11 = 0x0002000B,
> + HV_X64_REGISTER_R12 = 0x0002000C,
> + HV_X64_REGISTER_R13 = 0x0002000D,
> + HV_X64_REGISTER_R14 = 0x0002000E,
> + HV_X64_REGISTER_R15 = 0x0002000F,
> + HV_X64_REGISTER_RIP = 0x00020010,
> + HV_X64_REGISTER_RFLAGS = 0x00020011,
> +
> + /* X64 Floating Point and Vector Registers */
> + HV_X64_REGISTER_XMM0 = 0x00030000,
> + HV_X64_REGISTER_XMM1 = 0x00030001,
> + HV_X64_REGISTER_XMM2 = 0x00030002,
> + HV_X64_REGISTER_XMM3 = 0x00030003,
> + HV_X64_REGISTER_XMM4 = 0x00030004,
> + HV_X64_REGISTER_XMM5 = 0x00030005,
> + HV_X64_REGISTER_XMM6 = 0x00030006,
> + HV_X64_REGISTER_XMM7 = 0x00030007,
> + HV_X64_REGISTER_XMM8 = 0x00030008,
> + HV_X64_REGISTER_XMM9 = 0x00030009,
> + HV_X64_REGISTER_XMM10 = 0x0003000A,
> + HV_X64_REGISTER_XMM11 = 0x0003000B,
> + HV_X64_REGISTER_XMM12 = 0x0003000C,
> + HV_X64_REGISTER_XMM13 = 0x0003000D,
> + HV_X64_REGISTER_XMM14 = 0x0003000E,
> + HV_X64_REGISTER_XMM15 = 0x0003000F,
> + HV_X64_REGISTER_FP_MMX0 = 0x00030010,
> + HV_X64_REGISTER_FP_MMX1 = 0x00030011,
> + HV_X64_REGISTER_FP_MMX2 = 0x00030012,
> + HV_X64_REGISTER_FP_MMX3 = 0x00030013,
> + HV_X64_REGISTER_FP_MMX4 = 0x00030014,
> + HV_X64_REGISTER_FP_MMX5 = 0x00030015,
> + HV_X64_REGISTER_FP_MMX6 = 0x00030016,
> + HV_X64_REGISTER_FP_MMX7 = 0x00030017,
> + HV_X64_REGISTER_FP_CONTROL_STATUS = 0x00030018,
> + HV_X64_REGISTER_XMM_CONTROL_STATUS = 0x00030019,
> +
> + /* X64 Control Registers */
> + HV_X64_REGISTER_CR0 = 0x00040000,
> + HV_X64_REGISTER_CR2 = 0x00040001,
> + HV_X64_REGISTER_CR3 = 0x00040002,
> + HV_X64_REGISTER_CR4 = 0x00040003,
> + HV_X64_REGISTER_CR8 = 0x00040004,
> + HV_X64_REGISTER_XFEM = 0x00040005,
> +
> + /* X64 Intermediate Control Registers */
> + HV_X64_REGISTER_INTERMEDIATE_CR0 = 0x00041000,
> + HV_X64_REGISTER_INTERMEDIATE_CR4 = 0x00041003,
> + HV_X64_REGISTER_INTERMEDIATE_CR8 = 0x00041004,
> +
> + /* X64 Debug Registers */
> + HV_X64_REGISTER_DR0 = 0x00050000,
> + HV_X64_REGISTER_DR1 = 0x00050001,
> + HV_X64_REGISTER_DR2 = 0x00050002,
> + HV_X64_REGISTER_DR3 = 0x00050003,
> + HV_X64_REGISTER_DR6 = 0x00050004,
> + HV_X64_REGISTER_DR7 = 0x00050005,
> +
> + /* X64 Segment Registers */
> + HV_X64_REGISTER_ES = 0x00060000,
> + HV_X64_REGISTER_CS = 0x00060001,
> + HV_X64_REGISTER_SS = 0x00060002,
> + HV_X64_REGISTER_DS = 0x00060003,
> + HV_X64_REGISTER_FS = 0x00060004,
> + HV_X64_REGISTER_GS = 0x00060005,
> + HV_X64_REGISTER_LDTR = 0x00060006,
> + HV_X64_REGISTER_TR = 0x00060007,
> +
> + /* X64 Table Registers */
> + HV_X64_REGISTER_IDTR = 0x00070000,
> + HV_X64_REGISTER_GDTR = 0x00070001,
> +
> + /* X64 Virtualized MSRs */
> + HV_X64_REGISTER_TSC = 0x00080000,
> + HV_X64_REGISTER_EFER = 0x00080001,
> + HV_X64_REGISTER_KERNEL_GS_BASE = 0x00080002,
> + HV_X64_REGISTER_APIC_BASE = 0x00080003,
> + HV_X64_REGISTER_PAT = 0x00080004,
> + HV_X64_REGISTER_SYSENTER_CS = 0x00080005,
> + HV_X64_REGISTER_SYSENTER_EIP = 0x00080006,
> + HV_X64_REGISTER_SYSENTER_ESP = 0x00080007,
> + HV_X64_REGISTER_STAR = 0x00080008,
> + HV_X64_REGISTER_LSTAR = 0x00080009,
> + HV_X64_REGISTER_CSTAR = 0x0008000A,
> + HV_X64_REGISTER_SFMASK = 0x0008000B,
> + HV_X64_REGISTER_INITIAL_APIC_ID = 0x0008000C,
> +
> + /* X64 Cache control MSRs */
> + HV_X64_REGISTER_MSR_MTRR_CAP = 0x0008000D,
> + HV_X64_REGISTER_MSR_MTRR_DEF_TYPE = 0x0008000E,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_BASE0 = 0x00080010,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_BASE1 = 0x00080011,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_BASE2 = 0x00080012,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_BASE3 = 0x00080013,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_BASE4 = 0x00080014,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_BASE5 = 0x00080015,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_BASE6 = 0x00080016,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_BASE7 = 0x00080017,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_BASE8 = 0x00080018,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_BASE9 = 0x00080019,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_BASEA = 0x0008001A,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_BASEB = 0x0008001B,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_BASEC = 0x0008001C,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_BASED = 0x0008001D,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_BASEE = 0x0008001E,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_BASEF = 0x0008001F,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_MASK0 = 0x00080040,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_MASK1 = 0x00080041,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_MASK2 = 0x00080042,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_MASK3 = 0x00080043,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_MASK4 = 0x00080044,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_MASK5 = 0x00080045,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_MASK6 = 0x00080046,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_MASK7 = 0x00080047,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_MASK8 = 0x00080048,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_MASK9 = 0x00080049,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_MASKA = 0x0008004A,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_MASKB = 0x0008004B,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_MASKC = 0x0008004C,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_MASKD = 0x0008004D,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_MASKE = 0x0008004E,
> + HV_X64_REGISTER_MSR_MTRR_PHYS_MASKF = 0x0008004F,
> + HV_X64_REGISTER_MSR_MTRR_FIX64K00000 = 0x00080070,
> + HV_X64_REGISTER_MSR_MTRR_FIX16K80000 = 0x00080071,
> + HV_X64_REGISTER_MSR_MTRR_FIX16KA0000 = 0x00080072,
> + HV_X64_REGISTER_MSR_MTRR_FIX4KC0000 = 0x00080073,
> + HV_X64_REGISTER_MSR_MTRR_FIX4KC8000 = 0x00080074,
> + HV_X64_REGISTER_MSR_MTRR_FIX4KD0000 = 0x00080075,
> + HV_X64_REGISTER_MSR_MTRR_FIX4KD8000 = 0x00080076,
> + HV_X64_REGISTER_MSR_MTRR_FIX4KE0000 = 0x00080077,
> + HV_X64_REGISTER_MSR_MTRR_FIX4KE8000 = 0x00080078,
> + HV_X64_REGISTER_MSR_MTRR_FIX4KF0000 = 0x00080079,
> + HV_X64_REGISTER_MSR_MTRR_FIX4KF8000 = 0x0008007A,
> +
> + HV_X64_REGISTER_TSC_AUX = 0x0008007B,
> + HV_X64_REGISTER_BNDCFGS = 0x0008007C,
> + HV_X64_REGISTER_DEBUG_CTL = 0x0008007D,
> +
> + /* Available */
> + HV_X64_REGISTER_AVAILABLE0008007E = 0x0008007E,
> + HV_X64_REGISTER_AVAILABLE0008007F = 0x0008007F,
> +
> + HV_X64_REGISTER_SGX_LAUNCH_CONTROL0 = 0x00080080,
> + HV_X64_REGISTER_SGX_LAUNCH_CONTROL1 = 0x00080081,
> + HV_X64_REGISTER_SGX_LAUNCH_CONTROL2 = 0x00080082,
> + HV_X64_REGISTER_SGX_LAUNCH_CONTROL3 = 0x00080083,
> + HV_X64_REGISTER_SPEC_CTRL = 0x00080084,
> + HV_X64_REGISTER_PRED_CMD = 0x00080085,
> + HV_X64_REGISTER_VIRT_SPEC_CTRL = 0x00080086,
> +
> + /* Other MSRs */
> + HV_X64_REGISTER_MSR_IA32_MISC_ENABLE = 0x000800A0,
> + HV_X64_REGISTER_IA32_FEATURE_CONTROL = 0x000800A1,
> + HV_X64_REGISTER_IA32_VMX_BASIC = 0x000800A2,
> + HV_X64_REGISTER_IA32_VMX_PINBASED_CTLS = 0x000800A3,
> + HV_X64_REGISTER_IA32_VMX_PROCBASED_CTLS = 0x000800A4,
> + HV_X64_REGISTER_IA32_VMX_EXIT_CTLS = 0x000800A5,
> + HV_X64_REGISTER_IA32_VMX_ENTRY_CTLS = 0x000800A6,
> + HV_X64_REGISTER_IA32_VMX_MISC = 0x000800A7,
> + HV_X64_REGISTER_IA32_VMX_CR0_FIXED0 = 0x000800A8,
> + HV_X64_REGISTER_IA32_VMX_CR0_FIXED1 = 0x000800A9,
> + HV_X64_REGISTER_IA32_VMX_CR4_FIXED0 = 0x000800AA,
> + HV_X64_REGISTER_IA32_VMX_CR4_FIXED1 = 0x000800AB,
> + HV_X64_REGISTER_IA32_VMX_VMCS_ENUM = 0x000800AC,
> + HV_X64_REGISTER_IA32_VMX_PROCBASED_CTLS2 = 0x000800AD,
> + HV_X64_REGISTER_IA32_VMX_EPT_VPID_CAP = 0x000800AE,
> + HV_X64_REGISTER_IA32_VMX_TRUE_PINBASED_CTLS = 0x000800AF,
> + HV_X64_REGISTER_IA32_VMX_TRUE_PROCBASED_CTLS = 0x000800B0,
> + HV_X64_REGISTER_IA32_VMX_TRUE_EXIT_CTLS = 0x000800B1,
> + HV_X64_REGISTER_IA32_VMX_TRUE_ENTRY_CTLS = 0x000800B2,
> +
> + /* Performance monitoring MSRs */
> + HV_X64_REGISTER_PERF_GLOBAL_CTRL = 0x00081000,
> + HV_X64_REGISTER_PERF_GLOBAL_STATUS = 0x00081001,
> + HV_X64_REGISTER_PERF_GLOBAL_IN_USE = 0x00081002,
> + HV_X64_REGISTER_FIXED_CTR_CTRL = 0x00081003,
> + HV_X64_REGISTER_DS_AREA = 0x00081004,
> + HV_X64_REGISTER_PEBS_ENABLE = 0x00081005,
> + HV_X64_REGISTER_PEBS_LD_LAT = 0x00081006,
> + HV_X64_REGISTER_PEBS_FRONTEND = 0x00081007,
> + HV_X64_REGISTER_PERF_EVT_SEL0 = 0x00081100,
> + HV_X64_REGISTER_PMC0 = 0x00081200,
> + HV_X64_REGISTER_FIXED_CTR0 = 0x00081300,
> +
> + HV_X64_REGISTER_LBR_TOS = 0x00082000,
> + HV_X64_REGISTER_LBR_SELECT = 0x00082001,
> + HV_X64_REGISTER_LER_FROM_LIP = 0x00082002,
> + HV_X64_REGISTER_LER_TO_LIP = 0x00082003,
> + HV_X64_REGISTER_LBR_FROM0 = 0x00082100,
> + HV_X64_REGISTER_LBR_TO0 = 0x00082200,
> + HV_X64_REGISTER_LBR_INFO0 = 0x00083300,
> +
> + /* Intel processor trace MSRs */
> + HV_X64_REGISTER_RTIT_CTL = 0x00081008,
> + HV_X64_REGISTER_RTIT_STATUS = 0x00081009,
> + HV_X64_REGISTER_RTIT_OUTPUT_BASE = 0x0008100A,
> + HV_X64_REGISTER_RTIT_OUTPUT_MASK_PTRS = 0x0008100B,
> + HV_X64_REGISTER_RTIT_CR3_MATCH = 0x0008100C,
> + HV_X64_REGISTER_RTIT_ADDR0A = 0x00081400,
> +
> + /* RtitAddr0A/B - RtitAddr3A/B occupy 0x00081400-0x00081407. */
> +
> + /* X64 Apic registers. These match the equivalent x2APIC MSR offsets. */
> + HV_X64_REGISTER_APIC_ID = 0x00084802,
> + HV_X64_REGISTER_APIC_VERSION = 0x00084803,
> +
> + /* Hypervisor-defined registers (Misc) */
> + HV_X64_REGISTER_HYPERCALL = 0x00090001,
> +
> + /* X64 Virtual APIC registers synthetic MSRs */
> + HV_X64_REGISTER_SYNTHETIC_EOI = 0x00090010,
> + HV_X64_REGISTER_SYNTHETIC_ICR = 0x00090011,
> + HV_X64_REGISTER_SYNTHETIC_TPR = 0x00090012,
> +
> + /* Partition Timer Assist Registers */
> + HV_X64_REGISTER_EMULATED_TIMER_PERIOD = 0x00090030,
> + HV_X64_REGISTER_EMULATED_TIMER_CONTROL = 0x00090031,
> + HV_X64_REGISTER_PM_TIMER_ASSIST = 0x00090032,
> +
> + /* Intercept Control Registers */
> + HV_X64_REGISTER_CR_INTERCEPT_CONTROL = 0x000E0000,
> + HV_X64_REGISTER_CR_INTERCEPT_CR0_MASK = 0x000E0001,
> + HV_X64_REGISTER_CR_INTERCEPT_CR4_MASK = 0x000E0002,
> + HV_X64_REGISTER_CR_INTERCEPT_IA32_MISC_ENABLE_MASK = 0x000E0003,
> +
> +};
> +
> +struct hv_u128 {
> + __u64 high_part;
> + __u64 low_part;
> +};
> +
> +union hv_x64_fp_register {
> + struct hv_u128 as_uint128;
> + struct {
> + __u64 mantissa;
> + __u64 biased_exponent : 15;
> + __u64 sign : 1;
> + __u64 reserved : 48;
> + };
> +};
> +
> +union hv_x64_fp_control_status_register {
> + struct hv_u128 as_uint128;
> + struct {
> + __u16 fp_control;
> + __u16 fp_status;
> + __u8 fp_tag;
> + __u8 reserved;
> + __u16 last_fp_op;
> + union {
> + /* long mode */
> + __u64 last_fp_rip;
> + /* 32 bit mode */
> + struct {
> + __u32 last_fp_eip;
> + __u16 last_fp_cs;
> + };
> + };
> + };
> +};
> +
> +union hv_x64_xmm_control_status_register {
> + struct hv_u128 as_uint128;
> + struct {
> + union {
> + /* long mode */
> + __u64 last_fp_rdp;
> + /* 32 bit mode */
> + struct {
> + __u32 last_fp_dp;
> + __u16 last_fp_ds;
> + };
> + };
> + __u32 xmm_status_control;
> + __u32 xmm_status_control_mask;
> + };
> +};
> +
> +struct hv_x64_segment_register {
> + __u64 base;
> + __u32 limit;
> + __u16 selector;
> + union {
> + struct {
> + __u16 segment_type : 4;
> + __u16 non_system_segment : 1;
> + __u16 descriptor_privilege_level : 2;
> + __u16 present : 1;
> + __u16 reserved : 4;
> + __u16 available : 1;
> + __u16 _long : 1;
> + __u16 _default : 1;
> + __u16 granularity : 1;
> + };
> + __u16 attributes;
> + };
> +};
> +
> +struct hv_x64_table_register {
> + __u16 pad[3];
> + __u16 limit;
> + __u64 base;
> +};
> +
> +union hv_explicit_suspend_register {
> + __u64 as_uint64;
> + struct {
> + __u64 suspended : 1;
> + __u64 reserved : 63;
> + };
> +};
> +
> +union hv_intercept_suspend_register {
> + __u64 as_uint64;
> + struct {
> + __u64 suspended : 1;
> + __u64 reserved : 63;
> + };
> +};
> +
> +union hv_dispatch_suspend_register {
> + __u64 as_uint64;
> + struct {
> + __u64 suspended : 1;
> + __u64 reserved : 63;
> + };
> +};
> +
> +union hv_x64_interrupt_state_register {
> + __u64 as_uint64;
> + struct {
> + __u64 interrupt_shadow : 1;
> + __u64 nmi_masked : 1;
> + __u64 reserved : 62;
> + };
> +};
> +
> +union hv_x64_pending_interruption_register {
> + __u64 as_uint64;
> + struct {
> + __u32 interruption_pending : 1;
> + __u32 interruption_type : 3;
> + __u32 deliver_error_code : 1;
> + __u32 instruction_length : 4;
> + __u32 nested_event : 1;
> + __u32 reserved : 6;
> + __u32 interruption_vector : 16;
> + __u32 error_code;
> + };
> +};
> +
> +union hv_x64_msr_npiep_config_contents {
> + __u64 as_uint64;
> + struct {
> + /*
> + * These bits enable instruction execution prevention for
> + * specific instructions.
> + */
> + __u64 prevents_gdt : 1;
> + __u64 prevents_idt : 1;
> + __u64 prevents_ldt : 1;
> + __u64 prevents_tr : 1;
> +
> + /* The reserved bits must always be 0. */
> + __u64 reserved : 60;
> + };
> +};
> +
> +union hv_x64_pending_exception_event {
> + __u64 as_uint64[2];
> + struct {
> + __u32 event_pending : 1;
> + __u32 event_type : 3;
> + __u32 reserved0 : 4;
> + __u32 deliver_error_code : 1;
> + __u32 reserved1 : 7;
> + __u32 vector : 16;
> + __u32 error_code;
> + __u64 exception_parameter;
> + };
> +};
> +
> +union hv_x64_pending_virtualization_fault_event {
> + __u64 as_uint64[2];
> + struct {
> + __u32 event_pending : 1;
> + __u32 event_type : 3;
> + __u32 reserved0 : 4;
> + __u32 reserved1 : 8;
> + __u32 parameter0 : 16;
> + __u32 code;
> + __u64 parameter1;
> + };
> +};
> +
> +union hv_register_value {
> + struct hv_u128 reg128;
> + __u64 reg64;
> + __u32 reg32;
> + __u16 reg16;
> + __u8 reg8;
> + union hv_x64_fp_register fp;
> + union hv_x64_fp_control_status_register fp_control_status;
> + union hv_x64_xmm_control_status_register xmm_control_status;
> + struct hv_x64_segment_register segment;
> + struct hv_x64_table_register table;
> + union hv_explicit_suspend_register explicit_suspend;
> + union hv_intercept_suspend_register intercept_suspend;
> + union hv_dispatch_suspend_register dispatch_suspend;
> + union hv_x64_interrupt_state_register interrupt_state;
> + union hv_x64_pending_interruption_register pending_interruption;
> + union hv_x64_msr_npiep_config_contents npiep_config;
> + union hv_x64_pending_exception_event pending_exception_event;
> + union hv_x64_pending_virtualization_fault_event
> + pending_virtualization_fault_event;
> +};
> +
> #endif
> diff --git a/include/asm-generic/hyperv-tlfs.h b/include/asm-generic/hyperv-tlfs.h
> index 6e5072e29897..b9295400c20b 100644
> --- a/include/asm-generic/hyperv-tlfs.h
> +++ b/include/asm-generic/hyperv-tlfs.h
> @@ -622,53 +622,30 @@ struct hv_retarget_device_interrupt {
> } __packed __aligned(8);
>
>
> -/* HvGetVpRegisters hypercall input with variable size reg name list*/
> -struct hv_get_vp_registers_input {
> - struct {
> - u64 partitionid;
> - u32 vpindex;
> - u8 inputvtl;
> - u8 padding[3];
> - } header;
> - struct input {
> - u32 name0;
> - u32 name1;
> - } element[];
> -} __packed;
> -
> +/* HvGetVpRegisters hypercall with variable size reg name list*/
> +struct hv_get_vp_registers {
> + u64 partition_id;
> + u32 vp_index;
> + u8 input_vtl;
> + u8 rsvd_z8;
> + u16 rsvd_z16;
> + __aligned(8) enum hv_register_name names[];
> +} __aligned(8);
>
> -/* HvGetVpRegisters returns an array of these output elements */
> -struct hv_get_vp_registers_output {
> - union {
> - struct {
> - u32 a;
> - u32 b;
> - u32 c;
> - u32 d;
> - } as32 __packed;
> - struct {
> - u64 low;
> - u64 high;
> - } as64 __packed;
> - };
> +/* HvSetVpRegisters hypercall with variable size reg name/value list*/
> +struct hv_register_assoc {
> + enum hv_register_name name;
> + __aligned(16) union hv_register_value value;
> };
>
> -/* HvSetVpRegisters hypercall with variable size reg name/value list*/
> -struct hv_set_vp_registers_input {
> - struct {
> - u64 partitionid;
> - u32 vpindex;
> - u8 inputvtl;
> - u8 padding[3];
> - } header;
> - struct {
> - u32 name;
> - u32 padding1;
> - u64 padding2;
> - u64 valuelow;
> - u64 valuehigh;
> - } element[];
> -} __packed;
> +struct hv_set_vp_registers {
> + u64 partition_id;
> + u32 vp_index;
> + u8 input_vtl;
> + u8 rsvd_z8;
> + u16 rsvd_z16;
> + struct hv_register_assoc elements[];
> +} __aligned(16);

Throughout these structures, I think the approach needs to be more
explicit about the memory layout. The current definitions assume that
the compiler is inserting padding in the expected places, and not in
any unexpected places. My previous concerns about use of enum
also apply.

The code also removes some layouts that are used in the
not-yet-accepted patches for ARM64. Let sync on how to get
those back in.

>
> enum hv_device_type {
> HV_DEVICE_TYPE_LOGICAL = 0,
> diff --git a/include/linux/mshv.h b/include/linux/mshv.h
> index 50521c5f7948..dfe469f573f9 100644
> --- a/include/linux/mshv.h
> +++ b/include/linux/mshv.h
> @@ -17,6 +17,7 @@
> struct mshv_vp {
> u32 index;
> struct mshv_partition *partition;
> + struct mutex mutex;
> };
>
> struct mshv_mem_region {
> diff --git a/include/uapi/linux/mshv.h b/include/uapi/linux/mshv.h
> index 1f053eae68a6..5d53ed655429 100644
> --- a/include/uapi/linux/mshv.h
> +++ b/include/uapi/linux/mshv.h
> @@ -33,6 +33,14 @@ struct mshv_create_vp {
> __u32 vp_index;
> };
>
> +#define MSHV_VP_MAX_REGISTERS 128
> +
> +struct mshv_vp_registers {
> + int count; /* at most MSHV_VP_MAX_REGISTERS */
> + enum hv_register_name *names;
> + union hv_register_value *values;
> +};

Having separate arrays for the names and values results in an extra
copy of the data down in the ioctl code. Any reason the caller couldn't
supply the data as an array, where each entry is already a name/value
pair?

> +
> #define MSHV_IOCTL 0xB8
>
> /* mshv device */
> @@ -44,4 +52,8 @@ struct mshv_create_vp {
> #define MSHV_UNMAP_GUEST_MEMORY _IOW(MSHV_IOCTL, 0x03, struct
> mshv_user_mem_region)
> #define MSHV_CREATE_VP _IOW(MSHV_IOCTL, 0x04, struct mshv_create_vp)
>
> +/* vp device */
> +#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)
> +
> #endif
> diff --git a/virt/mshv/mshv_main.c b/virt/mshv/mshv_main.c
> index 3be9d9a468c1..2a10137a1e84 100644
> --- a/virt/mshv/mshv_main.c
> +++ b/virt/mshv/mshv_main.c
> @@ -74,6 +74,12 @@ static struct miscdevice mshv_dev = {
> #define HV_MAP_GPA_BATCH_SIZE \
> (PAGE_SIZE / sizeof(struct hv_map_gpa_pages) / sizeof(u64))
> #define PIN_PAGES_BATCH_SIZE (0x10000000 / PAGE_SIZE)
> +#define HV_GET_REGISTER_BATCH_SIZE \
> + (PAGE_SIZE / \
> + sizeof(struct hv_get_vp_registers) / sizeof(enum hv_register_name))
> +#define HV_SET_REGISTER_BATCH_SIZE \
> + (PAGE_SIZE / \
> + sizeof(struct hv_set_vp_registers) / sizeof(struct hv_register_assoc))

These new size calculations have the same bug as HV_MAP_GPA_BATCH_SIZE.
The first divide operations should be subtraction.

With the correct calculation, HV_GET_REGISTER_BATCH_SIZE will be
too large. The input page will accommodate more 32 bit register names
than the output page will accommodate 128 bit register values. The limit
should be based on the latter, not the former. Or calculate both the
input and output limit and use the minimum.

>
> static int
> hv_call_withdraw_memory(u64 count, int node, u64 partition_id)
> @@ -380,10 +386,258 @@ hv_call_unmap_gpa_pages(u64 partition_id,
> return ret;
> }
>
> +static int
> +hv_call_get_vp_registers(u32 vp_index,
> + u64 partition_id,
> + u16 count,
> + const enum hv_register_name *names,
> + union hv_register_value *values)
> +{
> + struct hv_get_vp_registers *input_page;
> + union hv_register_value *output_page;
> + u16 completed = 0;
> + u64 hypercall_status;
> + unsigned long remaining = count;
> + int rep_count;
> + int status;
> + unsigned long flags;
> +
> + local_irq_save(flags);
> +
> + input_page = (struct hv_get_vp_registers *)(*this_cpu_ptr(
> + hyperv_pcpu_input_arg));
> + output_page = (union hv_register_value *)(*this_cpu_ptr(
> + hyperv_pcpu_output_arg));
> +
> + input_page->partition_id = partition_id;
> + input_page->vp_index = vp_index;
> + input_page->input_vtl = 0;
> + input_page->rsvd_z8 = 0;
> + input_page->rsvd_z16 = 0;
> +
> + while (remaining) {
> + rep_count = min(remaining, HV_GET_REGISTER_BATCH_SIZE);
> + memcpy(input_page->names, names,
> + sizeof(enum hv_register_name) * rep_count);
> +
> + hypercall_status =
> + hv_do_rep_hypercall(HVCALL_GET_VP_REGISTERS, rep_count,
> + 0, input_page, output_page);
> + status = hypercall_status & HV_HYPERCALL_RESULT_MASK;
> + if (status != HV_STATUS_SUCCESS) {
> + pr_err("%s: completed %li out of %u, %s\n",
> + __func__,
> + count - remaining, count,
> + hv_status_to_string(status));
> + break;
> + }
> + completed = (hypercall_status & HV_HYPERCALL_REP_COMP_MASK) >>
> + HV_HYPERCALL_REP_COMP_OFFSET;
> + memcpy(values, output_page,
> + sizeof(union hv_register_value) * completed);
> +
> + names += completed;
> + values += completed;
> + remaining -= completed;
> + }
> + local_irq_restore(flags);
> +
> + return -hv_status_to_errno(status);
> +}
> +
> +static int
> +hv_call_set_vp_registers(u32 vp_index,
> + u64 partition_id,
> + u16 count,
> + struct hv_register_assoc *registers)
> +{
> + struct hv_set_vp_registers *input_page;
> + u16 completed = 0;
> + u64 hypercall_status;
> + unsigned long remaining = count;
> + int rep_count;
> + int status;
> + unsigned long flags;
> +
> + local_irq_save(flags);
> + input_page = (struct hv_set_vp_registers *)(*this_cpu_ptr(
> + hyperv_pcpu_input_arg));
> +
> + input_page->partition_id = partition_id;
> + input_page->vp_index = vp_index;
> + input_page->input_vtl = 0;
> + input_page->rsvd_z8 = 0;
> + input_page->rsvd_z16 = 0;
> +
> + while (remaining) {
> + rep_count = min(remaining, HV_SET_REGISTER_BATCH_SIZE);
> + memcpy(input_page->elements, registers,
> + sizeof(struct hv_register_assoc) * rep_count);
> +
> + hypercall_status =
> + hv_do_rep_hypercall(HVCALL_SET_VP_REGISTERS, rep_count,
> + 0, input_page, NULL);
> + status = hypercall_status & HV_HYPERCALL_RESULT_MASK;
> + if (status != HV_STATUS_SUCCESS) {
> + pr_err("%s: completed %li out of %u, %s\n",
> + __func__,
> + count - remaining, count,
> + hv_status_to_string(status));
> + break;
> + }
> + completed = (hypercall_status & HV_HYPERCALL_REP_COMP_MASK) >>
> + HV_HYPERCALL_REP_COMP_OFFSET;
> + registers += completed;
> + remaining -= completed;
> + }
> +
> + local_irq_restore(flags);
> +
> + return -hv_status_to_errno(status);
> +}
> +
> +static long
> +mshv_vp_ioctl_get_regs(struct mshv_vp *vp, void __user *user_args)
> +{
> + struct mshv_vp_registers args;
> + enum hv_register_name *names;
> + union hv_register_value *values;
> + long ret;
> +
> + if (copy_from_user(&args, user_args, sizeof(args)))
> + return -EFAULT;
> +
> + if (args.count > MSHV_VP_MAX_REGISTERS)
> + return -EINVAL;
> +
> + names = kmalloc_array(args.count,
> + sizeof(enum hv_register_name),
> + GFP_KERNEL);
> + if (!names)
> + return -ENOMEM;
> +
> + values = kmalloc_array(args.count,
> + sizeof(union hv_register_value),
> + GFP_KERNEL);
> + if (!values) {
> + kfree(names);
> + return -ENOMEM;
> + }
> +
> + if (copy_from_user(names, args.names,
> + sizeof(enum hv_register_name) * args.count)) {
> + ret = -EFAULT;
> + goto free_return;
> + }
> +
> + ret = hv_call_get_vp_registers(vp->index, vp->partition->id,
> + args.count, names, values);
> + if (ret)
> + goto free_return;
> +
> + if (copy_to_user(args.values, values,
> + sizeof(union hv_register_value) * args.count)) {
> + ret = -EFAULT;
> + }
> +
> +free_return:
> + kfree(names);
> + kfree(values);
> + return ret;
> +}
> +
> +static long
> +mshv_vp_ioctl_set_regs(struct mshv_vp *vp, void __user *user_args)
> +{
> + int i;
> + struct mshv_vp_registers args;
> + struct hv_register_assoc *registers;
> + enum hv_register_name *names;
> + union hv_register_value *values;
> + long ret;
> +
> + if (copy_from_user(&args, user_args, sizeof(args)))
> + return -EFAULT;
> +
> + if (args.count > MSHV_VP_MAX_REGISTERS)
> + return -EINVAL;
> +
> + names = kmalloc_array(args.count,
> + sizeof(enum hv_register_name),
> + GFP_KERNEL);
> + if (!names)
> + return -ENOMEM;
> +
> + values = kmalloc_array(args.count,
> + sizeof(union hv_register_value),
> + GFP_KERNEL);
> + if (!values) {
> + kfree(names);
> + return -ENOMEM;
> + }
> +
> + registers = kmalloc_array(args.count,
> + sizeof(struct hv_register_assoc),
> + GFP_KERNEL);
> + if (!registers) {
> + kfree(values);
> + kfree(names);
> + return -ENOMEM;
> + }
> +
> + if (copy_from_user(names, args.names,
> + sizeof(enum hv_register_name) * args.count)) {
> + ret = -EFAULT;
> + goto free_return;
> + }
> +
> + if (copy_from_user(values, args.values,
> + sizeof(union hv_register_value) * args.count)) {
> + ret = -EFAULT;
> + goto free_return;
> + }
> +
> + for (i = 0; i < args.count; i++) {
> + memcpy(&registers[i].name, &names[i],
> + sizeof(enum hv_register_name));
> + memcpy(&registers[i].value, &values[i],
> + sizeof(union hv_register_value));
> + }

The above will result in uninitialized memory being sent to
Hyper-V, since there is implicit padding associated with the
32 bit name field.

> +
> + ret = hv_call_set_vp_registers(vp->index, vp->partition->id,
> + args.count, registers);
> +
> +free_return:
> + kfree(names);
> + kfree(values);
> + kfree(registers);
> + return ret;
> +}
> +
> +
> static long
> mshv_vp_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
> {
> - return -ENOTTY;
> + struct mshv_vp *vp = filp->private_data;
> + long r = 0;
> +
> + if (mutex_lock_killable(&vp->mutex))
> + return -EINTR;
> +
> + switch (ioctl) {
> + case MSHV_GET_VP_REGISTERS:
> + r = mshv_vp_ioctl_get_regs(vp, (void __user *)arg);
> + break;
> + case MSHV_SET_VP_REGISTERS:
> + r = mshv_vp_ioctl_set_regs(vp, (void __user *)arg);
> + break;
> + default:
> + r = -ENOTTY;
> + break;
> + }
> + mutex_unlock(&vp->mutex);
> +
> + return r;
> }
>
> static int
> @@ -420,6 +674,8 @@ mshv_partition_ioctl_create_vp(struct mshv_partition *partition,
> if (!vp)
> return -ENOMEM;
>
> + mutex_init(&vp->mutex);
> +
> vp->index = args.vp_index;
> vp->partition = mshv_partition_get(partition);
> if (!vp->partition) {
> --
> 2.25.1