[PATCH v2 00/15] Introduce /dev/mshv drivers

[PATCH v2 00/15] Introduce /dev/mshv drivers

[Nuno Das Neves]

This series introduces support for creating and running guest machines
while running on the Microsoft Hypervisor. [0]
This is done via an IOCTL interface accessed through /dev/mshv, similar to
/dev/kvm. Another series introducing this support was previously posted.
[1]

These interfaces support VMMs running in:
1. The root patition - provided in the mshv_root module, and
2. VTL 2 - provided in the mshv_vtl module [2]

Patches breakdown
-----------------
The first 7 patches are refactoring and adding some helper functions.
They provide some benefit on their own and could be applied independently
as cleanup patches.

Patches 8-12 just set things up for the driver code to come. These are very
small. They come first so that the remaining patches are more self-contained.

The final 3 patches are the meat of the series:
- Patch 13 contains new header files used by the driver.
  These are designed to mirror the ABI headers exported by Hyper-V. This is
  done to avoid polluting hyperv-tlfs.h and help track changes to the ABIs
  that are still unstable. (See FAQ below).
- Patch 14 conditionally includes these new header files into mshyperv.h
  and linux/hyperv.h, in order to be able to use these files in the new
  drivers while remaining independent from hyperv-tlfs.h.
- Patch 15 contains the new driver code located in drivers/hv. This is a
  large amount of code and new files, but it is mostly self-contained and
  all within drivers/hv - apart from the IOCTL interface itself in uapi.

Patch 15 is rather big and has bounced back from some mailing lists. If you
did not get a copy in your inbox, you can view it here instead:
https://github.com/NunoDasNeves/linux/commit/4dd436f13d95a6a0daecd75da012a2caa6c57c8c

FAQ on include/uapi/hyperv/*.h
------------------------------
Q:
Why not just add these definitions to hyperv-tlfs.h?
A:
The intention of hyperv-tlfs.h is to contain stable definitions documented
in the public TLFS document. These new definitions don't fit that criteria,
so they should be separate.

Q:
Why are these files named hvgdk.h, hvgdk_mini.h, hvhdk.h and hvhdk_mini.h?
A:
The precise meaning of the names reflects conventions used internally at
Microsoft.
Naming them this way makes it easy to find where particular Hyper-V
definitions come from, and check their correctness.
It also facilitates the future work of automatically generating these files.

Q:
Why are they in uapi?
A:
In short, to keep things simple. There are many definitions needed in both
the kernel and the VMM in userspace. Separating them doesn't serve much
purpose, and makes it more laborious to import definitions from Hyper-V
code.

Q:
The new headers redefine many things that are already in hyperv-tlfs.h - why?
A:
Some definitions are extended compared to what is documented in the TLFS.
In order to avoid adding undocumented or unstable definitions to hyperv-tlfs.h,
the new headers must compile independently.
Therefore, the new headers must redefine many things in hyperv-tlfs.h in order
to compile.

--------------------------
[0] "Hyper-V" is more well-known, but it really refers to the whole stack
    including the hypervisor and other components that run in Windows
    kernel and userspace.
[1] Previous /dev/mshv patch series and discussion:
    https://lore.kernel.org/linux-hyperv/1632853875-20261-1-git-send-email-nunodasneves@linux.microsoft.com/
[2] Virtual Secure Mode (VSM) and Virtual Trust Levels (VTL):
    https://learn.microsoft.com/en-us/virtualization/hyper-v-on-windows/tlfs/vsm

--------------------------

Changes since v1:
    * Clean up formatting, capitalization in commit messages
    * Add detail to commit message for patch 15
    * Remove errant lines in Makefile and Kconfig in patch 15
    * Move a reference to CONFIG_MSHV_VTL from patch 9 to 15

Nuno Das Neves (15):
  hyperv-tlfs: Change shared HV_REGISTER_* defines to HV_MSR_*
  mshyperv: Introduce hv_get_hypervisor_version function
  mshyperv: Introduce numa_node_to_proximity_domain_info
  asm-generic/mshyperv: Introduce hv_recommend_using_aeoi()
  hyperv: Move hv_connection_id to hyperv-tlfs
  hyperv-tlfs: Introduce hv_status_to_string and hv_status_to_errno
  Drivers: hv: Move hv_call_deposit_pages and hv_call_create_vp to
    common code
  Drivers: hv: Introduce per-cpu event ring tail
  Drivers: hv: Introduce hv_output_arg_exists in hv_common.c
  x86: hyperv: Add mshv_handler irq handler and setup function
  Drivers: hv: export vmbus_isr, hv_context and hv_post_message
  Documentation: Reserve ioctl number for mshv driver
  uapi: hyperv: Add mshv driver headers hvhdk.h, hvhdk_mini.h, hvgdk.h,
    hvgdk_mini.h
  asm-generic: hyperv: Use mshv headers conditionally. Add
    asm-generic/hyperv-defs.h
  Drivers: hv: Add modules to expose /dev/mshv to VMMs running on
    Hyper-V

 .../userspace-api/ioctl/ioctl-number.rst      |    2 +
 arch/arm64/hyperv/mshyperv.c                  |   23 +-
 arch/arm64/include/asm/hyperv-tlfs.h          |   25 +
 arch/arm64/include/asm/mshyperv.h             |    2 +-
 arch/x86/hyperv/hv_init.c                     |    2 +-
 arch/x86/hyperv/hv_proc.c                     |  166 +-
 arch/x86/include/asm/hyperv-tlfs.h            |  137 +-
 arch/x86/include/asm/mshyperv.h               |   13 +-
 arch/x86/kernel/cpu/mshyperv.c                |   71 +-
 drivers/acpi/numa/srat.c                      |    1 +
 drivers/clocksource/hyperv_timer.c            |   24 +-
 drivers/hv/Kconfig                            |   50 +
 drivers/hv/Makefile                           |   20 +
 drivers/hv/hv.c                               |   46 +-
 drivers/hv/hv_call.c                          |  119 +
 drivers/hv/hv_common.c                        |  222 +-
 drivers/hv/hyperv_vmbus.h                     |    2 +-
 drivers/hv/mshv.h                             |  156 ++
 drivers/hv/mshv_eventfd.c                     |  758 +++++++
 drivers/hv/mshv_eventfd.h                     |   80 +
 drivers/hv/mshv_main.c                        |  208 ++
 drivers/hv/mshv_msi.c                         |  129 ++
 drivers/hv/mshv_portid_table.c                |   84 +
 drivers/hv/mshv_root.h                        |  194 ++
 drivers/hv/mshv_root_hv_call.c                | 1064 +++++++++
 drivers/hv/mshv_root_main.c                   | 1964 +++++++++++++++++
 drivers/hv/mshv_synic.c                       |  689 ++++++
 drivers/hv/mshv_vtl.h                         |   52 +
 drivers/hv/mshv_vtl_main.c                    | 1542 +++++++++++++
 drivers/hv/vmbus_drv.c                        |    3 +-
 drivers/hv/xfer_to_guest.c                    |   28 +
 include/asm-generic/hyperv-defs.h             |   26 +
 include/asm-generic/hyperv-tlfs.h             |   77 +-
 include/asm-generic/mshyperv.h                |   76 +-
 include/linux/hyperv.h                        |   11 +-
 include/uapi/hyperv/hvgdk.h                   |   41 +
 include/uapi/hyperv/hvgdk_mini.h              | 1077 +++++++++
 include/uapi/hyperv/hvhdk.h                   | 1352 ++++++++++++
 include/uapi/hyperv/hvhdk_mini.h              |  164 ++
 include/uapi/linux/mshv.h                     |  298 +++
 40 files changed, 10645 insertions(+), 353 deletions(-)
 create mode 100644 drivers/hv/hv_call.c
 create mode 100644 drivers/hv/mshv.h
 create mode 100644 drivers/hv/mshv_eventfd.c
 create mode 100644 drivers/hv/mshv_eventfd.h
 create mode 100644 drivers/hv/mshv_main.c
 create mode 100644 drivers/hv/mshv_msi.c
 create mode 100644 drivers/hv/mshv_portid_table.c
 create mode 100644 drivers/hv/mshv_root.h
 create mode 100644 drivers/hv/mshv_root_hv_call.c
 create mode 100644 drivers/hv/mshv_root_main.c
 create mode 100644 drivers/hv/mshv_synic.c
 create mode 100644 drivers/hv/mshv_vtl.h
 create mode 100644 drivers/hv/mshv_vtl_main.c
 create mode 100644 drivers/hv/xfer_to_guest.c
 create mode 100644 include/asm-generic/hyperv-defs.h
 create mode 100644 include/uapi/hyperv/hvgdk.h
 create mode 100644 include/uapi/hyperv/hvgdk_mini.h
 create mode 100644 include/uapi/hyperv/hvhdk.h
 create mode 100644 include/uapi/hyperv/hvhdk_mini.h
 create mode 100644 include/uapi/linux/mshv.h

-- 
2.25.1

[PATCH v2 01/15] hyperv-tlfs: Change shared HV_REGISTER_* defines to HV_MSR_*

[Nuno Das Neves]

In x86 hyperv-tlfs, HV_REGISTER_ prefix is used to indicate MSRs
accessed via rdmsrl/wrmsrl. But in ARM64, HV_REGISTER_ instead indicates
VP registers accessed via get/set vp registers hypercall.

This is due to HV_REGISTER_* names being used by hv_set/get_register,
with the arch-specific version delegating to the appropriate mechanism.

The problem is, using prefix HV_REGISTER_ for MSRs will conflict with
VP registers when they are introduced for x86 in future.

This patch solves the issue by:

1. Defining all the x86 MSRs with a consistent prefix: HV_X64_MSR_.
   This is so HV_REGISTER_ can be reserved for VP registers.

2. Change the non-arch-specific alias used by hv_set/get_register to
   HV_MSR_. This is also happens to be the same name HyperV uses for this
   purpose.

Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
---
 arch/arm64/include/asm/hyperv-tlfs.h |  25 +++++
 arch/x86/include/asm/hyperv-tlfs.h   | 137 +++++++++++++--------------
 arch/x86/include/asm/mshyperv.h      |   8 +-
 arch/x86/kernel/cpu/mshyperv.c       |  22 ++---
 drivers/clocksource/hyperv_timer.c   |  24 ++---
 drivers/hv/hv.c                      |  32 +++----
 drivers/hv/hv_common.c               |  18 ++--
 include/asm-generic/mshyperv.h       |   2 +-
 8 files changed, 146 insertions(+), 122 deletions(-)

diff --git a/arch/arm64/include/asm/hyperv-tlfs.h b/arch/arm64/include/asm/hyperv-tlfs.h
index bc6c7ac934a1..a6e852c2fc3a 100644
--- a/arch/arm64/include/asm/hyperv-tlfs.h
+++ b/arch/arm64/include/asm/hyperv-tlfs.h
@@ -64,6 +64,31 @@
 #define HV_REGISTER_STIMER0_CONFIG	0x000B0000
 #define HV_REGISTER_STIMER0_COUNT	0x000B0001
 
+/*
+ * To support non-arch-specific code calling hv_set/get_register:
+ * - On x86, HV_MSR_ indicates an MSR accessed via rdmsrl/wrmsrl
+ * - On ARM, HV_MSR_ indicates a VP register accessed via hypercall
+ */
+#define HV_MSR_VP_INDEX		(HV_REGISTER_VP_INDEX)
+#define HV_MSR_TIME_REF_COUNT	(HV_REGISTER_TIME_REF_COUNT)
+#define HV_MSR_REFERENCE_TS	(HV_REGISTER_REFERENCE_TSC)
+
+#define HV_MSR_STIMER0_CONFIG	(HV_REGISTER_STIMER0_CONFIG)
+#define HV_MSR_STIMER0_COUNT	(HV_REGISTER_STIMER0_COUNT)
+
+#define HV_MSR_SCONTROL		(HV_REGISTER_SCONTROL)
+#define HV_MSR_SIEFP		(HV_REGISTER_SIEFP)
+#define HV_MSR_SIMP		(HV_REGISTER_SIMP)
+#define HV_MSR_EOM		(HV_REGISTER_EOM)
+#define HV_MSR_SINT0		(HV_REGISTER_SINT0)
+
+#define HV_MSR_CRASH_P0		(HV_REGISTER_CRASH_P0)
+#define HV_MSR_CRASH_P1		(HV_REGISTER_CRASH_P1)
+#define HV_MSR_CRASH_P2		(HV_REGISTER_CRASH_P2)
+#define HV_MSR_CRASH_P3		(HV_REGISTER_CRASH_P3)
+#define HV_MSR_CRASH_P4		(HV_REGISTER_CRASH_P4)
+#define HV_MSR_CRASH_CTL	(HV_REGISTER_CRASH_CTL)
+
 union hv_msi_entry {
 	u64 as_uint64[2];
 	struct {
diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index cea95dcd27c2..40902a767733 100644
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/arch/x86/include/asm/hyperv-tlfs.h
@@ -181,7 +181,7 @@ enum hv_isolation_type {
 #define HV_X64_MSR_HYPERCALL			0x40000001
 
 /* MSR used to provide vcpu index */
-#define HV_REGISTER_VP_INDEX			0x40000002
+#define HV_X64_MSR_VP_INDEX			0x40000002
 
 /* MSR used to reset the guest OS. */
 #define HV_X64_MSR_RESET			0x40000003
@@ -190,10 +190,10 @@ enum hv_isolation_type {
 #define HV_X64_MSR_VP_RUNTIME			0x40000010
 
 /* MSR used to read the per-partition time reference counter */
-#define HV_REGISTER_TIME_REF_COUNT		0x40000020
+#define HV_X64_MSR_TIME_REF_COUNT		0x40000020
 
 /* A partition's reference time stamp counter (TSC) page */
-#define HV_REGISTER_REFERENCE_TSC		0x40000021
+#define HV_X64_MSR_REFERENCE_TSC		0x40000021
 
 /* MSR used to retrieve the TSC frequency */
 #define HV_X64_MSR_TSC_FREQUENCY		0x40000022
@@ -208,61 +208,61 @@ enum hv_isolation_type {
 #define HV_X64_MSR_VP_ASSIST_PAGE		0x40000073
 
 /* Define synthetic interrupt controller model specific registers. */
-#define HV_REGISTER_SCONTROL			0x40000080
-#define HV_REGISTER_SVERSION			0x40000081
-#define HV_REGISTER_SIEFP			0x40000082
-#define HV_REGISTER_SIMP			0x40000083
-#define HV_REGISTER_EOM				0x40000084
-#define HV_REGISTER_SINT0			0x40000090
-#define HV_REGISTER_SINT1			0x40000091
-#define HV_REGISTER_SINT2			0x40000092
-#define HV_REGISTER_SINT3			0x40000093
-#define HV_REGISTER_SINT4			0x40000094
-#define HV_REGISTER_SINT5			0x40000095
-#define HV_REGISTER_SINT6			0x40000096
-#define HV_REGISTER_SINT7			0x40000097
-#define HV_REGISTER_SINT8			0x40000098
-#define HV_REGISTER_SINT9			0x40000099
-#define HV_REGISTER_SINT10			0x4000009A
-#define HV_REGISTER_SINT11			0x4000009B
-#define HV_REGISTER_SINT12			0x4000009C
-#define HV_REGISTER_SINT13			0x4000009D
-#define HV_REGISTER_SINT14			0x4000009E
-#define HV_REGISTER_SINT15			0x4000009F
+#define HV_X64_MSR_SCONTROL			0x40000080
+#define HV_X64_MSR_SVERSION			0x40000081
+#define HV_X64_MSR_SIEFP			0x40000082
+#define HV_X64_MSR_SIMP				0x40000083
+#define HV_X64_MSR_EOM				0x40000084
+#define HV_X64_MSR_SINT0			0x40000090
+#define HV_X64_MSR_SINT1			0x40000091
+#define HV_X64_MSR_SINT2			0x40000092
+#define HV_X64_MSR_SINT3			0x40000093
+#define HV_X64_MSR_SINT4			0x40000094
+#define HV_X64_MSR_SINT5			0x40000095
+#define HV_X64_MSR_SINT6			0x40000096
+#define HV_X64_MSR_SINT7			0x40000097
+#define HV_X64_MSR_SINT8			0x40000098
+#define HV_X64_MSR_SINT9			0x40000099
+#define HV_X64_MSR_SINT10			0x4000009A
+#define HV_X64_MSR_SINT11			0x4000009B
+#define HV_X64_MSR_SINT12			0x4000009C
+#define HV_X64_MSR_SINT13			0x4000009D
+#define HV_X64_MSR_SINT14			0x4000009E
+#define HV_X64_MSR_SINT15			0x4000009F
 
 /*
  * Define synthetic interrupt controller model specific registers for
  * nested hypervisor.
  */
-#define HV_REGISTER_NESTED_SCONTROL            0x40001080
-#define HV_REGISTER_NESTED_SVERSION            0x40001081
-#define HV_REGISTER_NESTED_SIEFP               0x40001082
-#define HV_REGISTER_NESTED_SIMP                0x40001083
-#define HV_REGISTER_NESTED_EOM                 0x40001084
-#define HV_REGISTER_NESTED_SINT0               0x40001090
+#define HV_X64_MSR_NESTED_SCONTROL		0x40001080
+#define HV_X64_MSR_NESTED_SVERSION		0x40001081
+#define HV_X64_MSR_NESTED_SIEFP			0x40001082
+#define HV_X64_MSR_NESTED_SIMP			0x40001083
+#define HV_X64_MSR_NESTED_EOM			0x40001084
+#define HV_X64_MSR_NESTED_SINT0			0x40001090
 
 /*
  * Synthetic Timer MSRs. Four timers per vcpu.
  */
-#define HV_REGISTER_STIMER0_CONFIG		0x400000B0
-#define HV_REGISTER_STIMER0_COUNT		0x400000B1
-#define HV_REGISTER_STIMER1_CONFIG		0x400000B2
-#define HV_REGISTER_STIMER1_COUNT		0x400000B3
-#define HV_REGISTER_STIMER2_CONFIG		0x400000B4
-#define HV_REGISTER_STIMER2_COUNT		0x400000B5
-#define HV_REGISTER_STIMER3_CONFIG		0x400000B6
-#define HV_REGISTER_STIMER3_COUNT		0x400000B7
+#define HV_X64_MSR_STIMER0_CONFIG		0x400000B0
+#define HV_X64_MSR_STIMER0_COUNT		0x400000B1
+#define HV_X64_MSR_STIMER1_CONFIG		0x400000B2
+#define HV_X64_MSR_STIMER1_COUNT		0x400000B3
+#define HV_X64_MSR_STIMER2_CONFIG		0x400000B4
+#define HV_X64_MSR_STIMER2_COUNT		0x400000B5
+#define HV_X64_MSR_STIMER3_CONFIG		0x400000B6
+#define HV_X64_MSR_STIMER3_COUNT		0x400000B7
 
 /* Hyper-V guest idle MSR */
 #define HV_X64_MSR_GUEST_IDLE			0x400000F0
 
 /* Hyper-V guest crash notification MSR's */
-#define HV_REGISTER_CRASH_P0			0x40000100
-#define HV_REGISTER_CRASH_P1			0x40000101
-#define HV_REGISTER_CRASH_P2			0x40000102
-#define HV_REGISTER_CRASH_P3			0x40000103
-#define HV_REGISTER_CRASH_P4			0x40000104
-#define HV_REGISTER_CRASH_CTL			0x40000105
+#define HV_X64_MSR_CRASH_P0			0x40000100
+#define HV_X64_MSR_CRASH_P1			0x40000101
+#define HV_X64_MSR_CRASH_P2			0x40000102
+#define HV_X64_MSR_CRASH_P3			0x40000103
+#define HV_X64_MSR_CRASH_P4			0x40000104
+#define HV_X64_MSR_CRASH_CTL			0x40000105
 
 /* TSC emulation after migration */
 #define HV_X64_MSR_REENLIGHTENMENT_CONTROL	0x40000106
@@ -275,31 +275,30 @@ enum hv_isolation_type {
 /* HV_X64_MSR_TSC_INVARIANT_CONTROL bits */
 #define HV_EXPOSE_INVARIANT_TSC		BIT_ULL(0)
 
-/* Register name aliases for temporary compatibility */
-#define HV_X64_MSR_STIMER0_COUNT	HV_REGISTER_STIMER0_COUNT
-#define HV_X64_MSR_STIMER0_CONFIG	HV_REGISTER_STIMER0_CONFIG
-#define HV_X64_MSR_STIMER1_COUNT	HV_REGISTER_STIMER1_COUNT
-#define HV_X64_MSR_STIMER1_CONFIG	HV_REGISTER_STIMER1_CONFIG
-#define HV_X64_MSR_STIMER2_COUNT	HV_REGISTER_STIMER2_COUNT
-#define HV_X64_MSR_STIMER2_CONFIG	HV_REGISTER_STIMER2_CONFIG
-#define HV_X64_MSR_STIMER3_COUNT	HV_REGISTER_STIMER3_COUNT
-#define HV_X64_MSR_STIMER3_CONFIG	HV_REGISTER_STIMER3_CONFIG
-#define HV_X64_MSR_SCONTROL		HV_REGISTER_SCONTROL
-#define HV_X64_MSR_SVERSION		HV_REGISTER_SVERSION
-#define HV_X64_MSR_SIMP			HV_REGISTER_SIMP
-#define HV_X64_MSR_SIEFP		HV_REGISTER_SIEFP
-#define HV_X64_MSR_VP_INDEX		HV_REGISTER_VP_INDEX
-#define HV_X64_MSR_EOM			HV_REGISTER_EOM
-#define HV_X64_MSR_SINT0		HV_REGISTER_SINT0
-#define HV_X64_MSR_SINT15		HV_REGISTER_SINT15
-#define HV_X64_MSR_CRASH_P0		HV_REGISTER_CRASH_P0
-#define HV_X64_MSR_CRASH_P1		HV_REGISTER_CRASH_P1
-#define HV_X64_MSR_CRASH_P2		HV_REGISTER_CRASH_P2
-#define HV_X64_MSR_CRASH_P3		HV_REGISTER_CRASH_P3
-#define HV_X64_MSR_CRASH_P4		HV_REGISTER_CRASH_P4
-#define HV_X64_MSR_CRASH_CTL		HV_REGISTER_CRASH_CTL
-#define HV_X64_MSR_TIME_REF_COUNT	HV_REGISTER_TIME_REF_COUNT
-#define HV_X64_MSR_REFERENCE_TSC	HV_REGISTER_REFERENCE_TSC
+/*
+ * To support non-arch-specific code calling hv_set/get_register:
+ * - On x86, HV_MSR_ indicates an MSR accessed via rdmsrl/wrmsrl
+ * - On ARM, HV_MSR_ indicates a VP register accessed via hypercall
+ */
+#define HV_MSR_VP_INDEX		(HV_X64_MSR_VP_INDEX)
+#define HV_MSR_TIME_REF_COUNT	(HV_X64_MSR_TIME_REF_COUNT)
+#define HV_MSR_REFERENCE_TSC	(HV_X64_MSR_REFERENCE_TSC)
+
+#define HV_MSR_STIMER0_CONFIG	(HV_X64_MSR_STIMER0_CONFIG)
+#define HV_MSR_STIMER0_COUNT	(HV_X64_MSR_STIMER0_COUNT)
+
+#define HV_MSR_SCONTROL		(HV_X64_MSR_SCONTROL)
+#define HV_MSR_SIEFP		(HV_X64_MSR_SIEFP)
+#define HV_MSR_SIMP		(HV_X64_MSR_SIMP)
+#define HV_MSR_EOM		(HV_X64_MSR_EOM)
+#define HV_MSR_SINT0		(HV_X64_MSR_SINT0)
+
+#define HV_MSR_CRASH_P0		(HV_X64_MSR_CRASH_P0)
+#define HV_MSR_CRASH_P1		(HV_X64_MSR_CRASH_P1)
+#define HV_MSR_CRASH_P2		(HV_X64_MSR_CRASH_P2)
+#define HV_MSR_CRASH_P3		(HV_X64_MSR_CRASH_P3)
+#define HV_MSR_CRASH_P4		(HV_X64_MSR_CRASH_P4)
+#define HV_MSR_CRASH_CTL	(HV_X64_MSR_CRASH_CTL)
 
 /* Hyper-V memory host visibility */
 enum hv_mem_host_visibility {
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 88d9ef98e087..daaac502d411 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -242,14 +242,14 @@ extern bool hv_isolation_type_snp(void);
 
 static inline bool hv_is_synic_reg(unsigned int reg)
 {
-	return (reg >= HV_REGISTER_SCONTROL) &&
-	       (reg <= HV_REGISTER_SINT15);
+	return (reg >= HV_X64_MSR_SCONTROL) &&
+	       (reg <= HV_X64_MSR_SINT15);
 }
 
 static inline bool hv_is_sint_reg(unsigned int reg)
 {
-	return (reg >= HV_REGISTER_SINT0) &&
-	       (reg <= HV_REGISTER_SINT15);
+	return (reg >= HV_X64_MSR_SINT0) &&
+	       (reg <= HV_X64_MSR_SINT15);
 }
 
 u64 hv_get_register(unsigned int reg);
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index c7969e806c64..4d38cafe6f2c 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -43,19 +43,19 @@ struct ms_hyperv_info ms_hyperv;
 static inline unsigned int hv_get_nested_reg(unsigned int reg)
 {
 	if (hv_is_sint_reg(reg))
-		return reg - HV_REGISTER_SINT0 + HV_REGISTER_NESTED_SINT0;
+		return reg - HV_X64_MSR_SINT0 + HV_X64_MSR_NESTED_SINT0;
 
 	switch (reg) {
-	case HV_REGISTER_SIMP:
-		return HV_REGISTER_NESTED_SIMP;
-	case HV_REGISTER_SIEFP:
-		return HV_REGISTER_NESTED_SIEFP;
-	case HV_REGISTER_SVERSION:
-		return HV_REGISTER_NESTED_SVERSION;
-	case HV_REGISTER_SCONTROL:
-		return HV_REGISTER_NESTED_SCONTROL;
-	case HV_REGISTER_EOM:
-		return HV_REGISTER_NESTED_EOM;
+	case HV_X64_MSR_SIMP:
+		return HV_X64_MSR_NESTED_SIMP;
+	case HV_X64_MSR_SIEFP:
+		return HV_X64_MSR_NESTED_SIEFP;
+	case HV_X64_MSR_SVERSION:
+		return HV_X64_MSR_NESTED_SVERSION;
+	case HV_X64_MSR_SCONTROL:
+		return HV_X64_MSR_NESTED_SCONTROL;
+	case HV_X64_MSR_EOM:
+		return HV_X64_MSR_NESTED_EOM;
 	default:
 		return reg;
 	}
diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c
index e56307a81f4d..2e9fa88f25fe 100644
--- a/drivers/clocksource/hyperv_timer.c
+++ b/drivers/clocksource/hyperv_timer.c
@@ -81,14 +81,14 @@ static int hv_ce_set_next_event(unsigned long delta,
 
 	current_tick = hv_read_reference_counter();
 	current_tick += delta;
-	hv_set_register(HV_REGISTER_STIMER0_COUNT, current_tick);
+	hv_set_register(HV_MSR_STIMER0_COUNT, current_tick);
 	return 0;
 }
 
 static int hv_ce_shutdown(struct clock_event_device *evt)
 {
-	hv_set_register(HV_REGISTER_STIMER0_COUNT, 0);
-	hv_set_register(HV_REGISTER_STIMER0_CONFIG, 0);
+	hv_set_register(HV_MSR_STIMER0_COUNT, 0);
+	hv_set_register(HV_MSR_STIMER0_CONFIG, 0);
 	if (direct_mode_enabled && stimer0_irq >= 0)
 		disable_percpu_irq(stimer0_irq);
 
@@ -119,7 +119,7 @@ static int hv_ce_set_oneshot(struct clock_event_device *evt)
 		timer_cfg.direct_mode = 0;
 		timer_cfg.sintx = stimer0_message_sint;
 	}
-	hv_set_register(HV_REGISTER_STIMER0_CONFIG, timer_cfg.as_uint64);
+	hv_set_register(HV_MSR_STIMER0_CONFIG, timer_cfg.as_uint64);
 	return 0;
 }
 
@@ -373,10 +373,10 @@ static __always_inline u64 read_hv_clock_msr(void)
 	 * nanosecond units.
 	 *
 	 * Use hv_raw_get_register() because this function is used from
-	 * noinstr. Notable; while HV_REGISTER_TIME_REF_COUNT is a synthetic
+	 * noinstr. Notable; while HV_MSR_TIME_REF_COUNT is a synthetic
 	 * register it doesn't need the GHCB path.
 	 */
-	return hv_raw_get_register(HV_REGISTER_TIME_REF_COUNT);
+	return hv_raw_get_register(HV_MSR_TIME_REF_COUNT);
 }
 
 /*
@@ -439,9 +439,9 @@ static void suspend_hv_clock_tsc(struct clocksource *arg)
 	union hv_reference_tsc_msr tsc_msr;
 
 	/* Disable the TSC page */
-	tsc_msr.as_uint64 = hv_get_register(HV_REGISTER_REFERENCE_TSC);
+	tsc_msr.as_uint64 = hv_get_register(HV_MSR_REFERENCE_TSC);
 	tsc_msr.enable = 0;
-	hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64);
+	hv_set_register(HV_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
 }
 
 
@@ -450,10 +450,10 @@ static void resume_hv_clock_tsc(struct clocksource *arg)
 	union hv_reference_tsc_msr tsc_msr;
 
 	/* Re-enable the TSC page */
-	tsc_msr.as_uint64 = hv_get_register(HV_REGISTER_REFERENCE_TSC);
+	tsc_msr.as_uint64 = hv_get_register(HV_MSR_REFERENCE_TSC);
 	tsc_msr.enable = 1;
 	tsc_msr.pfn = tsc_pfn;
-	hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64);
+	hv_set_register(HV_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
 }
 
 #ifdef HAVE_VDSO_CLOCKMODE_HVCLOCK
@@ -555,14 +555,14 @@ static void __init hv_init_tsc_clocksource(void)
 	 * thus TSC clocksource will work even without the real TSC page
 	 * mapped.
 	 */
-	tsc_msr.as_uint64 = hv_get_register(HV_REGISTER_REFERENCE_TSC);
+	tsc_msr.as_uint64 = hv_get_register(HV_MSR_REFERENCE_TSC);
 	if (hv_root_partition)
 		tsc_pfn = tsc_msr.pfn;
 	else
 		tsc_pfn = HVPFN_DOWN(virt_to_phys(tsc_page));
 	tsc_msr.enable = 1;
 	tsc_msr.pfn = tsc_pfn;
-	hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64);
+	hv_set_register(HV_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
 
 	clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100);
 
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index de6708dbe0df..3ddacdebe886 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -167,7 +167,7 @@ void hv_synic_enable_regs(unsigned int cpu)
 	union hv_synic_scontrol sctrl;
 
 	/* Setup the Synic's message page */
-	simp.as_uint64 = hv_get_register(HV_REGISTER_SIMP);
+	simp.as_uint64 = hv_get_register(HV_MSR_SIMP);
 	simp.simp_enabled = 1;
 
 	if (hv_isolation_type_snp() || hv_root_partition) {
@@ -183,10 +183,10 @@ void hv_synic_enable_regs(unsigned int cpu)
 			>> HV_HYP_PAGE_SHIFT;
 	}
 
-	hv_set_register(HV_REGISTER_SIMP, simp.as_uint64);
+	hv_set_register(HV_MSR_SIMP, simp.as_uint64);
 
 	/* Setup the Synic's event page */
-	siefp.as_uint64 = hv_get_register(HV_REGISTER_SIEFP);
+	siefp.as_uint64 = hv_get_register(HV_MSR_SIEFP);
 	siefp.siefp_enabled = 1;
 
 	if (hv_isolation_type_snp() || hv_root_partition) {
@@ -202,12 +202,12 @@ void hv_synic_enable_regs(unsigned int cpu)
 			>> HV_HYP_PAGE_SHIFT;
 	}
 
-	hv_set_register(HV_REGISTER_SIEFP, siefp.as_uint64);
+	hv_set_register(HV_MSR_SIEFP, siefp.as_uint64);
 
 	/* Setup the shared SINT. */
 	if (vmbus_irq != -1)
 		enable_percpu_irq(vmbus_irq, 0);
-	shared_sint.as_uint64 = hv_get_register(HV_REGISTER_SINT0 +
+	shared_sint.as_uint64 = hv_get_register(HV_MSR_SINT0 +
 					VMBUS_MESSAGE_SINT);
 
 	shared_sint.vector = vmbus_interrupt;
@@ -223,14 +223,14 @@ void hv_synic_enable_regs(unsigned int cpu)
 #else
 	shared_sint.auto_eoi = 0;
 #endif
-	hv_set_register(HV_REGISTER_SINT0 + VMBUS_MESSAGE_SINT,
+	hv_set_register(HV_MSR_SINT0 + VMBUS_MESSAGE_SINT,
 				shared_sint.as_uint64);
 
 	/* Enable the global synic bit */
-	sctrl.as_uint64 = hv_get_register(HV_REGISTER_SCONTROL);
+	sctrl.as_uint64 = hv_get_register(HV_MSR_SCONTROL);
 	sctrl.enable = 1;
 
-	hv_set_register(HV_REGISTER_SCONTROL, sctrl.as_uint64);
+	hv_set_register(HV_MSR_SCONTROL, sctrl.as_uint64);
 }
 
 int hv_synic_init(unsigned int cpu)
@@ -254,17 +254,17 @@ void hv_synic_disable_regs(unsigned int cpu)
 	union hv_synic_siefp siefp;
 	union hv_synic_scontrol sctrl;
 
-	shared_sint.as_uint64 = hv_get_register(HV_REGISTER_SINT0 +
+	shared_sint.as_uint64 = hv_get_register(HV_MSR_SINT0 +
 					VMBUS_MESSAGE_SINT);
 
 	shared_sint.masked = 1;
 
 	/* Need to correctly cleanup in the case of SMP!!! */
 	/* Disable the interrupt */
-	hv_set_register(HV_REGISTER_SINT0 + VMBUS_MESSAGE_SINT,
+	hv_set_register(HV_MSR_SINT0 + VMBUS_MESSAGE_SINT,
 				shared_sint.as_uint64);
 
-	simp.as_uint64 = hv_get_register(HV_REGISTER_SIMP);
+	simp.as_uint64 = hv_get_register(HV_MSR_SIMP);
 	/*
 	 * In Isolation VM, sim and sief pages are allocated by
 	 * paravisor. These pages also will be used by kdump
@@ -279,9 +279,9 @@ void hv_synic_disable_regs(unsigned int cpu)
 		simp.base_simp_gpa = 0;
 	}
 
-	hv_set_register(HV_REGISTER_SIMP, simp.as_uint64);
+	hv_set_register(HV_MSR_SIMP, simp.as_uint64);
 
-	siefp.as_uint64 = hv_get_register(HV_REGISTER_SIEFP);
+	siefp.as_uint64 = hv_get_register(HV_MSR_SIEFP);
 	siefp.siefp_enabled = 0;
 
 	if (hv_isolation_type_snp() || hv_root_partition) {
@@ -291,12 +291,12 @@ void hv_synic_disable_regs(unsigned int cpu)
 		siefp.base_siefp_gpa = 0;
 	}
 
-	hv_set_register(HV_REGISTER_SIEFP, siefp.as_uint64);
+	hv_set_register(HV_MSR_SIEFP, siefp.as_uint64);
 
 	/* Disable the global synic bit */
-	sctrl.as_uint64 = hv_get_register(HV_REGISTER_SCONTROL);
+	sctrl.as_uint64 = hv_get_register(HV_MSR_SCONTROL);
 	sctrl.enable = 0;
-	hv_set_register(HV_REGISTER_SCONTROL, sctrl.as_uint64);
+	hv_set_register(HV_MSR_SCONTROL, sctrl.as_uint64);
 
 	if (vmbus_irq != -1)
 		disable_percpu_irq(vmbus_irq);
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
index 542a1d53b303..790b96290360 100644
--- a/drivers/hv/hv_common.c
+++ b/drivers/hv/hv_common.c
@@ -227,17 +227,17 @@ static void hv_kmsg_dump(struct kmsg_dumper *dumper,
 	 * contain the size of the panic data in that page. Rest of the
 	 * registers are no-op when the NOTIFY_MSG flag is set.
 	 */
-	hv_set_register(HV_REGISTER_CRASH_P0, 0);
-	hv_set_register(HV_REGISTER_CRASH_P1, 0);
-	hv_set_register(HV_REGISTER_CRASH_P2, 0);
-	hv_set_register(HV_REGISTER_CRASH_P3, virt_to_phys(hv_panic_page));
-	hv_set_register(HV_REGISTER_CRASH_P4, bytes_written);
+	hv_set_register(HV_MSR_CRASH_P0, 0);
+	hv_set_register(HV_MSR_CRASH_P1, 0);
+	hv_set_register(HV_MSR_CRASH_P2, 0);
+	hv_set_register(HV_MSR_CRASH_P3, virt_to_phys(hv_panic_page));
+	hv_set_register(HV_MSR_CRASH_P4, bytes_written);
 
 	/*
 	 * Let Hyper-V know there is crash data available along with
 	 * the panic message.
 	 */
-	hv_set_register(HV_REGISTER_CRASH_CTL,
+	hv_set_register(HV_MSR_CRASH_CTL,
 			(HV_CRASH_CTL_CRASH_NOTIFY |
 			 HV_CRASH_CTL_CRASH_NOTIFY_MSG));
 }
@@ -310,7 +310,7 @@ int __init hv_common_init(void)
 		 * Register for panic kmsg callback only if the right
 		 * capability is supported by the hypervisor.
 		 */
-		hyperv_crash_ctl = hv_get_register(HV_REGISTER_CRASH_CTL);
+		hyperv_crash_ctl = hv_get_register(HV_MSR_CRASH_CTL);
 		if (hyperv_crash_ctl & HV_CRASH_CTL_CRASH_NOTIFY_MSG)
 			hv_kmsg_dump_register();
 
@@ -380,7 +380,7 @@ int hv_common_cpu_init(unsigned int cpu)
 		}
 	}
 
-	msr_vp_index = hv_get_register(HV_REGISTER_VP_INDEX);
+	msr_vp_index = hv_get_register(HV_MSR_VP_INDEX);
 
 	hv_vp_index[cpu] = msr_vp_index;
 
@@ -477,7 +477,7 @@ EXPORT_SYMBOL_GPL(hv_is_hibernation_supported);
  */
 static u64 __hv_read_ref_counter(void)
 {
-	return hv_get_register(HV_REGISTER_TIME_REF_COUNT);
+	return hv_get_register(HV_MSR_TIME_REF_COUNT);
 }
 
 u64 (*hv_read_reference_counter)(void) = __hv_read_ref_counter;
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index 402a8c1c202d..094c57320ed1 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -149,7 +149,7 @@ static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
 		 * possibly deliver another msg from the
 		 * hypervisor
 		 */
-		hv_set_register(HV_REGISTER_EOM, 0);
+		hv_set_register(HV_MSR_EOM, 0);
 	}
 }
 
-- 
2.25.1

[PATCH v2 02/15] mshyperv: Introduce hv_get_hypervisor_version function

[Nuno Das Neves]

x86_64 and arm64 implementations to get the hypervisor version
information. Store these in hv_hypervisor_version_info structure to
simplify parsing the fields.

Replace the existing parsing when printing the version numbers at boot.

Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
---
 arch/arm64/hyperv/mshyperv.c      | 23 +++++++++++-------
 arch/x86/kernel/cpu/mshyperv.c    | 40 ++++++++++++++++++++-----------
 include/asm-generic/hyperv-tlfs.h | 23 ++++++++++++++++++
 include/asm-generic/mshyperv.h    |  2 ++
 4 files changed, 66 insertions(+), 22 deletions(-)

diff --git a/arch/arm64/hyperv/mshyperv.c b/arch/arm64/hyperv/mshyperv.c
index f1b8a04ee9f2..53bdd3bc81ac 100644
--- a/arch/arm64/hyperv/mshyperv.c
+++ b/arch/arm64/hyperv/mshyperv.c
@@ -19,10 +19,19 @@
 
 static bool hyperv_initialized;
 
+int hv_get_hypervisor_version(union hv_hypervisor_version_info *info)
+{
+	hv_get_vpreg_128(HV_REGISTER_HYPERVISOR_VERSION,
+			 (struct hv_get_vp_registers_output *)info);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hv_get_hypervisor_version);
+
 static int __init hyperv_init(void)
 {
-	struct hv_get_vp_registers_output	result;
-	u32	a, b, c, d;
+	struct hv_get_vp_registers_output result;
+	union hv_hypervisor_version_info version;
 	u64	guest_id;
 	int	ret;
 
@@ -55,13 +64,11 @@ static int __init hyperv_init(void)
 		ms_hyperv.misc_features);
 
 	/* Get information about the Hyper-V host version */
-	hv_get_vpreg_128(HV_REGISTER_HYPERVISOR_VERSION, &result);
-	a = result.as32.a;
-	b = result.as32.b;
-	c = result.as32.c;
-	d = result.as32.d;
+	hv_get_hypervisor_version(&version);
 	pr_info("Hyper-V: Host Build %d.%d.%d.%d-%d-%d\n",
-		b >> 16, b & 0xFFFF, a,	d & 0xFFFFFF, c, d >> 24);
+		version.major_version, version.minor_version,
+		version.build_number, version.service_number,
+		version.service_pack, version.service_branch);
 
 	ret = hv_common_init();
 	if (ret)
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 4d38cafe6f2c..e80e503c8cf5 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -313,13 +313,30 @@ static void __init hv_smp_prepare_cpus(unsigned int max_cpus)
 }
 #endif
 
+int hv_get_hypervisor_version(union hv_hypervisor_version_info *info)
+{
+	unsigned int hv_max_functions;
+
+	hv_max_functions = cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS);
+	if (hv_max_functions < HYPERV_CPUID_VERSION) {
+		pr_err("%s: Could not detect Hyper-V version\n",
+			__func__);
+		return -ENODEV;
+	}
+
+	info->eax = cpuid_eax(HYPERV_CPUID_VERSION);
+	info->ebx = cpuid_ebx(HYPERV_CPUID_VERSION);
+	info->ecx = cpuid_ecx(HYPERV_CPUID_VERSION);
+	info->edx = cpuid_edx(HYPERV_CPUID_VERSION);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hv_get_hypervisor_version);
+
 static void __init ms_hyperv_init_platform(void)
 {
 	int hv_max_functions_eax;
-	int hv_host_info_eax;
-	int hv_host_info_ebx;
-	int hv_host_info_ecx;
-	int hv_host_info_edx;
+	union hv_hypervisor_version_info version;
 
 #ifdef CONFIG_PARAVIRT
 	pv_info.name = "Hyper-V";
@@ -373,16 +390,11 @@ static void __init ms_hyperv_init_platform(void)
 	/*
 	 * Extract host information.
 	 */
-	if (hv_max_functions_eax >= HYPERV_CPUID_VERSION) {
-		hv_host_info_eax = cpuid_eax(HYPERV_CPUID_VERSION);
-		hv_host_info_ebx = cpuid_ebx(HYPERV_CPUID_VERSION);
-		hv_host_info_ecx = cpuid_ecx(HYPERV_CPUID_VERSION);
-		hv_host_info_edx = cpuid_edx(HYPERV_CPUID_VERSION);
-
-		pr_info("Hyper-V: Host Build %d.%d.%d.%d-%d-%d\n",
-			hv_host_info_ebx >> 16, hv_host_info_ebx & 0xFFFF,
-			hv_host_info_eax, hv_host_info_edx & 0xFFFFFF,
-			hv_host_info_ecx, hv_host_info_edx >> 24);
+	if (hv_get_hypervisor_version(&version) == 0) {
+		pr_info("Hyper-V Host Build:%d-%d.%d-%d-%d.%d\n",
+			version.build_number, version.major_version,
+			version.minor_version, version.service_pack,
+			version.service_branch, version.service_number);
 	}
 
 	if (ms_hyperv.features & HV_ACCESS_FREQUENCY_MSRS &&
diff --git a/include/asm-generic/hyperv-tlfs.h b/include/asm-generic/hyperv-tlfs.h
index f4e4cc4f965f..373f26efa18a 100644
--- a/include/asm-generic/hyperv-tlfs.h
+++ b/include/asm-generic/hyperv-tlfs.h
@@ -786,6 +786,29 @@ struct hv_input_unmap_device_interrupt {
 #define HV_SOURCE_SHADOW_NONE               0x0
 #define HV_SOURCE_SHADOW_BRIDGE_BUS_RANGE   0x1
 
+/*
+ * Version info reported by hypervisor
+ */
+union hv_hypervisor_version_info {
+	struct {
+		u32 build_number;
+
+		u32 minor_version : 16;
+		u32 major_version : 16;
+
+		u32 service_pack;
+
+		u32 service_number : 24;
+		u32 service_branch : 8;
+	};
+	struct {
+		u32 eax;
+		u32 ebx;
+		u32 ecx;
+		u32 edx;
+	};
+};
+
 /*
  * The whole argument should fit in a page to be able to pass to the hypervisor
  * in one hypercall.
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index 094c57320ed1..233c976344e5 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -153,6 +153,8 @@ static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
 	}
 }
 
+int hv_get_hypervisor_version(union hv_hypervisor_version_info *info);
+
 void hv_setup_vmbus_handler(void (*handler)(void));
 void hv_remove_vmbus_handler(void);
 void hv_setup_stimer0_handler(void (*handler)(void));
-- 
2.25.1

[PATCH v2 03/15] mshyperv: Introduce numa_node_to_proximity_domain_info

[Nuno Das Neves]

Factor out logic for converting numa node to proximity domain info into
a helper function, and export it.

Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
---
 arch/x86/hyperv/hv_proc.c      |  8 ++------
 drivers/acpi/numa/srat.c       |  1 +
 include/asm-generic/mshyperv.h | 18 ++++++++++++++++++
 3 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/arch/x86/hyperv/hv_proc.c b/arch/x86/hyperv/hv_proc.c
index 68a0843d4750..5ba5ca1b2089 100644
--- a/arch/x86/hyperv/hv_proc.c
+++ b/arch/x86/hyperv/hv_proc.c
@@ -121,7 +121,6 @@ int hv_call_add_logical_proc(int node, u32 lp_index, u32 apic_id)
 	u64 status;
 	unsigned long flags;
 	int ret = HV_STATUS_SUCCESS;
-	int pxm = node_to_pxm(node);
 
 	/*
 	 * When adding a logical processor, the hypervisor may return
@@ -137,11 +136,8 @@ int hv_call_add_logical_proc(int node, u32 lp_index, u32 apic_id)
 
 		input->lp_index = lp_index;
 		input->apic_id = apic_id;
-		input->flags = 0;
-		input->proximity_domain_info.domain_id = pxm;
-		input->proximity_domain_info.flags.reserved = 0;
-		input->proximity_domain_info.flags.proximity_info_valid = 1;
-		input->proximity_domain_info.flags.proximity_preferred = 1;
+		input->proximity_domain_info =
+			numa_node_to_proximity_domain_info(node);
 		status = hv_do_hypercall(HVCALL_ADD_LOGICAL_PROCESSOR,
 					 input, output);
 		local_irq_restore(flags);
diff --git a/drivers/acpi/numa/srat.c b/drivers/acpi/numa/srat.c
index 1f4fc5f8a819..0cf9f0574495 100644
--- a/drivers/acpi/numa/srat.c
+++ b/drivers/acpi/numa/srat.c
@@ -48,6 +48,7 @@ int node_to_pxm(int node)
 		return PXM_INVAL;
 	return node_to_pxm_map[node];
 }
+EXPORT_SYMBOL(node_to_pxm);
 
 static void __acpi_map_pxm_to_node(int pxm, int node)
 {
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index 233c976344e5..447e7ebe67ee 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -21,6 +21,7 @@
 #include <linux/types.h>
 #include <linux/atomic.h>
 #include <linux/bitops.h>
+#include <acpi/acpi_numa.h>
 #include <linux/cpumask.h>
 #include <linux/nmi.h>
 #include <asm/ptrace.h>
@@ -28,6 +29,23 @@
 
 #define VTPM_BASE_ADDRESS 0xfed40000
 
+static inline union hv_proximity_domain_info
+numa_node_to_proximity_domain_info(int node)
+{
+	union hv_proximity_domain_info proximity_domain_info;
+
+	if (node != NUMA_NO_NODE) {
+		proximity_domain_info.domain_id = node_to_pxm(node);
+		proximity_domain_info.flags.reserved = 0;
+		proximity_domain_info.flags.proximity_info_valid = 1;
+		proximity_domain_info.flags.proximity_preferred = 1;
+	} else {
+		proximity_domain_info.as_uint64 = 0;
+	}
+
+	return proximity_domain_info;
+}
+
 struct ms_hyperv_info {
 	u32 features;
 	u32 priv_high;
-- 
2.25.1

[PATCH v2 04/15] asm-generic/mshyperv: Introduce hv_recommend_using_aeoi()

[Nuno Das Neves]

Factor out logic for determining if we should set the auto eoi flag in SINT
register.

Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
---
 drivers/hv/hv.c                | 12 +-----------
 include/asm-generic/mshyperv.h | 13 +++++++++++++
 2 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 3ddacdebe886..7929554d32f7 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -212,17 +212,7 @@ void hv_synic_enable_regs(unsigned int cpu)
 
 	shared_sint.vector = vmbus_interrupt;
 	shared_sint.masked = false;
-
-	/*
-	 * On architectures where Hyper-V doesn't support AEOI (e.g., ARM64),
-	 * it doesn't provide a recommendation flag and AEOI must be disabled.
-	 */
-#ifdef HV_DEPRECATING_AEOI_RECOMMENDED
-	shared_sint.auto_eoi =
-			!(ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED);
-#else
-	shared_sint.auto_eoi = 0;
-#endif
+	shared_sint.auto_eoi = hv_recommend_using_aeoi();
 	hv_set_register(HV_MSR_SINT0 + VMBUS_MESSAGE_SINT,
 				shared_sint.as_uint64);
 
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index 447e7ebe67ee..90fcbb95f1ee 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -77,6 +77,19 @@ extern u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr);
 extern u64 hv_do_fast_hypercall8(u16 control, u64 input8);
 extern bool hv_isolation_type_snp(void);
 
+/*
+ * On architectures where Hyper-V doesn't support AEOI (e.g., ARM64),
+ * it doesn't provide a recommendation flag and AEOI must be disabled.
+ */
+static inline bool hv_recommend_using_aeoi(void)
+{
+#ifdef HV_DEPRECATING_AEOI_RECOMMENDED
+	return !(ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED);
+#else
+	return false;
+#endif
+}
+
 /* Helper functions that provide a consistent pattern for checking Hyper-V hypercall status. */
 static inline int hv_result(u64 status)
 {
-- 
2.25.1

[PATCH v2 05/15] hyperv: Move hv_connection_id to hyperv-tlfs

[Nuno Das Neves]

The definition conflicts with one added in hvgdk.h as part of the mshv
driver so must be moved to hyperv-tlfs.h.

This structure should be in hyperv-tlfs.h anyway, since it is part of
the TLFS document.

Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
---
 include/asm-generic/hyperv-tlfs.h | 9 +++++++++
 include/linux/hyperv.h            | 9 ---------
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/include/asm-generic/hyperv-tlfs.h b/include/asm-generic/hyperv-tlfs.h
index 373f26efa18a..8fc5e5a9d7cb 100644
--- a/include/asm-generic/hyperv-tlfs.h
+++ b/include/asm-generic/hyperv-tlfs.h
@@ -845,4 +845,13 @@ struct hv_mmio_write_input {
 	u8 data[HV_HYPERCALL_MMIO_MAX_DATA_LENGTH];
 } __packed;
 
+/* Define connection identifier type. */
+union hv_connection_id {
+	u32 asu32;
+	struct {
+		u32 id:24;
+		u32 reserved:8;
+	} u;
+};
+
 #endif
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index bfbc37ce223b..f90de5abcd50 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -748,15 +748,6 @@ struct vmbus_close_msg {
 	struct vmbus_channel_close_channel msg;
 };
 
-/* Define connection identifier type. */
-union hv_connection_id {
-	u32 asu32;
-	struct {
-		u32 id:24;
-		u32 reserved:8;
-	} u;
-};
-
 enum vmbus_device_type {
 	HV_IDE = 0,
 	HV_SCSI,
-- 
2.25.1

[PATCH v2 06/15] hyperv-tlfs: Introduce hv_status_to_string and hv_status_to_errno

[Nuno Das Neves]

hv_status_to_errno translates hyperv statuses to linux error codes.
This is useful for returning something linux-friendly from a hypercall
helper function.

hv_status_to_string improves clarity of error messages.

Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
---
 arch/x86/hyperv/hv_init.c         |  2 +-
 arch/x86/hyperv/hv_proc.c         |  6 ++---
 include/asm-generic/hyperv-tlfs.h | 45 ++++++++++++++++++++++---------
 include/asm-generic/mshyperv.h    | 33 +++++++++++++++++++++++
 4 files changed, 70 insertions(+), 16 deletions(-)

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 6c04b52f139b..5ce4aedc34d6 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -371,7 +371,7 @@ static void __init hv_get_partition_id(void)
 	status = hv_do_hypercall(HVCALL_GET_PARTITION_ID, NULL, output_page);
 	if (!hv_result_success(status)) {
 		/* No point in proceeding if this failed */
-		pr_err("Failed to get partition ID: %lld\n", status);
+		pr_err("Failed to get partition ID: %s\n", hv_status_to_string(status));
 		BUG();
 	}
 	hv_current_partition_id = output_page->partition_id;
diff --git a/arch/x86/hyperv/hv_proc.c b/arch/x86/hyperv/hv_proc.c
index 5ba5ca1b2089..ed80da64649e 100644
--- a/arch/x86/hyperv/hv_proc.c
+++ b/arch/x86/hyperv/hv_proc.c
@@ -144,9 +144,9 @@ int hv_call_add_logical_proc(int node, u32 lp_index, u32 apic_id)
 
 		if (hv_result(status) != HV_STATUS_INSUFFICIENT_MEMORY) {
 			if (!hv_result_success(status)) {
-				pr_err("%s: cpu %u apic ID %u, %lld\n", __func__,
-				       lp_index, apic_id, status);
-				ret = hv_result(status);
+				pr_err("%s: cpu %u apic ID %u, %s\n", __func__,
+				       lp_index, apic_id, hv_status_to_string(status));
+				ret = hv_status_to_errno(status);
 			}
 			break;
 		}
diff --git a/include/asm-generic/hyperv-tlfs.h b/include/asm-generic/hyperv-tlfs.h
index 8fc5e5a9d7cb..e7b468f06de7 100644
--- a/include/asm-generic/hyperv-tlfs.h
+++ b/include/asm-generic/hyperv-tlfs.h
@@ -212,18 +212,39 @@ enum HV_GENERIC_SET_FORMAT {
 					 HV_HYPERCALL_RSVD2_MASK)
 
 /* hypercall status code */
-#define HV_STATUS_SUCCESS			0
-#define HV_STATUS_INVALID_HYPERCALL_CODE	2
-#define HV_STATUS_INVALID_HYPERCALL_INPUT	3
-#define HV_STATUS_INVALID_ALIGNMENT		4
-#define HV_STATUS_INVALID_PARAMETER		5
-#define HV_STATUS_ACCESS_DENIED			6
-#define HV_STATUS_OPERATION_DENIED		8
-#define HV_STATUS_INSUFFICIENT_MEMORY		11
-#define HV_STATUS_INVALID_PORT_ID		17
-#define HV_STATUS_INVALID_CONNECTION_ID		18
-#define HV_STATUS_INSUFFICIENT_BUFFERS		19
-#define HV_STATUS_VTL_ALREADY_ENABLED		134
+#define __HV_STATUS_DEF(OP) \
+	OP(HV_STATUS_SUCCESS,				0x0) \
+	OP(HV_STATUS_INVALID_HYPERCALL_CODE,		0x2) \
+	OP(HV_STATUS_INVALID_HYPERCALL_INPUT,		0x3) \
+	OP(HV_STATUS_INVALID_ALIGNMENT,			0x4) \
+	OP(HV_STATUS_INVALID_PARAMETER,			0x5) \
+	OP(HV_STATUS_ACCESS_DENIED,			0x6) \
+	OP(HV_STATUS_INVALID_PARTITION_STATE,		0x7) \
+	OP(HV_STATUS_OPERATION_DENIED,			0x8) \
+	OP(HV_STATUS_UNKNOWN_PROPERTY,			0x9) \
+	OP(HV_STATUS_PROPERTY_VALUE_OUT_OF_RANGE,	0xA) \
+	OP(HV_STATUS_INSUFFICIENT_MEMORY,		0xB) \
+	OP(HV_STATUS_INVALID_PARTITION_ID,		0xD) \
+	OP(HV_STATUS_INVALID_VP_INDEX,			0xE) \
+	OP(HV_STATUS_NOT_FOUND,				0x10) \
+	OP(HV_STATUS_INVALID_PORT_ID,			0x11) \
+	OP(HV_STATUS_INVALID_CONNECTION_ID,		0x12) \
+	OP(HV_STATUS_INSUFFICIENT_BUFFERS,		0x13) \
+	OP(HV_STATUS_NOT_ACKNOWLEDGED,			0x14) \
+	OP(HV_STATUS_INVALID_VP_STATE,			0x15) \
+	OP(HV_STATUS_NO_RESOURCES,			0x1D) \
+	OP(HV_STATUS_PROCESSOR_FEATURE_NOT_SUPPORTED,	0x20) \
+	OP(HV_STATUS_INVALID_LP_INDEX,			0x41) \
+	OP(HV_STATUS_INVALID_REGISTER_VALUE,		0x50) \
+	OP(HV_STATUS_CALL_PENDING,			0x79) \
+	OP(HV_STATUS_VTL_ALREADY_ENABLED,		0x86)
+
+#define __HV_MAKE_HV_STATUS_ENUM(NAME, VAL) NAME = (VAL),
+#define __HV_MAKE_HV_STATUS_CASE(NAME, VAL) case (NAME): return (#NAME);
+
+enum hv_status {
+	__HV_STATUS_DEF(__HV_MAKE_HV_STATUS_ENUM)
+};
 
 /*
  * The Hyper-V TimeRefCount register and the TSC
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index 90fcbb95f1ee..bf87721828f6 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -300,6 +300,39 @@ static inline int cpumask_to_vpset_skip(struct hv_vpset *vpset,
 	return __cpumask_to_vpset(vpset, cpus, func);
 }
 
+
+static inline int hv_status_to_errno(u64 hv_status)
+{
+	switch (hv_result(hv_status)) {
+	case HV_STATUS_SUCCESS:
+		return 0;
+	case HV_STATUS_INVALID_PARAMETER:
+	case HV_STATUS_UNKNOWN_PROPERTY:
+	case HV_STATUS_PROPERTY_VALUE_OUT_OF_RANGE:
+	case HV_STATUS_INVALID_VP_INDEX:
+	case HV_STATUS_INVALID_REGISTER_VALUE:
+	case HV_STATUS_INVALID_LP_INDEX:
+	case HV_STATUS_PROCESSOR_FEATURE_NOT_SUPPORTED:
+		return -EINVAL;
+	case HV_STATUS_ACCESS_DENIED:
+	case HV_STATUS_OPERATION_DENIED:
+		return -EACCES;
+	case HV_STATUS_NOT_ACKNOWLEDGED:
+	case HV_STATUS_INVALID_VP_STATE:
+	case HV_STATUS_INVALID_PARTITION_STATE:
+		return -EBADFD;
+	}
+	return -ENOTRECOVERABLE;
+}
+
+static inline const char *hv_status_to_string(u64 hv_status)
+{
+	switch (hv_result(hv_status)) {
+	__HV_STATUS_DEF(__HV_MAKE_HV_STATUS_CASE)
+	default : return "Unknown";
+	}
+}
+
 void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die);
 bool hv_is_hyperv_initialized(void);
 bool hv_is_hibernation_supported(void);
-- 
2.25.1

[PATCH v2 07/15] Drivers: hv: Move hv_call_deposit_pages and hv_call_create_vp to common code

[Nuno Das Neves]

These hypercalls are not arch-specific. Move them to common code.

Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
---
 arch/x86/hyperv/hv_proc.c       | 152 --------------------------------
 arch/x86/include/asm/mshyperv.h |   2 -
 drivers/hv/hv_common.c          | 147 ++++++++++++++++++++++++++++++
 include/asm-generic/mshyperv.h  |   2 +
 4 files changed, 149 insertions(+), 154 deletions(-)

diff --git a/arch/x86/hyperv/hv_proc.c b/arch/x86/hyperv/hv_proc.c
index ed80da64649e..0a35cb865427 100644
--- a/arch/x86/hyperv/hv_proc.c
+++ b/arch/x86/hyperv/hv_proc.c
@@ -3,7 +3,6 @@
 #include <linux/vmalloc.h>
 #include <linux/mm.h>
 #include <linux/clockchips.h>
-#include <linux/acpi.h>
 #include <linux/hyperv.h>
 #include <linux/slab.h>
 #include <linux/cpuhotplug.h>
@@ -14,106 +13,6 @@
 
 #include <asm/trace/hyperv.h>
 
-/*
- * See struct hv_deposit_memory. The first u64 is partition ID, the rest
- * are GPAs.
- */
-#define HV_DEPOSIT_MAX (HV_HYP_PAGE_SIZE / sizeof(u64) - 1)
-
-/* Deposits exact number of pages. Must be called with interrupts enabled.  */
-int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages)
-{
-	struct page **pages, *page;
-	int *counts;
-	int num_allocations;
-	int i, j, page_count;
-	int order;
-	u64 status;
-	int ret;
-	u64 base_pfn;
-	struct hv_deposit_memory *input_page;
-	unsigned long flags;
-
-	if (num_pages > HV_DEPOSIT_MAX)
-		return -E2BIG;
-	if (!num_pages)
-		return 0;
-
-	/* One buffer for page pointers and counts */
-	page = alloc_page(GFP_KERNEL);
-	if (!page)
-		return -ENOMEM;
-	pages = page_address(page);
-
-	counts = kcalloc(HV_DEPOSIT_MAX, sizeof(int), GFP_KERNEL);
-	if (!counts) {
-		free_page((unsigned long)pages);
-		return -ENOMEM;
-	}
-
-	/* Allocate all the pages before disabling interrupts */
-	i = 0;
-
-	while (num_pages) {
-		/* Find highest order we can actually allocate */
-		order = 31 - __builtin_clz(num_pages);
-
-		while (1) {
-			pages[i] = alloc_pages_node(node, GFP_KERNEL, order);
-			if (pages[i])
-				break;
-			if (!order) {
-				ret = -ENOMEM;
-				num_allocations = i;
-				goto err_free_allocations;
-			}
-			--order;
-		}
-
-		split_page(pages[i], order);
-		counts[i] = 1 << order;
-		num_pages -= counts[i];
-		i++;
-	}
-	num_allocations = i;
-
-	local_irq_save(flags);
-
-	input_page = *this_cpu_ptr(hyperv_pcpu_input_arg);
-
-	input_page->partition_id = partition_id;
-
-	/* Populate gpa_page_list - these will fit on the input page */
-	for (i = 0, page_count = 0; i < num_allocations; ++i) {
-		base_pfn = page_to_pfn(pages[i]);
-		for (j = 0; j < counts[i]; ++j, ++page_count)
-			input_page->gpa_page_list[page_count] = base_pfn + j;
-	}
-	status = hv_do_rep_hypercall(HVCALL_DEPOSIT_MEMORY,
-				     page_count, 0, input_page, NULL);
-	local_irq_restore(flags);
-	if (!hv_result_success(status)) {
-		pr_err("Failed to deposit pages: %lld\n", status);
-		ret = hv_result(status);
-		goto err_free_allocations;
-	}
-
-	ret = 0;
-	goto free_buf;
-
-err_free_allocations:
-	for (i = 0; i < num_allocations; ++i) {
-		base_pfn = page_to_pfn(pages[i]);
-		for (j = 0; j < counts[i]; ++j)
-			__free_page(pfn_to_page(base_pfn + j));
-	}
-
-free_buf:
-	free_page((unsigned long)pages);
-	kfree(counts);
-	return ret;
-}
-
 int hv_call_add_logical_proc(int node, u32 lp_index, u32 apic_id)
 {
 	struct hv_add_logical_processor_in *input;
@@ -156,54 +55,3 @@ int hv_call_add_logical_proc(int node, u32 lp_index, u32 apic_id)
 	return ret;
 }
 
-int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u32 flags)
-{
-	struct hv_create_vp *input;
-	u64 status;
-	unsigned long irq_flags;
-	int ret = HV_STATUS_SUCCESS;
-	int pxm = node_to_pxm(node);
-
-	/* Root VPs don't seem to need pages deposited */
-	if (partition_id != hv_current_partition_id) {
-		/* The value 90 is empirically determined. It may change. */
-		ret = hv_call_deposit_pages(node, partition_id, 90);
-		if (ret)
-			return ret;
-	}
-
-	do {
-		local_irq_save(irq_flags);
-
-		input = *this_cpu_ptr(hyperv_pcpu_input_arg);
-
-		input->partition_id = partition_id;
-		input->vp_index = vp_index;
-		input->flags = flags;
-		input->subnode_type = HvSubnodeAny;
-		if (node != NUMA_NO_NODE) {
-			input->proximity_domain_info.domain_id = pxm;
-			input->proximity_domain_info.flags.reserved = 0;
-			input->proximity_domain_info.flags.proximity_info_valid = 1;
-			input->proximity_domain_info.flags.proximity_preferred = 1;
-		} else {
-			input->proximity_domain_info.as_uint64 = 0;
-		}
-		status = hv_do_hypercall(HVCALL_CREATE_VP, input, NULL);
-		local_irq_restore(irq_flags);
-
-		if (hv_result(status) != HV_STATUS_INSUFFICIENT_MEMORY) {
-			if (!hv_result_success(status)) {
-				pr_err("%s: vcpu %u, lp %u, %lld\n", __func__,
-				       vp_index, flags, status);
-				ret = hv_result(status);
-			}
-			break;
-		}
-		ret = hv_call_deposit_pages(node, partition_id, 1);
-
-	} while (!ret);
-
-	return ret;
-}
-
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index daaac502d411..79ffc7913016 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -47,9 +47,7 @@ extern u64 hv_current_partition_id;
 
 extern union hv_ghcb * __percpu *hv_ghcb_pg;
 
-int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages);
 int hv_call_add_logical_proc(int node, u32 lp_index, u32 acpi_id);
-int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u32 flags);
 
 static inline u64 hv_do_hypercall(u64 control, void *input, void *output)
 {
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
index 790b96290360..7364ef027cd7 100644
--- a/drivers/hv/hv_common.c
+++ b/drivers/hv/hv_common.c
@@ -542,3 +542,150 @@ u64 __weak hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_s
 	return HV_STATUS_INVALID_PARAMETER;
 }
 EXPORT_SYMBOL_GPL(hv_ghcb_hypercall);
+
+int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u32 flags)
+{
+	struct hv_create_vp *input;
+	u64 status;
+	unsigned long irq_flags;
+	int ret = HV_STATUS_SUCCESS;
+
+	/* Root VPs don't seem to need pages deposited */
+	if (partition_id != hv_current_partition_id) {
+		/* The value 90 is empirically determined. It may change. */
+		ret = hv_call_deposit_pages(node, partition_id, 90);
+		if (ret)
+			return ret;
+	}
+
+	do {
+		local_irq_save(irq_flags);
+
+		input = *this_cpu_ptr(hyperv_pcpu_input_arg);
+
+		input->partition_id = partition_id;
+		input->vp_index = vp_index;
+		input->flags = flags;
+		input->subnode_type = HvSubnodeAny;
+		input->proximity_domain_info =
+			numa_node_to_proximity_domain_info(node);
+		status = hv_do_hypercall(HVCALL_CREATE_VP, input, NULL);
+		local_irq_restore(irq_flags);
+
+		if (hv_result(status) != HV_STATUS_INSUFFICIENT_MEMORY) {
+			if (!hv_result_success(status)) {
+				pr_err("%s: vcpu %u, lp %u, %s\n", __func__,
+				       vp_index, flags, hv_status_to_string(status));
+				ret = hv_status_to_errno(status);
+			}
+			break;
+		}
+		ret = hv_call_deposit_pages(node, partition_id, 1);
+
+	} while (!ret);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(hv_call_create_vp);
+
+/*
+ * See struct hv_deposit_memory. The first u64 is partition ID, the rest
+ * are GPAs.
+ */
+#define HV_DEPOSIT_MAX (HV_HYP_PAGE_SIZE / sizeof(u64) - 1)
+
+/* Deposits exact number of pages. Must be called with interrupts enabled.  */
+int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages)
+{
+	struct page **pages, *page;
+	int *counts;
+	int num_allocations;
+	int i, j, page_count;
+	int order;
+	u64 status;
+	int ret;
+	u64 base_pfn;
+	struct hv_deposit_memory *input_page;
+	unsigned long flags;
+
+	if (num_pages > HV_DEPOSIT_MAX)
+		return -E2BIG;
+	if (!num_pages)
+		return 0;
+
+	/* One buffer for page pointers and counts */
+	page = alloc_page(GFP_KERNEL);
+	if (!page)
+		return -ENOMEM;
+	pages = page_address(page);
+
+	counts = kcalloc(HV_DEPOSIT_MAX, sizeof(int), GFP_KERNEL);
+	if (!counts) {
+		free_page((unsigned long)pages);
+		return -ENOMEM;
+	}
+
+	/* Allocate all the pages before disabling interrupts */
+	i = 0;
+
+	while (num_pages) {
+		/* Find highest order we can actually allocate */
+		order = 31 - __builtin_clz(num_pages);
+
+		while (1) {
+			pages[i] = alloc_pages_node(node, GFP_KERNEL, order);
+			if (pages[i])
+				break;
+			if (!order) {
+				ret = -ENOMEM;
+				num_allocations = i;
+				goto err_free_allocations;
+			}
+			--order;
+		}
+
+		split_page(pages[i], order);
+		counts[i] = 1 << order;
+		num_pages -= counts[i];
+		i++;
+	}
+	num_allocations = i;
+
+	local_irq_save(flags);
+
+	input_page = *this_cpu_ptr(hyperv_pcpu_input_arg);
+
+	input_page->partition_id = partition_id;
+
+	/* Populate gpa_page_list - these will fit on the input page */
+	for (i = 0, page_count = 0; i < num_allocations; ++i) {
+		base_pfn = page_to_pfn(pages[i]);
+		for (j = 0; j < counts[i]; ++j, ++page_count)
+			input_page->gpa_page_list[page_count] = base_pfn + j;
+	}
+	status = hv_do_rep_hypercall(HVCALL_DEPOSIT_MEMORY,
+				     page_count, 0, input_page, NULL);
+	local_irq_restore(flags);
+	if (!hv_result_success(status)) {
+		pr_err("Failed to deposit pages: %s\n", hv_status_to_string(status));
+		ret = hv_status_to_errno(status);
+		goto err_free_allocations;
+	}
+
+	ret = 0;
+	goto free_buf;
+
+err_free_allocations:
+	for (i = 0; i < num_allocations; ++i) {
+		base_pfn = page_to_pfn(pages[i]);
+		for (j = 0; j < counts[i]; ++j)
+			__free_page(pfn_to_page(base_pfn + j));
+	}
+
+free_buf:
+	free_page((unsigned long)pages);
+	kfree(counts);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(hv_call_deposit_pages);
+
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index bf87721828f6..0c94d20b4d44 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -343,6 +343,8 @@ u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size);
 void hyperv_cleanup(void);
 bool hv_query_ext_cap(u64 cap_query);
 void hv_setup_dma_ops(struct device *dev, bool coherent);
+int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u32 flags);
+int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages);
 #else /* CONFIG_HYPERV */
 static inline bool hv_is_hyperv_initialized(void) { return false; }
 static inline bool hv_is_hibernation_supported(void) { return false; }
-- 
2.25.1

[PATCH v2 08/15] Drivers: hv: Introduce per-cpu event ring tail

[Nuno Das Neves]

Add a pointer hv_synic_eventring_tail to track the tail pointer for the
SynIC event ring buffer for each SINT.

This will be used by the mshv driver, but must be tracked independently
since the driver module could be removed and re-inserted.

Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
---
 drivers/hv/hv_common.c         | 28 ++++++++++++++++++++++++++--
 include/asm-generic/mshyperv.h |  2 ++
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
index 7364ef027cd7..0dd3091beef3 100644
--- a/drivers/hv/hv_common.c
+++ b/drivers/hv/hv_common.c
@@ -61,6 +61,16 @@ static void hv_kmsg_dump_unregister(void);
 
 static struct ctl_table_header *hv_ctl_table_hdr;
 
+/*
+ * Per-cpu array holding the tail pointer for the SynIC event ring buffer
+ * for each SINT.
+ *
+ * We cannot maintain this in mshv driver because the tail pointer should
+ * persist even if the mshv driver is unloaded.
+ */
+u8 __percpu **hv_synic_eventring_tail;
+EXPORT_SYMBOL_GPL(hv_synic_eventring_tail);
+
 /*
  * Hyper-V specific initialization and shutdown code that is
  * common across all architectures.  Called from architecture
@@ -83,6 +93,9 @@ void __init hv_common_free(void)
 
 	free_percpu(hyperv_pcpu_input_arg);
 	hyperv_pcpu_input_arg = NULL;
+
+	free_percpu(hv_synic_eventring_tail);
+	hv_synic_eventring_tail = NULL;
 }
 
 /*
@@ -332,6 +345,8 @@ int __init hv_common_init(void)
 	if (hv_root_partition) {
 		hyperv_pcpu_output_arg = alloc_percpu(void *);
 		BUG_ON(!hyperv_pcpu_output_arg);
+		hv_synic_eventring_tail = alloc_percpu(u8 *);
+		BUG_ON(hv_synic_eventring_tail == NULL);
 	}
 
 	hv_vp_index = kmalloc_array(num_possible_cpus(), sizeof(*hv_vp_index),
@@ -356,6 +371,7 @@ int __init hv_common_init(void)
 int hv_common_cpu_init(unsigned int cpu)
 {
 	void **inputarg, **outputarg;
+	u8 **synic_eventring_tail;
 	u64 msr_vp_index;
 	gfp_t flags;
 	int pgcount = hv_root_partition ? 2 : 1;
@@ -366,8 +382,8 @@ int hv_common_cpu_init(unsigned int cpu)
 	inputarg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
 
 	/*
-	 * hyperv_pcpu_input_arg and hyperv_pcpu_output_arg memory is already
-	 * allocated if this CPU was previously online and then taken offline
+	 * The per-cpu memory is already allocated if this CPU was previously
+	 * online and then taken offline
 	 */
 	if (!*inputarg) {
 		*inputarg = kmalloc(pgcount * HV_HYP_PAGE_SIZE, flags);
@@ -377,6 +393,14 @@ int hv_common_cpu_init(unsigned int cpu)
 		if (hv_root_partition) {
 			outputarg = (void **)this_cpu_ptr(hyperv_pcpu_output_arg);
 			*outputarg = (char *)(*inputarg) + HV_HYP_PAGE_SIZE;
+			synic_eventring_tail = (u8 **)this_cpu_ptr(hv_synic_eventring_tail);
+			*synic_eventring_tail = kcalloc(HV_SYNIC_SINT_COUNT, sizeof(u8),
+							flags);
+
+			if (unlikely(!*synic_eventring_tail)) {
+				kfree(*inputarg);
+				return -ENOMEM;
+			}
 		}
 	}
 
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index 0c94d20b4d44..9118d678b27a 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -73,6 +73,8 @@ extern bool hv_nested;
 extern void * __percpu *hyperv_pcpu_input_arg;
 extern void * __percpu *hyperv_pcpu_output_arg;
 
+extern u8 __percpu **hv_synic_eventring_tail;
+
 extern u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr);
 extern u64 hv_do_fast_hypercall8(u16 control, u64 input8);
 extern bool hv_isolation_type_snp(void);
-- 
2.25.1

[PATCH v2 09/15] Drivers: hv: Introduce hv_output_arg_exists in hv_common.c

[Nuno Das Neves]

This is a more flexible approach for determining whether to allocate the
output page.

Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
---
 drivers/hv/hv_common.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
index 0dd3091beef3..79efedc8bf39 100644
--- a/drivers/hv/hv_common.c
+++ b/drivers/hv/hv_common.c
@@ -57,6 +57,14 @@ EXPORT_SYMBOL_GPL(hyperv_pcpu_input_arg);
 void * __percpu *hyperv_pcpu_output_arg;
 EXPORT_SYMBOL_GPL(hyperv_pcpu_output_arg);
 
+/*
+ * Determine whether output arg is needed
+ */
+static inline bool hv_output_arg_exists(void)
+{
+	return hv_root_partition ? true : false;
+}
+
 static void hv_kmsg_dump_unregister(void);
 
 static struct ctl_table_header *hv_ctl_table_hdr;
@@ -341,10 +349,12 @@ int __init hv_common_init(void)
 	hyperv_pcpu_input_arg = alloc_percpu(void  *);
 	BUG_ON(!hyperv_pcpu_input_arg);
 
-	/* Allocate the per-CPU state for output arg for root */
-	if (hv_root_partition) {
+	if (hv_output_arg_exists()) {
 		hyperv_pcpu_output_arg = alloc_percpu(void *);
 		BUG_ON(!hyperv_pcpu_output_arg);
+	}
+
+	if (hv_root_partition) {
 		hv_synic_eventring_tail = alloc_percpu(u8 *);
 		BUG_ON(hv_synic_eventring_tail == NULL);
 	}
@@ -374,7 +384,7 @@ int hv_common_cpu_init(unsigned int cpu)
 	u8 **synic_eventring_tail;
 	u64 msr_vp_index;
 	gfp_t flags;
-	int pgcount = hv_root_partition ? 2 : 1;
+	int pgcount = hv_output_arg_exists() ? 2 : 1;
 
 	/* hv_cpu_init() can be called with IRQs disabled from hv_resume() */
 	flags = irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL;
@@ -390,9 +400,11 @@ int hv_common_cpu_init(unsigned int cpu)
 		if (!(*inputarg))
 			return -ENOMEM;
 
-		if (hv_root_partition) {
+		if (hv_output_arg_exists()) {
 			outputarg = (void **)this_cpu_ptr(hyperv_pcpu_output_arg);
 			*outputarg = (char *)(*inputarg) + HV_HYP_PAGE_SIZE;
+		}
+		if (hv_root_partition) {
 			synic_eventring_tail = (u8 **)this_cpu_ptr(hv_synic_eventring_tail);
 			*synic_eventring_tail = kcalloc(HV_SYNIC_SINT_COUNT, sizeof(u8),
 							flags);
-- 
2.25.1

[PATCH v2 10/15] x86: hyperv: Add mshv_handler irq handler and setup function

[Nuno Das Neves]

This will handle SYNIC interrupts such as intercepts, doorbells, and
scheduling messages intended for the mshv driver.

Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
---
 arch/x86/kernel/cpu/mshyperv.c | 9 +++++++++
 drivers/hv/hv_common.c         | 5 +++++
 include/asm-generic/mshyperv.h | 2 ++
 3 files changed, 16 insertions(+)

diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index e80e503c8cf5..6568d73e7d60 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -105,6 +105,7 @@ void hv_set_register(unsigned int reg, u64 value)
 }
 EXPORT_SYMBOL_GPL(hv_set_register);
 
+static void (*mshv_handler)(void);
 static void (*vmbus_handler)(void);
 static void (*hv_stimer0_handler)(void);
 static void (*hv_kexec_handler)(void);
@@ -115,6 +116,9 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_callback)
 	struct pt_regs *old_regs = set_irq_regs(regs);
 
 	inc_irq_stat(irq_hv_callback_count);
+	if (mshv_handler)
+		mshv_handler();
+
 	if (vmbus_handler)
 		vmbus_handler();
 
@@ -124,6 +128,11 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_callback)
 	set_irq_regs(old_regs);
 }
 
+void hv_setup_mshv_irq(void (*handler)(void))
+{
+	mshv_handler = handler;
+}
+
 void hv_setup_vmbus_handler(void (*handler)(void))
 {
 	vmbus_handler = handler;
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
index 79efedc8bf39..13f972e72375 100644
--- a/drivers/hv/hv_common.c
+++ b/drivers/hv/hv_common.c
@@ -548,6 +548,11 @@ void __weak hv_remove_vmbus_handler(void)
 }
 EXPORT_SYMBOL_GPL(hv_remove_vmbus_handler);
 
+void __weak hv_setup_mshv_irq(void (*handler)(void))
+{
+}
+EXPORT_SYMBOL_GPL(hv_setup_mshv_irq);
+
 void __weak hv_setup_kexec_handler(void (*handler)(void))
 {
 }
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index 9118d678b27a..2b20994d809e 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -193,6 +193,8 @@ void hv_remove_vmbus_handler(void);
 void hv_setup_stimer0_handler(void (*handler)(void));
 void hv_remove_stimer0_handler(void);
 
+void hv_setup_mshv_irq(void (*handler)(void));
+
 void hv_setup_kexec_handler(void (*handler)(void));
 void hv_remove_kexec_handler(void);
 void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs));
-- 
2.25.1

[PATCH v2 11/15] Drivers: hv: export vmbus_isr, hv_context and hv_post_message

[Nuno Das Neves]

These will be used by the mshv_vtl driver.

Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
---
 drivers/hv/hv.c           | 2 ++
 drivers/hv/hyperv_vmbus.h | 1 +
 drivers/hv/vmbus_drv.c    | 3 ++-
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 7929554d32f7..62333ed5fe08 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -24,6 +24,7 @@
 
 /* The one and only */
 struct hv_context hv_context;
+EXPORT_SYMBOL_GPL(hv_context);
 
 /*
  * hv_init - Main initialization routine.
@@ -75,6 +76,7 @@ int hv_post_message(union hv_connection_id connection_id,
 
 	return hv_result(status);
 }
+EXPORT_SYMBOL_GPL(hv_post_message);
 
 int hv_synic_alloc(void)
 {
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 55f2086841ae..85f3c08bb42b 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -32,6 +32,7 @@
  */
 #define HV_UTIL_NEGO_TIMEOUT 55
 
+void vmbus_isr(void);
 
 /* Definitions for the monitored notification facility */
 union hv_monitor_trigger_group {
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 67f95a29aeca..d688bc6b8bea 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -1286,7 +1286,7 @@ static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu)
 	}
 }
 
-static void vmbus_isr(void)
+void vmbus_isr(void)
 {
 	struct hv_per_cpu_context *hv_cpu
 		= this_cpu_ptr(hv_context.cpu_context);
@@ -1309,6 +1309,7 @@ static void vmbus_isr(void)
 
 	add_interrupt_randomness(vmbus_interrupt);
 }
+EXPORT_SYMBOL_GPL(vmbus_isr);
 
 static irqreturn_t vmbus_percpu_isr(int irq, void *dev_id)
 {
-- 
2.25.1

[PATCH v2 12/15] Documentation: Reserve ioctl number for mshv driver

[Nuno Das Neves]

Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Acked-by: Jonathan Corbet <corbet@lwn.net>
---
 Documentation/userspace-api/ioctl/ioctl-number.rst | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
index 4ea5b837399a..71e6d23070ca 100644
--- a/Documentation/userspace-api/ioctl/ioctl-number.rst
+++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
@@ -355,6 +355,8 @@ Code  Seq#    Include File                                           Comments
 0xB6  all    linux/fpga-dfl.h
 0xB7  all    uapi/linux/remoteproc_cdev.h                            <mailto:linux-remoteproc@vger.kernel.org>
 0xB7  all    uapi/linux/nsfs.h                                       <mailto:Andrei Vagin <avagin@openvz.org>>
+0xB8  all    uapi/linux/mshv.h                                       Microsoft Hypervisor VM management APIs
+                                                                     <mailto:linux-hyperv@vger.kernel.org>
 0xC0  00-0F  linux/usb/iowarrior.h
 0xCA  00-0F  uapi/misc/cxl.h
 0xCA  10-2F  uapi/misc/ocxl.h
-- 
2.25.1

[PATCH v2 13/15] uapi: hyperv: Add mshv driver headers hvhdk.h, hvhdk_mini.h, hvgdk.h, hvgdk_mini.h

[Nuno Das Neves]

Containing hypervisor ABI definitions to use in mshv driver.

Version numbers for each file:
hvhdk.h		25212
hvhdk_mini.h	25294
hvgdk.h		25125
hvgdk_mini.h	25294

These are unstable interfaces and as such must be compiled independently
from published interfaces found in hyperv-tlfs.h.

These are in uapi because they will be used in the mshv ioctl API.

Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
---
 include/uapi/hyperv/hvgdk.h      |   41 +
 include/uapi/hyperv/hvgdk_mini.h | 1077 ++++++++++++++++++++++++
 include/uapi/hyperv/hvhdk.h      | 1352 ++++++++++++++++++++++++++++++
 include/uapi/hyperv/hvhdk_mini.h |  164 ++++
 4 files changed, 2634 insertions(+)
 create mode 100644 include/uapi/hyperv/hvgdk.h
 create mode 100644 include/uapi/hyperv/hvgdk_mini.h
 create mode 100644 include/uapi/hyperv/hvhdk.h
 create mode 100644 include/uapi/hyperv/hvhdk_mini.h

diff --git a/include/uapi/hyperv/hvgdk.h b/include/uapi/hyperv/hvgdk.h
new file mode 100644
index 000000000000..9bcbb7d902b2
--- /dev/null
+++ b/include/uapi/hyperv/hvgdk.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright (c) 2023, Microsoft Corporation.
+ *
+ * These files (hvhdk.h, hvhdk_mini.h, hvgdk.h, hvgdk_mini.h) define APIs for
+ * communicating with the Microsoft Hypervisor.
+ *
+ * These definitions are subject to change across hypervisor versions, and as
+ * such are separate and independent from hyperv-tlfs.h.
+ *
+ * The naming of these headers reflects conventions used in the Microsoft
+ * Hypervisor.
+ */
+#ifndef _UAPI_HV_HVGDK_H
+#define _UAPI_HV_HVGDK_H
+
+#include "hvgdk_mini.h"
+
+enum hv_unimplemented_msr_action {
+	HV_UNIMPLEMENTED_MSR_ACTION_FAULT = 0,
+	HV_UNIMPLEMENTED_MSR_ACTION_IGNORE_WRITE_READ_ZERO = 1,
+	HV_UNIMPLEMENTED_MSR_ACTION_COUNT = 2,
+};
+
+/* Define connection identifier type. */
+union hv_connection_id {
+	__u32 asu32;
+	struct {
+		__u32 id:24;
+		__u32 reserved:8;
+	} __packed u;
+};
+
+struct hv_input_unmap_gpa_pages {
+	__u64 target_partition_id;
+	__u64 target_gpa_base;
+	__u32 unmap_flags;
+	__u32 padding;
+} __packed;
+
+#endif /* #ifndef _UAPI_HV_HVGDK_H */
diff --git a/include/uapi/hyperv/hvgdk_mini.h b/include/uapi/hyperv/hvgdk_mini.h
new file mode 100644
index 000000000000..86d825ef6062
--- /dev/null
+++ b/include/uapi/hyperv/hvgdk_mini.h
@@ -0,0 +1,1077 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright (c) 2023, Microsoft Corporation.
+ *
+ * These files (hvhdk.h, hvhdk_mini.h, hvgdk.h, hvgdk_mini.h) define APIs for
+ * communicating with the Microsoft Hypervisor.
+ *
+ * These definitions are subject to change across hypervisor versions, and as
+ * such are separate and independent from hyperv-tlfs.h.
+ *
+ * The naming of these headers reflects conventions used in the Microsoft
+ * Hypervisor.
+ */
+#ifndef _UAPI_HV_HVGDK_MINI_H
+#define _UAPI_HV_HVGDK_MINI_H
+
+struct hv_u128 {
+	__u64 low_part;
+	__u64 high_part;
+} __packed;
+
+/* hypercall status code */
+#define __HV_STATUS_DEF(OP) \
+	OP(HV_STATUS_SUCCESS,				0x0) \
+	OP(HV_STATUS_INVALID_HYPERCALL_CODE,		0x2) \
+	OP(HV_STATUS_INVALID_HYPERCALL_INPUT,		0x3) \
+	OP(HV_STATUS_INVALID_ALIGNMENT,			0x4) \
+	OP(HV_STATUS_INVALID_PARAMETER,			0x5) \
+	OP(HV_STATUS_ACCESS_DENIED,			0x6) \
+	OP(HV_STATUS_INVALID_PARTITION_STATE,		0x7) \
+	OP(HV_STATUS_OPERATION_DENIED,			0x8) \
+	OP(HV_STATUS_UNKNOWN_PROPERTY,			0x9) \
+	OP(HV_STATUS_PROPERTY_VALUE_OUT_OF_RANGE,	0xA) \
+	OP(HV_STATUS_INSUFFICIENT_MEMORY,		0xB) \
+	OP(HV_STATUS_INVALID_PARTITION_ID,		0xD) \
+	OP(HV_STATUS_INVALID_VP_INDEX,			0xE) \
+	OP(HV_STATUS_NOT_FOUND,				0x10) \
+	OP(HV_STATUS_INVALID_PORT_ID,			0x11) \
+	OP(HV_STATUS_INVALID_CONNECTION_ID,		0x12) \
+	OP(HV_STATUS_INSUFFICIENT_BUFFERS,		0x13) \
+	OP(HV_STATUS_NOT_ACKNOWLEDGED,			0x14) \
+	OP(HV_STATUS_INVALID_VP_STATE,			0x15) \
+	OP(HV_STATUS_NO_RESOURCES,			0x1D) \
+	OP(HV_STATUS_PROCESSOR_FEATURE_NOT_SUPPORTED,	0x20) \
+	OP(HV_STATUS_INVALID_LP_INDEX,			0x41) \
+	OP(HV_STATUS_INVALID_REGISTER_VALUE,		0x50) \
+	OP(HV_STATUS_CALL_PENDING,			0x79)
+
+#define __HV_MAKE_HV_STATUS_ENUM(NAME, VAL) NAME = (VAL),
+#define __HV_MAKE_HV_STATUS_CASE(NAME, VAL) case (NAME): return (#NAME);
+
+enum hv_status {
+	__HV_STATUS_DEF(__HV_MAKE_HV_STATUS_ENUM)
+};
+
+/* TODO not in hv headers */
+#define HV_LINUX_VENDOR_ID              0x8100
+#define HV_HYP_PAGE_SHIFT		12
+#define HV_HYP_PAGE_SIZE		BIT(HV_HYP_PAGE_SHIFT)
+#define HV_HYP_PAGE_MASK		(~(HV_HYP_PAGE_SIZE - 1))
+
+#define HV_PARTITION_ID_INVALID		((__u64) 0)
+#define HV_PARTITION_ID_SELF		((__u64)-1)
+
+/* Hyper-V specific model specific registers (MSRs) */
+
+/* HV_X64_SYNTHETIC_MSR */
+/* MSR used to identify the guest OS. */
+#define HV_X64_MSR_GUEST_OS_ID			0x40000000
+
+/* MSR used to setup pages used to communicate with the hypervisor. */
+#define HV_X64_MSR_HYPERCALL			0x40000001
+
+/* MSR used to provide vcpu index */
+#define HV_X64_MSR_VP_INDEX			0x40000002
+
+/* MSR used to reset the guest OS. */
+#define HV_X64_MSR_RESET			0x40000003
+
+/* MSR used to provide vcpu runtime in 100ns units */
+#define HV_X64_MSR_VP_RUNTIME			0x40000010
+
+/* MSR used to read the per-partition time reference counter */
+#define HV_X64_MSR_TIME_REF_COUNT		0x40000020
+
+/* A partition's reference time stamp counter (TSC) page */
+#define HV_X64_MSR_REFERENCE_TSC		0x40000021
+
+/* MSR used to retrieve the TSC frequency */
+#define HV_X64_MSR_TSC_FREQUENCY		0x40000022
+
+/* MSR used to retrieve the local APIC timer frequency */
+#define HV_X64_MSR_APIC_FREQUENCY		0x40000023
+
+/* Define the virtual APIC registers */
+#define HV_X64_MSR_EOI				0x40000070
+#define HV_X64_MSR_ICR				0x40000071
+#define HV_X64_MSR_TPR				0x40000072
+#define HV_X64_MSR_VP_ASSIST_PAGE		0x40000073
+
+/* Define synthetic interrupt controller model specific registers. */
+#define HV_X64_MSR_SCONTROL			0x40000080
+#define HV_X64_MSR_SVERSION			0x40000081
+#define HV_X64_MSR_SIEFP			0x40000082
+#define HV_X64_MSR_SIMP				0x40000083
+#define HV_X64_MSR_EOM				0x40000084
+#define HV_X64_MSR_SIRBP			0x40000085
+#define HV_X64_MSR_SINT0			0x40000090
+#define HV_X64_MSR_SINT1			0x40000091
+#define HV_X64_MSR_SINT2			0x40000092
+#define HV_X64_MSR_SINT3			0x40000093
+#define HV_X64_MSR_SINT4			0x40000094
+#define HV_X64_MSR_SINT5			0x40000095
+#define HV_X64_MSR_SINT6			0x40000096
+#define HV_X64_MSR_SINT7			0x40000097
+#define HV_X64_MSR_SINT8			0x40000098
+#define HV_X64_MSR_SINT9			0x40000099
+#define HV_X64_MSR_SINT10			0x4000009A
+#define HV_X64_MSR_SINT11			0x4000009B
+#define HV_X64_MSR_SINT12			0x4000009C
+#define HV_X64_MSR_SINT13			0x4000009D
+#define HV_X64_MSR_SINT14			0x4000009E
+#define HV_X64_MSR_SINT15			0x4000009F
+
+/* Define synthetic interrupt controller model specific registers for nested hypervisor */
+#define HV_X64_MSR_NESTED_SCONTROL		0x40001080
+#define HV_X64_MSR_NESTED_SVERSION		0x40001081
+#define HV_X64_MSR_NESTED_SIEFP			0x40001082
+#define HV_X64_MSR_NESTED_SIMP			0x40001083
+#define HV_X64_MSR_NESTED_EOM			0x40001084
+#define HV_X64_MSR_NESTED_SINT0			0x40001090
+
+/*
+ * Synthetic Timer MSRs. Four timers per vcpu.
+ */
+#define HV_X64_MSR_STIMER0_CONFIG		0x400000B0
+#define HV_X64_MSR_STIMER0_COUNT		0x400000B1
+#define HV_X64_MSR_STIMER1_CONFIG		0x400000B2
+#define HV_X64_MSR_STIMER1_COUNT		0x400000B3
+#define HV_X64_MSR_STIMER2_CONFIG		0x400000B4
+#define HV_X64_MSR_STIMER2_COUNT		0x400000B5
+#define HV_X64_MSR_STIMER3_CONFIG		0x400000B6
+#define HV_X64_MSR_STIMER3_COUNT		0x400000B7
+
+/* Hyper-V guest idle MSR */
+#define HV_X64_MSR_GUEST_IDLE			0x400000F0
+
+/* Hyper-V guest crash notification MSR's */
+#define HV_X64_MSR_CRASH_P0			0x40000100
+#define HV_X64_MSR_CRASH_P1			0x40000101
+#define HV_X64_MSR_CRASH_P2			0x40000102
+#define HV_X64_MSR_CRASH_P3			0x40000103
+#define HV_X64_MSR_CRASH_P4			0x40000104
+#define HV_X64_MSR_CRASH_CTL			0x40000105
+
+/* TSC emulation after migration */
+#define HV_X64_MSR_REENLIGHTENMENT_CONTROL	0x40000106
+#define HV_X64_MSR_TSC_EMULATION_CONTROL	0x40000107
+#define HV_X64_MSR_TSC_EMULATION_STATUS		0x40000108
+
+/* TSC invariant control */
+#define HV_X64_MSR_TSC_INVARIANT_CONTROL	0x40000118
+
+/*
+ * Version info reported by hypervisor
+ * Changed to a union for convenience
+ */
+union hv_hypervisor_version_info {
+	struct {
+		__u32 build_number;
+
+		__u32 minor_version : 16;
+		__u32 major_version : 16;
+
+		__u32 service_pack;
+
+		__u32 service_number : 24;
+		__u32 service_branch : 8;
+	};
+	struct {
+		__u32 eax;
+		__u32 ebx;
+		__u32 ecx;
+		__u32 edx;
+	};
+};
+
+/* HV_CPUID_FUNCTION */
+#define HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS	0x40000000
+#define HYPERV_CPUID_VERSION			0x40000002
+
+/* HV_X64_ENLIGHTENMENT_INFORMATION */
+
+/* DeprecateAutoEoi */
+#define HV_DEPRECATING_AEOI_RECOMMENDED		BIT(9)
+
+#define HV_MAXIMUM_PROCESSORS       2048
+
+#define HV_MAX_VP_INDEX			(HV_MAXIMUM_PROCESSORS - 1)
+#define HV_VP_INDEX_SELF		((__u32)-2)
+#define HV_ANY_VP			((__u32)-1)
+
+/* Declare the various hypercall operations. */
+/* HV_CALL_CODE */
+#define HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE	0x0002
+#define HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST	0x0003
+#define HVCALL_NOTIFY_LONG_SPIN_WAIT		0x0008
+#define HVCALL_SEND_IPI				0x000b
+#define HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX	0x0013
+#define HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX	0x0014
+#define HVCALL_SEND_IPI_EX			0x0015
+#define HVCALL_CREATE_PARTITION			0x0040
+#define HVCALL_INITIALIZE_PARTITION		0x0041
+#define HVCALL_FINALIZE_PARTITION		0x0042
+#define HVCALL_DELETE_PARTITION			0x0043
+#define HVCALL_GET_PARTITION_PROPERTY		0x0044
+#define HVCALL_SET_PARTITION_PROPERTY		0x0045
+#define HVCALL_GET_PARTITION_ID			0x0046
+#define HVCALL_DEPOSIT_MEMORY			0x0048
+#define HVCALL_WITHDRAW_MEMORY			0x0049
+#define HVCALL_MAP_GPA_PAGES			0x004b
+#define HVCALL_UNMAP_GPA_PAGES			0x004c
+#define HVCALL_INSTALL_INTERCEPT		0x004d
+#define HVCALL_CREATE_VP			0x004e
+#define HVCALL_GET_VP_REGISTERS			0x0050
+#define HVCALL_SET_VP_REGISTERS			0x0051
+#define HVCALL_TRANSLATE_VIRTUAL_ADDRESS	0x0052
+#define HVCALL_CLEAR_VIRTUAL_INTERRUPT		0x0056
+#define HVCALL_DELETE_PORT			0x0058
+#define HVCALL_DISCONNECT_PORT			0x005b
+#define HVCALL_POST_MESSAGE			0x005c
+#define HVCALL_SIGNAL_EVENT			0x005d
+#define HVCALL_POST_DEBUG_DATA			0x0069
+#define HVCALL_RETRIEVE_DEBUG_DATA		0x006a
+#define HVCALL_RESET_DEBUG_SESSION		0x006b
+#define HVCALL_ADD_LOGICAL_PROCESSOR		0x0076
+#define HVCALL_GET_SYSTEM_PROPERTY		0x007b
+#define HVCALL_MAP_DEVICE_INTERRUPT		0x007c
+#define HVCALL_UNMAP_DEVICE_INTERRUPT		0x007d
+#define HVCALL_RETARGET_INTERRUPT		0x007e
+#define HVCALL_NOTIFY_PORT_RING_EMPTY		0x008b
+#define HVCALL_REGISTER_INTERCEPT_RESULT	0x0091
+#define HVCALL_ASSERT_VIRTUAL_INTERRUPT		0x0094
+#define HVCALL_CREATE_PORT			0x0095
+#define HVCALL_CONNECT_PORT			0x0096
+#define HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE	0x00af
+#define HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_LIST	0x00b0
+#define HVCALL_GET_GPA_PAGES_ACCESS_STATES	0x00c9
+#define HVCALL_SIGNAL_EVENT_DIRECT		0x00c0
+#define HVCALL_POST_MESSAGE_DIRECT		0x00c1
+#define HVCALL_DISPATCH_VP			0x00c2
+#define HVCALL_MAP_VP_STATE_PAGE		0x00e1
+#define HVCALL_UNMAP_VP_STATE_PAGE		0x00e2
+#define HVCALL_GET_VP_STATE			0x00e3
+#define HVCALL_SET_VP_STATE			0x00e4
+#define HVCALL_GET_VP_CPUID_VALUES		0x00f4
+
+/*
+ * Some macros - i.e. GENMASK_ULL and BIT_ULL - are not currently supported by
+ * userspace rust bindings generation tool.
+ * As the below are not currently needed in userspace, don't export them and
+ * avoid the issue altogether for now.
+ */
+#if defined(__KERNEL__)
+
+/* HV_HYPERCALL_INPUT */
+#define HV_HYPERCALL_RESULT_MASK	GENMASK_ULL(15, 0)
+#define HV_HYPERCALL_FAST_BIT		BIT(16)
+#define HV_HYPERCALL_VARHEAD_OFFSET	17
+#define HV_HYPERCALL_NESTED		BIT(31)
+#define HV_HYPERCALL_REP_COMP_OFFSET	32
+#define HV_HYPERCALL_REP_COMP_1		BIT_ULL(32)
+#define HV_HYPERCALL_REP_COMP_MASK	GENMASK_ULL(43, 32)
+#define HV_HYPERCALL_REP_START_OFFSET	48
+#define HV_HYPERCALL_REP_START_MASK	GENMASK_ULL(59, 48)
+
+#endif /* __KERNEL__ */
+
+union hv_gpa_page_range {
+	u64 address_space;
+	struct {
+		u64 additional_pages:11;
+		u64 largepage:1;
+		u64 basepfn:52;
+	} page;
+	struct {
+		u64 reserved:12;
+		u64 page_size:1;
+		u64 reserved1:8;
+		u64 base_large_pfn:43;
+	};
+};
+
+/* Define the number of synthetic interrupt sources. */
+#define HV_SYNIC_SINT_COUNT (16)
+
+/* Hyper-V defined statically assigned SINTs */
+#define HV_SYNIC_INTERCEPTION_SINT_INDEX 0x00000000
+#define HV_SYNIC_IOMMU_FAULT_SINT_INDEX  0x00000001
+#define HV_SYNIC_VMBUS_SINT_INDEX        0x00000002
+#define HV_SYNIC_FIRST_UNUSED_SINT_INDEX 0x00000005
+
+/* mshv assigned SINT for doorbell */
+#define HV_SYNIC_DOORBELL_SINT_INDEX     HV_SYNIC_FIRST_UNUSED_SINT_INDEX
+
+enum hv_interrupt_type {
+	HV_X64_INTERRUPT_TYPE_FIXED		= 0x0000,
+	HV_X64_INTERRUPT_TYPE_LOWESTPRIORITY	= 0x0001,
+	HV_X64_INTERRUPT_TYPE_SMI		= 0x0002,
+	HV_X64_INTERRUPT_TYPE_REMOTEREAD	= 0x0003,
+	HV_X64_INTERRUPT_TYPE_NMI		= 0x0004,
+	HV_X64_INTERRUPT_TYPE_INIT		= 0x0005,
+	HV_X64_INTERRUPT_TYPE_SIPI		= 0x0006,
+	HV_X64_INTERRUPT_TYPE_EXTINT		= 0x0007,
+	HV_X64_INTERRUPT_TYPE_LOCALINT0		= 0x0008,
+	HV_X64_INTERRUPT_TYPE_LOCALINT1		= 0x0009,
+	HV_X64_INTERRUPT_TYPE_MAXIMUM		= 0x000A,
+};
+
+/* Define synthetic interrupt source. */
+union hv_synic_sint {
+	__u64 as_uint64;
+	struct {
+		__u64 vector : 8;
+		__u64 reserved1 : 8;
+		__u64 masked : 1;
+		__u64 auto_eoi : 1;
+		__u64 polling : 1;
+		__u64 as_intercept : 1;
+		__u64 proxy : 1;
+		__u64 reserved2 : 43;
+	} __packed;
+};
+
+union hv_x64_xsave_xfem_register {
+	__u64 as_uint64;
+	struct {
+		__u32 low_uint32;
+		__u32 high_uint32;
+	} __packed;
+	struct {
+		__u64 legacy_x87 : 1;
+		__u64 legacy_sse : 1;
+		__u64 avx : 1;
+		__u64 mpx_bndreg : 1;
+		__u64 mpx_bndcsr : 1;
+		__u64 avx_512_op_mask : 1;
+		__u64 avx_512_zmmhi : 1;
+		__u64 avx_512_zmm16_31 : 1;
+		__u64 rsvd8_9 : 2;
+		__u64 pasid : 1;
+		__u64 cet_u : 1;
+		__u64 cet_s : 1;
+		__u64 rsvd13_16 : 4;
+		__u64 xtile_cfg : 1;
+		__u64 xtile_data : 1;
+		__u64 rsvd19_63 : 45;
+	} __packed;
+};
+
+/* Define the number of synthetic timers */
+#define HV_SYNIC_STIMER_COUNT	(4)
+
+/* Define port identifier type. */
+union hv_port_id {
+	__u32 asu32;
+	struct {
+		__u32 id : 24;
+		__u32 reserved : 8;
+	} __packed u; // TODO remove this u
+};
+
+#define HV_MESSAGE_SIZE			(256)
+#define HV_MESSAGE_PAYLOAD_BYTE_COUNT	(240)
+#define HV_MESSAGE_PAYLOAD_QWORD_COUNT	(30)
+
+/* Define hypervisor message types. */
+enum hv_message_type {
+	HVMSG_NONE				= 0x00000000,
+
+	/* Memory access messages. */
+	HVMSG_UNMAPPED_GPA			= 0x80000000,
+	HVMSG_GPA_INTERCEPT			= 0x80000001,
+
+	/* Timer notification messages. */
+	HVMSG_TIMER_EXPIRED			= 0x80000010,
+
+	/* Error messages. */
+	HVMSG_INVALID_VP_REGISTER_VALUE		= 0x80000020,
+	HVMSG_UNRECOVERABLE_EXCEPTION		= 0x80000021,
+	HVMSG_UNSUPPORTED_FEATURE		= 0x80000022,
+
+	/*
+	 * Opaque intercept message. The original intercept message is only
+	 * accessible from the mapped intercept message page.
+	 */
+	HVMSG_OPAQUE_INTERCEPT			= 0x8000003F,
+
+	/* Trace buffer complete messages. */
+	HVMSG_EVENTLOG_BUFFERCOMPLETE		= 0x80000040,
+
+	/* Hypercall intercept */
+	HVMSG_HYPERCALL_INTERCEPT		= 0x80000050,
+
+	/* SynIC intercepts */
+	HVMSG_SYNIC_EVENT_INTERCEPT		= 0x80000060,
+	HVMSG_SYNIC_SINT_INTERCEPT		= 0x80000061,
+	HVMSG_SYNIC_SINT_DELIVERABLE	= 0x80000062,
+
+	/* Async call completion intercept */
+	HVMSG_ASYNC_CALL_COMPLETION		= 0x80000070,
+
+	/* Root scheduler messages */
+	HVMSG_SCHEDULER_VP_SIGNAL_BITSET	= 0x80000100,
+	HVMSG_SCHEDULER_VP_SIGNAL_PAIR		= 0x80000101,
+
+	/* Platform-specific processor intercept messages. */
+	HVMSG_X64_IO_PORT_INTERCEPT		= 0x80010000,
+	HVMSG_X64_MSR_INTERCEPT			= 0x80010001,
+	HVMSG_X64_CPUID_INTERCEPT		= 0x80010002,
+	HVMSG_X64_EXCEPTION_INTERCEPT		= 0x80010003,
+	HVMSG_X64_APIC_EOI			= 0x80010004,
+	HVMSG_X64_LEGACY_FP_ERROR		= 0x80010005,
+	HVMSG_X64_IOMMU_PRQ			= 0x80010006,
+	HVMSG_X64_HALT				= 0x80010007,
+	HVMSG_X64_INTERRUPTION_DELIVERABLE	= 0x80010008,
+	HVMSG_X64_SIPI_INTERCEPT		= 0x80010009,
+};
+
+/* Define the format of the SIMP register */
+union hv_synic_simp {
+	__u64 as_uint64;
+	struct {
+		__u64 simp_enabled : 1;
+		__u64 preserved : 11;
+		__u64 base_simp_gpa : 52;
+	} __packed;
+};
+
+union hv_message_flags {
+	__u8 asu8;
+	struct {
+		__u8 msg_pending : 1;
+		__u8 reserved : 7;
+	} __packed;
+};
+
+struct hv_message_header {
+	__u32 message_type;
+	__u8 payload_size;
+	union hv_message_flags message_flags;
+	__u8 reserved[2];
+	union {
+		__u64 sender;
+		union hv_port_id port;
+	};
+} __packed;
+
+/*
+ * Message format for notifications delivered via
+ * intercept message(as_intercept=1)
+ */
+struct hv_notification_message_payload {
+	__u32 sint_index;
+} __packed;
+
+struct hv_message {
+	struct hv_message_header header;
+	union {
+		__u64 payload[HV_MESSAGE_PAYLOAD_QWORD_COUNT];
+	} u;
+} __packed;
+
+/* Define the synthetic interrupt message page layout. */
+struct hv_message_page {
+	struct hv_message sint_message[HV_SYNIC_SINT_COUNT];
+} __packed;
+
+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;
+		} __packed;
+		__u16 attributes;
+	};
+} __packed;
+
+struct hv_x64_table_register {
+	__u16 pad[3];
+	__u16 limit;
+	__u64 base;
+} __packed;
+
+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;
+				__u16 padding;
+			} __packed;
+		};
+	} __packed;
+} __packed;
+
+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;
+				__u16 padding;
+			} __packed;
+		};
+		__u32 xmm_status_control;
+		__u32 xmm_status_control_mask;
+	} __packed;
+} __packed;
+
+union hv_x64_fp_register {
+	struct hv_u128 as_uint128;
+	struct {
+		__u64 mantissa;
+		__u64 biased_exponent : 15;
+		__u64 sign : 1;
+		__u64 reserved : 48;
+	} __packed;
+} __packed;
+
+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;
+	} __packed;
+};
+
+union hv_input_vtl {
+	__u8 as_uint8;
+	struct {
+		__u8 target_vtl : 4;
+		__u8 use_target_vtl : 1;
+		__u8 reserved_z : 3;
+	};
+} __packed;
+
+/* Note: not in hvgdk_mini.h */
+#define HV_SUPPORTS_REGISTER_DELIVERABILITY_NOTIFICATIONS
+
+union hv_register_vsm_partition_config {
+	__u64 as_u64;
+	struct {
+		__u64 enable_vtl_protection : 1;
+		__u64 default_vtl_protection_mask : 4;
+		__u64 zero_memory_on_reset : 1;
+		__u64 deny_lower_vtl_startup : 1;
+		__u64 intercept_acceptance : 1;
+		__u64 intercept_enable_vtl_protection : 1;
+		__u64 intercept_vp_startup : 1;
+		__u64 intercept_cpuid_unimplemented : 1;
+		__u64 intercept_unrecoverable_exception : 1;
+		__u64 intercept_page : 1;
+		__u64 mbz : 51;
+	};
+};
+
+struct hv_nested_enlightenments_control {
+	struct {
+		__u32 directhypercall : 1;
+		__u32 reserved : 31;
+	} __packed features;
+	struct {
+		__u32 inter_partition_comm : 1;
+		__u32 reserved : 31;
+	} __packed hypercall_controls;
+} __packed;
+
+/* Define virtual processor assist page structure. */
+struct hv_vp_assist_page {
+	__u32 apic_assist;
+	__u32 reserved1;
+	__u32 vtl_entry_reason;
+	__u32 vtl_reserved;
+	__u64 vtl_ret_x64rax;
+	__u64 vtl_ret_x64rcx;
+	struct hv_nested_enlightenments_control nested_control;
+	__u8 enlighten_vmentry;
+	__u8 reserved2[7];
+	__u64 current_nested_vmcs;
+	__u8 synthetic_time_unhalted_timer_expired;
+	__u8 reserved3[7];
+	__u8 virtualization_fault_information[40];
+	__u8 reserved4[8];
+	__u8 intercept_message[256];
+	__u8 vtl_ret_actions[256];
+} __packed;
+
+enum hv_register_name {
+	/* Suspend Registers */
+	HV_REGISTER_EXPLICIT_SUSPEND		= 0x00000000,
+	HV_REGISTER_INTERCEPT_SUSPEND		= 0x00000001,
+	HV_REGISTER_DISPATCH_SUSPEND		= 0x00000003,
+
+	HV_REGISTER_VP_ROOT_SIGNAL_COUNT        = 0x00090014,
+
+	/* Synthetic VSM registers */
+	HV_REGISTER_VSM_CODE_PAGE_OFFSETS	= 0x000D0002,
+	HV_REGISTER_VSM_CAPABILITIES		= 0x000D0006,
+	HV_REGISTER_VSM_PARTITION_CONFIG	= 0x000D0007,
+
+	/* 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,
+
+	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,
+	HV_X64_REGISTER_TSC_ADJUST		= 0x00080096,
+
+	/* 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,
+
+	HV_X64_REGISTER_REG_PAGE	= 0x0009001C,
+};
+
+
+/*
+ * Arch compatibility regs for use with hv_set/get_register
+ */
+#define HV_MSR_VP_INDEX		(HV_X64_MSR_VP_INDEX)
+#define HV_MSR_TIME_REF_COUNT	(HV_X64_MSR_TIME_REF_COUNT)
+#define HV_MSR_REFERENCE_TSC	(HV_X64_MSR_REFERENCE_TSC)
+#define HV_MSR_STIMER0_CONFIG	(HV_X64_MSR_STIMER0_CONFIG)
+#define HV_MSR_STIMER0_COUNT	(HV_X64_MSR_STIMER0_COUNT)
+
+#define HV_MSR_SCONTROL		(HV_X64_MSR_SCONTROL)
+#define HV_MSR_SIEFP		(HV_X64_MSR_SIEFP)
+#define HV_MSR_SIMP		(HV_X64_MSR_SIMP)
+#define HV_MSR_SIRBP		(HV_X64_MSR_SIRBP)
+#define HV_MSR_EOM		(HV_X64_MSR_EOM)
+#define HV_MSR_SINT0		(HV_X64_MSR_SINT0)
+
+#define HV_MSR_NESTED_SCONTROL	(HV_X64_MSR_NESTED_SCONTROL)
+#define HV_MSR_NESTED_SIEFP	(HV_X64_MSR_NESTED_SIEFP)
+#define HV_MSR_NESTED_SIMP	(HV_X64_MSR_NESTED_SIMP)
+#define HV_MSR_NESTED_EOM	(HV_X64_MSR_NESTED_EOM)
+#define HV_MSR_NESTED_SINT0	(HV_X64_MSR_NESTED_SINT0)
+
+#define HV_MSR_CRASH_P0		(HV_X64_MSR_CRASH_P0)
+#define HV_MSR_CRASH_P1		(HV_X64_MSR_CRASH_P1)
+#define HV_MSR_CRASH_P2		(HV_X64_MSR_CRASH_P2)
+#define HV_MSR_CRASH_P3		(HV_X64_MSR_CRASH_P3)
+#define HV_MSR_CRASH_P4		(HV_X64_MSR_CRASH_P4)
+#define HV_MSR_CRASH_CTL	(HV_X64_MSR_CRASH_CTL)
+
+/* General Hypervisor Register Content Definitions */
+
+union hv_explicit_suspend_register {
+	__u64 as_uint64;
+	struct {
+		__u64 suspended : 1;
+		__u64 reserved : 63;
+	} __packed;
+};
+
+union hv_intercept_suspend_register {
+	__u64 as_uint64;
+	struct {
+		__u64 suspended : 1;
+		__u64 reserved : 63;
+	} __packed;
+};
+
+union hv_dispatch_suspend_register {
+	__u64 as_uint64;
+	struct {
+		__u64 suspended : 1;
+		__u64 reserved : 63;
+	} __packed;
+};
+
+union hv_x64_interrupt_state_register {
+	__u64 as_uint64;
+	struct {
+		__u64 interrupt_shadow : 1;
+		__u64 nmi_masked : 1;
+		__u64 reserved : 62;
+	} __packed;
+};
+
+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;
+	} __packed;
+};
+
+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;
+	} __packed;
+};
+
+// bunch of stuff in between
+
+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;
+	} __packed;
+};
+
+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;
+};
+
+struct hv_register_assoc {
+	__u32 name;			/* enum hv_register_name */
+	__u32 reserved1;
+	__u64 reserved2;
+	union hv_register_value value;
+} __packed;
+
+struct hv_input_get_vp_registers {
+	__u64 partition_id;
+	__u32 vp_index;
+	union hv_input_vtl input_vtl;
+	__u8  rsvd_z8;
+	__u16 rsvd_z16;
+	__u32 names[];
+} __packed;
+
+struct hv_input_set_vp_registers {
+	__u64 partition_id;
+	__u32 vp_index;
+	union hv_input_vtl input_vtl;
+	__u8  rsvd_z8;
+	__u16 rsvd_z16;
+	struct hv_register_assoc elements[];
+} __packed;
+
+union hv_msi_entry {
+	u64 as_uint64;
+	struct {
+		u32 address;
+		u32 data;
+	} __packed;
+};
+
+enum hv_interrupt_source {
+	HV_INTERRUPT_SOURCE_MSI = 1, /* MSI and MSI-X */
+	HV_INTERRUPT_SOURCE_IOAPIC,
+};
+
+union hv_ioapic_rte {
+	u64 as_uint64;
+
+	struct {
+		u32 vector:8;
+		u32 delivery_mode:3;
+		u32 destination_mode:1;
+		u32 delivery_status:1;
+		u32 interrupt_polarity:1;
+		u32 remote_irr:1;
+		u32 trigger_mode:1;
+		u32 interrupt_mask:1;
+		u32 reserved1:15;
+
+		u32 reserved2:24;
+		u32 destination_id:8;
+	};
+
+	struct {
+		u32 low_uint32;
+		u32 high_uint32;
+	};
+} __packed;
+
+struct hv_interrupt_entry {
+	u32 source; /* enum hv_interrupt_source */
+	u32 reserved1;
+	union {
+		union hv_msi_entry msi_entry;
+		union hv_ioapic_rte ioapic_rte;
+	};
+} __packed;
+
+enum hv_intercept_type {
+	HV_INTERCEPT_TYPE_X64_IO_PORT			= 0X00000000,
+	HV_INTERCEPT_TYPE_X64_MSR			= 0X00000001,
+	HV_INTERCEPT_TYPE_X64_CPUID			= 0X00000002,
+	HV_INTERCEPT_TYPE_EXCEPTION			= 0X00000003,
+	HV_INTERCEPT_TYPE_REGISTER			= 0X00000004,
+	HV_INTERCEPT_TYPE_MMIO				= 0X00000005,
+	HV_INTERCEPT_TYPE_X64_GLOBAL_CPUID		= 0X00000006,
+	HV_INTERCEPT_TYPE_X64_APIC_SMI			= 0X00000007,
+	HV_INTERCEPT_TYPE_HYPERCALL			= 0X00000008,
+	HV_INTERCEPT_TYPE_X64_APIC_INIT_SIPI		= 0X00000009,
+	HV_INTERCEPT_TYPE_X64_APIC_WRITE		= 0X0000000B,
+	HV_INTERCEPT_TYPE_X64_MSR_INDEX			= 0X0000000C,
+	HV_INTERCEPT_TYPE_MAX,
+	HV_INTERCEPT_TYPE_INVALID			= 0XFFFFFFFF,
+};
+
+union hv_intercept_parameters {
+	/*  HV_INTERCEPT_PARAMETERS is defined to be an 8-byte field. */
+	__u64 as_uint64;
+	/* HV_INTERCEPT_TYPE_X64_IO_PORT */
+	__u16 io_port;
+	/* HV_INTERCEPT_TYPE_X64_CPUID */
+	__u32 cpuid_index;
+	/* HV_INTERCEPT_TYPE_X64_APIC_WRITE */
+	__u32 apic_write_mask;
+	/* HV_INTERCEPT_TYPE_EXCEPTION */
+	__u16 exception_vector;
+	/* HV_INTERCEPT_TYPE_X64_MSR_INDEX */
+	__u32 msr_index;
+	/* N.B. Other intercept types do not have any parameters. */
+};
+
+/* Access types for the install intercept hypercall parameter */
+#define HV_INTERCEPT_ACCESS_MASK_NONE		0x00
+#define HV_INTERCEPT_ACCESS_MASK_READ		0X01
+#define HV_INTERCEPT_ACCESS_MASK_WRITE		0x02
+#define HV_INTERCEPT_ACCESS_MASK_EXECUTE	0x04
+
+struct hv_input_install_intercept {
+	__u64 partition_id;
+	__u32 access_type;	/* mask */
+	__u32 intercept_type;	/* hv_intercept_type */
+	union hv_intercept_parameters intercept_parameter;
+} __packed;
+
+#endif /* _UAPI_HV_HVGDK_MINI_H */
diff --git a/include/uapi/hyperv/hvhdk.h b/include/uapi/hyperv/hvhdk.h
new file mode 100644
index 000000000000..90184628db8b
--- /dev/null
+++ b/include/uapi/hyperv/hvhdk.h
@@ -0,0 +1,1352 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright (c) 2023, Microsoft Corporation.
+ *
+ * These files (hvhdk.h, hvhdk_mini.h, hvgdk.h, hvgdk_mini.h) define APIs for
+ * communicating with the Microsoft Hypervisor.
+ *
+ * These definitions are subject to change across hypervisor versions, and as
+ * such are separate and independent from hyperv-tlfs.h.
+ *
+ * The naming of these headers reflects conventions used in the Microsoft
+ * Hypervisor.
+ */
+#ifndef _UAPI_HV_HVHDK_H
+#define _UAPI_HV_HVHDK_H
+
+#include "hvhdk_mini.h"
+#include "hvgdk.h"
+
+/* Bits for dirty mask of hv_vp_register_page */
+#define HV_X64_REGISTER_CLASS_GENERAL	0
+#define HV_X64_REGISTER_CLASS_IP	1
+#define HV_X64_REGISTER_CLASS_XMM	2
+#define HV_X64_REGISTER_CLASS_SEGMENT	3
+#define HV_X64_REGISTER_CLASS_FLAGS	4
+
+#define HV_VP_REGISTER_PAGE_VERSION_1	1u
+
+struct hv_vp_register_page {
+	__u16 version;
+	__u8 isvalid;
+	__u8 rsvdz;
+	__u32 dirty;
+	union {
+		struct {
+			/* General purpose registers
+			 * (HV_X64_REGISTER_CLASS_GENERAL)
+			 */
+			union {
+				struct {
+					__u64 rax;
+					__u64 rcx;
+					__u64 rdx;
+					__u64 rbx;
+					__u64 rsp;
+					__u64 rbp;
+					__u64 rsi;
+					__u64 rdi;
+					__u64 r8;
+					__u64 r9;
+					__u64 r10;
+					__u64 r11;
+					__u64 r12;
+					__u64 r13;
+					__u64 r14;
+					__u64 r15;
+				} __packed;
+
+				__u64 gp_registers[16];
+			};
+			/* Instruction pointer (HV_X64_REGISTER_CLASS_IP) */
+			__u64 rip;
+			/* Flags (HV_X64_REGISTER_CLASS_FLAGS) */
+			__u64 rflags;
+		} __packed;
+
+		__u64 registers[18];
+	};
+	/* 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;
+		} __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;
+		} __packed;
+
+		struct hv_x64_segment_register segment_registers[6];
+	};
+	/* Misc. control registers (cannot be set via this interface) */
+	__u64 cr0;
+	__u64 cr3;
+	__u64 cr4;
+	__u64 cr8;
+	__u64 efer;
+	__u64 dr7;
+	union hv_x64_pending_interruption_register pending_interruption;
+	union hv_x64_interrupt_state_register interrupt_state;
+	__u64 instruction_emulation_hints;
+} __packed;
+
+#define HV_PARTITION_PROCESSOR_FEATURES_BANKS 2
+
+union hv_partition_processor_features {
+	__u64 as_uint64[HV_PARTITION_PROCESSOR_FEATURES_BANKS];
+	struct {
+		__u64 sse3_support:1;
+		__u64 lahf_sahf_support:1;
+		__u64 ssse3_support:1;
+		__u64 sse4_1_support:1;
+		__u64 sse4_2_support:1;
+		__u64 sse4a_support:1;
+		__u64 xop_support:1;
+		__u64 pop_cnt_support:1;
+		__u64 cmpxchg16b_support:1;
+		__u64 altmovcr8_support:1;
+		__u64 lzcnt_support:1;
+		__u64 mis_align_sse_support:1;
+		__u64 mmx_ext_support:1;
+		__u64 amd3dnow_support:1;
+		__u64 extended_amd3dnow_support:1;
+		__u64 page_1gb_support:1;
+		__u64 aes_support:1;
+		__u64 pclmulqdq_support:1;
+		__u64 pcid_support:1;
+		__u64 fma4_support:1;
+		__u64 f16c_support:1;
+		__u64 rd_rand_support:1;
+		__u64 rd_wr_fs_gs_support:1;
+		__u64 smep_support:1;
+		__u64 enhanced_fast_string_support:1;
+		__u64 bmi1_support:1;
+		__u64 bmi2_support:1;
+		__u64 hle_support_deprecated:1;
+		__u64 rtm_support_deprecated:1;
+		__u64 movbe_support:1;
+		__u64 npiep1_support:1;
+		__u64 dep_x87_fpu_save_support:1;
+		__u64 rd_seed_support:1;
+		__u64 adx_support:1;
+		__u64 intel_prefetch_support:1;
+		__u64 smap_support:1;
+		__u64 hle_support:1;
+		__u64 rtm_support:1;
+		__u64 rdtscp_support:1;
+		__u64 clflushopt_support:1;
+		__u64 clwb_support:1;
+		__u64 sha_support:1;
+		__u64 x87_pointers_saved_support:1;
+		__u64 invpcid_support:1;
+		__u64 ibrs_support:1;
+		__u64 stibp_support:1;
+		__u64 ibpb_support: 1;
+		__u64 unrestricted_guest_support:1;
+		__u64 mdd_support:1;
+		__u64 fast_short_rep_mov_support:1;
+		__u64 l1dcache_flush_support:1;
+		__u64 rdcl_no_support:1;
+		__u64 ibrs_all_support:1;
+		__u64 skip_l1df_support:1;
+		__u64 ssb_no_support:1;
+		__u64 rsb_a_no_support:1;
+		__u64 virt_spec_ctrl_support:1;
+		__u64 rd_pid_support:1;
+		__u64 umip_support:1;
+		__u64 mbs_no_support:1;
+		__u64 mb_clear_support:1;
+		__u64 taa_no_support:1;
+		__u64 tsx_ctrl_support:1;
+		/*
+		 * N.B. The final processor feature bit in bank 0 is reserved to
+		 * simplify potential downlevel backports.
+		 */
+		__u64 reserved_bank0:1;
+
+		/* N.B. Begin bank 1 processor features. */
+		__u64 acount_mcount_support:1;
+		__u64 tsc_invariant_support:1;
+		__u64 cl_zero_support:1;
+		__u64 rdpru_support:1;
+		__u64 la57_support:1;
+		__u64 mbec_support:1;
+		__u64 nested_virt_support:1;
+		__u64 psfd_support:1;
+		__u64 cet_ss_support:1;
+		__u64 cet_ibt_support:1;
+		__u64 vmx_exception_inject_support:1;
+		__u64 enqcmd_support:1;
+		__u64 umwait_tpause_support:1;
+		__u64 movdiri_support:1;
+		__u64 movdir64b_support:1;
+		__u64 cldemote_support:1;
+		__u64 serialize_support:1;
+		__u64 tsc_deadline_tmr_support:1;
+		__u64 tsc_adjust_support:1;
+		__u64 fzlrep_movsb:1;
+		__u64 fsrep_stosb:1;
+		__u64 fsrep_cmpsb:1;
+		__u64 reserved_bank1:42;
+	} __packed;
+};
+
+union hv_partition_processor_xsave_features {
+	struct {
+		__u64 xsave_support : 1;
+		__u64 xsaveopt_support : 1;
+		__u64 avx_support : 1;
+		__u64 reserved1 : 61;
+	} __packed;
+	__u64 as_uint64;
+};
+
+struct hv_partition_creation_properties {
+	union hv_partition_processor_features disabled_processor_features;
+	union hv_partition_processor_xsave_features
+		disabled_processor_xsave_features;
+} __packed;
+
+
+/*
+ * Definition of the partition isolation state. Used for
+ * HV_PARTITION_PROPERTY_ISOLATION_STATE.
+ *
+ *
+ * The isolation states (hv_partition_isolation_state) are sub-states of
+ * ObPartitionActive that apply to VBS and hardware isolated partitions.
+ * For VBS isolation, the trusted host VTL 1 component uses the isolation
+ * state to establish a binding between a hypervisor partition and its
+ * own partition context, and to enforce certain invariants.
+ *
+ * Hardware-isolated partitions (including partitions that simulate
+ * hardware isolation) also use isolation states to track the progression
+ * of the partition security state through the architectural state machine.
+ * Insecure states indicate that there is no architectural state
+ * associated with the partition, and Secure indicates that the partition
+ * has secure architectural state.
+ *
+ * ObPartitionRestoring is treated differently for isolated partitions.
+ * Only the trusted host component is allowed to restore partition state,
+ * and ObPartitionRestoring can only transition directly to/from secure.
+ *
+ *
+ * ..................................................................
+ * .         UNINITIALIZED     FINALIZED                            .
+ * .               |           ^       ^                            .
+ * .    Initialize |          /         \                           .
+ * .               |         /           \                          .
+ * . --------------|--------/--- ACTIVE --\------------------------ .
+ * . |             |       /               \                      | .
+ * . |             |      / Finalize        \ Finalize            | .
+ * . |             v     /                   \                    | .
+ * . |       INSECURE-CLEAN <---------------- INSECURE-DIRTY      | .
+ * . |                   \        Scrub      ^                    | .
+ * . |                    \                 /                     | .
+ * . |                     \               /                      | .
+ * . |               Secure \             / Unsecure              | .
+ * . |                       \           /                        | .
+ * . |                        \         /                         | .
+ * . |                         v       /                          | .
+ * . |                           SECURE                           | .
+ * . |                             ^                              | .
+ * . |_____________________________|______________________________| .
+ * .                               |                                .
+ * .                               v                                .
+ * .                           RESTORING                            .
+ * ..................................................................
+ */
+enum hv_partition_isolation_state {
+	/*
+	 * Initial and final state for all non-isolated partitions.
+	 */
+	HV_PARTITION_ISOLATION_INVALID             = 0,
+
+	/*
+	 * An "Insecure" partition is not being used by the trusted host
+	 * component. In this state, VPs can be created and deleted. VPs cannot
+	 * be started, and VP registers cannot be modified.
+
+	 * Initial state of an isolated partition as result of Initialize or
+	 * Scrub hypercalls. Guest-visible partition and VP state is considered
+	 * "clean", in the sense that a call to ObScrubPartition should not
+	 * result in any changes. Also, there are no accepted or confidential
+	 * pages assigned to the partition. InsecureRundown is enabled.
+	 */
+	HV_PARTITION_ISOLATION_INSECURE_CLEAN       = 1,
+
+	/*
+	 * Guest-visible partition and VP state is not "clean". Hence it must
+	 * be scrubbed first. One of 2 explicit states the trusted host
+	 * component can request. It cannot transition the state to Secure. In
+	 * this state,
+	 *  - IsolationControl is clear.
+	 *  - Secure rundowns are completely disabled.
+	 *  - No assigned pages exist.
+	 */
+	HV_PARTITION_ISOLATION_INSECURE_DIRTY       = 2,
+
+	/*
+	 * The partition is being used by the trusted host component (and is
+	 * typically bound to a single partition context in that component).
+	 * One of 2 explicit states the trusted host component can request. In
+	 * this state,
+	 *  - VPs cannot be created or deleted.
+	 *  - Partition cannot be finalized, scrubbed.
+	 *  - Insecure rundowns are completely disabled.
+	 */
+	HV_PARTITION_ISOLATION_SECURE              = 3,
+
+	/*
+	 * Represents a failed attempt to transition to Secure state. Partition
+	 * in this state cannot be finalized, scrubbed since one or more pages
+	 * may be assigned.
+	 */
+	HV_PARTITION_ISOLATION_SECURE_DIRTY         = 4,
+
+	/*
+	 * An internal state indicating that a partition is in the process of
+	 * transitioning from Secure to InsecureDirty.
+	 */
+	HV_PARTITION_ISOLATION_SECURE_TERMINATING   = 5,
+};
+
+
+#define HV_PARTITION_SYNTHETIC_PROCESSOR_FEATURES_BANKS 1
+
+union hv_partition_synthetic_processor_features {
+	__u64 as_uint64[HV_PARTITION_SYNTHETIC_PROCESSOR_FEATURES_BANKS];
+
+	struct {
+		/* Report a hypervisor is present. CPUID leaves
+		 * 0x40000000 and 0x40000001 are supported.
+		 */
+		__u64 hypervisor_present:1;
+
+		/*
+		 * Features associated with HV#1:
+		 */
+
+		/* Report support for Hv1 (CPUID leaves 0x40000000 - 0x40000006). */
+		__u64 hv1:1;
+
+		/* Access to HV_X64_MSR_VP_RUNTIME.
+		 * Corresponds to access_vp_run_time_reg privilege.
+		 */
+		__u64 access_vp_run_time_reg:1;
+
+		/* Access to HV_X64_MSR_TIME_REF_COUNT.
+		 * Corresponds to access_partition_reference_counter privilege.
+		 */
+		__u64 access_partition_reference_counter:1;
+
+		/* Access to SINT-related registers (HV_X64_MSR_SCONTROL through
+		 * HV_X64_MSR_EOM and HV_X64_MSR_SINT0 through HV_X64_MSR_SINT15).
+		 * Corresponds to access_synic_regs privilege.
+		 */
+		__u64 access_synic_regs:1;
+
+		/* Access to synthetic timers and associated MSRs
+		 * (HV_X64_MSR_STIMER0_CONFIG through HV_X64_MSR_STIMER3_COUNT).
+		 * Corresponds to access_synthetic_timer_regs privilege.
+		 */
+		__u64 access_synthetic_timer_regs:1;
+
+		/* Access to APIC MSRs (HV_X64_MSR_EOI, HV_X64_MSR_ICR and HV_X64_MSR_TPR)
+		 * as well as the VP assist page.
+		 * Corresponds to access_intr_ctrl_regs privilege.
+		 */
+		__u64 access_intr_ctrl_regs:1;
+
+		/* Access to registers associated with hypercalls (HV_X64_MSR_GUEST_OS_ID
+		 * and HV_X64_MSR_HYPERCALL).
+		 * Corresponds to access_hypercall_msrs privilege.
+		 */
+		__u64 access_hypercall_regs:1;
+
+		/* VP index can be queried. corresponds to access_vp_index privilege. */
+		__u64 access_vp_index:1;
+
+		/* Access to the reference TSC. Corresponds to access_partition_reference_tsc
+		 * privilege.
+		 */
+		__u64 access_partition_reference_tsc:1;
+
+		/* Partition has access to the guest idle reg. Corresponds to
+		 * access_guest_idle_reg privilege.
+		 */
+		__u64 access_guest_idle_reg:1;
+
+		/* Partition has access to frequency regs. corresponds to access_frequency_regs
+		 * privilege.
+		 */
+		__u64 access_frequency_regs:1;
+
+		__u64 reserved_z12:1; /* Reserved for access_reenlightenment_controls. */
+		__u64 reserved_z13:1; /* Reserved for access_root_scheduler_reg. */
+		__u64 reserved_z14:1; /* Reserved for access_tsc_invariant_controls. */
+
+		/* Extended GVA ranges for HvCallFlushVirtualAddressList hypercall.
+		 * Corresponds to privilege.
+		 */
+		__u64 enable_extended_gva_ranges_for_flush_virtual_address_list:1;
+
+		__u64 reserved_z16:1; /* Reserved for access_vsm. */
+		__u64 reserved_z17:1; /* Reserved for access_vp_registers. */
+
+		/* Use fast hypercall output. Corresponds to privilege. */
+		__u64 fast_hypercall_output:1;
+
+		__u64 reserved_z19:1; /* Reserved for enable_extended_hypercalls. */
+
+		/*
+		 * HvStartVirtualProcessor can be used to start virtual processors.
+		 * Corresponds to privilege.
+		 */
+		__u64 start_virtual_processor:1;
+
+		__u64 reserved_z21:1; /* Reserved for Isolation. */
+
+		/* Synthetic timers in direct mode. */
+		__u64 direct_synthetic_timers:1;
+
+		__u64 reserved_z23:1; /* Reserved for synthetic time unhalted timer */
+
+		/* Use extended processor masks. */
+		__u64 extended_processor_masks:1;
+
+		/* HvCallFlushVirtualAddressSpace / HvCallFlushVirtualAddressList are supported. */
+		__u64 tb_flush_hypercalls:1;
+
+		/* HvCallSendSyntheticClusterIpi is supported. */
+		__u64 synthetic_cluster_ipi:1;
+
+		/* HvCallNotifyLongSpinWait is supported. */
+		__u64 notify_long_spin_wait:1;
+
+		/* HvCallQueryNumaDistance is supported. */
+		__u64 query_numa_distance:1;
+
+		/* HvCallSignalEvent is supported. Corresponds to privilege. */
+		__u64 signal_events:1;
+
+		/* HvCallRetargetDeviceInterrupt is supported. */
+		__u64 retarget_device_interrupt:1;
+
+		/* HvCallRestorePartitionTime is supported. */
+		__u64 restore_time:1;
+
+		/* EnlightenedVmcs nested enlightenment is supported. */
+		__u64 enlightened_vmcs:1;
+
+		__u64 reserved:31;
+	} __packed;
+};
+
+#define HV_MAKE_COMPATIBILITY_VERSION(major_, minor_)	\
+	((__u32)((major_) << 8 | (minor_)))
+
+#define HV_COMPATIBILITY_21_H2		HV_MAKE_COMPATIBILITY_VERSION(0X6, 0X9)
+
+union hv_partition_isolation_properties {
+	__u64 as_uint64;
+	struct {
+		__u64 isolation_type: 5;
+		__u64 isolation_host_type : 2;
+		__u64 rsvd_z: 5;
+		__u64 shared_gpa_boundary_page_number: 52;
+	} __packed;
+};
+
+/*
+ * Various isolation types supported by MSHV.
+ */
+#define HV_PARTITION_ISOLATION_TYPE_NONE            0
+#define HV_PARTITION_ISOLATION_TYPE_SNP             2
+#define HV_PARTITION_ISOLATION_TYPE_TDX             3
+
+/*
+ * Various host isolation types supported by MSHV.
+ */
+#define HV_PARTITION_ISOLATION_HOST_TYPE_NONE       0x0
+#define HV_PARTITION_ISOLATION_HOST_TYPE_HARDWARE   0x1
+#define HV_PARTITION_ISOLATION_HOST_TYPE_RESERVED   0x2
+
+/* Note: Exo partition is enabled by default */
+#define HV_PARTITION_CREATION_FLAG_EXO_PARTITION                    (1 << 8)
+#define HV_PARTITION_CREATION_FLAG_LAPIC_ENABLED                    (1 << 13)
+#define HV_PARTITION_CREATION_FLAG_INTERCEPT_MESSAGE_PAGE_ENABLED   (1 << 19)
+#define HV_PARTITION_CREATION_FLAG_X2APIC_CAPABLE                   (1 << 22)
+
+struct hv_input_create_partition {
+	__u64 flags;
+	union hv_proximity_domain_info proximity_domain_info;
+	__u32 compatibility_version;
+	__u32 padding;
+	struct hv_partition_creation_properties partition_creation_properties;
+	union hv_partition_isolation_properties isolation_properties;
+} __packed;
+
+struct hv_output_create_partition {
+	__u64 partition_id;
+} __packed;
+
+struct hv_input_initialize_partition {
+	__u64 partition_id;
+} __packed;
+
+struct hv_input_finalize_partition {
+	__u64 partition_id;
+} __packed;
+
+struct hv_input_delete_partition {
+	__u64 partition_id;
+} __packed;
+
+struct hv_input_get_partition_property {
+	__u64 partition_id;
+	__u32 property_code; /* enum hv_partition_property_code */
+	__u32 padding;
+} __packed;
+
+struct hv_output_get_partition_property {
+	__u64 property_value;
+} __packed;
+
+struct hv_input_set_partition_property {
+	__u64 partition_id;
+	__u32 property_code; /* enum hv_partition_property_code */
+	__u32 padding;
+	__u64 property_value;
+} __packed;
+
+enum hv_vp_state_page_type {
+	HV_VP_STATE_PAGE_REGISTERS = 0,
+	HV_VP_STATE_PAGE_INTERCEPT_MESSAGE = 1,
+	HV_VP_STATE_PAGE_COUNT
+};
+
+struct hv_input_map_vp_state_page {
+	__u64 partition_id;
+	__u32 vp_index;
+	__u32 type; /* enum hv_vp_state_page_type */
+} __packed;
+
+struct hv_output_map_vp_state_page {
+	__u64 map_location; /* GPA page number */
+} __packed;
+
+struct hv_input_unmap_vp_state_page {
+	__u64 partition_id;
+	__u32 vp_index;
+	__u32 type; /* enum hv_vp_state_page_type */
+} __packed;
+
+struct hv_cpuid_leaf_info {
+	__u32 eax;
+	__u32 ecx;
+	__u64 xfem;
+	__u64 xss;
+} __packed;
+
+union hv_get_vp_cpuid_values_flags {
+	__u32 as_uint32;
+	struct {
+		__u32 use_vp_xfem_xss: 1;
+		__u32 apply_registered_values: 1;
+		__u32 reserved: 30;
+	} __packed;
+} __packed;
+
+struct hv_input_get_vp_cpuid_values {
+	__u64 partition_id;
+	__u32 vp_index;
+	union hv_get_vp_cpuid_values_flags flags;
+	__u32 reserved;
+	__u32 padding;
+	struct hv_cpuid_leaf_info cpuid_leaf_info[];
+} __packed;
+
+// NOTE: Not in hvhdk headers
+union hv_output_get_vp_cpuid_values {
+	__u32 as_uint32[4];
+	struct {
+		__u32 eax;
+		__u32 ebx;
+		__u32 ecx;
+		__u32 edx;
+	} __packed;
+};
+
+enum hv_translate_gva_result_code {
+	HV_TRANSLATE_GVA_SUCCESS			= 0,
+
+	/* Translation failures. */
+	HV_TRANSLATE_GVA_PAGE_NOT_PRESENT		= 1,
+	HV_TRANSLATE_GVA_PRIVILEGE_VIOLATION		= 2,
+	HV_TRANSLATE_GVA_INVALID_PAGE_TABLE_FLAGS	= 3,
+
+	/* GPA access failures. */
+	HV_TRANSLATE_GVA_GPA_UNMAPPED			= 4,
+	HV_TRANSLATE_GVA_GPA_NO_READ_ACCESS		= 5,
+	HV_TRANSLATE_GVA_GPA_NO_WRITE_ACCESS		= 6,
+	HV_TRANSLATE_GVA_GPA_ILLEGAL_OVERLAY_ACCESS	= 7,
+
+	/*
+	 * Intercept for memory access by either
+	 *  - a higher VTL
+	 *  - a nested hypervisor (due to a violation of the nested page table)
+	 */
+	HV_TRANSLATE_GVA_INTERCEPT			= 8,
+
+	HV_TRANSLATE_GVA_GPA_UNACCEPTED			= 9,
+};
+
+union hv_translate_gva_result {
+	__u64 as_uint64;
+	struct {
+		__u32 result_code; /* enum hv_translate_hva_result_code */
+		__u32 cache_type : 8;
+		__u32 overlay_page : 1;
+		__u32 reserved : 23;
+	} __packed;
+};
+
+/* Define synthetic interrupt controller flag constants. */
+#define HV_EVENT_FLAGS_COUNT		(256 * 8)
+#define HV_EVENT_FLAGS_BYTE_COUNT	(256)
+#define HV_EVENT_FLAGS_LONG_COUNT	(256 / sizeof(__u32))
+
+struct hv_x64_apic_eoi_message {
+	__u32 vp_index;
+	__u32 interrupt_vector;
+} __packed;
+
+static inline int hv_get_interrupt_vector_from_payload(__u64 payload)
+{
+	struct hv_x64_apic_eoi_message *eoi_msg =
+		(struct hv_x64_apic_eoi_message *)payload;
+
+	return eoi_msg->interrupt_vector;
+}
+
+struct hv_opaque_intercept_message {
+	__u32 vp_index;
+} __packed;
+
+enum hv_port_type {
+	HV_PORT_TYPE_MESSAGE = 1,
+	HV_PORT_TYPE_EVENT   = 2,
+	HV_PORT_TYPE_MONITOR = 3,
+	HV_PORT_TYPE_DOORBELL = 4	/* Root Partition only */
+};
+
+struct hv_port_info {
+	__u32 port_type; /* enum hv_port_type */
+	__u32 padding;
+	union {
+		struct {
+			__u32 target_sint;
+			__u32 target_vp;
+			__u64 rsvdz;
+		} message_port_info;
+		struct {
+			__u32 target_sint;
+			__u32 target_vp;
+			__u16 base_flag_number;
+			__u16 flag_count;
+			__u32 rsvdz;
+		} event_port_info;
+		struct {
+			__u64 monitor_address;
+			__u64 rsvdz;
+		} monitor_port_info;
+		struct {
+			__u32 target_sint;
+			__u32 target_vp;
+			__u64 rsvdz;
+		} doorbell_port_info;
+	};
+} __packed;
+
+struct hv_connection_info {
+	__u32 port_type;
+	__u32 padding;
+	union {
+		struct {
+			__u64 rsvdz;
+		} message_connection_info;
+		struct {
+			__u64 rsvdz;
+		} event_connection_info;
+		struct {
+			__u64 monitor_address;
+		} monitor_connection_info;
+		struct {
+			__u64 gpa;
+			__u64 trigger_value;
+			__u64 flags;
+		} doorbell_connection_info;
+	};
+} __packed;
+
+/* Define the synthetic interrupt controller event flags format. */
+union hv_synic_event_flags {
+	unsigned char flags8[HV_EVENT_FLAGS_BYTE_COUNT];
+	unsigned long flags[HV_EVENT_FLAGS_LONG_COUNT];
+};
+
+struct hv_synic_event_flags_page {
+	union hv_synic_event_flags event_flags[HV_SYNIC_SINT_COUNT];
+};
+
+#define HV_SYNIC_EVENT_RING_MESSAGE_COUNT 63
+
+struct hv_synic_event_ring {
+	__u8  signal_masked;
+	__u8  ring_full;
+	__u16 reserved_z;
+	__u32 data[HV_SYNIC_EVENT_RING_MESSAGE_COUNT];
+} __packed;
+
+struct hv_synic_event_ring_page {
+	struct hv_synic_event_ring sint_event_ring[HV_SYNIC_SINT_COUNT];
+};
+
+union hv_synic_scontrol {
+	__u64 as_uint64;
+	struct {
+		__u64 enable:1;
+		__u64 reserved:63;
+	} __packed;
+};
+
+union hv_synic_siefp {
+	__u64 as_uint64;
+	struct {
+		__u64 siefp_enabled:1;
+		__u64 preserved:11;
+		__u64 base_siefp_gpa:52;
+	} __packed;
+};
+
+union hv_synic_sirbp {
+	__u64 as_uint64;
+	struct {
+		__u64 sirbp_enabled:1;
+		__u64 preserved:11;
+		__u64 base_sirbp_gpa:52;
+	} __packed;
+};
+
+union hv_interrupt_control {
+	__u64 as_uint64;
+	struct {
+		__u32 interrupt_type; /* enum hv_interrupt type */
+		__u32 level_triggered : 1;
+		__u32 logical_dest_mode : 1;
+		__u32 rsvd : 30;
+	} __packed;
+};
+
+struct hv_local_interrupt_controller_state {
+	/* HV_X64_INTERRUPT_CONTROLLER_STATE */
+	__u32 apic_id;
+	__u32 apic_version;
+	__u32 apic_ldr;
+	__u32 apic_dfr;
+	__u32 apic_spurious;
+	__u32 apic_isr[8];
+	__u32 apic_tmr[8];
+	__u32 apic_irr[8];
+	__u32 apic_esr;
+	__u32 apic_icr_high;
+	__u32 apic_icr_low;
+	__u32 apic_lvt_timer;
+	__u32 apic_lvt_thermal;
+	__u32 apic_lvt_perfmon;
+	__u32 apic_lvt_lint0;
+	__u32 apic_lvt_lint1;
+	__u32 apic_lvt_error;
+	__u32 apic_lvt_cmci;
+	__u32 apic_error_status;
+	__u32 apic_initial_count;
+	__u32 apic_counter_value;
+	__u32 apic_divide_configuration;
+	__u32 apic_remote_read;
+} __packed;
+
+struct hv_stimer_state {
+	struct {
+		/*
+		 * Indicates if there is an undelivered timer expiry message.
+		 */
+		__u32 undelivered_msg_pending:1;
+		__u32 reserved:31;
+	} __packed flags;
+
+	__u32 resvd;
+
+	/* Timer configuration and count. */
+	__u64 config;
+	__u64 count;
+
+	/* Timer adjustment. */
+	__u64 adjustment;
+
+	/* Expiration time of the undelivered message. */
+	__u64 undelivered_exp_time;
+} __packed;
+
+struct hv_synthetic_timers_state {
+	struct hv_stimer_state timers[HV_SYNIC_STIMER_COUNT];
+
+	/* Reserved space for time unhalted timer. */
+	__u64 reserved[5];
+} __packed;
+
+union hv_x64_vp_execution_state {
+	__u16 as_uint16;
+	struct {
+		__u16 cpl:2;
+		__u16 cr0_pe:1;
+		__u16 cr0_am:1;
+		__u16 efer_lma:1;
+		__u16 debug_active:1;
+		__u16 interruption_pending:1;
+		__u16 vtl:4;
+		__u16 enclave_mode:1;
+		__u16 interrupt_shadow:1;
+		__u16 virtualization_fault_active:1;
+		__u16 reserved:2;
+	} __packed;
+};
+
+struct hv_x64_intercept_message_header {
+	__u32 vp_index;
+	__u8 instruction_length:4;
+	__u8 cr8:4; /* Only set for exo partitions */
+	__u8 intercept_access_type;
+	union hv_x64_vp_execution_state execution_state;
+	struct hv_x64_segment_register cs_segment;
+	__u64 rip;
+	__u64 rflags;
+} __packed;
+
+#define HV_HYPERCALL_INTERCEPT_MAX_XMM_REGISTERS 6
+
+struct hv_x64_hypercall_intercept_message {
+	struct hv_x64_intercept_message_header header;
+	__u64 rax;
+	__u64 rbx;
+	__u64 rcx;
+	__u64 rdx;
+	__u64 r8;
+	__u64 rsi;
+	__u64 rdi;
+	struct hv_u128 xmmregisters[HV_HYPERCALL_INTERCEPT_MAX_XMM_REGISTERS];
+	struct {
+		__u32 isolated:1;
+		__u32 reserved:31;
+	} __packed;
+} __packed;
+
+union hv_x64_register_access_info {
+	union hv_register_value source_value;
+	__u32 destination_register;
+	__u64 source_address;
+	__u64 destination_address;
+};
+
+struct hv_x64_register_intercept_message {
+	struct hv_x64_intercept_message_header header;
+	struct {
+		__u8 is_memory_op:1;
+		__u8 reserved:7;
+	} __packed;
+	__u8 reserved8;
+	__u16 reserved16;
+	__u32 register_name;
+	union hv_x64_register_access_info access_info;
+} __packed;
+
+union hv_x64_memory_access_info {
+	__u8 as_uint8;
+	struct {
+		__u8 gva_valid:1;
+		__u8 gva_gpa_valid:1;
+		__u8 hypercall_output_pending:1;
+		__u8 tlb_locked_no_overlay:1;
+		__u8 reserved:4;
+	} __packed;
+};
+
+union hv_x64_io_port_access_info {
+	__u8 as_uint8;
+	struct {
+		__u8 access_size:3;
+		__u8 string_op:1;
+		__u8 rep_prefix:1;
+		__u8 reserved:3;
+	} __packed;
+};
+
+union hv_x64_exception_info {
+	__u8 as_uint8;
+	struct {
+		__u8 error_code_valid:1;
+		__u8 software_exception:1;
+		__u8 reserved:6;
+	} __packed;
+};
+
+struct hv_x64_memory_intercept_message {
+	struct hv_x64_intercept_message_header header;
+	__u32 cache_type; /* enum hv_cache_type */
+	__u8 instruction_byte_count;
+	union hv_x64_memory_access_info memory_access_info;
+	__u8 tpr_priority;
+	__u8 reserved1;
+	__u64 guest_virtual_address;
+	__u64 guest_physical_address;
+	__u8 instruction_bytes[16];
+} __packed;
+
+struct hv_x64_cpuid_intercept_message {
+	struct hv_x64_intercept_message_header header;
+	__u64 rax;
+	__u64 rcx;
+	__u64 rdx;
+	__u64 rbx;
+	__u64 default_result_rax;
+	__u64 default_result_rcx;
+	__u64 default_result_rdx;
+	__u64 default_result_rbx;
+} __packed;
+
+struct hv_x64_msr_intercept_message {
+	struct hv_x64_intercept_message_header header;
+	__u32 msr_number;
+	__u32 reserved;
+	__u64 rdx;
+	__u64 rax;
+} __packed;
+
+struct hv_x64_io_port_intercept_message {
+	struct hv_x64_intercept_message_header header;
+	__u16 port_number;
+	union hv_x64_io_port_access_info access_info;
+	__u8 instruction_byte_count;
+	__u32 reserved;
+	__u64 rax;
+	__u8 instruction_bytes[16];
+	struct hv_x64_segment_register ds_segment;
+	struct hv_x64_segment_register es_segment;
+	__u64 rcx;
+	__u64 rsi;
+	__u64 rdi;
+} __packed;
+
+struct hv_x64_exception_intercept_message {
+	struct hv_x64_intercept_message_header header;
+	__u16 exception_vector;
+	union hv_x64_exception_info exception_info;
+	__u8 instruction_byte_count;
+	__u32 error_code;
+	__u64 exception_parameter;
+	__u64 reserved;
+	__u8 instruction_bytes[16];
+	struct hv_x64_segment_register ds_segment;
+	struct hv_x64_segment_register ss_segment;
+	__u64 rax;
+	__u64 rcx;
+	__u64 rdx;
+	__u64 rbx;
+	__u64 rsp;
+	__u64 rbp;
+	__u64 rsi;
+	__u64 rdi;
+	__u64 r8;
+	__u64 r9;
+	__u64 r10;
+	__u64 r11;
+	__u64 r12;
+	__u64 r13;
+	__u64 r14;
+	__u64 r15;
+} __packed;
+
+struct hv_x64_invalid_vp_register_message {
+	__u32 vp_index;
+	__u32 reserved;
+} __packed;
+
+struct hv_x64_unrecoverable_exception_message {
+	struct hv_x64_intercept_message_header header;
+} __packed;
+
+#define HV_UNSUPPORTED_FEATURE_INTERCEPT	1
+#define HV_UNSUPPORTED_FEATURE_TASK_SWITCH_TSS	2
+
+struct hv_x64_unsupported_feature_message {
+	__u32 vp_index;
+	__u32 feature_code;
+	__u64 feature_parameter;
+} __packed;
+
+struct hv_x64_halt_message {
+	struct hv_x64_intercept_message_header header;
+} __packed;
+
+#define HV_X64_PENDING_INTERRUPT	0
+#define HV_X64_PENDING_NMI		2
+#define HV_X64_PENDING_EXCEPTION	3
+
+struct hv_x64_interruption_deliverable_message {
+	struct hv_x64_intercept_message_header header;
+	__u32 deliverable_type; /* pending interruption type */
+	__u32 rsvd;
+} __packed;
+
+struct hv_x64_sint_deliverable_message {
+	struct hv_x64_intercept_message_header header;
+	__u16 deliverable_sints;
+	__u16 rsvd1;
+	__u32 rsvd2;
+} __packed;
+
+struct hv_x64_sipi_intercept_message {
+	struct hv_x64_intercept_message_header header;
+	__u32 target_vp_index;
+	__u32 interrupt_vector;
+} __packed;
+
+struct hv_register_x64_cpuid_result_parameters {
+	struct {
+		__u32 eax;
+		__u32 ecx;
+		__u8 subleaf_specific;
+		__u8 always_override;
+		__u16 padding;
+	} __packed input;
+	struct {
+		__u32 eax;
+		__u32 eax_mask;
+		__u32 ebx;
+		__u32 ebx_mask;
+		__u32 ecx;
+		__u32 ecx_mask;
+		__u32 edx;
+		__u32 edx_mask;
+	} __packed result;
+} __packed;
+
+struct hv_register_x64_msr_result_parameters {
+	__u32 msr_index;
+	__u32 access_type;
+	__u32 action; /* enum hv_unimplemented_msr_action */
+} __packed;
+
+union hv_register_intercept_result_parameters {
+	struct hv_register_x64_cpuid_result_parameters cpuid;
+	struct hv_register_x64_msr_result_parameters msr;
+} __packed;
+
+struct hv_async_completion_message_payload {
+	__u64 partition_id;
+	__u32 status;
+	__u32 completion_count;
+	__u64 sub_status;
+} __packed;
+
+struct hv_input_translate_virtual_address {
+	__u64 partition_id;
+	__u32 vp_index;
+	__u32 padding;
+	__u64 control_flags;
+	__u64 gva_page;
+} __packed;
+
+struct hv_output_translate_virtual_address {
+	union hv_translate_gva_result translation_result;
+	__u64 gpa_page;
+} __packed;
+
+enum hv_cache_type {
+	HV_CACHE_TYPE_UNCACHED		= 0,
+	HV_CACHE_TYPE_WRITE_COMBINING	= 1,
+	HV_CACHE_TYPE_WRITE_THROUGH	= 4,
+	HV_CACHE_TYPE_WRITE_PROTECTED	= 5,
+	HV_CACHE_TYPE_WRITE_BACK	= 6,
+};
+
+#define HV_SUPPORTS_REGISTER_INTERCEPT
+
+struct hv_input_register_intercept_result {
+	__u64 partition_id;
+	__u32 vp_index;
+	__u32 intercept_type; /* enum hv_intercept_type */
+	union hv_register_intercept_result_parameters parameters;
+} __packed;
+
+struct hv_input_assert_virtual_interrupt {
+	__u64 partition_id;
+	union hv_interrupt_control control;
+	__u64 dest_addr; /* cpu's apic id */
+	__u32 vector;
+	__u8 target_vtl;
+	__u8 rsvd_z0;
+	__u16 rsvd_z1;
+} __packed;
+
+struct hv_input_create_port {
+	__u64 port_partition_id;
+	union hv_port_id port_id;
+	__u8 port_vtl;
+	__u8 min_connection_vtl;
+	__u16 padding;
+	__u64 connection_partition_id;
+	struct hv_port_info port_info;
+	union hv_proximity_domain_info proximity_domain_info;
+} __packed;
+
+union hv_input_delete_port {
+	__u64 as_uint64[2];
+	struct {
+		__u64 port_partition_id;
+		union hv_port_id port_id;
+		__u32 reserved;
+	};
+} __packed;
+
+struct hv_input_connect_port {
+	__u64 connection_partition_id;
+	union hv_connection_id connection_id;
+	__u8 connection_vtl;
+	__u8 rsvdz0;
+	__u16 rsvdz1;
+	__u64 port_partition_id;
+	union hv_port_id port_id;
+	__u32 reserved2;
+	struct hv_connection_info connection_info;
+	union hv_proximity_domain_info proximity_domain_info;
+} __packed;
+
+union hv_input_disconnect_port {
+	__u64 as_uint64[2];
+	struct {
+		__u64 connection_partition_id;
+		union hv_connection_id connection_id;
+		__u32 is_doorbell: 1;
+		__u32 reserved: 31;
+	} __packed;
+} __packed;
+
+union hv_input_notify_port_ring_empty {
+	__u64 as_uint64;
+	struct {
+		__u32 sint_index;
+		__u32 reserved;
+	};
+} __packed;
+
+struct hv_input_signal_event_direct {
+	__u64 target_partition;
+	__u32 target_vp;
+	__u8  target_vtl;
+	__u8  target_sint;
+	__u16 flag_number;
+} __packed;
+
+struct hv_output_signal_event_direct {
+	__u8	newly_signaled;
+	__u8	reserved[7];
+} __packed;
+
+struct hv_input_post_message_direct {
+	__u64 partition_id;
+	__u32 vp_index;
+	__u8  vtl;
+	__u8  padding[3];
+	__u32 sint_index;
+	__u8  message[HV_MESSAGE_SIZE];
+	__u32 padding2;
+} __packed;
+
+struct hv_guest_mapping_flush_list { /* HV_INPUT_FLUSH_GUEST_PHYSICAL_ADDRESS_LIST */
+	u64 address_space;
+	u64 flags;
+	union hv_gpa_page_range gpa_list[];
+};
+
+#define HV_SUPPORTS_VP_STATE
+
+struct hv_vp_state_data_xsave {
+	__u64 flags;
+	union hv_x64_xsave_xfem_register states;
+} __packed;
+
+/*
+ * For getting and setting VP state, there are two options based on the state type:
+ *
+ *     1.) Data that is accessed by PFNs in the input hypercall page. This is used
+ *         for state which may not fit into the hypercall pages.
+ *     2.) Data that is accessed directly in the input\output hypercall pages.
+ *         This is used for state that will always fit into the hypercall pages.
+ *
+ * In the future this could be dynamic based on the size if needed.
+ *
+ * Note these hypercalls have an 8-byte aligned variable header size as per the tlfs
+ */
+
+#define HV_GET_SET_VP_STATE_TYPE_PFN	(1 << 31)
+
+enum hv_get_set_vp_state_type {
+	HV_GET_SET_VP_STATE_LOCAL_INTERRUPT_CONTROLLER_STATE = 0 | HV_GET_SET_VP_STATE_TYPE_PFN,
+
+	HV_GET_SET_VP_STATE_XSAVE		= 1 | HV_GET_SET_VP_STATE_TYPE_PFN,
+	/* Synthetic message page */
+	HV_GET_SET_VP_STATE_SIM_PAGE		= 2 | HV_GET_SET_VP_STATE_TYPE_PFN,
+	/* Synthetic interrupt event flags page. */
+	HV_GET_SET_VP_STATE_SIEF_PAGE		= 3 | HV_GET_SET_VP_STATE_TYPE_PFN,
+
+	/* Synthetic timers. */
+	HV_GET_SET_VP_STATE_SYNTHETIC_TIMERS	= 4,
+};
+
+struct hv_vp_state_data {
+	__u32 type;
+	__u32 rsvd;
+	struct hv_vp_state_data_xsave xsave;
+} __packed;
+
+struct hv_input_get_vp_state {
+	__u64 partition_id;
+	__u32 vp_index;
+	__u8 input_vtl;
+	__u8 rsvd0;
+	__u16 rsvd1;
+	struct hv_vp_state_data state_data;
+	__u64 output_data_pfns[];
+} __packed;
+
+union hv_output_get_vp_state {
+	struct hv_local_interrupt_controller_state interrupt_controller_state;
+	struct hv_synthetic_timers_state synthetic_timers_state;
+} __packed;
+
+union hv_input_set_vp_state_data {
+	__u64 pfns;
+	__u8 bytes;
+} __packed;
+
+struct hv_input_set_vp_state {
+	__u64 partition_id;
+	__u32 vp_index;
+	__u8 input_vtl;
+	__u8 rsvd0;
+	__u16 rsvd1;
+	struct hv_vp_state_data state_data;
+	union hv_input_set_vp_state_data data[];
+} __packed;
+
+/*
+ * Dispatch state for the VP communicated by the hypervisor to the
+ * VP-dispatching thread in the root on return from HVCALL_DISPATCH_VP.
+ */
+enum hv_vp_dispatch_state {
+	HV_VP_DISPATCH_STATE_INVALID = 0,
+	HV_VP_DISPATCH_STATE_BLOCKED = 1,
+	HV_VP_DISPATCH_STATE_READY = 2,
+};
+
+/*
+ * Dispatch event that caused the current dispatch state on return from
+ * HVCALL_DISPATCH_VP.
+ */
+enum hv_vp_dispatch_event {
+	HV_VP_DISPATCH_EVENT_INVALID =	0x00000000,
+	HV_VP_DISPATCH_EVENT_SUSPEND = 0x00000001,
+	HV_VP_DISPATCH_EVENT_INTERCEPT = 0x00000002,
+};
+
+#define HV_ROOT_SCHEDULER_MAX_VPS_PER_CHILD_PARTITION   1024
+/* The maximum array size of HV_GENERIC_SET (vp_set) buffer */
+#define HV_GENERIC_SET_QWORD_COUNT(max) (((((max) - 1) >> 6) + 1) + 2)
+
+struct hv_vp_signal_bitset_scheduler_message {
+	__u64 partition_id;
+	__u32 overflow_count;
+	__u16 vp_count;
+	__u16 reserved;
+
+#define BITSET_BUFFER_SIZE \
+	HV_GENERIC_SET_QWORD_COUNT(HV_ROOT_SCHEDULER_MAX_VPS_PER_CHILD_PARTITION)
+	union {
+		struct hv_vpset bitset;
+		__u64 bitset_buffer[BITSET_BUFFER_SIZE];
+	} vp_bitset;
+#undef BITSET_BUFFER_SIZE
+} __packed;
+
+#if defined(__KERNEL__)
+static_assert(sizeof(struct hv_vp_signal_bitset_scheduler_message) <=
+	(sizeof(struct hv_message) - sizeof(struct hv_message_header)));
+#endif
+
+#define HV_MESSAGE_MAX_PARTITION_VP_PAIR_COUNT \
+	(((sizeof(struct hv_message) - sizeof(struct hv_message_header)) / \
+	 (sizeof(__u64 /* partition id */) + sizeof(__u32 /* vp index */))) - 1)
+
+struct hv_vp_signal_pair_scheduler_message {
+	__u32 overflow_count;
+	__u8 vp_count;
+	__u8 reserved1[3];
+
+	__u64 partition_ids[HV_MESSAGE_MAX_PARTITION_VP_PAIR_COUNT];
+	__u32 vp_indexes[HV_MESSAGE_MAX_PARTITION_VP_PAIR_COUNT];
+
+	__u8 reserved2[4];
+} __packed;
+
+#if defined(__KERNEL__)
+static_assert(sizeof(struct hv_vp_signal_pair_scheduler_message) ==
+	(sizeof(struct hv_message) - sizeof(struct hv_message_header)));
+#endif
+
+/* Input and output structures for HVCALL_DISPATCH_VP */
+#define HV_DISPATCH_VP_FLAG_CLEAR_INTERCEPT_SUSPEND 0x1
+#define HV_DISPATCH_VP_FLAG_ENABLE_CALLER_INTERRUPTS 0x2
+#define HV_DISPATCH_VP_FLAG_SET_CALLER_SPEC_CTRL 0x4
+#define HV_DISPATCH_VP_FLAG_SKIP_VP_SPEC_FLUSH 0x8
+#define HV_DISPATCH_VP_FLAG_SKIP_CALLER_SPEC_FLUSH 0x10
+#define HV_DISPATCH_VP_FLAG_SKIP_CALLER_USER_SPEC_FLUSH 0x20
+
+struct hv_input_dispatch_vp {
+	__u64 partition_id;
+	__u32 vp_index;
+	__u32 flags;
+	__u64 time_slice; /* in 100ns */
+	__u64 spec_ctrl;
+} __packed;
+
+struct hv_output_dispatch_vp {
+	__u32 dispatch_state; /* enum hv_vp_dispatch_state */
+	__u32 dispatch_event; /* enum hv_vp_dispatch_event */
+} __packed;
+
+#endif /* _UAPI_HV_HVHDK_H */
diff --git a/include/uapi/hyperv/hvhdk_mini.h b/include/uapi/hyperv/hvhdk_mini.h
new file mode 100644
index 000000000000..c1c1cae127e5
--- /dev/null
+++ b/include/uapi/hyperv/hvhdk_mini.h
@@ -0,0 +1,164 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright (c) 2023, Microsoft Corporation.
+ *
+ * These files (hvhdk.h, hvhdk_mini.h, hvgdk.h, hvgdk_mini.h) define APIs for
+ * communicating with the Microsoft Hypervisor.
+ *
+ * These definitions are subject to change across hypervisor versions, and as
+ * such are separate and independent from hyperv-tlfs.h.
+ *
+ * The naming of these headers reflects conventions used in the Microsoft
+ * Hypervisor.
+ */
+#ifndef _UAPI_HV_HVHDK_MINI_H
+#define _UAPI_HV_HVHDK_MINI_H
+
+#include "hvgdk_mini.h"
+
+/*
+ * Doorbell connection_info flags.
+ */
+#define HV_DOORBELL_FLAG_TRIGGER_SIZE_MASK  0x00000007
+#define HV_DOORBELL_FLAG_TRIGGER_SIZE_ANY   0x00000000
+#define HV_DOORBELL_FLAG_TRIGGER_SIZE_BYTE  0x00000001
+#define HV_DOORBELL_FLAG_TRIGGER_SIZE_WORD  0x00000002
+#define HV_DOORBELL_FLAG_TRIGGER_SIZE_DWORD 0x00000003
+#define HV_DOORBELL_FLAG_TRIGGER_SIZE_QWORD 0x00000004
+#define HV_DOORBELL_FLAG_TRIGGER_ANY_VALUE  0x80000000
+
+/* Each generic set contains 64 elements */
+#define HV_GENERIC_SET_SHIFT		(6)
+#define HV_GENERIC_SET_MASK		(63)
+
+enum hv_generic_set_format {
+	HV_GENERIC_SET_SPARSE_4K,
+	HV_GENERIC_SET_ALL,
+};
+
+
+/* NOTE: following two #defines are not defined in Hyper-V code */
+/* The maximum number of sparse vCPU banks which can be encoded by 'struct hv_vpset' */
+#define HV_MAX_SPARSE_VCPU_BANKS (64)
+/* The number of vCPUs in one sparse bank */
+#define HV_VCPUS_PER_SPARSE_BANK (64)
+
+enum hv_scheduler_type {
+	HV_SCHEDULER_TYPE_LP = 1, /* Classic scheduler w/o SMT */
+	HV_SCHEDULER_TYPE_LP_SMT = 2, /* Classic scheduler w/ SMT */
+	HV_SCHEDULER_TYPE_CORE_SMT = 3, /* Core scheduler */
+	HV_SCHEDULER_TYPE_ROOT = 4, /* Root / integrated scheduler */
+	HV_SCHEDULER_TYPE_MAX
+};
+
+struct hv_vpset {		/* HV_VP_SET */
+	__u64 format;
+	__u64 valid_bank_mask;
+	__u64 bank_contents[];
+} __packed;
+
+enum hv_partition_property_code {
+	/* Privilege properties */
+	HV_PARTITION_PROPERTY_PRIVILEGE_FLAGS				= 0x00010000,
+	HV_PARTITION_PROPERTY_SYNTHETIC_PROC_FEATURES			= 0x00010001,
+
+	/* Resource properties */
+	HV_PARTITION_PROPERTY_GPA_PAGE_ACCESS_TRACKING			= 0x00050005,
+	HV_PARTITION_PROPERTY_ISOLATION_STATE				= 0x0005000c,
+	HV_PARTITION_PROPERTY_UNIMPLEMENTED_MSR_ACTION                  = 0x00050017,
+
+	/* Compatibility properties */
+	HV_PARTITION_PROPERTY_PROCESSOR_XSAVE_FEATURES			= 0x00060002,
+	HV_PARTITION_PROPERTY_MAX_XSAVE_DATA_SIZE			= 0x00060008,
+	HV_PARTITION_PROPERTY_PROCESSOR_CLOCK_FREQUENCY			= 0x00060009,
+};
+
+enum hv_system_property {
+	/* Add more values when needed */
+	HV_SYSTEM_PROPERTY_SCHEDULER_TYPE = 15,
+};
+struct hv_input_get_system_property {
+	__u32 property_id; /* enum hv_system_property */
+	union {
+		__u32 as_uint32;
+		/* More fields to be filled in when needed */
+	};
+} __packed;
+
+struct hv_output_get_system_property {
+	union {
+		__u32 scheduler_type; /* enum hv_scheduler_type */
+	};
+} __packed;
+
+struct hv_proximity_domain_flags {
+	__u32 proximity_preferred : 1;
+	__u32 reserved : 30;
+	__u32 proximity_info_valid : 1;
+} __packed;
+
+/* Not a union in windows but useful for zeroing */
+union hv_proximity_domain_info {
+	struct {
+		__u32 domain_id;
+		struct hv_proximity_domain_flags flags;
+	};
+	__u64 as_uint64;
+} __packed;
+
+struct hv_input_withdraw_memory {
+	__u64 partition_id;
+	union hv_proximity_domain_info proximity_domain_info;
+} __packed;
+
+struct hv_output_withdraw_memory {
+	/* Hack - compiler doesn't like empty array size
+	 * in struct with no other members
+	 */
+	__u64 gpa_page_list[0];
+} __packed;
+
+/* HV Map GPA (Guest Physical Address) Flags */
+#define HV_MAP_GPA_PERMISSIONS_NONE     0x0
+#define HV_MAP_GPA_READABLE             0x1
+#define HV_MAP_GPA_WRITABLE             0x2
+#define HV_MAP_GPA_KERNEL_EXECUTABLE    0x4
+#define HV_MAP_GPA_USER_EXECUTABLE      0x8
+#define HV_MAP_GPA_EXECUTABLE           0xC
+#define HV_MAP_GPA_PERMISSIONS_MASK     0xF
+
+struct hv_input_map_gpa_pages {
+	__u64 target_partition_id;
+	__u64 target_gpa_base;
+	__u32 map_flags;
+	__u32 padding;
+	__u64 source_gpa_page_list[];
+} __packed;
+
+union hv_gpa_page_access_state_flags {
+	struct {
+		__u64 clear_accessed : 1;
+		__u64 set_access : 1;
+		__u64 clear_dirty : 1;
+		__u64 set_dirty : 1;
+		__u64 reserved : 60;
+	} __packed;
+	__u64 as_uint64;
+};
+
+struct hv_input_get_gpa_pages_access_state {
+	__u64  partition_id;
+	union hv_gpa_page_access_state_flags flags;
+	__u64 hv_gpa_page_number;
+} __packed;
+
+union hv_gpa_page_access_state {
+	struct {
+		__u8 accessed : 1;
+		__u8 dirty : 1;
+		__u8 reserved: 6;
+	};
+	__u8 as_uint8;
+} __packed;
+
+#endif /* _UAPI_HV_HVHDK_MINI_H */
-- 
2.25.1

[PATCH v2 14/15] asm-generic: hyperv: Use mshv headers conditionally. Add asm-generic/hyperv-defs.h

[Nuno Das Neves]

Add hyperv-defs.h to replace some inclusions of hyperv-tlfs.h.

It includes hyperv-tlfs.h or hvhdk.h depending on a compile-time constant
HV_HYPERV_DEFS which will be defined in the mshv driver.

This is needed to keep unstable Hyper-V interfaces independent of
hyperv-tlfs.h. This ensures hvhdk.h replaces hyperv-tlfs.h in the mshv driver,
even via indirect includes.

Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
---
 arch/arm64/include/asm/mshyperv.h |  2 +-
 arch/x86/include/asm/mshyperv.h   |  3 +--
 drivers/hv/hyperv_vmbus.h         |  1 -
 include/asm-generic/hyperv-defs.h | 26 ++++++++++++++++++++++++++
 include/asm-generic/mshyperv.h    |  2 +-
 include/linux/hyperv.h            |  2 +-
 6 files changed, 30 insertions(+), 6 deletions(-)
 create mode 100644 include/asm-generic/hyperv-defs.h

diff --git a/arch/arm64/include/asm/mshyperv.h b/arch/arm64/include/asm/mshyperv.h
index 20070a847304..8ec14caf3d4f 100644
--- a/arch/arm64/include/asm/mshyperv.h
+++ b/arch/arm64/include/asm/mshyperv.h
@@ -20,7 +20,7 @@
 
 #include <linux/types.h>
 #include <linux/arm-smccc.h>
-#include <asm/hyperv-tlfs.h>
+#include <asm-generic/hyperv-defs.h>
 
 /*
  * Declare calls to get and set Hyper-V VP register values on ARM64, which
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 79ffc7913016..c009e9c71445 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -6,10 +6,9 @@
 #include <linux/nmi.h>
 #include <linux/msi.h>
 #include <asm/io.h>
-#include <asm/hyperv-tlfs.h>
 #include <asm/nospec-branch.h>
 #include <asm/paravirt.h>
-#include <asm/mshyperv.h>
+#include <asm-generic/hyperv-defs.h>
 
 /*
  * Hyper-V always provides a single IO-APIC at this MMIO address.
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 85f3c08bb42b..49529f0b8b99 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -15,7 +15,6 @@
 #include <linux/list.h>
 #include <linux/bitops.h>
 #include <asm/sync_bitops.h>
-#include <asm/hyperv-tlfs.h>
 #include <linux/atomic.h>
 #include <linux/hyperv.h>
 #include <linux/interrupt.h>
diff --git a/include/asm-generic/hyperv-defs.h b/include/asm-generic/hyperv-defs.h
new file mode 100644
index 000000000000..ac6fcba35c8c
--- /dev/null
+++ b/include/asm-generic/hyperv-defs.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_GENERIC_HYPERV_DEFS_H
+#define _ASM_GENERIC_HYPERV_DEFS_H
+
+/*
+ * There are cases where Microsoft Hypervisor ABIs are needed which may not be
+ * stable or present in the Hyper-V TLFS document. E.g. the mshv_root driver.
+ *
+ * As these interfaces are unstable and may differ from hyperv-tlfs.h, they
+ * must be kept separate and independent.
+ *
+ * However, code from files that depend on hyperv-tlfs.h (such as mshyperv.h)
+ * is still needed, so work around the issue by conditionally including the
+ * correct definitions.
+ *
+ * Note: Since they are independent of each other, there are many definitions
+ * duplicated in both hyperv-tlfs.h and uapi/hyperv/hv*.h files.
+ */
+#ifdef HV_HYPERV_DEFS
+#include <uapi/hyperv/hvhdk.h>
+#else
+#include <asm/hyperv-tlfs.h>
+#endif
+
+#endif /* _ASM_GENERIC_HYPERV_DEFS_H */
+
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index 2b20994d809e..e86b6f51fb64 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -25,7 +25,7 @@
 #include <linux/cpumask.h>
 #include <linux/nmi.h>
 #include <asm/ptrace.h>
-#include <asm/hyperv-tlfs.h>
+#include <asm-generic/hyperv-defs.h>
 
 #define VTPM_BASE_ADDRESS 0xfed40000
 
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index f90de5abcd50..66ed8b3e5d89 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -24,7 +24,7 @@
 #include <linux/mod_devicetable.h>
 #include <linux/interrupt.h>
 #include <linux/reciprocal_div.h>
-#include <asm/hyperv-tlfs.h>
+#include <asm-generic/hyperv-defs.h>
 
 #define MAX_PAGE_BUFFER_COUNT				32
 #define MAX_MULTIPAGE_BUFFER_COUNT			32 /* 128K */
-- 
2.25.1

Re: [PATCH v2 13/15] uapi: hyperv: Add mshv driver headers hvhdk.h, hvhdk_mini.h, hvgdk.h, hvgdk_mini.h

[Wei Liu]

On Thu, Aug 17, 2023 at 03:01:49PM -0700, Nuno Das Neves wrote:
> Containing hypervisor ABI definitions to use in mshv driver.
> 
> Version numbers for each file:
> hvhdk.h		25212
> hvhdk_mini.h	25294
> hvgdk.h		25125
> hvgdk_mini.h	25294
> 
> These are unstable interfaces and as such must be compiled independently
> from published interfaces found in hyperv-tlfs.h.
> 
> These are in uapi because they will be used in the mshv ioctl API.
> 
> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
> Acked-by: Wei Liu <wei.liu@kernel.org>

There were some concerns raised internally about the stability of the
APIs when they are put into UAPI.

I think this is still okay, for a few reasons:

  1. When KVM was first introduced into the kernel tree, it was
     experimental. It was only made stable after some time.
  2. There are other experimental or unstable APIs in UAPI. They
     are clearly marked so.
  3. The coda file system, which has been in tree since 2008, has a
     header file in UAPI which clearly marks as experimental.

All in all introducing a set of unstable / experimental APIs under UAPI
is not unheard of. Rules could've changed now, but I don't find any
document under Documentation/.

I think it will be valuable to have this driver in tree sooner rather
than later, so that it can evolve with Linux kernel, and we can in turn
go back to the hypervisor side to gradually stabilize the APIs.

Greg, I'm told that you may have a strong opinion in this area. Please
let me know what you think about this.

KY, do you have an opinion here?

Thanks,
Wei.

Re: [PATCH v2 02/15] mshyperv: Introduce hv_get_hypervisor_version function

[Dave Hansen]

On 8/17/23 15:01, Nuno Das Neves wrote:
> +int hv_get_hypervisor_version(union hv_hypervisor_version_info *info)
> +{
> +	hv_get_vpreg_128(HV_REGISTER_HYPERVISOR_VERSION,
> +			 (struct hv_get_vp_registers_output *)info);
> +
> +	return 0;
> +}
...
> +int hv_get_hypervisor_version(union hv_hypervisor_version_info *info)
> +{
> +	unsigned int hv_max_functions;
> +
> +	hv_max_functions = cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS);
> +	if (hv_max_functions < HYPERV_CPUID_VERSION) {
> +		pr_err("%s: Could not detect Hyper-V version\n",
> +			__func__);
> +		return -ENODEV;
> +	}
> +
> +	info->eax = cpuid_eax(HYPERV_CPUID_VERSION);
> +	info->ebx = cpuid_ebx(HYPERV_CPUID_VERSION);
> +	info->ecx = cpuid_ecx(HYPERV_CPUID_VERSION);
> +	info->edx = cpuid_edx(HYPERV_CPUID_VERSION);
> +
> +	return 0;
> +}

I can't help but notice that the ARM version does *one* call to the
hardware while the x86 version does CPUID four different times, once to
get *EACH* register and throwing away the other three registers each
time.  Also recall that CPUID is a big, fat architecturally serializing
instruction.  This isn't a fast path, but CPUID is about as slow as you get.

Is there any reason you can't just have an x86 version of
hv_get_vpreg_128() that gets the 128 bits bytes of data that comes back
in the 4 CPUID registers?

That might even let you share some more code.

Re: [PATCH v2 03/15] mshyperv: Introduce numa_node_to_proximity_domain_info

[Dave Hansen]

On 8/17/23 15:01, Nuno Das Neves wrote:
> +static inline union hv_proximity_domain_info
> +numa_node_to_proximity_domain_info(int node)
> +{
> +	union hv_proximity_domain_info proximity_domain_info;
> +
> +	if (node != NUMA_NO_NODE) {
> +		proximity_domain_info.domain_id = node_to_pxm(node);
> +		proximity_domain_info.flags.reserved = 0;
> +		proximity_domain_info.flags.proximity_info_valid = 1;
> +		proximity_domain_info.flags.proximity_preferred = 1;
> +	} else {
> +		proximity_domain_info.as_uint64 = 0;
> +	}
> +
> +	return proximity_domain_info;
> +}

Pop quiz: What are the rules for the 30 bits of uninitialized data of
proximity_domain_info.flags in the (node != NUMA_NO_NODE) case?

I actually don't know off the top of my head.  I generally avoid
bitfields, but if they were normal stack-allocated variable space,
they'd be garbage.

I'd also *much* rather see the "as_uint64 = 0" coded up as a memset() or
even explicitly zeroing all the same variables as the other half of the
if().  As it stands, it's not 100% obvious that proximity_domain_info is
64 bits and that .as_uint64=0 zeroes the whole thing.  It *WOULD* be
totally obvious if it were a memset().

Re: [PATCH v2 02/15] mshyperv: Introduce hv_get_hypervisor_version function

[Nuno Das Neves]

On 8/17/2023 4:14 PM, Dave Hansen wrote:
> On 8/17/23 15:01, Nuno Das Neves wrote:
>> +int hv_get_hypervisor_version(union hv_hypervisor_version_info *info)
>> +{
>> +	hv_get_vpreg_128(HV_REGISTER_HYPERVISOR_VERSION,
>> +			 (struct hv_get_vp_registers_output *)info);
>> +
>> +	return 0;
>> +}
> ...
>> +int hv_get_hypervisor_version(union hv_hypervisor_version_info *info)
>> +{
>> +	unsigned int hv_max_functions;
>> +
>> +	hv_max_functions = cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS);
>> +	if (hv_max_functions < HYPERV_CPUID_VERSION) {
>> +		pr_err("%s: Could not detect Hyper-V version\n",
>> +			__func__);
>> +		return -ENODEV;
>> +	}
>> +
>> +	info->eax = cpuid_eax(HYPERV_CPUID_VERSION);
>> +	info->ebx = cpuid_ebx(HYPERV_CPUID_VERSION);
>> +	info->ecx = cpuid_ecx(HYPERV_CPUID_VERSION);
>> +	info->edx = cpuid_edx(HYPERV_CPUID_VERSION);
>> +
>> +	return 0;
>> +}
> 
> I can't help but notice that the ARM version does *one* call to the
> hardware while the x86 version does CPUID four different times, once to
> get *EACH* register and throwing away the other three registers each
> time.  Also recall that CPUID is a big, fat architecturally serializing
> instruction.  This isn't a fast path, but CPUID is about as slow as you get.
> 

Good point, it is quite wasteful. I just went and checked cpuid.h, and of
course there is a generic cpuid() function that can get all 4 at once.
I will update it to use this in the next version. Thanks!

> Is there any reason you can't just have an x86 version of
> hv_get_vpreg_128() that gets the 128 bits bytes of data that comes back
> in the 4 CPUID registers?
> 
> That might even let you share some more code.

Unfortunately, for some reason the hypervisor only lets you get this data via
CPUID on x86_64, and via hypercall - i.e. hv_get_vpreg_128() - on ARM64.

Re: [PATCH v2 03/15] mshyperv: Introduce numa_node_to_proximity_domain_info

[Nuno Das Neves]

On 8/17/2023 4:22 PM, Dave Hansen wrote:
> On 8/17/23 15:01, Nuno Das Neves wrote:
>> +static inline union hv_proximity_domain_info
>> +numa_node_to_proximity_domain_info(int node)
>> +{
>> +	union hv_proximity_domain_info proximity_domain_info;
>> +
>> +	if (node != NUMA_NO_NODE) {
>> +		proximity_domain_info.domain_id = node_to_pxm(node);
>> +		proximity_domain_info.flags.reserved = 0;
>> +		proximity_domain_info.flags.proximity_info_valid = 1;
>> +		proximity_domain_info.flags.proximity_preferred = 1;
>> +	} else {
>> +		proximity_domain_info.as_uint64 = 0;
>> +	}
>> +
>> +	return proximity_domain_info;
>> +}
> 
> Pop quiz: What are the rules for the 30 bits of uninitialized data of
> proximity_domain_info.flags in the (node != NUMA_NO_NODE) case?
> 
> I actually don't know off the top of my head.  I generally avoid
> bitfields, but if they were normal stack-allocated variable space,
> they'd be garbage.

I'm not sure what you are getting at here - all the fields are
initialized.

> 
> I'd also *much* rather see the "as_uint64 = 0" coded up as a memset() or
> even explicitly zeroing all the same variables as the other half of the
> if().  As it stands, it's not 100% obvious that proximity_domain_info is
> 64 bits and that .as_uint64=0 zeroes the whole thing.  It *WOULD* be
> totally obvious if it were a memset().

I agree that it could be made clearer with memset().
Now that I'm thinking about it, hv_proximity_domain_info should really
just be a struct...then zeroing it is just:

	struct hv_proximity_domain_info proximity_domain_info = {};

and I can remove the else branch and zeroing the reserved bits.

Re: [PATCH v2 03/15] mshyperv: Introduce numa_node_to_proximity_domain_info

[Dave Hansen]

On 8/17/23 17:17, Nuno Das Neves wrote:
>>> +	if (node != NUMA_NO_NODE) {
>>> +		proximity_domain_info.domain_id = node_to_pxm(node);
>>> +		proximity_domain_info.flags.reserved = 0;
>>> +		proximity_domain_info.flags.proximity_info_valid = 1;
>>> +		proximity_domain_info.flags.proximity_preferred = 1;
>>> +	} else {
>>> +		proximity_domain_info.as_uint64 = 0;
>>> +	}
>>> +
>>> +	return proximity_domain_info;
>>> +}
>> Pop quiz: What are the rules for the 30 bits of uninitialized data of
>> proximity_domain_info.flags in the (node != NUMA_NO_NODE) case?
>>
>> I actually don't know off the top of my head.  I generally avoid
>> bitfields, but if they were normal stack-allocated variable space,
>> they'd be garbage.
> I'm not sure what you are getting at here - all the fields are
> initialized.

Whoops, I somehow missed the reserved field initialization.  But, yeah,
a struct would be nice instead of the union here.

RE: [PATCH v2 15/15] Drivers: hv: Add modules to expose /dev/mshv to VMMs running on Hyper-V

[Saurabh Singh Sengar]

> -----Original Message-----
> From: Nuno Das Neves <nunodasneves@linux.microsoft.com>
> Sent: Friday, August 18, 2023 3:32 AM
> To: linux-hyperv@vger.kernel.org; linux-kernel@vger.kernel.org;
> x86@kernel.org; linux-arm-kernel@lists.infradead.org; linux-
> arch@vger.kernel.org
> Cc: patches@lists.linux.dev; Michael Kelley (LINUX)
> <mikelley@microsoft.com>; KY Srinivasan <kys@microsoft.com>;
> wei.liu@kernel.org; Haiyang Zhang <haiyangz@microsoft.com>; Dexuan Cui
> <decui@microsoft.com>; apais@linux.microsoft.com; Tianyu Lan
> <Tianyu.Lan@microsoft.com>; ssengar@linux.microsoft.com; MUKESH
> RATHOR <mukeshrathor@microsoft.com>; stanislav.kinsburskiy@gmail.com;
> jinankjain@linux.microsoft.com; vkuznets <vkuznets@redhat.com>;
> tglx@linutronix.de; mingo@redhat.com; bp@alien8.de;
> dave.hansen@linux.intel.com; hpa@zytor.com; will@kernel.org;
> catalin.marinas@arm.com
> Subject: [PATCH v2 15/15] Drivers: hv: Add modules to expose /dev/mshv to
> VMMs running on Hyper-V
> 
> Add mshv, mshv_root, and mshv_vtl modules:
> 
> Module mshv is the parent module to the other two. It provides /dev/mshv,
> plus
> some common hypercall helper code. When one of the child modules is
> loaded, it
> is registered with the mshv module, which then provides entry point(s) to the
> child module via the IOCTLs defined in uapi/linux/mshv.h.
> 
> E.g. When the mshv_root module is loaded, it registers itself, and the
> MSHV_CREATE_PARTITION IOCTL becomes available in /dev/mshv. That is
> used to
> get a partition fd managed by mshv_root.
> 
> Similarly for mshv_vtl module, there is MSHV_CREATE_VTL, which creates
> an fd representing the lower vtl, managed by mshv_vtl.
> 
> Module mshv_root provides APIs for creating and managing child partitions.
> It
> defines abstractions for partitions (vms), vps (vcpus), and other things
> related to running a guest. It exposes the userspace interfaces for a VMM to
> manage the guest.
> 
> Module mshv_vtl provides VTL (Virtual Trust Level) support for VMMs. In
> this scenario, the host kernel and VMM run in a higher trust level than the
> guest, but within the same partition. This provides better isolation and
> performance.
> 
> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
> ---
>  drivers/hv/Kconfig             |   50 +
>  drivers/hv/Makefile            |   20 +
>  drivers/hv/hv_call.c           |  119 ++
>  drivers/hv/hv_common.c         |    4 +
>  drivers/hv/mshv.h              |  156 +++
>  drivers/hv/mshv_eventfd.c      |  758 ++++++++++++
>  drivers/hv/mshv_eventfd.h      |   80 ++
>  drivers/hv/mshv_main.c         |  208 ++++
>  drivers/hv/mshv_msi.c          |  129 +++
>  drivers/hv/mshv_portid_table.c |   84 ++
>  drivers/hv/mshv_root.h         |  194 ++++
>  drivers/hv/mshv_root_hv_call.c | 1064 +++++++++++++++++
>  drivers/hv/mshv_root_main.c    | 1964
> ++++++++++++++++++++++++++++++++
>  drivers/hv/mshv_synic.c        |  689 +++++++++++
>  drivers/hv/mshv_vtl.h          |   52 +
>  drivers/hv/mshv_vtl_main.c     | 1542 +++++++++++++++++++++++++
>  drivers/hv/xfer_to_guest.c     |   28 +
>  include/uapi/linux/mshv.h      |  298 +++++
>  18 files changed, 7439 insertions(+)
>  create mode 100644 drivers/hv/hv_call.c
>  create mode 100644 drivers/hv/mshv.h
>  create mode 100644 drivers/hv/mshv_eventfd.c
>  create mode 100644 drivers/hv/mshv_eventfd.h
>  create mode 100644 drivers/hv/mshv_main.c
>  create mode 100644 drivers/hv/mshv_msi.c
>  create mode 100644 drivers/hv/mshv_portid_table.c
>  create mode 100644 drivers/hv/mshv_root.h
>  create mode 100644 drivers/hv/mshv_root_hv_call.c
>  create mode 100644 drivers/hv/mshv_root_main.c
>  create mode 100644 drivers/hv/mshv_synic.c
>  create mode 100644 drivers/hv/mshv_vtl.h
>  create mode 100644 drivers/hv/mshv_vtl_main.c
>  create mode 100644 drivers/hv/xfer_to_guest.c
>  create mode 100644 include/uapi/linux/mshv.h
> 
> diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig
> index 00242107d62e..0d9aefc07b15 100644
> --- a/drivers/hv/Kconfig
> +++ b/drivers/hv/Kconfig
> @@ -54,4 +54,54 @@ config HYPERV_BALLOON
>  	help
>  	  Select this option to enable Hyper-V Balloon driver.
> 
> +config MSHV
> +	tristate "Microsoft Hypervisor root partition interfaces: /dev/mshv"
> +	depends on X86_64 && HYPERV
> +	select EVENTFD
> +	select MSHV_XFER_TO_GUEST_WORK
> +	help
> +	  Select this option to enable core functionality for managing guest
> +	  virtual machines running under the Microsoft Hypervisor.
> +
> +	  The interfaces are provided via a device named /dev/mshv.
> +
> +	  To compile this as a module, choose M here.
> +
> +	  If unsure, say N.
> +
> +config MSHV_ROOT
> +	tristate "Microsoft Hyper-V root partition APIs driver"
> +	depends on MSHV
> +	help
> +	  Select this option to provide /dev/mshv interfaces specific to
> +	  running as the root partition on Microsoft Hypervisor.
> +
> +	  To compile this as a module, choose M here.
> +
> +	  If unsure, say N.
> +
> +config MSHV_VTL
> +	tristate "Microsoft Hyper-V VTL driver"
> +	depends on MSHV
> +	select HYPERV_VTL_MODE
> +	select TRANSPARENT_HUGEPAGE

TRANSPARENT_HUGEPAGE can be avoided for now.

> +	help
> +	  Select this option to enable Hyper-V VTL driver.
> +	  Virtual Secure Mode (VSM) is a set of hypervisor capabilities and
> +	  enlightenments offered to host and guest partitions which enables
> +	  the creation and management of new security boundaries within
> +	  operating system software.
> +
> +	  VSM achieves and maintains isolation through Virtual Trust Levels
> +	  (VTLs). Virtual Trust Levels are hierarchical, with higher levels
> +	  being more privileged than lower levels. VTL0 is the least privileged
> +	  level, and currently only other level supported is VTL2.
> +
> +	  To compile this as a module, choose M here.
> +
> +	  If unsure, say N.
> +
> +config MSHV_XFER_TO_GUEST_WORK
> +	bool
> +
>  endmenu
> diff --git a/drivers/hv/Makefile b/drivers/hv/Makefile
> index d76df5c8c2a9..da7aa7542b05 100644
> --- a/drivers/hv/Makefile
> +++ b/drivers/hv/Makefile
> @@ -2,10 +2,30 @@
>  obj-$(CONFIG_HYPERV)		+= hv_vmbus.o
>  obj-$(CONFIG_HYPERV_UTILS)	+= hv_utils.o
>  obj-$(CONFIG_HYPERV_BALLOON)	+= hv_balloon.o
> +obj-$(CONFIG_MSHV)			+= mshv.o
> +obj-$(CONFIG_MSHV_VTL)		+= mshv_vtl.o
> +obj-$(CONFIG_MSHV_ROOT)		+= mshv_root.o
> 
>  CFLAGS_hv_trace.o = -I$(src)
>  CFLAGS_hv_balloon.o = -I$(src)
> 
> +CFLAGS_mshv_main.o			= -DHV_HYPERV_DEFS
> +CFLAGS_hv_call.o			= -DHV_HYPERV_DEFS
> +CFLAGS_mshv_root_main.o		= -DHV_HYPERV_DEFS
> +CFLAGS_mshv_root_hv_call.o	= -DHV_HYPERV_DEFS
> +CFLAGS_mshv_synic.o			= -DHV_HYPERV_DEFS
> +CFLAGS_mshv_portid_table.o	= -DHV_HYPERV_DEFS
> +CFLAGS_mshv_eventfd.o		= -DHV_HYPERV_DEFS
> +CFLAGS_mshv_msi.o			= -DHV_HYPERV_DEFS
> +CFLAGS_mshv_vtl_main.o		= -DHV_HYPERV_DEFS
> +
> +mshv-y				+= mshv_main.o
> +mshv_root-y			:= mshv_root_main.o mshv_synic.o
> mshv_portid_table.o \
> +						mshv_eventfd.o mshv_msi.o
> mshv_root_hv_call.o hv_call.o
> +mshv_vtl-y			:= mshv_vtl_main.o hv_call.o
> +
> +obj-$(CONFIG_MSHV_XFER_TO_GUEST_WORK) += xfer_to_guest.o
> +
>  hv_vmbus-y := vmbus_drv.o \
>  		 hv.o connection.o channel.o \
>  		 channel_mgmt.o ring_buffer.o hv_trace.o
> diff --git a/drivers/hv/hv_call.c b/drivers/hv/hv_call.c
> new file mode 100644
> index 000000000000..4455001d8545
> --- /dev/null
> +++ b/drivers/hv/hv_call.c
> @@ -0,0 +1,119 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2023, Microsoft Corporation.
> + *
> + * Hypercall helper functions shared between mshv modules.
> + *
> + * Authors:
> + *   Nuno Das Neves <nunodasneves@linux.microsoft.com>
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/mm.h>
> +#include <asm/mshyperv.h>
> +
> +#define HV_GET_REGISTER_BATCH_SIZE	\
> +	(HV_HYP_PAGE_SIZE / sizeof(union hv_register_value))
> +#define HV_SET_REGISTER_BATCH_SIZE	\
> +	((HV_HYP_PAGE_SIZE - sizeof(struct hv_input_set_vp_registers)) \
> +		/ sizeof(struct hv_register_assoc))
> +
> +int hv_call_get_vp_registers(
> +		u32 vp_index,
> +		u64 partition_id,
> +		u16 count,
> +		union hv_input_vtl input_vtl,
> +		struct hv_register_assoc *registers)
> +{
> +	struct hv_input_get_vp_registers *input_page;
> +	union hv_register_value *output_page;
> +	u16 completed = 0;
> +	unsigned long remaining = count;
> +	int rep_count, i;
> +	u64 status;
> +	unsigned long flags;
> +
> +	local_irq_save(flags);
> +
> +	input_page = *this_cpu_ptr(hyperv_pcpu_input_arg);
> +	output_page = *this_cpu_ptr(hyperv_pcpu_output_arg);
> +
> +	input_page->partition_id = partition_id;
> +	input_page->vp_index = vp_index;
> +	input_page->input_vtl.as_uint8 = input_vtl.as_uint8;
> +	input_page->rsvd_z8 = 0;
> +	input_page->rsvd_z16 = 0;
> +
> +	while (remaining) {
> +		rep_count = min(remaining, HV_GET_REGISTER_BATCH_SIZE);
> +		for (i = 0; i < rep_count; ++i)
> +			input_page->names[i] = registers[i].name;
> +
> +		status = hv_do_rep_hypercall(HVCALL_GET_VP_REGISTERS,
> rep_count,
> +					     0, input_page, output_page);

Is there any possibility that count value is passed 0 by mistake ? In that case
status will remain uninitialized. 

> +		if (!hv_result_success(status)) {
> +			pr_err("%s: completed %li out of %u, %s\n",
> +			       __func__,
> +			       count - remaining, count,
> +			       hv_status_to_string(status));
> +			break;
> +		}
> +		completed = hv_repcomp(status);
> +		for (i = 0; i < completed; ++i)
> +			registers[i].value = output_page[i];
> +
> +		registers += completed;
> +		remaining -= completed;
> +	}
> +	local_irq_restore(flags);
> +
> +	return hv_status_to_errno(status);
> +}
> +
> +int hv_call_set_vp_registers(
> +		u32 vp_index,
> +		u64 partition_id,
> +		u16 count,
> +		union hv_input_vtl input_vtl,
> +		struct hv_register_assoc *registers)
> +{
> +	struct hv_input_set_vp_registers *input_page;
> +	u16 completed = 0;
> +	unsigned long remaining = count;
> +	int rep_count;
> +	u64 status;
> +	unsigned long flags;
> +
> +	local_irq_save(flags);
> +	input_page = *this_cpu_ptr(hyperv_pcpu_input_arg);
> +
> +	input_page->partition_id = partition_id;
> +	input_page->vp_index = vp_index;
> +	input_page->input_vtl.as_uint8 = input_vtl.as_uint8;
> +	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);
> +
> +		status = hv_do_rep_hypercall(HVCALL_SET_VP_REGISTERS,
> rep_count,
> +					     0, input_page, NULL);
> +		if (!hv_result_success(status)) {
> +			pr_err("%s: completed %li out of %u, %s\n",
> +			       __func__,
> +			       count - remaining, count,
> +			       hv_status_to_string(status));
> +			break;
> +		}
> +		completed = hv_repcomp(status);
> +		registers += completed;
> +		remaining -= completed;
> +	}
> +
> +	local_irq_restore(flags);
> +
> +	return hv_status_to_errno(status);
> +}
> +
> diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
> index 13f972e72375..ccd76f30a638 100644
> --- a/drivers/hv/hv_common.c
> +++ b/drivers/hv/hv_common.c
> @@ -62,7 +62,11 @@ EXPORT_SYMBOL_GPL(hyperv_pcpu_output_arg);
>   */
>  static inline bool hv_output_arg_exists(void)
>  {
> +#ifdef CONFIG_MSHV_VTL

Although today both the option works together. But thinking
which is more accurate CONFIG_HYPERV_VTL_MODE or
CONFIG_MSHV_VTL here for scalability of VTL modules.

> +	return true;
> +#else
>  	return hv_root_partition ? true : false;
> +#endif
>  }
> 
>  static void hv_kmsg_dump_unregister(void);
> diff --git a/drivers/hv/mshv.h b/drivers/hv/mshv.h
> new file mode 100644
> index 000000000000..166480a73f3f
> --- /dev/null
> +++ b/drivers/hv/mshv.h
> @@ -0,0 +1,156 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (c) 2023, Microsoft Corporation.
> + */
> +
> +#ifndef _MSHV_H_
> +#define _MSHV_H_
> +
> +#include <linux/spinlock.h>
> +#include <linux/mutex.h>
> +#include <linux/semaphore.h>
> +#include <linux/sched.h>
> +#include <linux/srcu.h>
> +#include <linux/wait.h>
> +#include <uapi/linux/mshv.h>
> +
> +/*
> + * Hyper-V hypercalls
> + */
> +
> +int hv_call_withdraw_memory(u64 count, int node, u64 partition_id);
> +int hv_call_create_partition(
> +		u64 flags,
> +		struct hv_partition_creation_properties creation_properties,
> +		union hv_partition_isolation_properties isolation_properties,
> +		u64 *partition_id);
> +int hv_call_initialize_partition(u64 partition_id);
> +int hv_call_finalize_partition(u64 partition_id);
> +int hv_call_delete_partition(u64 partition_id);
> +int hv_call_map_gpa_pages(
> +		u64 partition_id,
> +		u64 gpa_target,
> +		u64 page_count, u32 flags,
> +		struct page **pages);
> +int hv_call_unmap_gpa_pages(
> +		u64 partition_id,
> +		u64 gpa_target,
> +		u64 page_count, u32 flags);
> +int hv_call_get_vp_registers(
> +		u32 vp_index,
> +		u64 partition_id,
> +		u16 count,
> +		union hv_input_vtl input_vtl,
> +		struct hv_register_assoc *registers);
> +int hv_call_get_gpa_access_states(
> +		u64 partition_id,
> +		u32 count,
> +		u64 gpa_base_pfn,
> +		u64 state_flags,
> +		int *written_total,
> +		union hv_gpa_page_access_state *states);
> +
> +int hv_call_set_vp_registers(
> +		u32 vp_index,
> +		u64 partition_id,
> +		u16 count,
> +		union hv_input_vtl input_vtl,
> +		struct hv_register_assoc *registers);

Nit: Opportunity to fix many of the checkpatch.pl related to line break here
and many other places.

> +int hv_call_install_intercept(u64 partition_id, u32 access_type,
> +		enum hv_intercept_type intercept_type,
> +		union hv_intercept_parameters intercept_parameter);
> +int hv_call_assert_virtual_interrupt(
> +		u64 partition_id,
> +		u32 vector,
> +		u64 dest_addr,
> +		union hv_interrupt_control control);
> +int hv_call_clear_virtual_interrupt(u64 partition_id);
> +
> +#ifdef HV_SUPPORTS_VP_STATE
> +int hv_call_get_vp_state(
> +		u32 vp_index,
> +		u64 partition_id,
> +		enum hv_get_set_vp_state_type type,
> +		struct hv_vp_state_data_xsave xsave,
> +		/* Choose between pages and ret_output */
> +		u64 page_count,
> +		struct page **pages,
> +		union hv_output_get_vp_state *ret_output);
> +int hv_call_set_vp_state(
> +		u32 vp_index,
> +		u64 partition_id,
> +		enum hv_get_set_vp_state_type type,
> +		struct hv_vp_state_data_xsave xsave,
> +		/* Choose between pages and bytes */
> +		u64 page_count,
> +		struct page **pages,
> +		u32 num_bytes,
> +		u8 *bytes);
> +#endif
> +
> +int hv_call_map_vp_state_page(u64 partition_id, u32 vp_index, u32 type,
> +				struct page **state_page);
> +int hv_call_unmap_vp_state_page(u64 partition_id, u32 vp_index, u32
> type);
> +int hv_call_get_partition_property(
> +		u64 partition_id,
> +		u64 property_code,
> +		u64 *property_value);
> +int hv_call_set_partition_property(
> +	u64 partition_id, u64 property_code, u64 property_value,
> +	void (*completion_handler)(void * /* data */, u64 * /* status */),
> +	void *completion_data);
> +int hv_call_translate_virtual_address(
> +		u32 vp_index,
> +		u64 partition_id,
> +		u64 flags,
> +		u64 gva,
> +		u64 *gpa,
> +		union hv_translate_gva_result *result);
> +int hv_call_get_vp_cpuid_values(
> +		u32 vp_index,
> +		u64 partition_id,
> +		union hv_get_vp_cpuid_values_flags values_flags,
> +		struct hv_cpuid_leaf_info *info,
> +		union hv_output_get_vp_cpuid_values *result);
> +
> +int hv_call_create_port(u64 port_partition_id, union hv_port_id port_id,
> +			u64 connection_partition_id, struct hv_port_info
> *port_info,
> +			u8 port_vtl, u8 min_connection_vtl, int node);
> +int hv_call_delete_port(u64 port_partition_id, union hv_port_id port_id);
> +int hv_call_connect_port(u64 port_partition_id, union hv_port_id port_id,
> +			 u64 connection_partition_id,
> +			 union hv_connection_id connection_id,
> +			 struct hv_connection_info *connection_info,
> +			 u8 connection_vtl, int node);
> +int hv_call_disconnect_port(u64 connection_partition_id,
> +			    union hv_connection_id connection_id);
> +int hv_call_notify_port_ring_empty(u32 sint_index);
> +#ifdef HV_SUPPORTS_REGISTER_INTERCEPT
> +int hv_call_register_intercept_result(u32 vp_index,
> +				  u64 partition_id,
> +				  enum hv_intercept_type intercept_type,
> +				  union
> hv_register_intercept_result_parameters *params);
> +#endif
> +int hv_call_signal_event_direct(u32 vp_index,
> +				u64 partition_id,
> +				u8 vtl,
> +				u8 sint,
> +				u16 flag_number,
> +				u8 *newly_signaled);
> +int hv_call_post_message_direct(u32 vp_index,
> +				u64 partition_id,
> +				u8 vtl,
> +				u32 sint_index,
> +				u8 *message);
> +
> +struct mshv_partition *mshv_partition_find(u64 partition_id)
> __must_hold(RCU);
> +
> +int mshv_xfer_to_guest_mode_handle_work(unsigned long ti_work);
> +
> +typedef long (*mshv_create_func_t)(void __user *user_arg);
> +typedef long (*mshv_check_ext_func_t)(u32 arg);
> +int mshv_setup_vtl_func(const mshv_create_func_t create_vtl,
> +			const mshv_check_ext_func_t check_ext);
> +int mshv_set_create_partition_func(const mshv_create_func_t func);
> +
> +#endif /* _MSHV_H */
> diff --git a/drivers/hv/mshv_eventfd.c b/drivers/hv/mshv_eventfd.c
> new file mode 100644
> index 000000000000..ddc64fe3920e
> --- /dev/null
> +++ b/drivers/hv/mshv_eventfd.c
> @@ -0,0 +1,758 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * eventfd support for mshv
> + *
> + * Heavily inspired from KVM implementation of irqfd/ioeventfd. The basic
> + * framework code is taken from the kvm implementation.
> + *
> + * All credits to kvm developers.
> + */
> +
> +#include <linux/syscalls.h>
> +#include <linux/wait.h>
> +#include <linux/poll.h>
> +#include <linux/file.h>
> +#include <linux/list.h>
> +#include <linux/workqueue.h>
> +#include <linux/eventfd.h>
> +
> +#include "mshv_eventfd.h"
> +#include "mshv.h"
> +#include "mshv_root.h"
> +
> +static struct workqueue_struct *irqfd_cleanup_wq;
> +
> +void
> +mshv_register_irq_ack_notifier(struct mshv_partition *partition,
> +			       struct mshv_irq_ack_notifier *mian)
> +{
> +	mutex_lock(&partition->irq_lock);
> +	hlist_add_head_rcu(&mian->link, &partition->irq_ack_notifier_list);
> +	mutex_unlock(&partition->irq_lock);
> +}
> +
> +void
> +mshv_unregister_irq_ack_notifier(struct mshv_partition *partition,
> +				 struct mshv_irq_ack_notifier *mian)
> +{
> +	mutex_lock(&partition->irq_lock);
> +	hlist_del_init_rcu(&mian->link);
> +	mutex_unlock(&partition->irq_lock);
> +	synchronize_rcu();
> +}
> +
> +bool
> +mshv_notify_acked_gsi(struct mshv_partition *partition, int gsi)
> +{
> +	struct mshv_irq_ack_notifier *mian;
> +	bool acked = false;
> +
> +	rcu_read_lock();
> +	hlist_for_each_entry_rcu(mian, &partition->irq_ack_notifier_list,
> +			link) {
> +		if (mian->gsi == gsi) {
> +			mian->irq_acked(mian);
> +			acked = true;
> +		}
> +	}
> +	rcu_read_unlock();
> +
> +	return acked;
> +}
> +
> +static inline bool hv_should_clear_interrupt(enum hv_interrupt_type type)
> +{
> +	return type == HV_X64_INTERRUPT_TYPE_EXTINT;
> +}
> +
> +static void
> +irqfd_resampler_ack(struct mshv_irq_ack_notifier *mian)
> +{
> +	struct mshv_kernel_irqfd_resampler *resampler;
> +	struct mshv_partition *partition;
> +	struct mshv_kernel_irqfd *irqfd;
> +	int idx;
> +
> +	resampler = container_of(mian,
> +			struct mshv_kernel_irqfd_resampler, notifier);
> +	partition = resampler->partition;
> +
> +	idx = srcu_read_lock(&partition->irq_srcu);
> +
> +	hlist_for_each_entry_rcu(irqfd, &resampler->irqfds_list,
> resampler_hnode) {
> +		if (hv_should_clear_interrupt(irqfd-
> >lapic_irq.control.interrupt_type))
> +			hv_call_clear_virtual_interrupt(partition->id);
> +
> +		eventfd_signal(irqfd->resamplefd, 1);
> +	}
> +
> +	srcu_read_unlock(&partition->irq_srcu, idx);
> +}
> +
> +static void
> +irqfd_assert(struct work_struct *work)
> +{
> +	struct mshv_kernel_irqfd *irqfd =
> +		container_of(work, struct mshv_kernel_irqfd, assert);
> +	struct mshv_lapic_irq *irq = &irqfd->lapic_irq;
> +
> +	hv_call_assert_virtual_interrupt(irqfd->partition->id,
> +					 irq->vector, irq->apic_id,
> +					 irq->control);
> +}
> +
> +static void
> +irqfd_inject(struct mshv_kernel_irqfd *irqfd)
> +{
> +	struct mshv_partition *partition = irqfd->partition;
> +	struct mshv_lapic_irq *irq = &irqfd->lapic_irq;
> +	unsigned int seq;
> +	int idx;
> +
> +	WARN_ON(irqfd->resampler &&
> +		!irq->control.level_triggered);
> +
> +	idx = srcu_read_lock(&partition->irq_srcu);
> +	if (irqfd->msi_entry.gsi) {
> +		if (!irqfd->msi_entry.entry_valid) {
> +			pr_warn("Invalid routing info for gsi %u",
> +				irqfd->msi_entry.gsi);
> +			srcu_read_unlock(&partition->irq_srcu, idx);
> +			return;
> +		}
> +
> +		do {
> +			seq = read_seqcount_begin(&irqfd->msi_entry_sc);
> +		} while (read_seqcount_retry(&irqfd->msi_entry_sc, seq));
> +	}
> +
> +	srcu_read_unlock(&partition->irq_srcu, idx);
> +
> +	schedule_work(&irqfd->assert);
> +}
> +
> +static void
> +irqfd_resampler_shutdown(struct mshv_kernel_irqfd *irqfd)
> +{
> +	struct mshv_kernel_irqfd_resampler *resampler = irqfd->resampler;
> +	struct mshv_partition *partition = resampler->partition;
> +
> +	mutex_lock(&partition->irqfds.resampler_lock);
> +
> +	hlist_del_rcu(&irqfd->resampler_hnode);
> +	synchronize_srcu(&partition->irq_srcu);
> +
> +	if (hlist_empty(&resampler->irqfds_list)) {
> +		hlist_del(&resampler->hnode);
> +		mshv_unregister_irq_ack_notifier(partition, &resampler-
> >notifier);
> +		kfree(resampler);
> +	}
> +
> +	mutex_unlock(&partition->irqfds.resampler_lock);
> +}
> +
> +/*
> + * Race-free decouple logic (ordering is critical)
> + */
> +static void
> +irqfd_shutdown(struct work_struct *work)
> +{
> +	struct mshv_kernel_irqfd *irqfd =
> +		container_of(work, struct mshv_kernel_irqfd, shutdown);
> +
> +	/*
> +	 * Synchronize with the wait-queue and unhook ourselves to prevent
> +	 * further events.
> +	 */
> +	remove_wait_queue(irqfd->wqh, &irqfd->wait);
> +
> +	if (irqfd->resampler) {
> +		irqfd_resampler_shutdown(irqfd);
> +		eventfd_ctx_put(irqfd->resamplefd);
> +	}
> +
> +	/*
> +	 * We know no new events will be scheduled at this point, so block
> +	 * until all previously outstanding events have completed
> +	 */
> +	flush_work(&irqfd->assert);
> +
> +	/*
> +	 * It is now safe to release the object's resources
> +	 */
> +	eventfd_ctx_put(irqfd->eventfd);
> +	kfree(irqfd);
> +}
> +
> +/* assumes partition->irqfds.lock is held */
> +static bool
> +irqfd_is_active(struct mshv_kernel_irqfd *irqfd)
> +{
> +	return !hlist_unhashed(&irqfd->hnode);
> +}
> +
> +/*
> + * Mark the irqfd as inactive and schedule it for removal
> + *
> + * assumes partition->irqfds.lock is held
> + */
> +static void
> +irqfd_deactivate(struct mshv_kernel_irqfd *irqfd)
> +{
> +	WARN_ON(!irqfd_is_active(irqfd));
> +
> +	hlist_del(&irqfd->hnode);
> +
> +	queue_work(irqfd_cleanup_wq, &irqfd->shutdown);
> +}
> +
> +/*
> + * Called with wqh->lock held and interrupts disabled
> + */
> +static int
> +irqfd_wakeup(wait_queue_entry_t *wait, unsigned int mode,
> +		int sync, void *key)
> +{
> +	struct mshv_kernel_irqfd *irqfd =
> +		container_of(wait, struct mshv_kernel_irqfd, wait);
> +	unsigned long flags = (unsigned long)key;
> +	int idx;
> +	unsigned int seq;
> +	struct mshv_partition *partition = irqfd->partition;
> +	int ret = 0;
> +
> +	if (flags & POLLIN) {
> +		u64 cnt;
> +
> +		eventfd_ctx_do_read(irqfd->eventfd, &cnt);
> +		idx = srcu_read_lock(&partition->irq_srcu);
> +		do {
> +			seq = read_seqcount_begin(&irqfd->msi_entry_sc);
> +		} while (read_seqcount_retry(&irqfd->msi_entry_sc, seq));
> +
> +		/* An event has been signaled, inject an interrupt */
> +		irqfd_inject(irqfd);
> +		srcu_read_unlock(&partition->irq_srcu, idx);
> +
> +		ret = 1;
> +	}
> +
> +	if (flags & POLLHUP) {
> +		/* The eventfd is closing, detach from Partition */
> +		unsigned long flags;
> +
> +		spin_lock_irqsave(&partition->irqfds.lock, flags);
> +
> +		/*
> +		 * We must check if someone deactivated the irqfd before
> +		 * we could acquire the irqfds.lock since the item is
> +		 * deactivated from the mshv side before it is unhooked from
> +		 * the wait-queue.  If it is already deactivated, we can
> +		 * simply return knowing the other side will cleanup for us.
> +		 * We cannot race against the irqfd going away since the
> +		 * other side is required to acquire wqh->lock, which we hold
> +		 */
> +		if (irqfd_is_active(irqfd))
> +			irqfd_deactivate(irqfd);
> +
> +		spin_unlock_irqrestore(&partition->irqfds.lock, flags);
> +	}
> +
> +	return ret;
> +}
> +
> +/* Must be called under irqfds.lock */
> +static void irqfd_update(struct mshv_partition *partition,
> +			 struct mshv_kernel_irqfd *irqfd)
> +{
> +	write_seqcount_begin(&irqfd->msi_entry_sc);
> +	irqfd->msi_entry = mshv_msi_map_gsi(partition, irqfd->gsi);
> +	mshv_set_msi_irq(&irqfd->msi_entry, &irqfd->lapic_irq);
> +	write_seqcount_end(&irqfd->msi_entry_sc);
> +}
> +
> +void mshv_irqfd_routing_update(struct mshv_partition *partition)
> +{
> +	struct mshv_kernel_irqfd *irqfd;
> +
> +	spin_lock_irq(&partition->irqfds.lock);
> +	hlist_for_each_entry(irqfd, &partition->irqfds.items, hnode)
> +		irqfd_update(partition, irqfd);
> +	spin_unlock_irq(&partition->irqfds.lock);
> +}
> +
> +static void
> +irqfd_ptable_queue_proc(struct file *file, wait_queue_head_t *wqh,
> +			poll_table *pt)
> +{
> +	struct mshv_kernel_irqfd *irqfd =
> +		container_of(pt, struct mshv_kernel_irqfd, pt);
> +
> +	irqfd->wqh = wqh;
> +	add_wait_queue_priority(wqh, &irqfd->wait);
> +}
> +
> +static int
> +mshv_irqfd_assign(struct mshv_partition *partition,
> +		  struct mshv_irqfd *args)
> +{
> +	struct eventfd_ctx *eventfd = NULL, *resamplefd = NULL;
> +	struct mshv_kernel_irqfd *irqfd, *tmp;
> +	unsigned int events;
> +	struct fd f;
> +	int ret;
> +	int idx;
> +
> +	irqfd = kzalloc(sizeof(*irqfd), GFP_KERNEL);
> +	if (!irqfd)
> +		return -ENOMEM;
> +
> +	irqfd->partition = partition;
> +	irqfd->gsi = args->gsi;
> +	INIT_WORK(&irqfd->shutdown, irqfd_shutdown);
> +	INIT_WORK(&irqfd->assert, irqfd_assert);
> +	seqcount_spinlock_init(&irqfd->msi_entry_sc,
> +			       &partition->irqfds.lock);
> +
> +	f = fdget(args->fd);
> +	if (!f.file) {
> +		ret = -EBADF;
> +		goto out;
> +	}
> +
> +	eventfd = eventfd_ctx_fileget(f.file);
> +	if (IS_ERR(eventfd)) {
> +		ret = PTR_ERR(eventfd);
> +		goto fail;
> +	}
> +
> +	irqfd->eventfd = eventfd;
> +
> +	if (args->flags & MSHV_IRQFD_FLAG_RESAMPLE) {
> +		struct mshv_kernel_irqfd_resampler *resampler;
> +
> +		resamplefd = eventfd_ctx_fdget(args->resamplefd);
> +		if (IS_ERR(resamplefd)) {
> +			ret = PTR_ERR(resamplefd);
> +			goto fail;
> +		}
> +
> +		irqfd->resamplefd = resamplefd;
> +
> +		mutex_lock(&partition->irqfds.resampler_lock);
> +
> +		hlist_for_each_entry(resampler,
> +				    &partition->irqfds.resampler_list, hnode) {
> +			if (resampler->notifier.gsi == irqfd->gsi) {
> +				irqfd->resampler = resampler;
> +				break;
> +			}
> +		}
> +
> +		if (!irqfd->resampler) {
> +			resampler = kzalloc(sizeof(*resampler),
> +					    GFP_KERNEL_ACCOUNT);
> +			if (!resampler) {
> +				ret = -ENOMEM;
> +				mutex_unlock(&partition-
> >irqfds.resampler_lock);
> +				goto fail;
> +			}
> +
> +			resampler->partition = partition;
> +			INIT_HLIST_HEAD(&resampler->irqfds_list);
> +			resampler->notifier.gsi = irqfd->gsi;
> +			resampler->notifier.irq_acked = irqfd_resampler_ack;
> +
> +			hlist_add_head(&resampler->hnode, &partition-
> >irqfds.resampler_list);
> +			mshv_register_irq_ack_notifier(partition,
> +						      &resampler->notifier);
> +			irqfd->resampler = resampler;
> +		}
> +
> +		hlist_add_head_rcu(&irqfd->resampler_hnode, &irqfd-
> >resampler->irqfds_list);
> +
> +		mutex_unlock(&partition->irqfds.resampler_lock);
> +	}
> +
> +	/*
> +	 * Install our own custom wake-up handling so we are notified via
> +	 * a callback whenever someone signals the underlying eventfd
> +	 */
> +	init_waitqueue_func_entry(&irqfd->wait, irqfd_wakeup);
> +	init_poll_funcptr(&irqfd->pt, irqfd_ptable_queue_proc);
> +
> +	spin_lock_irq(&partition->irqfds.lock);
> +	if (args->flags & MSHV_IRQFD_FLAG_RESAMPLE &&
> +	    !irqfd->lapic_irq.control.level_triggered) {
> +		/*
> +		 * Resample Fd must be for level triggered interrupt
> +		 * Otherwise return with failure
> +		 */
> +		spin_unlock_irq(&partition->irqfds.lock);
> +		ret = -EINVAL;
> +		goto fail;
> +	}
> +	ret = 0;
> +	hlist_for_each_entry(tmp, &partition->irqfds.items, hnode) {
> +		if (irqfd->eventfd != tmp->eventfd)
> +			continue;
> +		/* This fd is used for another irq already. */
> +		ret = -EBUSY;
> +		spin_unlock_irq(&partition->irqfds.lock);
> +		goto fail;
> +	}
> +
> +	idx = srcu_read_lock(&partition->irq_srcu);
> +	irqfd_update(partition, irqfd);
> +	hlist_add_head(&irqfd->hnode, &partition->irqfds.items);
> +	spin_unlock_irq(&partition->irqfds.lock);
> +
> +	/*
> +	 * Check if there was an event already pending on the eventfd
> +	 * before we registered, and trigger it as if we didn't miss it.
> +	 */
> +	events = vfs_poll(f.file, &irqfd->pt);
> +
> +	if (events & POLLIN)
> +		irqfd_inject(irqfd);
> +
> +	srcu_read_unlock(&partition->irq_srcu, idx);
> +	/*
> +	 * do not drop the file until the irqfd is fully initialized, otherwise
> +	 * we might race against the POLLHUP
> +	 */
> +	fdput(f);
> +
> +	return 0;
> +
> +fail:
> +	if (irqfd->resampler)
> +		irqfd_resampler_shutdown(irqfd);
> +
> +	if (resamplefd && !IS_ERR(resamplefd))
> +		eventfd_ctx_put(resamplefd);
> +
> +	if (eventfd && !IS_ERR(eventfd))
> +		eventfd_ctx_put(eventfd);
> +
> +	fdput(f);
> +
> +out:
> +	kfree(irqfd);
> +	return ret;
> +}
> +
> +/*
> + * shutdown any irqfd's that match fd+gsi
> + */
> +static int
> +mshv_irqfd_deassign(struct mshv_partition *partition,
> +		    struct mshv_irqfd *args)
> +{
> +	struct mshv_kernel_irqfd *irqfd;
> +	struct hlist_node *n;
> +	struct eventfd_ctx *eventfd;
> +
> +	eventfd = eventfd_ctx_fdget(args->fd);
> +	if (IS_ERR(eventfd))
> +		return PTR_ERR(eventfd);
> +
> +	hlist_for_each_entry_safe(irqfd, n, &partition->irqfds.items, hnode) {
> +		if (irqfd->eventfd == eventfd && irqfd->gsi == args->gsi)
> +			irqfd_deactivate(irqfd);
> +	}
> +
> +	eventfd_ctx_put(eventfd);
> +
> +	/*
> +	 * Block until we know all outstanding shutdown jobs have completed
> +	 * so that we guarantee there will not be any more interrupts on this
> +	 * gsi once this deassign function returns.
> +	 */
> +	flush_workqueue(irqfd_cleanup_wq);
> +
> +	return 0;
> +}
> +
> +int
> +mshv_irqfd(struct mshv_partition *partition, struct mshv_irqfd *args)
> +{
> +	if (args->flags & MSHV_IRQFD_FLAG_DEASSIGN)
> +		return mshv_irqfd_deassign(partition, args);
> +
> +	return mshv_irqfd_assign(partition, args);
> +}
> +
> +/*
> + * This function is called as the mshv VM fd is being released.
> + * Shutdown all irqfds that still remain open
> + */
> +static void
> +mshv_irqfd_release(struct mshv_partition *partition)
> +{
> +	struct mshv_kernel_irqfd *irqfd;
> +	struct hlist_node *n;
> +
> +	spin_lock_irq(&partition->irqfds.lock);
> +
> +	hlist_for_each_entry_safe(irqfd, n, &partition->irqfds.items, hnode)
> +		irqfd_deactivate(irqfd);
> +
> +	spin_unlock_irq(&partition->irqfds.lock);
> +
> +	/*
> +	 * Block until we know all outstanding shutdown jobs have completed
> +	 * since we do not take a mshv_partition* reference.
> +	 */
> +	flush_workqueue(irqfd_cleanup_wq);
> +
> +}
> +
> +int mshv_irqfd_wq_init(void)
> +{
> +	irqfd_cleanup_wq = alloc_workqueue("mshv-irqfd-cleanup", 0, 0);
> +	if (!irqfd_cleanup_wq)
> +		return -ENOMEM;
> +
> +	return 0;
> +}
> +
> +void mshv_irqfd_wq_cleanup(void)
> +{
> +	destroy_workqueue(irqfd_cleanup_wq);
> +}
> +
> +/*
> + * --------------------------------------------------------------------
> + * ioeventfd: translate a MMIO memory write to an eventfd signal.
> + *
> + * userspace can register a MMIO address with an eventfd for receiving
> + * notification when the memory has been touched.
> + *
> + * TODO: Implement eventfd for PIO as well.
> + * --------------------------------------------------------------------
> + */
> +
> +static void
> +ioeventfd_release(struct kernel_mshv_ioeventfd *p, u64 partition_id)
> +{
> +	if (p->doorbell_id > 0)
> +		mshv_unregister_doorbell(partition_id, p->doorbell_id);
> +	eventfd_ctx_put(p->eventfd);
> +	kfree(p);
> +}
> +
> +/* MMIO writes trigger an event if the addr/val match */
> +static void
> +ioeventfd_mmio_write(int doorbell_id, void *data)
> +{
> +	struct mshv_partition *partition = (struct mshv_partition *)data;
> +	struct kernel_mshv_ioeventfd *p;
> +
> +	rcu_read_lock();
> +	hlist_for_each_entry_rcu(p, &partition->ioeventfds.items, hnode) {
> +		if (p->doorbell_id == doorbell_id) {
> +			eventfd_signal(p->eventfd, 1);
> +			break;
> +		}
> +	}
> +	rcu_read_unlock();
> +}
> +
> +static bool
> +ioeventfd_check_collision(struct mshv_partition *partition,
> +			  struct kernel_mshv_ioeventfd *p)
> +	__must_hold(&partition->mutex)
> +{
> +	struct kernel_mshv_ioeventfd *_p;
> +
> +	hlist_for_each_entry(_p, &partition->ioeventfds.items, hnode)
> +		if (_p->addr == p->addr && _p->length == p->length &&
> +		    (_p->wildcard || p->wildcard ||
> +		     _p->datamatch == p->datamatch))
> +			return true;
> +
> +	return false;
> +}
> +
> +static int
> +mshv_assign_ioeventfd(struct mshv_partition *partition,
> +		      struct mshv_ioeventfd *args)
> +	__must_hold(&partition->mutex)
> +{
> +	struct kernel_mshv_ioeventfd *p;
> +	struct eventfd_ctx *eventfd;
> +	u64 doorbell_flags = 0;
> +	int ret;
> +
> +	/* This mutex is currently protecting ioeventfd.items list */
> +	WARN_ON_ONCE(!mutex_is_locked(&partition->mutex));
> +
> +	if (args->flags & MSHV_IOEVENTFD_FLAG_PIO)
> +		return -EOPNOTSUPP;
> +
> +	/* must be natural-word sized */
> +	switch (args->len) {
> +	case 0:
> +		doorbell_flags = HV_DOORBELL_FLAG_TRIGGER_SIZE_ANY;
> +		break;
> +	case 1:
> +		doorbell_flags = HV_DOORBELL_FLAG_TRIGGER_SIZE_BYTE;
> +		break;
> +	case 2:
> +		doorbell_flags = HV_DOORBELL_FLAG_TRIGGER_SIZE_WORD;
> +		break;
> +	case 4:
> +		doorbell_flags =
> HV_DOORBELL_FLAG_TRIGGER_SIZE_DWORD;
> +		break;
> +	case 8:
> +		doorbell_flags =
> HV_DOORBELL_FLAG_TRIGGER_SIZE_QWORD;
> +		break;
> +	default:
> +		pr_warn("ioeventfd: invalid length specified\n");
> +		return -EINVAL;
> +	}
> +
> +	/* check for range overflow */
> +	if (args->addr + args->len < args->addr)
> +		return -EINVAL;
> +
> +	/* check for extra flags that we don't understand */
> +	if (args->flags & ~MSHV_IOEVENTFD_VALID_FLAG_MASK)
> +		return -EINVAL;
> +
> +	eventfd = eventfd_ctx_fdget(args->fd);
> +	if (IS_ERR(eventfd))
> +		return PTR_ERR(eventfd);
> +
> +	p = kzalloc(sizeof(*p), GFP_KERNEL);
> +	if (!p) {
> +		ret = -ENOMEM;
> +		goto fail;
> +	}
> +
> +	p->addr    = args->addr;
> +	p->length  = args->len;
> +	p->eventfd = eventfd;
> +
> +	/* The datamatch feature is optional, otherwise this is a wildcard */
> +	if (args->flags & MSHV_IOEVENTFD_FLAG_DATAMATCH)
> +		p->datamatch = args->datamatch;
> +	else {
> +		p->wildcard = true;
> +		doorbell_flags |=
> HV_DOORBELL_FLAG_TRIGGER_ANY_VALUE;
> +	}
> +
> +	if (ioeventfd_check_collision(partition, p)) {
> +		ret = -EEXIST;
> +		goto unlock_fail;
> +	}
> +
> +	ret = mshv_register_doorbell(partition->id, ioeventfd_mmio_write,
> +				     (void *)partition, p->addr,
> +				     p->datamatch, doorbell_flags);
> +	if (ret < 0) {
> +		pr_err("Failed to register ioeventfd doorbell!\n");

Nit: Do we like to print function name at the start of pr_err. 

- Saurabh

Re: [PATCH v2 01/15] hyperv-tlfs: Change shared HV_REGISTER_* defines to HV_MSR_*

[Wei Liu]

Hi Michael, Long and Haiyang

On Thu, Aug 17, 2023 at 03:01:37PM -0700, Nuno Das Neves wrote:
> In x86 hyperv-tlfs, HV_REGISTER_ prefix is used to indicate MSRs
> accessed via rdmsrl/wrmsrl. But in ARM64, HV_REGISTER_ instead indicates
> VP registers accessed via get/set vp registers hypercall.
> 
> This is due to HV_REGISTER_* names being used by hv_set/get_register,
> with the arch-specific version delegating to the appropriate mechanism.
> 
> The problem is, using prefix HV_REGISTER_ for MSRs will conflict with
> VP registers when they are introduced for x86 in future.
> 
> This patch solves the issue by:
> 
> 1. Defining all the x86 MSRs with a consistent prefix: HV_X64_MSR_.
>    This is so HV_REGISTER_ can be reserved for VP registers.
> 
> 2. Change the non-arch-specific alias used by hv_set/get_register to
>    HV_MSR_. This is also happens to be the same name HyperV uses for this
>    purpose.
> 
> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>

I think this patch contains mostly mechanical changes, so I'm hoping
it's not too controversial.

Can you give an ack or nack on this patch?

Thanks,
Wei.

> ---
>  arch/arm64/include/asm/hyperv-tlfs.h |  25 +++++
>  arch/x86/include/asm/hyperv-tlfs.h   | 137 +++++++++++++--------------
>  arch/x86/include/asm/mshyperv.h      |   8 +-
>  arch/x86/kernel/cpu/mshyperv.c       |  22 ++---
>  drivers/clocksource/hyperv_timer.c   |  24 ++---
>  drivers/hv/hv.c                      |  32 +++----
>  drivers/hv/hv_common.c               |  18 ++--
>  include/asm-generic/mshyperv.h       |   2 +-
>  8 files changed, 146 insertions(+), 122 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/hyperv-tlfs.h b/arch/arm64/include/asm/hyperv-tlfs.h
> index bc6c7ac934a1..a6e852c2fc3a 100644
> --- a/arch/arm64/include/asm/hyperv-tlfs.h
> +++ b/arch/arm64/include/asm/hyperv-tlfs.h
> @@ -64,6 +64,31 @@
>  #define HV_REGISTER_STIMER0_CONFIG	0x000B0000
>  #define HV_REGISTER_STIMER0_COUNT	0x000B0001
>  
> +/*
> + * To support non-arch-specific code calling hv_set/get_register:
> + * - On x86, HV_MSR_ indicates an MSR accessed via rdmsrl/wrmsrl
> + * - On ARM, HV_MSR_ indicates a VP register accessed via hypercall
> + */
> +#define HV_MSR_VP_INDEX		(HV_REGISTER_VP_INDEX)
> +#define HV_MSR_TIME_REF_COUNT	(HV_REGISTER_TIME_REF_COUNT)
> +#define HV_MSR_REFERENCE_TS	(HV_REGISTER_REFERENCE_TSC)
> +
> +#define HV_MSR_STIMER0_CONFIG	(HV_REGISTER_STIMER0_CONFIG)
> +#define HV_MSR_STIMER0_COUNT	(HV_REGISTER_STIMER0_COUNT)
> +
> +#define HV_MSR_SCONTROL		(HV_REGISTER_SCONTROL)
> +#define HV_MSR_SIEFP		(HV_REGISTER_SIEFP)
> +#define HV_MSR_SIMP		(HV_REGISTER_SIMP)
> +#define HV_MSR_EOM		(HV_REGISTER_EOM)
> +#define HV_MSR_SINT0		(HV_REGISTER_SINT0)
> +
> +#define HV_MSR_CRASH_P0		(HV_REGISTER_CRASH_P0)
> +#define HV_MSR_CRASH_P1		(HV_REGISTER_CRASH_P1)
> +#define HV_MSR_CRASH_P2		(HV_REGISTER_CRASH_P2)
> +#define HV_MSR_CRASH_P3		(HV_REGISTER_CRASH_P3)
> +#define HV_MSR_CRASH_P4		(HV_REGISTER_CRASH_P4)
> +#define HV_MSR_CRASH_CTL	(HV_REGISTER_CRASH_CTL)
> +
>  union hv_msi_entry {
>  	u64 as_uint64[2];
>  	struct {
> diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
> index cea95dcd27c2..40902a767733 100644
> --- a/arch/x86/include/asm/hyperv-tlfs.h
> +++ b/arch/x86/include/asm/hyperv-tlfs.h
> @@ -181,7 +181,7 @@ enum hv_isolation_type {
>  #define HV_X64_MSR_HYPERCALL			0x40000001
>  
>  /* MSR used to provide vcpu index */
> -#define HV_REGISTER_VP_INDEX			0x40000002
> +#define HV_X64_MSR_VP_INDEX			0x40000002
>  
>  /* MSR used to reset the guest OS. */
>  #define HV_X64_MSR_RESET			0x40000003
> @@ -190,10 +190,10 @@ enum hv_isolation_type {
>  #define HV_X64_MSR_VP_RUNTIME			0x40000010
>  
>  /* MSR used to read the per-partition time reference counter */
> -#define HV_REGISTER_TIME_REF_COUNT		0x40000020
> +#define HV_X64_MSR_TIME_REF_COUNT		0x40000020
>  
>  /* A partition's reference time stamp counter (TSC) page */
> -#define HV_REGISTER_REFERENCE_TSC		0x40000021
> +#define HV_X64_MSR_REFERENCE_TSC		0x40000021
>  
>  /* MSR used to retrieve the TSC frequency */
>  #define HV_X64_MSR_TSC_FREQUENCY		0x40000022
> @@ -208,61 +208,61 @@ enum hv_isolation_type {
>  #define HV_X64_MSR_VP_ASSIST_PAGE		0x40000073
>  
>  /* Define synthetic interrupt controller model specific registers. */
> -#define HV_REGISTER_SCONTROL			0x40000080
> -#define HV_REGISTER_SVERSION			0x40000081
> -#define HV_REGISTER_SIEFP			0x40000082
> -#define HV_REGISTER_SIMP			0x40000083
> -#define HV_REGISTER_EOM				0x40000084
> -#define HV_REGISTER_SINT0			0x40000090
> -#define HV_REGISTER_SINT1			0x40000091
> -#define HV_REGISTER_SINT2			0x40000092
> -#define HV_REGISTER_SINT3			0x40000093
> -#define HV_REGISTER_SINT4			0x40000094
> -#define HV_REGISTER_SINT5			0x40000095
> -#define HV_REGISTER_SINT6			0x40000096
> -#define HV_REGISTER_SINT7			0x40000097
> -#define HV_REGISTER_SINT8			0x40000098
> -#define HV_REGISTER_SINT9			0x40000099
> -#define HV_REGISTER_SINT10			0x4000009A
> -#define HV_REGISTER_SINT11			0x4000009B
> -#define HV_REGISTER_SINT12			0x4000009C
> -#define HV_REGISTER_SINT13			0x4000009D
> -#define HV_REGISTER_SINT14			0x4000009E
> -#define HV_REGISTER_SINT15			0x4000009F
> +#define HV_X64_MSR_SCONTROL			0x40000080
> +#define HV_X64_MSR_SVERSION			0x40000081
> +#define HV_X64_MSR_SIEFP			0x40000082
> +#define HV_X64_MSR_SIMP				0x40000083
> +#define HV_X64_MSR_EOM				0x40000084
> +#define HV_X64_MSR_SINT0			0x40000090
> +#define HV_X64_MSR_SINT1			0x40000091
> +#define HV_X64_MSR_SINT2			0x40000092
> +#define HV_X64_MSR_SINT3			0x40000093
> +#define HV_X64_MSR_SINT4			0x40000094
> +#define HV_X64_MSR_SINT5			0x40000095
> +#define HV_X64_MSR_SINT6			0x40000096
> +#define HV_X64_MSR_SINT7			0x40000097
> +#define HV_X64_MSR_SINT8			0x40000098
> +#define HV_X64_MSR_SINT9			0x40000099
> +#define HV_X64_MSR_SINT10			0x4000009A
> +#define HV_X64_MSR_SINT11			0x4000009B
> +#define HV_X64_MSR_SINT12			0x4000009C
> +#define HV_X64_MSR_SINT13			0x4000009D
> +#define HV_X64_MSR_SINT14			0x4000009E
> +#define HV_X64_MSR_SINT15			0x4000009F
>  
>  /*
>   * Define synthetic interrupt controller model specific registers for
>   * nested hypervisor.
>   */
> -#define HV_REGISTER_NESTED_SCONTROL            0x40001080
> -#define HV_REGISTER_NESTED_SVERSION            0x40001081
> -#define HV_REGISTER_NESTED_SIEFP               0x40001082
> -#define HV_REGISTER_NESTED_SIMP                0x40001083
> -#define HV_REGISTER_NESTED_EOM                 0x40001084
> -#define HV_REGISTER_NESTED_SINT0               0x40001090
> +#define HV_X64_MSR_NESTED_SCONTROL		0x40001080
> +#define HV_X64_MSR_NESTED_SVERSION		0x40001081
> +#define HV_X64_MSR_NESTED_SIEFP			0x40001082
> +#define HV_X64_MSR_NESTED_SIMP			0x40001083
> +#define HV_X64_MSR_NESTED_EOM			0x40001084
> +#define HV_X64_MSR_NESTED_SINT0			0x40001090
>  
>  /*
>   * Synthetic Timer MSRs. Four timers per vcpu.
>   */
> -#define HV_REGISTER_STIMER0_CONFIG		0x400000B0
> -#define HV_REGISTER_STIMER0_COUNT		0x400000B1
> -#define HV_REGISTER_STIMER1_CONFIG		0x400000B2
> -#define HV_REGISTER_STIMER1_COUNT		0x400000B3
> -#define HV_REGISTER_STIMER2_CONFIG		0x400000B4
> -#define HV_REGISTER_STIMER2_COUNT		0x400000B5
> -#define HV_REGISTER_STIMER3_CONFIG		0x400000B6
> -#define HV_REGISTER_STIMER3_COUNT		0x400000B7
> +#define HV_X64_MSR_STIMER0_CONFIG		0x400000B0
> +#define HV_X64_MSR_STIMER0_COUNT		0x400000B1
> +#define HV_X64_MSR_STIMER1_CONFIG		0x400000B2
> +#define HV_X64_MSR_STIMER1_COUNT		0x400000B3
> +#define HV_X64_MSR_STIMER2_CONFIG		0x400000B4
> +#define HV_X64_MSR_STIMER2_COUNT		0x400000B5
> +#define HV_X64_MSR_STIMER3_CONFIG		0x400000B6
> +#define HV_X64_MSR_STIMER3_COUNT		0x400000B7
>  
>  /* Hyper-V guest idle MSR */
>  #define HV_X64_MSR_GUEST_IDLE			0x400000F0
>  
>  /* Hyper-V guest crash notification MSR's */
> -#define HV_REGISTER_CRASH_P0			0x40000100
> -#define HV_REGISTER_CRASH_P1			0x40000101
> -#define HV_REGISTER_CRASH_P2			0x40000102
> -#define HV_REGISTER_CRASH_P3			0x40000103
> -#define HV_REGISTER_CRASH_P4			0x40000104
> -#define HV_REGISTER_CRASH_CTL			0x40000105
> +#define HV_X64_MSR_CRASH_P0			0x40000100
> +#define HV_X64_MSR_CRASH_P1			0x40000101
> +#define HV_X64_MSR_CRASH_P2			0x40000102
> +#define HV_X64_MSR_CRASH_P3			0x40000103
> +#define HV_X64_MSR_CRASH_P4			0x40000104
> +#define HV_X64_MSR_CRASH_CTL			0x40000105
>  
>  /* TSC emulation after migration */
>  #define HV_X64_MSR_REENLIGHTENMENT_CONTROL	0x40000106
> @@ -275,31 +275,30 @@ enum hv_isolation_type {
>  /* HV_X64_MSR_TSC_INVARIANT_CONTROL bits */
>  #define HV_EXPOSE_INVARIANT_TSC		BIT_ULL(0)
>  
> -/* Register name aliases for temporary compatibility */
> -#define HV_X64_MSR_STIMER0_COUNT	HV_REGISTER_STIMER0_COUNT
> -#define HV_X64_MSR_STIMER0_CONFIG	HV_REGISTER_STIMER0_CONFIG
> -#define HV_X64_MSR_STIMER1_COUNT	HV_REGISTER_STIMER1_COUNT
> -#define HV_X64_MSR_STIMER1_CONFIG	HV_REGISTER_STIMER1_CONFIG
> -#define HV_X64_MSR_STIMER2_COUNT	HV_REGISTER_STIMER2_COUNT
> -#define HV_X64_MSR_STIMER2_CONFIG	HV_REGISTER_STIMER2_CONFIG
> -#define HV_X64_MSR_STIMER3_COUNT	HV_REGISTER_STIMER3_COUNT
> -#define HV_X64_MSR_STIMER3_CONFIG	HV_REGISTER_STIMER3_CONFIG
> -#define HV_X64_MSR_SCONTROL		HV_REGISTER_SCONTROL
> -#define HV_X64_MSR_SVERSION		HV_REGISTER_SVERSION
> -#define HV_X64_MSR_SIMP			HV_REGISTER_SIMP
> -#define HV_X64_MSR_SIEFP		HV_REGISTER_SIEFP
> -#define HV_X64_MSR_VP_INDEX		HV_REGISTER_VP_INDEX
> -#define HV_X64_MSR_EOM			HV_REGISTER_EOM
> -#define HV_X64_MSR_SINT0		HV_REGISTER_SINT0
> -#define HV_X64_MSR_SINT15		HV_REGISTER_SINT15
> -#define HV_X64_MSR_CRASH_P0		HV_REGISTER_CRASH_P0
> -#define HV_X64_MSR_CRASH_P1		HV_REGISTER_CRASH_P1
> -#define HV_X64_MSR_CRASH_P2		HV_REGISTER_CRASH_P2
> -#define HV_X64_MSR_CRASH_P3		HV_REGISTER_CRASH_P3
> -#define HV_X64_MSR_CRASH_P4		HV_REGISTER_CRASH_P4
> -#define HV_X64_MSR_CRASH_CTL		HV_REGISTER_CRASH_CTL
> -#define HV_X64_MSR_TIME_REF_COUNT	HV_REGISTER_TIME_REF_COUNT
> -#define HV_X64_MSR_REFERENCE_TSC	HV_REGISTER_REFERENCE_TSC
> +/*
> + * To support non-arch-specific code calling hv_set/get_register:
> + * - On x86, HV_MSR_ indicates an MSR accessed via rdmsrl/wrmsrl
> + * - On ARM, HV_MSR_ indicates a VP register accessed via hypercall
> + */
> +#define HV_MSR_VP_INDEX		(HV_X64_MSR_VP_INDEX)
> +#define HV_MSR_TIME_REF_COUNT	(HV_X64_MSR_TIME_REF_COUNT)
> +#define HV_MSR_REFERENCE_TSC	(HV_X64_MSR_REFERENCE_TSC)
> +
> +#define HV_MSR_STIMER0_CONFIG	(HV_X64_MSR_STIMER0_CONFIG)
> +#define HV_MSR_STIMER0_COUNT	(HV_X64_MSR_STIMER0_COUNT)
> +
> +#define HV_MSR_SCONTROL		(HV_X64_MSR_SCONTROL)
> +#define HV_MSR_SIEFP		(HV_X64_MSR_SIEFP)
> +#define HV_MSR_SIMP		(HV_X64_MSR_SIMP)
> +#define HV_MSR_EOM		(HV_X64_MSR_EOM)
> +#define HV_MSR_SINT0		(HV_X64_MSR_SINT0)
> +
> +#define HV_MSR_CRASH_P0		(HV_X64_MSR_CRASH_P0)
> +#define HV_MSR_CRASH_P1		(HV_X64_MSR_CRASH_P1)
> +#define HV_MSR_CRASH_P2		(HV_X64_MSR_CRASH_P2)
> +#define HV_MSR_CRASH_P3		(HV_X64_MSR_CRASH_P3)
> +#define HV_MSR_CRASH_P4		(HV_X64_MSR_CRASH_P4)
> +#define HV_MSR_CRASH_CTL	(HV_X64_MSR_CRASH_CTL)
>  
>  /* Hyper-V memory host visibility */
>  enum hv_mem_host_visibility {
> diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
> index 88d9ef98e087..daaac502d411 100644
> --- a/arch/x86/include/asm/mshyperv.h
> +++ b/arch/x86/include/asm/mshyperv.h
> @@ -242,14 +242,14 @@ extern bool hv_isolation_type_snp(void);
>  
>  static inline bool hv_is_synic_reg(unsigned int reg)
>  {
> -	return (reg >= HV_REGISTER_SCONTROL) &&
> -	       (reg <= HV_REGISTER_SINT15);
> +	return (reg >= HV_X64_MSR_SCONTROL) &&
> +	       (reg <= HV_X64_MSR_SINT15);
>  }
>  
>  static inline bool hv_is_sint_reg(unsigned int reg)
>  {
> -	return (reg >= HV_REGISTER_SINT0) &&
> -	       (reg <= HV_REGISTER_SINT15);
> +	return (reg >= HV_X64_MSR_SINT0) &&
> +	       (reg <= HV_X64_MSR_SINT15);
>  }
>  
>  u64 hv_get_register(unsigned int reg);
> diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
> index c7969e806c64..4d38cafe6f2c 100644
> --- a/arch/x86/kernel/cpu/mshyperv.c
> +++ b/arch/x86/kernel/cpu/mshyperv.c
> @@ -43,19 +43,19 @@ struct ms_hyperv_info ms_hyperv;
>  static inline unsigned int hv_get_nested_reg(unsigned int reg)
>  {
>  	if (hv_is_sint_reg(reg))
> -		return reg - HV_REGISTER_SINT0 + HV_REGISTER_NESTED_SINT0;
> +		return reg - HV_X64_MSR_SINT0 + HV_X64_MSR_NESTED_SINT0;
>  
>  	switch (reg) {
> -	case HV_REGISTER_SIMP:
> -		return HV_REGISTER_NESTED_SIMP;
> -	case HV_REGISTER_SIEFP:
> -		return HV_REGISTER_NESTED_SIEFP;
> -	case HV_REGISTER_SVERSION:
> -		return HV_REGISTER_NESTED_SVERSION;
> -	case HV_REGISTER_SCONTROL:
> -		return HV_REGISTER_NESTED_SCONTROL;
> -	case HV_REGISTER_EOM:
> -		return HV_REGISTER_NESTED_EOM;
> +	case HV_X64_MSR_SIMP:
> +		return HV_X64_MSR_NESTED_SIMP;
> +	case HV_X64_MSR_SIEFP:
> +		return HV_X64_MSR_NESTED_SIEFP;
> +	case HV_X64_MSR_SVERSION:
> +		return HV_X64_MSR_NESTED_SVERSION;
> +	case HV_X64_MSR_SCONTROL:
> +		return HV_X64_MSR_NESTED_SCONTROL;
> +	case HV_X64_MSR_EOM:
> +		return HV_X64_MSR_NESTED_EOM;
>  	default:
>  		return reg;
>  	}
> diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c
> index e56307a81f4d..2e9fa88f25fe 100644
> --- a/drivers/clocksource/hyperv_timer.c
> +++ b/drivers/clocksource/hyperv_timer.c
> @@ -81,14 +81,14 @@ static int hv_ce_set_next_event(unsigned long delta,
>  
>  	current_tick = hv_read_reference_counter();
>  	current_tick += delta;
> -	hv_set_register(HV_REGISTER_STIMER0_COUNT, current_tick);
> +	hv_set_register(HV_MSR_STIMER0_COUNT, current_tick);
>  	return 0;
>  }
>  
>  static int hv_ce_shutdown(struct clock_event_device *evt)
>  {
> -	hv_set_register(HV_REGISTER_STIMER0_COUNT, 0);
> -	hv_set_register(HV_REGISTER_STIMER0_CONFIG, 0);
> +	hv_set_register(HV_MSR_STIMER0_COUNT, 0);
> +	hv_set_register(HV_MSR_STIMER0_CONFIG, 0);
>  	if (direct_mode_enabled && stimer0_irq >= 0)
>  		disable_percpu_irq(stimer0_irq);
>  
> @@ -119,7 +119,7 @@ static int hv_ce_set_oneshot(struct clock_event_device *evt)
>  		timer_cfg.direct_mode = 0;
>  		timer_cfg.sintx = stimer0_message_sint;
>  	}
> -	hv_set_register(HV_REGISTER_STIMER0_CONFIG, timer_cfg.as_uint64);
> +	hv_set_register(HV_MSR_STIMER0_CONFIG, timer_cfg.as_uint64);
>  	return 0;
>  }
>  
> @@ -373,10 +373,10 @@ static __always_inline u64 read_hv_clock_msr(void)
>  	 * nanosecond units.
>  	 *
>  	 * Use hv_raw_get_register() because this function is used from
> -	 * noinstr. Notable; while HV_REGISTER_TIME_REF_COUNT is a synthetic
> +	 * noinstr. Notable; while HV_MSR_TIME_REF_COUNT is a synthetic
>  	 * register it doesn't need the GHCB path.
>  	 */
> -	return hv_raw_get_register(HV_REGISTER_TIME_REF_COUNT);
> +	return hv_raw_get_register(HV_MSR_TIME_REF_COUNT);
>  }
>  
>  /*
> @@ -439,9 +439,9 @@ static void suspend_hv_clock_tsc(struct clocksource *arg)
>  	union hv_reference_tsc_msr tsc_msr;
>  
>  	/* Disable the TSC page */
> -	tsc_msr.as_uint64 = hv_get_register(HV_REGISTER_REFERENCE_TSC);
> +	tsc_msr.as_uint64 = hv_get_register(HV_MSR_REFERENCE_TSC);
>  	tsc_msr.enable = 0;
> -	hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64);
> +	hv_set_register(HV_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
>  }
>  
>  
> @@ -450,10 +450,10 @@ static void resume_hv_clock_tsc(struct clocksource *arg)
>  	union hv_reference_tsc_msr tsc_msr;
>  
>  	/* Re-enable the TSC page */
> -	tsc_msr.as_uint64 = hv_get_register(HV_REGISTER_REFERENCE_TSC);
> +	tsc_msr.as_uint64 = hv_get_register(HV_MSR_REFERENCE_TSC);
>  	tsc_msr.enable = 1;
>  	tsc_msr.pfn = tsc_pfn;
> -	hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64);
> +	hv_set_register(HV_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
>  }
>  
>  #ifdef HAVE_VDSO_CLOCKMODE_HVCLOCK
> @@ -555,14 +555,14 @@ static void __init hv_init_tsc_clocksource(void)
>  	 * thus TSC clocksource will work even without the real TSC page
>  	 * mapped.
>  	 */
> -	tsc_msr.as_uint64 = hv_get_register(HV_REGISTER_REFERENCE_TSC);
> +	tsc_msr.as_uint64 = hv_get_register(HV_MSR_REFERENCE_TSC);
>  	if (hv_root_partition)
>  		tsc_pfn = tsc_msr.pfn;
>  	else
>  		tsc_pfn = HVPFN_DOWN(virt_to_phys(tsc_page));
>  	tsc_msr.enable = 1;
>  	tsc_msr.pfn = tsc_pfn;
> -	hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64);
> +	hv_set_register(HV_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
>  
>  	clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100);
>  
> diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
> index de6708dbe0df..3ddacdebe886 100644
> --- a/drivers/hv/hv.c
> +++ b/drivers/hv/hv.c
> @@ -167,7 +167,7 @@ void hv_synic_enable_regs(unsigned int cpu)
>  	union hv_synic_scontrol sctrl;
>  
>  	/* Setup the Synic's message page */
> -	simp.as_uint64 = hv_get_register(HV_REGISTER_SIMP);
> +	simp.as_uint64 = hv_get_register(HV_MSR_SIMP);
>  	simp.simp_enabled = 1;
>  
>  	if (hv_isolation_type_snp() || hv_root_partition) {
> @@ -183,10 +183,10 @@ void hv_synic_enable_regs(unsigned int cpu)
>  			>> HV_HYP_PAGE_SHIFT;
>  	}
>  
> -	hv_set_register(HV_REGISTER_SIMP, simp.as_uint64);
> +	hv_set_register(HV_MSR_SIMP, simp.as_uint64);
>  
>  	/* Setup the Synic's event page */
> -	siefp.as_uint64 = hv_get_register(HV_REGISTER_SIEFP);
> +	siefp.as_uint64 = hv_get_register(HV_MSR_SIEFP);
>  	siefp.siefp_enabled = 1;
>  
>  	if (hv_isolation_type_snp() || hv_root_partition) {
> @@ -202,12 +202,12 @@ void hv_synic_enable_regs(unsigned int cpu)
>  			>> HV_HYP_PAGE_SHIFT;
>  	}
>  
> -	hv_set_register(HV_REGISTER_SIEFP, siefp.as_uint64);
> +	hv_set_register(HV_MSR_SIEFP, siefp.as_uint64);
>  
>  	/* Setup the shared SINT. */
>  	if (vmbus_irq != -1)
>  		enable_percpu_irq(vmbus_irq, 0);
> -	shared_sint.as_uint64 = hv_get_register(HV_REGISTER_SINT0 +
> +	shared_sint.as_uint64 = hv_get_register(HV_MSR_SINT0 +
>  					VMBUS_MESSAGE_SINT);
>  
>  	shared_sint.vector = vmbus_interrupt;
> @@ -223,14 +223,14 @@ void hv_synic_enable_regs(unsigned int cpu)
>  #else
>  	shared_sint.auto_eoi = 0;
>  #endif
> -	hv_set_register(HV_REGISTER_SINT0 + VMBUS_MESSAGE_SINT,
> +	hv_set_register(HV_MSR_SINT0 + VMBUS_MESSAGE_SINT,
>  				shared_sint.as_uint64);
>  
>  	/* Enable the global synic bit */
> -	sctrl.as_uint64 = hv_get_register(HV_REGISTER_SCONTROL);
> +	sctrl.as_uint64 = hv_get_register(HV_MSR_SCONTROL);
>  	sctrl.enable = 1;
>  
> -	hv_set_register(HV_REGISTER_SCONTROL, sctrl.as_uint64);
> +	hv_set_register(HV_MSR_SCONTROL, sctrl.as_uint64);
>  }
>  
>  int hv_synic_init(unsigned int cpu)
> @@ -254,17 +254,17 @@ void hv_synic_disable_regs(unsigned int cpu)
>  	union hv_synic_siefp siefp;
>  	union hv_synic_scontrol sctrl;
>  
> -	shared_sint.as_uint64 = hv_get_register(HV_REGISTER_SINT0 +
> +	shared_sint.as_uint64 = hv_get_register(HV_MSR_SINT0 +
>  					VMBUS_MESSAGE_SINT);
>  
>  	shared_sint.masked = 1;
>  
>  	/* Need to correctly cleanup in the case of SMP!!! */
>  	/* Disable the interrupt */
> -	hv_set_register(HV_REGISTER_SINT0 + VMBUS_MESSAGE_SINT,
> +	hv_set_register(HV_MSR_SINT0 + VMBUS_MESSAGE_SINT,
>  				shared_sint.as_uint64);
>  
> -	simp.as_uint64 = hv_get_register(HV_REGISTER_SIMP);
> +	simp.as_uint64 = hv_get_register(HV_MSR_SIMP);
>  	/*
>  	 * In Isolation VM, sim and sief pages are allocated by
>  	 * paravisor. These pages also will be used by kdump
> @@ -279,9 +279,9 @@ void hv_synic_disable_regs(unsigned int cpu)
>  		simp.base_simp_gpa = 0;
>  	}
>  
> -	hv_set_register(HV_REGISTER_SIMP, simp.as_uint64);
> +	hv_set_register(HV_MSR_SIMP, simp.as_uint64);
>  
> -	siefp.as_uint64 = hv_get_register(HV_REGISTER_SIEFP);
> +	siefp.as_uint64 = hv_get_register(HV_MSR_SIEFP);
>  	siefp.siefp_enabled = 0;
>  
>  	if (hv_isolation_type_snp() || hv_root_partition) {
> @@ -291,12 +291,12 @@ void hv_synic_disable_regs(unsigned int cpu)
>  		siefp.base_siefp_gpa = 0;
>  	}
>  
> -	hv_set_register(HV_REGISTER_SIEFP, siefp.as_uint64);
> +	hv_set_register(HV_MSR_SIEFP, siefp.as_uint64);
>  
>  	/* Disable the global synic bit */
> -	sctrl.as_uint64 = hv_get_register(HV_REGISTER_SCONTROL);
> +	sctrl.as_uint64 = hv_get_register(HV_MSR_SCONTROL);
>  	sctrl.enable = 0;
> -	hv_set_register(HV_REGISTER_SCONTROL, sctrl.as_uint64);
> +	hv_set_register(HV_MSR_SCONTROL, sctrl.as_uint64);
>  
>  	if (vmbus_irq != -1)
>  		disable_percpu_irq(vmbus_irq);
> diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
> index 542a1d53b303..790b96290360 100644
> --- a/drivers/hv/hv_common.c
> +++ b/drivers/hv/hv_common.c
> @@ -227,17 +227,17 @@ static void hv_kmsg_dump(struct kmsg_dumper *dumper,
>  	 * contain the size of the panic data in that page. Rest of the
>  	 * registers are no-op when the NOTIFY_MSG flag is set.
>  	 */
> -	hv_set_register(HV_REGISTER_CRASH_P0, 0);
> -	hv_set_register(HV_REGISTER_CRASH_P1, 0);
> -	hv_set_register(HV_REGISTER_CRASH_P2, 0);
> -	hv_set_register(HV_REGISTER_CRASH_P3, virt_to_phys(hv_panic_page));
> -	hv_set_register(HV_REGISTER_CRASH_P4, bytes_written);
> +	hv_set_register(HV_MSR_CRASH_P0, 0);
> +	hv_set_register(HV_MSR_CRASH_P1, 0);
> +	hv_set_register(HV_MSR_CRASH_P2, 0);
> +	hv_set_register(HV_MSR_CRASH_P3, virt_to_phys(hv_panic_page));
> +	hv_set_register(HV_MSR_CRASH_P4, bytes_written);
>  
>  	/*
>  	 * Let Hyper-V know there is crash data available along with
>  	 * the panic message.
>  	 */
> -	hv_set_register(HV_REGISTER_CRASH_CTL,
> +	hv_set_register(HV_MSR_CRASH_CTL,
>  			(HV_CRASH_CTL_CRASH_NOTIFY |
>  			 HV_CRASH_CTL_CRASH_NOTIFY_MSG));
>  }
> @@ -310,7 +310,7 @@ int __init hv_common_init(void)
>  		 * Register for panic kmsg callback only if the right
>  		 * capability is supported by the hypervisor.
>  		 */
> -		hyperv_crash_ctl = hv_get_register(HV_REGISTER_CRASH_CTL);
> +		hyperv_crash_ctl = hv_get_register(HV_MSR_CRASH_CTL);
>  		if (hyperv_crash_ctl & HV_CRASH_CTL_CRASH_NOTIFY_MSG)
>  			hv_kmsg_dump_register();
>  
> @@ -380,7 +380,7 @@ int hv_common_cpu_init(unsigned int cpu)
>  		}
>  	}
>  
> -	msr_vp_index = hv_get_register(HV_REGISTER_VP_INDEX);
> +	msr_vp_index = hv_get_register(HV_MSR_VP_INDEX);
>  
>  	hv_vp_index[cpu] = msr_vp_index;
>  
> @@ -477,7 +477,7 @@ EXPORT_SYMBOL_GPL(hv_is_hibernation_supported);
>   */
>  static u64 __hv_read_ref_counter(void)
>  {
> -	return hv_get_register(HV_REGISTER_TIME_REF_COUNT);
> +	return hv_get_register(HV_MSR_TIME_REF_COUNT);
>  }
>  
>  u64 (*hv_read_reference_counter)(void) = __hv_read_ref_counter;
> diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
> index 402a8c1c202d..094c57320ed1 100644
> --- a/include/asm-generic/mshyperv.h
> +++ b/include/asm-generic/mshyperv.h
> @@ -149,7 +149,7 @@ static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
>  		 * possibly deliver another msg from the
>  		 * hypervisor
>  		 */
> -		hv_set_register(HV_REGISTER_EOM, 0);
> +		hv_set_register(HV_MSR_EOM, 0);
>  	}
>  }
>  
> -- 
> 2.25.1
> 

Re: [PATCH v2 15/15] Drivers: hv: Add modules to expose /dev/mshv to VMMs running on Hyper-V

[Nuno Das Neves]

On 8/18/2023 6:08 AM, Saurabh Singh Sengar wrote:
>> +
>> +config MSHV_VTL
>> +	tristate "Microsoft Hyper-V VTL driver"
>> +	depends on MSHV
>> +	select HYPERV_VTL_MODE
>> +	select TRANSPARENT_HUGEPAGE
> 
> TRANSPARENT_HUGEPAGE can be avoided for now.
> 

I will remove it in the next version. Thanks.
>> +
>> +#define HV_GET_REGISTER_BATCH_SIZE	\
>> +	(HV_HYP_PAGE_SIZE / sizeof(union hv_register_value))
>> +#define HV_SET_REGISTER_BATCH_SIZE	\
>> +	((HV_HYP_PAGE_SIZE - sizeof(struct hv_input_set_vp_registers)) \
>> +		/ sizeof(struct hv_register_assoc))
>> +
>> +int hv_call_get_vp_registers(
>> +		u32 vp_index,
>> +		u64 partition_id,
>> +		u16 count,
>> +		union hv_input_vtl input_vtl,
>> +		struct hv_register_assoc *registers)
>> +{
>> +	struct hv_input_get_vp_registers *input_page;
>> +	union hv_register_value *output_page;
>> +	u16 completed = 0;
>> +	unsigned long remaining = count;
>> +	int rep_count, i;
>> +	u64 status;
>> +	unsigned long flags;
>> +
>> +	local_irq_save(flags);
>> +
>> +	input_page = *this_cpu_ptr(hyperv_pcpu_input_arg);
>> +	output_page = *this_cpu_ptr(hyperv_pcpu_output_arg);
>> +
>> +	input_page->partition_id = partition_id;
>> +	input_page->vp_index = vp_index;
>> +	input_page->input_vtl.as_uint8 = input_vtl.as_uint8;
>> +	input_page->rsvd_z8 = 0;
>> +	input_page->rsvd_z16 = 0;
>> +
>> +	while (remaining) {
>> +		rep_count = min(remaining, HV_GET_REGISTER_BATCH_SIZE);
>> +		for (i = 0; i < rep_count; ++i)
>> +			input_page->names[i] = registers[i].name;
>> +
>> +		status = hv_do_rep_hypercall(HVCALL_GET_VP_REGISTERS,
>> rep_count,
>> +					     0, input_page, output_page);
> 
> Is there any possibility that count value is passed 0 by mistake ? In that case
> status will remain uninitialized. 
> 

These lines ensure rep_count is never 0 here:

	while (remaining) {
		rep_count = min(remaining, HV_GET_REGISTER_BATCH_SIZE);

Remaining can't be 0 or the loop would exit, and HV_GET_REGISTER_BATCH_SIZE
is not 0, or we would never get any registers.

>> diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
>> index 13f972e72375..ccd76f30a638 100644
>> --- a/drivers/hv/hv_common.c
>> +++ b/drivers/hv/hv_common.c
>> @@ -62,7 +62,11 @@ EXPORT_SYMBOL_GPL(hyperv_pcpu_output_arg);
>>   */
>>  static inline bool hv_output_arg_exists(void)
>>  {
>> +#ifdef CONFIG_MSHV_VTL
> 
> Although today both the option works together. But thinking
> which is more accurate CONFIG_HYPERV_VTL_MODE or
> CONFIG_MSHV_VTL here for scalability of VTL modules.
> 

Good point. Though I'm not sure it matters too much right now,
since as you mention they will always be enabled together.

Does CONFIG_HYPERV_VTL_MODE use the output arg?

>> diff --git a/drivers/hv/mshv.h b/drivers/hv/mshv.h
>> new file mode 100644
>> index 000000000000..166480a73f3f
>> --- /dev/null
>> +++ b/drivers/hv/mshv.h
>> @@ -0,0 +1,156 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +/*
>> + * Copyright (c) 2023, Microsoft Corporation.
>> + */
>> +
>> +#ifndef _MSHV_H_
>> +#define _MSHV_H_
>> +
>> +#include <linux/spinlock.h>
>> +#include <linux/mutex.h>
>> +#include <linux/semaphore.h>
>> +#include <linux/sched.h>
>> +#include <linux/srcu.h>
>> +#include <linux/wait.h>
>> +#include <uapi/linux/mshv.h>
>> +
>> +/*
>> + * Hyper-V hypercalls
>> + */
>> +
>> +int hv_call_withdraw_memory(u64 count, int node, u64 partition_id);
>> +int hv_call_create_partition(
>> +		u64 flags,
>> +		struct hv_partition_creation_properties creation_properties,
>> +		union hv_partition_isolation_properties isolation_properties,
>> +		u64 *partition_id);
>> +int hv_call_initialize_partition(u64 partition_id);
>> +int hv_call_finalize_partition(u64 partition_id);
>> +int hv_call_delete_partition(u64 partition_id);
>> +int hv_call_map_gpa_pages(
>> +		u64 partition_id,
>> +		u64 gpa_target,
>> +		u64 page_count, u32 flags,
>> +		struct page **pages);
>> +int hv_call_unmap_gpa_pages(
>> +		u64 partition_id,
>> +		u64 gpa_target,
>> +		u64 page_count, u32 flags);
>> +int hv_call_get_vp_registers(
>> +		u32 vp_index,
>> +		u64 partition_id,
>> +		u16 count,
>> +		union hv_input_vtl input_vtl,
>> +		struct hv_register_assoc *registers);
>> +int hv_call_get_gpa_access_states(
>> +		u64 partition_id,
>> +		u32 count,
>> +		u64 gpa_base_pfn,
>> +		u64 state_flags,
>> +		int *written_total,
>> +		union hv_gpa_page_access_state *states);
>> +
>> +int hv_call_set_vp_registers(
>> +		u32 vp_index,
>> +		u64 partition_id,
>> +		u16 count,
>> +		union hv_input_vtl input_vtl,
>> +		struct hv_register_assoc *registers);
> 
> Nit: Opportunity to fix many of the checkpatch.pl related to line break here
> and many other places.
> 

checkpatch.pl doesn't complain about anything in this file.

>> +static int
>> +mshv_assign_ioeventfd(struct mshv_partition *partition,
>> +		      struct mshv_ioeventfd *args)
>> +	__must_hold(&partition->mutex)
>> +{
>> +	struct kernel_mshv_ioeventfd *p;
>> +	struct eventfd_ctx *eventfd;
>> +	u64 doorbell_flags = 0;
>> +	int ret;
>> +
>> +	/* This mutex is currently protecting ioeventfd.items list */
>> +	WARN_ON_ONCE(!mutex_is_locked(&partition->mutex));
>> +
>> +	if (args->flags & MSHV_IOEVENTFD_FLAG_PIO)
>> +		return -EOPNOTSUPP;
>> +
>> +	/* must be natural-word sized */
>> +	switch (args->len) {
>> +	case 0:
>> +		doorbell_flags = HV_DOORBELL_FLAG_TRIGGER_SIZE_ANY;
>> +		break;
>> +	case 1:
>> +		doorbell_flags = HV_DOORBELL_FLAG_TRIGGER_SIZE_BYTE;
>> +		break;
>> +	case 2:
>> +		doorbell_flags = HV_DOORBELL_FLAG_TRIGGER_SIZE_WORD;
>> +		break;
>> +	case 4:
>> +		doorbell_flags =
>> HV_DOORBELL_FLAG_TRIGGER_SIZE_DWORD;
>> +		break;
>> +	case 8:
>> +		doorbell_flags =
>> HV_DOORBELL_FLAG_TRIGGER_SIZE_QWORD;
>> +		break;
>> +	default:
>> +		pr_warn("ioeventfd: invalid length specified\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	/* check for range overflow */
>> +	if (args->addr + args->len < args->addr)
>> +		return -EINVAL;
>> +
>> +	/* check for extra flags that we don't understand */
>> +	if (args->flags & ~MSHV_IOEVENTFD_VALID_FLAG_MASK)
>> +		return -EINVAL;
>> +
>> +	eventfd = eventfd_ctx_fdget(args->fd);
>> +	if (IS_ERR(eventfd))
>> +		return PTR_ERR(eventfd);
>> +
>> +	p = kzalloc(sizeof(*p), GFP_KERNEL);
>> +	if (!p) {
>> +		ret = -ENOMEM;
>> +		goto fail;
>> +	}
>> +
>> +	p->addr    = args->addr;
>> +	p->length  = args->len;
>> +	p->eventfd = eventfd;
>> +
>> +	/* The datamatch feature is optional, otherwise this is a wildcard */
>> +	if (args->flags & MSHV_IOEVENTFD_FLAG_DATAMATCH)
>> +		p->datamatch = args->datamatch;
>> +	else {
>> +		p->wildcard = true;
>> +		doorbell_flags |=
>> HV_DOORBELL_FLAG_TRIGGER_ANY_VALUE;
>> +	}
>> +
>> +	if (ioeventfd_check_collision(partition, p)) {
>> +		ret = -EEXIST;
>> +		goto unlock_fail;
>> +	}
>> +
>> +	ret = mshv_register_doorbell(partition->id, ioeventfd_mmio_write,
>> +				     (void *)partition, p->addr,
>> +				     p->datamatch, doorbell_flags);
>> +	if (ret < 0) {
>> +		pr_err("Failed to register ioeventfd doorbell!\n");
> 
> Nit: Do we like to print function name at the start of pr_err. 
> 

Yes, we should. I will fix it. Thanks!

Re: [PATCH v2 05/15] hyperv: Move hv_connection_id to hyperv-tlfs

[Wei Liu]

On Thu, Aug 17, 2023 at 03:01:41PM -0700, Nuno Das Neves wrote:
> The definition conflicts with one added in hvgdk.h as part of the mshv
> driver so must be moved to hyperv-tlfs.h.
> 
> This structure should be in hyperv-tlfs.h anyway, since it is part of
> the TLFS document.
> 
> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>

Acked-by: Wei Liu <wei.liu@kernel.org>

Re: [PATCH v2 06/15] hyperv-tlfs: Introduce hv_status_to_string and hv_status_to_errno

[Wei Liu]

On Thu, Aug 17, 2023 at 03:01:42PM -0700, Nuno Das Neves wrote:
> hv_status_to_errno translates hyperv statuses to linux error codes.
> This is useful for returning something linux-friendly from a hypercall
> helper function.
> 
> hv_status_to_string improves clarity of error messages.
> 
> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>

Acked-by: Wei Liu <wei.liu@kernel.org>

Re: [PATCH v2 09/15] Drivers: hv: Introduce hv_output_arg_exists in hv_common.c

[Wei Liu]

On Thu, Aug 17, 2023 at 03:01:45PM -0700, Nuno Das Neves wrote:
> This is a more flexible approach for determining whether to allocate the
> output page.
> 
> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>

Acked-by: Wei Liu <wei.liu@kernel.org>

Re: [PATCH v2 12/15] Documentation: Reserve ioctl number for mshv driver

[Wei Liu]

On Thu, Aug 17, 2023 at 03:01:48PM -0700, Nuno Das Neves wrote:
> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
> Acked-by: Jonathan Corbet <corbet@lwn.net>

Acked-by: Wei Liu <wei.liu@kernel.org>

Re: [PATCH v2 08/15] Drivers: hv: Introduce per-cpu event ring tail

[Wei Liu]

On Thu, Aug 17, 2023 at 03:01:44PM -0700, Nuno Das Neves wrote:
> Add a pointer hv_synic_eventring_tail to track the tail pointer for the
> SynIC event ring buffer for each SINT.
> 
> This will be used by the mshv driver, but must be tracked independently
> since the driver module could be removed and re-inserted.
> 
> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>

Reviewed-by: Wei Liu <wei.liu@kernel.org>

Re: [PATCH v2 14/15] asm-generic: hyperv: Use mshv headers conditionally. Add asm-generic/hyperv-defs.h

[Wei Liu]

On Thu, Aug 17, 2023 at 03:01:50PM -0700, Nuno Das Neves wrote:
> Add hyperv-defs.h to replace some inclusions of hyperv-tlfs.h.
> 
> It includes hyperv-tlfs.h or hvhdk.h depending on a compile-time constant
> HV_HYPERV_DEFS which will be defined in the mshv driver.
> 
> This is needed to keep unstable Hyper-V interfaces independent of
> hyperv-tlfs.h. This ensures hvhdk.h replaces hyperv-tlfs.h in the mshv driver,
> even via indirect includes.
> 
> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>

Acked-by: Wei Liu <wei.liu@kernel.org>

Re: [PATCH v2 13/15] uapi: hyperv: Add mshv driver headers hvhdk.h, hvhdk_mini.h, hvgdk.h, hvgdk_mini.h

[Greg KH]

On Thu, Aug 17, 2023 at 11:01:46PM +0000, Wei Liu wrote:
> On Thu, Aug 17, 2023 at 03:01:49PM -0700, Nuno Das Neves wrote:
> > Containing hypervisor ABI definitions to use in mshv driver.
> > 
> > Version numbers for each file:
> > hvhdk.h		25212
> > hvhdk_mini.h	25294
> > hvgdk.h		25125
> > hvgdk_mini.h	25294
> > 
> > These are unstable interfaces and as such must be compiled independently
> > from published interfaces found in hyperv-tlfs.h.
> > 
> > These are in uapi because they will be used in the mshv ioctl API.
> > 
> > Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
> > Acked-by: Wei Liu <wei.liu@kernel.org>
> 
> There were some concerns raised internally about the stability of the
> APIs when they are put into UAPI.
> 
> I think this is still okay, for a few reasons:
> 
>   1. When KVM was first introduced into the kernel tree, it was
>      experimental. It was only made stable after some time.
>   2. There are other experimental or unstable APIs in UAPI. They
>      are clearly marked so.
>   3. The coda file system, which has been in tree since 2008, has a
>      header file in UAPI which clearly marks as experimental.
> 
> All in all introducing a set of unstable / experimental APIs under UAPI
> is not unheard of. Rules could've changed now, but I don't find any
> document under Documentation/.
> 
> I think it will be valuable to have this driver in tree sooner rather
> than later, so that it can evolve with Linux kernel, and we can in turn
> go back to the hypervisor side to gradually stabilize the APIs.
> 
> Greg, I'm told that you may have a strong opinion in this area. Please
> let me know what you think about this.

My "strong" opinion is the one kernel development rule that we have,
"you can not break userspace".  So, if you change these
values/structures/whatever in the future, and userspace tools break,
that's not ok and the changes have to be reverted.

If you can control both sides of the API here (with open tools that you
can guarantee everyone will always update to), then yes, you can change
the api in the future.

It's really really hard to make a stable api the first time around, but
we have "tricks" for how to do it well, and ensure that you can slowly
change it over time (proper use of flags and zero-checked padding), but
almost always the simplest way is to just add new apis and keep
supporting the old ones by internally calling the new functions instead.

So, what do you think will change here in the future and why can't you
say "this is stable" now?  You have working userspace code for this api,
right?  What is left to be developed for it?

thanks,

greg k-h

RE: [PATCH v2 15/15] Drivers: hv: Add modules to expose /dev/mshv to VMMs running on Hyper-V

[Saurabh Singh Sengar]

> -----Original Message-----
> From: Nuno Das Neves <nunodasneves@linux.microsoft.com>
> Sent: Saturday, August 19, 2023 12:30 AM
> To: Saurabh Singh Sengar <ssengar@microsoft.com>; linux-
> hyperv@vger.kernel.org; linux-kernel@vger.kernel.org; x86@kernel.org; linux-
> arm-kernel@lists.infradead.org; linux-arch@vger.kernel.org
> Cc: patches@lists.linux.dev; Michael Kelley (LINUX)
> <mikelley@microsoft.com>; KY Srinivasan <kys@microsoft.com>;
> wei.liu@kernel.org; Haiyang Zhang <haiyangz@microsoft.com>; Dexuan Cui
> <decui@microsoft.com>; apais@linux.microsoft.com; Tianyu Lan
> <Tianyu.Lan@microsoft.com>; ssengar@linux.microsoft.com; MUKESH
> RATHOR <mukeshrathor@microsoft.com>; stanislav.kinsburskiy@gmail.com;
> jinankjain@linux.microsoft.com; vkuznets <vkuznets@redhat.com>;
> tglx@linutronix.de; mingo@redhat.com; bp@alien8.de;
> dave.hansen@linux.intel.com; hpa@zytor.com; will@kernel.org;
> catalin.marinas@arm.com
> Subject: Re: [PATCH v2 15/15] Drivers: hv: Add modules to expose /dev/mshv
> to VMMs running on Hyper-V
> 
> On 8/18/2023 6:08 AM, Saurabh Singh Sengar wrote:
> >> +
> >> +config MSHV_VTL
> >> +	tristate "Microsoft Hyper-V VTL driver"
> >> +	depends on MSHV
> >> +	select HYPERV_VTL_MODE
> >> +	select TRANSPARENT_HUGEPAGE
> >
> > TRANSPARENT_HUGEPAGE can be avoided for now.
> >
> 
> I will remove it in the next version. Thanks.
> >> +
> >> +#define HV_GET_REGISTER_BATCH_SIZE	\
> >> +	(HV_HYP_PAGE_SIZE / sizeof(union hv_register_value))
> >> +#define HV_SET_REGISTER_BATCH_SIZE	\
> >> +	((HV_HYP_PAGE_SIZE - sizeof(struct hv_input_set_vp_registers)) \
> >> +		/ sizeof(struct hv_register_assoc))
> >> +
> >> +int hv_call_get_vp_registers(
> >> +		u32 vp_index,
> >> +		u64 partition_id,
> >> +		u16 count,
> >> +		union hv_input_vtl input_vtl,
> >> +		struct hv_register_assoc *registers) {
> >> +	struct hv_input_get_vp_registers *input_page;
> >> +	union hv_register_value *output_page;
> >> +	u16 completed = 0;
> >> +	unsigned long remaining = count;
> >> +	int rep_count, i;
> >> +	u64 status;
> >> +	unsigned long flags;
> >> +
> >> +	local_irq_save(flags);
> >> +
> >> +	input_page = *this_cpu_ptr(hyperv_pcpu_input_arg);
> >> +	output_page = *this_cpu_ptr(hyperv_pcpu_output_arg);
> >> +
> >> +	input_page->partition_id = partition_id;
> >> +	input_page->vp_index = vp_index;
> >> +	input_page->input_vtl.as_uint8 = input_vtl.as_uint8;
> >> +	input_page->rsvd_z8 = 0;
> >> +	input_page->rsvd_z16 = 0;
> >> +
> >> +	while (remaining) {
> >> +		rep_count = min(remaining, HV_GET_REGISTER_BATCH_SIZE);
> >> +		for (i = 0; i < rep_count; ++i)
> >> +			input_page->names[i] = registers[i].name;
> >> +
> >> +		status = hv_do_rep_hypercall(HVCALL_GET_VP_REGISTERS,
> >> rep_count,
> >> +					     0, input_page, output_page);
> >
> > Is there any possibility that count value is passed 0 by mistake ? In
> > that case status will remain uninitialized.
> >
> 
> These lines ensure rep_count is never 0 here:
> 
> 	while (remaining) {
> 		rep_count = min(remaining, HV_GET_REGISTER_BATCH_SIZE);
> 
> Remaining can't be 0 or the loop would exit, and
> HV_GET_REGISTER_BATCH_SIZE is not 0, or we would never get any registers.

There is a parameter in this function "count". I was checking if there is any possibility
that is passed as 0 by mistake ? this will lead to "remaining" value as 0 and loop will never
execute. Which results using "status" uninitialized later in the function.


> 
> >> diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c index
> >> 13f972e72375..ccd76f30a638 100644
> >> --- a/drivers/hv/hv_common.c
> >> +++ b/drivers/hv/hv_common.c
> >> @@ -62,7 +62,11 @@ EXPORT_SYMBOL_GPL(hyperv_pcpu_output_arg);
> >>   */
> >>  static inline bool hv_output_arg_exists(void)  {
> >> +#ifdef CONFIG_MSHV_VTL
> >
> > Although today both the option works together. But thinking
> > which is more accurate CONFIG_HYPERV_VTL_MODE or
> > CONFIG_MSHV_VTL here for scalability of VTL modules.
> >
> 
> Good point. Though I'm not sure it matters too much right now,
> since as you mention they will always be enabled together.
> 
> Does CONFIG_HYPERV_VTL_MODE use the output arg?

Currently its not, I think MSHV_VTL is good for now. Thanks.

> 
> >> diff --git a/drivers/hv/mshv.h b/drivers/hv/mshv.h
> >> new file mode 100644
> >> index 000000000000..166480a73f3f
> >> --- /dev/null
> >> +++ b/drivers/hv/mshv.h
> >> @@ -0,0 +1,156 @@
> >> +/* SPDX-License-Identifier: GPL-2.0-only */
> >> +/*
> >> + * Copyright (c) 2023, Microsoft Corporation.
> >> + */
> >> +
> >> +#ifndef _MSHV_H_
> >> +#define _MSHV_H_
> >> +
> >> +#include <linux/spinlock.h>
> >> +#include <linux/mutex.h>
> >> +#include <linux/semaphore.h>
> >> +#include <linux/sched.h>
> >> +#include <linux/srcu.h>
> >> +#include <linux/wait.h>
> >> +#include <uapi/linux/mshv.h>
> >> +
> >> +/*
> >> + * Hyper-V hypercalls
> >> + */
> >> +
> >> +int hv_call_withdraw_memory(u64 count, int node, u64 partition_id);
> >> +int hv_call_create_partition(
> >> +		u64 flags,
> >> +		struct hv_partition_creation_properties creation_properties,
> >> +		union hv_partition_isolation_properties isolation_properties,
> >> +		u64 *partition_id);
> >> +int hv_call_initialize_partition(u64 partition_id);
> >> +int hv_call_finalize_partition(u64 partition_id);
> >> +int hv_call_delete_partition(u64 partition_id);
> >> +int hv_call_map_gpa_pages(
> >> +		u64 partition_id,
> >> +		u64 gpa_target,
> >> +		u64 page_count, u32 flags,
> >> +		struct page **pages);
> >> +int hv_call_unmap_gpa_pages(
> >> +		u64 partition_id,
> >> +		u64 gpa_target,
> >> +		u64 page_count, u32 flags);
> >> +int hv_call_get_vp_registers(
> >> +		u32 vp_index,
> >> +		u64 partition_id,
> >> +		u16 count,
> >> +		union hv_input_vtl input_vtl,
> >> +		struct hv_register_assoc *registers);
> >> +int hv_call_get_gpa_access_states(
> >> +		u64 partition_id,
> >> +		u32 count,
> >> +		u64 gpa_base_pfn,
> >> +		u64 state_flags,
> >> +		int *written_total,
> >> +		union hv_gpa_page_access_state *states);
> >> +
> >> +int hv_call_set_vp_registers(
> >> +		u32 vp_index,
> >> +		u64 partition_id,
> >> +		u16 count,
> >> +		union hv_input_vtl input_vtl,
> >> +		struct hv_register_assoc *registers);
> >
> > Nit: Opportunity to fix many of the checkpatch.pl related to line break here
> > and many other places.
> >
> 
> checkpatch.pl doesn't complain about anything in this file.

If we use --strict switch with checkpatch.pl we observe additional CHECK(s).
I observe 159 CHECK(s) with this patch overall.
(total: 1 errors, 7 warnings, 159 checks, 7460 lines checked)
Few examples:

CHECK: Lines should not end with a '('
#240: FILE: drivers/hv/hv_call.c:73:
+int hv_call_set_vp_registers(

CHECK: Alignment should match open parenthesis
#266: FILE: drivers/hv/hv_call.c:99:
+               memcpy(input_page->elements, registers,
+                       sizeof(struct hv_register_assoc) * rep_count);


I also see an error with flexible array, possibly we can fix that as well.

ERROR: Use C99 flexible arrays - see https://docs.kernel.org/process/deprecated.html#zero-length-and-one-element-arrays
#7468: FILE: include/uapi/linux/mshv.h:134:
+       struct mshv_msi_routing_entry entries[0];
+};

- Saurabh

RE: [PATCH v2 15/15] Drivers: hv: Add modules to expose /dev/mshv to VMMs running on Hyper-V

[Saurabh Singh Sengar]

> -----Original Message-----
> From: Nuno Das Neves <nunodasneves@linux.microsoft.com>
> Sent: Friday, August 18, 2023 3:32 AM
> To: linux-hyperv@vger.kernel.org; linux-kernel@vger.kernel.org;
> x86@kernel.org; linux-arm-kernel@lists.infradead.org; linux-
> arch@vger.kernel.org
> Cc: patches@lists.linux.dev; Michael Kelley (LINUX)
> <mikelley@microsoft.com>; KY Srinivasan <kys@microsoft.com>;
> wei.liu@kernel.org; Haiyang Zhang <haiyangz@microsoft.com>; Dexuan Cui
> <decui@microsoft.com>; apais@linux.microsoft.com; Tianyu Lan
> <Tianyu.Lan@microsoft.com>; ssengar@linux.microsoft.com; MUKESH
> RATHOR <mukeshrathor@microsoft.com>; stanislav.kinsburskiy@gmail.com;
> jinankjain@linux.microsoft.com; vkuznets <vkuznets@redhat.com>;
> tglx@linutronix.de; mingo@redhat.com; bp@alien8.de;
> dave.hansen@linux.intel.com; hpa@zytor.com; will@kernel.org;
> catalin.marinas@arm.com
> Subject: [PATCH v2 15/15] Drivers: hv: Add modules to expose /dev/mshv to
> VMMs running on Hyper-V
> 
> Add mshv, mshv_root, and mshv_vtl modules:
> 

<snip>

> +	ret = mshv_set_vp_registers(vp->index, vp->partition->id,
> +				    1, &dispatch_suspend);
> +	if (ret)
> +		pr_err("%s: failed to suspend partition %llu vp %u\n",
> +			__func__, vp->partition->id, vp->index);
> +
> +	return ret;
> +}
> +
> +static int
> +get_vp_signaled_count(struct mshv_vp *vp, u64 *count)
> +{
> +	int ret;
> +	struct hv_register_assoc root_signal_count = {
> +		.name = HV_REGISTER_VP_ROOT_SIGNAL_COUNT,
> +	};
> +
> +	ret = mshv_get_vp_registers(vp->index, vp->partition->id,
> +				    1, &root_signal_count);
> +
> +	if (ret) {
> +		pr_err("%s: failed to get root signal count for partition %llu vp
> %u",
> +			__func__, vp->partition->id, vp->index);
> +		*count = 0;

Have we missed a return here ?
Moreover, the return type of this function is never checked consider
checking it or change it to void.

<snip>

> +
> +/* Retrieve and stash the supported scheduler type */
> +static int __init mshv_retrieve_scheduler_type(void)
> +{
> +	struct hv_input_get_system_property *input;
> +	struct hv_output_get_system_property *output;
> +	unsigned long flags;
> +	u64 status;
> +
> +	local_irq_save(flags);
> +	input = *this_cpu_ptr(hyperv_pcpu_input_arg);
> +	output = *this_cpu_ptr(hyperv_pcpu_output_arg);
> +
> +	memset(input, 0, sizeof(*input));
> +	memset(output, 0, sizeof(*output));
> +	input->property_id = HV_SYSTEM_PROPERTY_SCHEDULER_TYPE;
> +
> +	status = hv_do_hypercall(HVCALL_GET_SYSTEM_PROPERTY, input,
> output);
> +	if (!hv_result_success(status)) {
> +		local_irq_restore(flags);
> +		pr_err("%s: %s\n", __func__, hv_status_to_string(status));
> +		return hv_status_to_errno(status);
> +	}
> +
> +	hv_scheduler_type = output->scheduler_type;
> +	local_irq_restore(flags);
> +
> +	pr_info("mshv: hypervisor using %s\n",
> scheduler_type_to_string(hv_scheduler_type));

Nit: In this file we are using two styles of prints, few are appended with
"mshv:" and few with "__func__".  It's better to have a single style
for one module.

Re: [PATCH v2 15/15] Drivers: hv: Add modules to expose /dev/mshv to VMMs running on Hyper-V

[Nuno Das Neves]

On 8/19/2023 10:19 PM, Saurabh Singh Sengar wrote:
> 
> 
>> -----Original Message-----
>> From: Nuno Das Neves <nunodasneves@linux.microsoft.com>
>> Sent: Saturday, August 19, 2023 12:30 AM
>> To: Saurabh Singh Sengar <ssengar@microsoft.com>; linux-
>> hyperv@vger.kernel.org; linux-kernel@vger.kernel.org; x86@kernel.org; linux-
>> arm-kernel@lists.infradead.org; linux-arch@vger.kernel.org
>> Cc: patches@lists.linux.dev; Michael Kelley (LINUX)
>> <mikelley@microsoft.com>; KY Srinivasan <kys@microsoft.com>;
>> wei.liu@kernel.org; Haiyang Zhang <haiyangz@microsoft.com>; Dexuan Cui
>> <decui@microsoft.com>; apais@linux.microsoft.com; Tianyu Lan
>> <Tianyu.Lan@microsoft.com>; ssengar@linux.microsoft.com; MUKESH
>> RATHOR <mukeshrathor@microsoft.com>; stanislav.kinsburskiy@gmail.com;
>> jinankjain@linux.microsoft.com; vkuznets <vkuznets@redhat.com>;
>> tglx@linutronix.de; mingo@redhat.com; bp@alien8.de;
>> dave.hansen@linux.intel.com; hpa@zytor.com; will@kernel.org;
>> catalin.marinas@arm.com
>> Subject: Re: [PATCH v2 15/15] Drivers: hv: Add modules to expose /dev/mshv
>> to VMMs running on Hyper-V
>>
>> On 8/18/2023 6:08 AM, Saurabh Singh Sengar wrote:
>>>> +
>>>> +config MSHV_VTL
>>>> +	tristate "Microsoft Hyper-V VTL driver"
>>>> +	depends on MSHV
>>>> +	select HYPERV_VTL_MODE
>>>> +	select TRANSPARENT_HUGEPAGE
>>>
>>> TRANSPARENT_HUGEPAGE can be avoided for now.
>>>
>>
>> I will remove it in the next version. Thanks.
>>>> +
>>>> +#define HV_GET_REGISTER_BATCH_SIZE	\
>>>> +	(HV_HYP_PAGE_SIZE / sizeof(union hv_register_value))
>>>> +#define HV_SET_REGISTER_BATCH_SIZE	\
>>>> +	((HV_HYP_PAGE_SIZE - sizeof(struct hv_input_set_vp_registers)) \
>>>> +		/ sizeof(struct hv_register_assoc))
>>>> +
>>>> +int hv_call_get_vp_registers(
>>>> +		u32 vp_index,
>>>> +		u64 partition_id,
>>>> +		u16 count,
>>>> +		union hv_input_vtl input_vtl,
>>>> +		struct hv_register_assoc *registers) {
>>>> +	struct hv_input_get_vp_registers *input_page;
>>>> +	union hv_register_value *output_page;
>>>> +	u16 completed = 0;
>>>> +	unsigned long remaining = count;
>>>> +	int rep_count, i;
>>>> +	u64 status;
>>>> +	unsigned long flags;
>>>> +
>>>> +	local_irq_save(flags);
>>>> +
>>>> +	input_page = *this_cpu_ptr(hyperv_pcpu_input_arg);
>>>> +	output_page = *this_cpu_ptr(hyperv_pcpu_output_arg);
>>>> +
>>>> +	input_page->partition_id = partition_id;
>>>> +	input_page->vp_index = vp_index;
>>>> +	input_page->input_vtl.as_uint8 = input_vtl.as_uint8;
>>>> +	input_page->rsvd_z8 = 0;
>>>> +	input_page->rsvd_z16 = 0;
>>>> +
>>>> +	while (remaining) {
>>>> +		rep_count = min(remaining, HV_GET_REGISTER_BATCH_SIZE);
>>>> +		for (i = 0; i < rep_count; ++i)
>>>> +			input_page->names[i] = registers[i].name;
>>>> +
>>>> +		status = hv_do_rep_hypercall(HVCALL_GET_VP_REGISTERS,
>>>> rep_count,
>>>> +					     0, input_page, output_page);
>>>
>>> Is there any possibility that count value is passed 0 by mistake ? In
>>> that case status will remain uninitialized.
>>>
>>
>> These lines ensure rep_count is never 0 here:
>>
>> 	while (remaining) {
>> 		rep_count = min(remaining, HV_GET_REGISTER_BATCH_SIZE);
>>
>> Remaining can't be 0 or the loop would exit, and
>> HV_GET_REGISTER_BATCH_SIZE is not 0, or we would never get any registers.
> 
> There is a parameter in this function "count". I was checking if there is any possibility
> that is passed as 0 by mistake ? this will lead to "remaining" value as 0 and loop will never
> execute. Which results using "status" uninitialized later in the function.
> 
> 

Ah ok, thanks! I will change it to return immediately in case count is 0.
>>>> diff --git a/drivers/hv/mshv.h b/drivers/hv/mshv.h
>>>> new file mode 100644
>>>> index 000000000000..166480a73f3f
>>>> --- /dev/null
>>>> +++ b/drivers/hv/mshv.h
>>>> @@ -0,0 +1,156 @@
>>>> +/* SPDX-License-Identifier: GPL-2.0-only */
>>>> +/*
>>>> + * Copyright (c) 2023, Microsoft Corporation.
>>>> + */
>>>> +
>>>> +#ifndef _MSHV_H_
>>>> +#define _MSHV_H_
>>>> +
>>>> +#include <linux/spinlock.h>
>>>> +#include <linux/mutex.h>
>>>> +#include <linux/semaphore.h>
>>>> +#include <linux/sched.h>
>>>> +#include <linux/srcu.h>
>>>> +#include <linux/wait.h>
>>>> +#include <uapi/linux/mshv.h>
>>>> +
>>>> +/*
>>>> + * Hyper-V hypercalls
>>>> + */
>>>> +
>>>> +int hv_call_withdraw_memory(u64 count, int node, u64 partition_id);
>>>> +int hv_call_create_partition(
>>>> +		u64 flags,
>>>> +		struct hv_partition_creation_properties creation_properties,
>>>> +		union hv_partition_isolation_properties isolation_properties,
>>>> +		u64 *partition_id);
>>>> +int hv_call_initialize_partition(u64 partition_id);
>>>> +int hv_call_finalize_partition(u64 partition_id);
>>>> +int hv_call_delete_partition(u64 partition_id);
>>>> +int hv_call_map_gpa_pages(
>>>> +		u64 partition_id,
>>>> +		u64 gpa_target,
>>>> +		u64 page_count, u32 flags,
>>>> +		struct page **pages);
>>>> +int hv_call_unmap_gpa_pages(
>>>> +		u64 partition_id,
>>>> +		u64 gpa_target,
>>>> +		u64 page_count, u32 flags);
>>>> +int hv_call_get_vp_registers(
>>>> +		u32 vp_index,
>>>> +		u64 partition_id,
>>>> +		u16 count,
>>>> +		union hv_input_vtl input_vtl,
>>>> +		struct hv_register_assoc *registers);
>>>> +int hv_call_get_gpa_access_states(
>>>> +		u64 partition_id,
>>>> +		u32 count,
>>>> +		u64 gpa_base_pfn,
>>>> +		u64 state_flags,
>>>> +		int *written_total,
>>>> +		union hv_gpa_page_access_state *states);
>>>> +
>>>> +int hv_call_set_vp_registers(
>>>> +		u32 vp_index,
>>>> +		u64 partition_id,
>>>> +		u16 count,
>>>> +		union hv_input_vtl input_vtl,
>>>> +		struct hv_register_assoc *registers);
>>>
>>> Nit: Opportunity to fix many of the checkpatch.pl related to line break here
>>> and many other places.
>>>
>>
>> checkpatch.pl doesn't complain about anything in this file.
> 
> If we use --strict switch with checkpatch.pl we observe additional CHECK(s).
> I observe 159 CHECK(s) with this patch overall.
> (total: 1 errors, 7 warnings, 159 checks, 7460 lines checked)
> Few examples:
> 
> CHECK: Lines should not end with a '('
> #240: FILE: drivers/hv/hv_call.c:73:
> +int hv_call_set_vp_registers(
> 
> CHECK: Alignment should match open parenthesis
> #266: FILE: drivers/hv/hv_call.c:99:
> +               memcpy(input_page->elements, registers,
> +                       sizeof(struct hv_register_assoc) * rep_count);
> 
> 

I didn't try --strict before. Thanks, I'll fix up the formatting.

> I also see an error with flexible array, possibly we can fix that as well.
> 
> ERROR: Use C99 flexible arrays - see https://docs.kernel.org/process/deprecated.html#zero-length-and-one-element-arrays
> #7468: FILE: include/uapi/linux/mshv.h:134:
> +       struct mshv_msi_routing_entry entries[0];
> +};
> 

Indeed, I'll fix it too.

Re: [PATCH v2 15/15] Drivers: hv: Add modules to expose /dev/mshv to VMMs running on Hyper-V

[Nuno Das Neves]

On 8/21/2023 11:18 AM, Saurabh Singh Sengar wrote:
> 
> 
>> -----Original Message-----
>> From: Nuno Das Neves <nunodasneves@linux.microsoft.com>
>> Sent: Friday, August 18, 2023 3:32 AM
>> To: linux-hyperv@vger.kernel.org; linux-kernel@vger.kernel.org;
>> x86@kernel.org; linux-arm-kernel@lists.infradead.org; linux-
>> arch@vger.kernel.org
>> Cc: patches@lists.linux.dev; Michael Kelley (LINUX)
>> <mikelley@microsoft.com>; KY Srinivasan <kys@microsoft.com>;
>> wei.liu@kernel.org; Haiyang Zhang <haiyangz@microsoft.com>; Dexuan Cui
>> <decui@microsoft.com>; apais@linux.microsoft.com; Tianyu Lan
>> <Tianyu.Lan@microsoft.com>; ssengar@linux.microsoft.com; MUKESH
>> RATHOR <mukeshrathor@microsoft.com>; stanislav.kinsburskiy@gmail.com;
>> jinankjain@linux.microsoft.com; vkuznets <vkuznets@redhat.com>;
>> tglx@linutronix.de; mingo@redhat.com; bp@alien8.de;
>> dave.hansen@linux.intel.com; hpa@zytor.com; will@kernel.org;
>> catalin.marinas@arm.com
>> Subject: [PATCH v2 15/15] Drivers: hv: Add modules to expose /dev/mshv to
>> VMMs running on Hyper-V
>>
>> Add mshv, mshv_root, and mshv_vtl modules:
>>
> 
> <snip>
> 
>> +	ret = mshv_set_vp_registers(vp->index, vp->partition->id,
>> +				    1, &dispatch_suspend);
>> +	if (ret)
>> +		pr_err("%s: failed to suspend partition %llu vp %u\n",
>> +			__func__, vp->partition->id, vp->index);
>> +
>> +	return ret;
>> +}
>> +
>> +static int
>> +get_vp_signaled_count(struct mshv_vp *vp, u64 *count)
>> +{
>> +	int ret;
>> +	struct hv_register_assoc root_signal_count = {
>> +		.name = HV_REGISTER_VP_ROOT_SIGNAL_COUNT,
>> +	};
>> +
>> +	ret = mshv_get_vp_registers(vp->index, vp->partition->id,
>> +				    1, &root_signal_count);
>> +
>> +	if (ret) {
>> +		pr_err("%s: failed to get root signal count for partition %llu vp
>> %u",
>> +			__func__, vp->partition->id, vp->index);
>> +		*count = 0;
> 
> Have we missed a return here ?
> Moreover, the return type of this function is never checked consider
> checking it or change it to void.
> 

Thanks, we do need to return here.

This function is called on a cleanup path (deleting the guest VM), so if it fails
something is wrong. Instead of returning void, I think we should check the return
value with WARN_ON(), and abort the cleanup if it failed.

>> +
>> +/* Retrieve and stash the supported scheduler type */
>> +static int __init mshv_retrieve_scheduler_type(void)
>> +{
>> +	struct hv_input_get_system_property *input;
>> +	struct hv_output_get_system_property *output;
>> +	unsigned long flags;
>> +	u64 status;
>> +
>> +	local_irq_save(flags);
>> +	input = *this_cpu_ptr(hyperv_pcpu_input_arg);
>> +	output = *this_cpu_ptr(hyperv_pcpu_output_arg);
>> +
>> +	memset(input, 0, sizeof(*input));
>> +	memset(output, 0, sizeof(*output));
>> +	input->property_id = HV_SYSTEM_PROPERTY_SCHEDULER_TYPE;
>> +
>> +	status = hv_do_hypercall(HVCALL_GET_SYSTEM_PROPERTY, input,
>> output);
>> +	if (!hv_result_success(status)) {
>> +		local_irq_restore(flags);
>> +		pr_err("%s: %s\n", __func__, hv_status_to_string(status));
>> +		return hv_status_to_errno(status);
>> +	}
>> +
>> +	hv_scheduler_type = output->scheduler_type;
>> +	local_irq_restore(flags);
>> +
>> +	pr_info("mshv: hypervisor using %s\n",
>> scheduler_type_to_string(hv_scheduler_type));
> 
> Nit: In this file we are using two styles of prints, few are appended with
> "mshv:" and few with "__func__".  It's better to have a single style
> for one module.

Thanks, I'll switch them all to __func__

RE: [PATCH v2 15/15] Drivers: hv: Add modules to expose /dev/mshv to VMMs running on Hyper-V

[Saurabh Singh Sengar]

> -----Original Message-----
> From: Nuno Das Neves <nunodasneves@linux.microsoft.com>
> Sent: Wednesday, August 23, 2023 1:49 AM
> To: Saurabh Singh Sengar <ssengar@microsoft.com>; linux-
> hyperv@vger.kernel.org; linux-kernel@vger.kernel.org; x86@kernel.org; linux-
> arm-kernel@lists.infradead.org; linux-arch@vger.kernel.org
> Cc: patches@lists.linux.dev; Michael Kelley (LINUX)
> <mikelley@microsoft.com>; KY Srinivasan <kys@microsoft.com>;
> wei.liu@kernel.org; Haiyang Zhang <haiyangz@microsoft.com>; Dexuan Cui
> <decui@microsoft.com>; apais@linux.microsoft.com; Tianyu Lan
> <Tianyu.Lan@microsoft.com>; ssengar@linux.microsoft.com; MUKESH
> RATHOR <mukeshrathor@microsoft.com>; stanislav.kinsburskiy@gmail.com;
> jinankjain@linux.microsoft.com; vkuznets <vkuznets@redhat.com>;
> tglx@linutronix.de; mingo@redhat.com; bp@alien8.de;
> dave.hansen@linux.intel.com; hpa@zytor.com; will@kernel.org;
> catalin.marinas@arm.com
> Subject: Re: [PATCH v2 15/15] Drivers: hv: Add modules to expose /dev/mshv
> to VMMs running on Hyper-V
> 
> On 8/19/2023 10:19 PM, Saurabh Singh Sengar wrote:
> >
> >
> >> -----Original Message-----
> >> From: Nuno Das Neves <nunodasneves@linux.microsoft.com>
> >> Sent: Saturday, August 19, 2023 12:30 AM
> >> To: Saurabh Singh Sengar <ssengar@microsoft.com>; linux-
> >> hyperv@vger.kernel.org; linux-kernel@vger.kernel.org; x86@kernel.org;
> >> linux- arm-kernel@lists.infradead.org; linux-arch@vger.kernel.org
> >> Cc: patches@lists.linux.dev; Michael Kelley (LINUX)
> >> <mikelley@microsoft.com>; KY Srinivasan <kys@microsoft.com>;
> >> wei.liu@kernel.org; Haiyang Zhang <haiyangz@microsoft.com>; Dexuan
> >> Cui <decui@microsoft.com>; apais@linux.microsoft.com; Tianyu Lan
> >> <Tianyu.Lan@microsoft.com>; ssengar@linux.microsoft.com; MUKESH
> >> RATHOR <mukeshrathor@microsoft.com>;
> stanislav.kinsburskiy@gmail.com;
> >> jinankjain@linux.microsoft.com; vkuznets <vkuznets@redhat.com>;
> >> tglx@linutronix.de; mingo@redhat.com; bp@alien8.de;
> >> dave.hansen@linux.intel.com; hpa@zytor.com; will@kernel.org;
> >> catalin.marinas@arm.com
> >> Subject: Re: [PATCH v2 15/15] Drivers: hv: Add modules to expose
> >> /dev/mshv to VMMs running on Hyper-V
> >>
> >> On 8/18/2023 6:08 AM, Saurabh Singh Sengar wrote:
> >>>> +
> >>>> +config MSHV_VTL
> >>>> +	tristate "Microsoft Hyper-V VTL driver"
> >>>> +	depends on MSHV
> >>>> +	select HYPERV_VTL_MODE
> >>>> +	select TRANSPARENT_HUGEPAGE
> >>>
> >>> TRANSPARENT_HUGEPAGE can be avoided for now.
> >>>
> >>
> >> I will remove it in the next version. Thanks.
> >>>> +
> >>>> +#define HV_GET_REGISTER_BATCH_SIZE	\
> >>>> +	(HV_HYP_PAGE_SIZE / sizeof(union hv_register_value))
> >>>> +#define HV_SET_REGISTER_BATCH_SIZE	\
> >>>> +	((HV_HYP_PAGE_SIZE - sizeof(struct hv_input_set_vp_registers)) \
> >>>> +		/ sizeof(struct hv_register_assoc))
> >>>> +
> >>>> +int hv_call_get_vp_registers(
> >>>> +		u32 vp_index,
> >>>> +		u64 partition_id,
> >>>> +		u16 count,
> >>>> +		union hv_input_vtl input_vtl,
> >>>> +		struct hv_register_assoc *registers) {
> >>>> +	struct hv_input_get_vp_registers *input_page;
> >>>> +	union hv_register_value *output_page;
> >>>> +	u16 completed = 0;
> >>>> +	unsigned long remaining = count;
> >>>> +	int rep_count, i;
> >>>> +	u64 status;
> >>>> +	unsigned long flags;
> >>>> +
> >>>> +	local_irq_save(flags);
> >>>> +
> >>>> +	input_page = *this_cpu_ptr(hyperv_pcpu_input_arg);
> >>>> +	output_page = *this_cpu_ptr(hyperv_pcpu_output_arg);
> >>>> +
> >>>> +	input_page->partition_id = partition_id;
> >>>> +	input_page->vp_index = vp_index;
> >>>> +	input_page->input_vtl.as_uint8 = input_vtl.as_uint8;
> >>>> +	input_page->rsvd_z8 = 0;
> >>>> +	input_page->rsvd_z16 = 0;
> >>>> +
> >>>> +	while (remaining) {
> >>>> +		rep_count = min(remaining, HV_GET_REGISTER_BATCH_SIZE);
> >>>> +		for (i = 0; i < rep_count; ++i)
> >>>> +			input_page->names[i] = registers[i].name;
> >>>> +
> >>>> +		status = hv_do_rep_hypercall(HVCALL_GET_VP_REGISTERS,
> >>>> rep_count,
> >>>> +					     0, input_page, output_page);
> >>>
> >>> Is there any possibility that count value is passed 0 by mistake ?
> >>> In that case status will remain uninitialized.
> >>>
> >>
> >> These lines ensure rep_count is never 0 here:
> >>
> >> 	while (remaining) {
> >> 		rep_count = min(remaining, HV_GET_REGISTER_BATCH_SIZE);
> >>
> >> Remaining can't be 0 or the loop would exit, and
> >> HV_GET_REGISTER_BATCH_SIZE is not 0, or we would never get any
> registers.
> >
> > There is a parameter in this function "count". I was checking if there
> > is any possibility that is passed as 0 by mistake ? this will lead to
> > "remaining" value as 0 and loop will never execute. Which results using
> "status" uninitialized later in the function.
> >
> >
> 
> Ah ok, thanks! I will change it to return immediately in case count is 0.

Or you can initialize status with appropriate error value, either way is fine.
Please consider fixing the same issue in hv_call_set_vp_registers as well.

- Saurabh

Re: [PATCH v2 15/15] Drivers: hv: Add modules to expose /dev/mshv to VMMs running on Hyper-V

[Boqun Feng]

On Thu, Aug 17, 2023 at 03:01:51PM -0700, Nuno Das Neves wrote:
[...]
> +static long
> +mshv_dev_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
> +{
> +	switch (ioctl) {
> +	case MSHV_CHECK_EXTENSION:
> +		return mshv_ioctl_check_extension((void __user *)arg);
> +	case MSHV_CREATE_PARTITION:
> +		return mshv.create_partition((void __user *)arg);
> +	case MSHV_CREATE_VTL:
> +		return mshv.create_vtl((void __user *)arg);
> +	}
> +

Shouldn't we also have a MSHV_GET_API_VERSION ioctl similar as KVM? So
that in the future when we change these ioctl interfaces or semantics,
we can bump up the API version to avoid breaking userspace?

Regards,
Boqun

Re: [PATCH v2 13/15] uapi: hyperv: Add mshv driver headers hvhdk.h, hvhdk_mini.h, hvgdk.h, hvgdk_mini.h

[Nuno Das Neves]

On 8/19/2023 3:26 AM, Greg KH wrote:
> 
> My "strong" opinion is the one kernel development rule that we have,
> "you can not break userspace".  So, if you change these
> values/structures/whatever in the future, and userspace tools break,
> that's not ok and the changes have to be reverted.
> 
> If you can control both sides of the API here (with open tools that you
> can guarantee everyone will always update to), then yes, you can change
> the api in the future.
> 

This is true for us - we contribute and maintain support for this driver
in Cloud Hypervisor[1], an open source VMM.

We also do a check of the hypervisor version when the driver loads, and
refuse to proceed if it is running on an incompatible hypervisor.

Thanks,
Nuno Das Neves


[1] https://github.com/cloud-hypervisor/cloud-hypervisor

Re: [PATCH v2 15/15] Drivers: hv: Add modules to expose /dev/mshv to VMMs running on Hyper-V

[Nuno Das Neves]

On 8/23/2023 12:40 AM, Saurabh Singh Sengar wrote:
> 
> 
>> -----Original Message-----
>> From: Nuno Das Neves <nunodasneves@linux.microsoft.com>
>> Sent: Wednesday, August 23, 2023 1:49 AM
>> To: Saurabh Singh Sengar <ssengar@microsoft.com>; linux-
>> hyperv@vger.kernel.org; linux-kernel@vger.kernel.org; x86@kernel.org; linux-
>> arm-kernel@lists.infradead.org; linux-arch@vger.kernel.org
>> Cc: patches@lists.linux.dev; Michael Kelley (LINUX)
>> <mikelley@microsoft.com>; KY Srinivasan <kys@microsoft.com>;
>> wei.liu@kernel.org; Haiyang Zhang <haiyangz@microsoft.com>; Dexuan Cui
>> <decui@microsoft.com>; apais@linux.microsoft.com; Tianyu Lan
>> <Tianyu.Lan@microsoft.com>; ssengar@linux.microsoft.com; MUKESH
>> RATHOR <mukeshrathor@microsoft.com>; stanislav.kinsburskiy@gmail.com;
>> jinankjain@linux.microsoft.com; vkuznets <vkuznets@redhat.com>;
>> tglx@linutronix.de; mingo@redhat.com; bp@alien8.de;
>> dave.hansen@linux.intel.com; hpa@zytor.com; will@kernel.org;
>> catalin.marinas@arm.com
>> Subject: Re: [PATCH v2 15/15] Drivers: hv: Add modules to expose /dev/mshv
>> to VMMs running on Hyper-V
>>
>> On 8/19/2023 10:19 PM, Saurabh Singh Sengar wrote:
>>>
>>>
>>>> -----Original Message-----
>>>> From: Nuno Das Neves <nunodasneves@linux.microsoft.com>
>>>> Sent: Saturday, August 19, 2023 12:30 AM
>>>> To: Saurabh Singh Sengar <ssengar@microsoft.com>; linux-
>>>> hyperv@vger.kernel.org; linux-kernel@vger.kernel.org; x86@kernel.org;
>>>> linux- arm-kernel@lists.infradead.org; linux-arch@vger.kernel.org
>>>> Cc: patches@lists.linux.dev; Michael Kelley (LINUX)
>>>> <mikelley@microsoft.com>; KY Srinivasan <kys@microsoft.com>;
>>>> wei.liu@kernel.org; Haiyang Zhang <haiyangz@microsoft.com>; Dexuan
>>>> Cui <decui@microsoft.com>; apais@linux.microsoft.com; Tianyu Lan
>>>> <Tianyu.Lan@microsoft.com>; ssengar@linux.microsoft.com; MUKESH
>>>> RATHOR <mukeshrathor@microsoft.com>;
>> stanislav.kinsburskiy@gmail.com;
>>>> jinankjain@linux.microsoft.com; vkuznets <vkuznets@redhat.com>;
>>>> tglx@linutronix.de; mingo@redhat.com; bp@alien8.de;
>>>> dave.hansen@linux.intel.com; hpa@zytor.com; will@kernel.org;
>>>> catalin.marinas@arm.com
>>>> Subject: Re: [PATCH v2 15/15] Drivers: hv: Add modules to expose
>>>> /dev/mshv to VMMs running on Hyper-V
>>>>
>>>> On 8/18/2023 6:08 AM, Saurabh Singh Sengar wrote:
>>>>>> +
>>>>>> +config MSHV_VTL
>>>>>> +	tristate "Microsoft Hyper-V VTL driver"
>>>>>> +	depends on MSHV
>>>>>> +	select HYPERV_VTL_MODE
>>>>>> +	select TRANSPARENT_HUGEPAGE
>>>>>
>>>>> TRANSPARENT_HUGEPAGE can be avoided for now.
>>>>>
>>>>
>>>> I will remove it in the next version. Thanks.
>>>>>> +
>>>>>> +#define HV_GET_REGISTER_BATCH_SIZE	\
>>>>>> +	(HV_HYP_PAGE_SIZE / sizeof(union hv_register_value))
>>>>>> +#define HV_SET_REGISTER_BATCH_SIZE	\
>>>>>> +	((HV_HYP_PAGE_SIZE - sizeof(struct hv_input_set_vp_registers)) \
>>>>>> +		/ sizeof(struct hv_register_assoc))
>>>>>> +
>>>>>> +int hv_call_get_vp_registers(
>>>>>> +		u32 vp_index,
>>>>>> +		u64 partition_id,
>>>>>> +		u16 count,
>>>>>> +		union hv_input_vtl input_vtl,
>>>>>> +		struct hv_register_assoc *registers) {
>>>>>> +	struct hv_input_get_vp_registers *input_page;
>>>>>> +	union hv_register_value *output_page;
>>>>>> +	u16 completed = 0;
>>>>>> +	unsigned long remaining = count;
>>>>>> +	int rep_count, i;
>>>>>> +	u64 status;
>>>>>> +	unsigned long flags;
>>>>>> +
>>>>>> +	local_irq_save(flags);
>>>>>> +
>>>>>> +	input_page = *this_cpu_ptr(hyperv_pcpu_input_arg);
>>>>>> +	output_page = *this_cpu_ptr(hyperv_pcpu_output_arg);
>>>>>> +
>>>>>> +	input_page->partition_id = partition_id;
>>>>>> +	input_page->vp_index = vp_index;
>>>>>> +	input_page->input_vtl.as_uint8 = input_vtl.as_uint8;
>>>>>> +	input_page->rsvd_z8 = 0;
>>>>>> +	input_page->rsvd_z16 = 0;
>>>>>> +
>>>>>> +	while (remaining) {
>>>>>> +		rep_count = min(remaining, HV_GET_REGISTER_BATCH_SIZE);
>>>>>> +		for (i = 0; i < rep_count; ++i)
>>>>>> +			input_page->names[i] = registers[i].name;
>>>>>> +
>>>>>> +		status = hv_do_rep_hypercall(HVCALL_GET_VP_REGISTERS,
>>>>>> rep_count,
>>>>>> +					     0, input_page, output_page);
>>>>>
>>>>> Is there any possibility that count value is passed 0 by mistake ?
>>>>> In that case status will remain uninitialized.
>>>>>
>>>>
>>>> These lines ensure rep_count is never 0 here:
>>>>
>>>> 	while (remaining) {
>>>> 		rep_count = min(remaining, HV_GET_REGISTER_BATCH_SIZE);
>>>>
>>>> Remaining can't be 0 or the loop would exit, and
>>>> HV_GET_REGISTER_BATCH_SIZE is not 0, or we would never get any
>> registers.
>>>
>>> There is a parameter in this function "count". I was checking if there
>>> is any possibility that is passed as 0 by mistake ? this will lead to
>>> "remaining" value as 0 and loop will never execute. Which results using
>> "status" uninitialized later in the function.
>>>
>>>
>>
>> Ah ok, thanks! I will change it to return immediately in case count is 0.
> 
> Or you can initialize status with appropriate error value, either way is fine.
> Please consider fixing the same issue in hv_call_set_vp_registers as well.
> 

Thanks again - noted.

Re: [PATCH v2 15/15] Drivers: hv: Add modules to expose /dev/mshv to VMMs running on Hyper-V

[Nuno Das Neves]

On 8/24/2023 11:31 AM, Boqun Feng wrote:
> On Thu, Aug 17, 2023 at 03:01:51PM -0700, Nuno Das Neves wrote:
> [...]
>> +static long
>> +mshv_dev_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
>> +{
>> +	switch (ioctl) {
>> +	case MSHV_CHECK_EXTENSION:
>> +		return mshv_ioctl_check_extension((void __user *)arg);
>> +	case MSHV_CREATE_PARTITION:
>> +		return mshv.create_partition((void __user *)arg);
>> +	case MSHV_CREATE_VTL:
>> +		return mshv.create_vtl((void __user *)arg);
>> +	}
>> +
> 
> Shouldn't we also have a MSHV_GET_API_VERSION ioctl similar as KVM? So
> that in the future when we change these ioctl interfaces or semantics,
> we can bump up the API version to avoid breaking userspace?
> 

Note that we contribute and maintain support for this driver in
Cloud Hypervisor, so we control both sides of this API - if we break
userspace we can fix it ourselves.

For now the MSHV_CHECK_EXTENSION ioctl is sufficient - we can pass it
MSHV_CAP_CORE_API_STABLE, and it will return 0 to indicate that the API
is not yet stable.

A version check may be useful in the future, but is not needed right now.

Thanks
Nuno Das Neves

Re: [PATCH v2 15/15] Drivers: hv: Add modules to expose /dev/mshv to VMMs running on Hyper-V

[Boqun Feng]

On Fri, Aug 25, 2023 at 11:41:35AM -0700, Nuno Das Neves wrote:
> On 8/24/2023 11:31 AM, Boqun Feng wrote:
> > On Thu, Aug 17, 2023 at 03:01:51PM -0700, Nuno Das Neves wrote:
> > [...]
> >> +static long
> >> +mshv_dev_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
> >> +{
> >> +	switch (ioctl) {
> >> +	case MSHV_CHECK_EXTENSION:
> >> +		return mshv_ioctl_check_extension((void __user *)arg);
> >> +	case MSHV_CREATE_PARTITION:
> >> +		return mshv.create_partition((void __user *)arg);
> >> +	case MSHV_CREATE_VTL:
> >> +		return mshv.create_vtl((void __user *)arg);
> >> +	}
> >> +
> > 
> > Shouldn't we also have a MSHV_GET_API_VERSION ioctl similar as KVM? So
> > that in the future when we change these ioctl interfaces or semantics,
> > we can bump up the API version to avoid breaking userspace?
> > 
> 
> Note that we contribute and maintain support for this driver in
> Cloud Hypervisor, so we control both sides of this API - if we break
> userspace we can fix it ourselves.
> 

This actually doesn't always work, e.g. old Clould Hypervisor + new
kernel, but..

> For now the MSHV_CHECK_EXTENSION ioctl is sufficient - we can pass it
> MSHV_CAP_CORE_API_STABLE, and it will return 0 to indicate that the API
> is not yet stable.
> 

.. I missed that we are using this to report API is not stable, so I
agree, the API version is not needed for now.

> A version check may be useful in the future, but is not needed right now.
> 

Thanks for the explanation.

Regards,
Boqun

> Thanks
> Nuno Das Neves

Re: [PATCH v2 10/15] x86: hyperv: Add mshv_handler irq handler and setup function

[Tianyu Lan]

On 8/18/2023 6:01 AM, Nuno Das Neves wrote:
> This will handle SYNIC interrupts such as intercepts, doorbells, and
> scheduling messages intended for the mshv driver.
> 
> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
> Reviewed-by: Wei Liu <wei.liu@kernel.org>
> ---
>   arch/x86/kernel/cpu/mshyperv.c | 9 +++++++++
>   drivers/hv/hv_common.c         | 5 +++++
>   include/asm-generic/mshyperv.h | 2 ++
>   3 files changed, 16 insertions(+)

Reviewed-by: Tianyu Lan <tiala@microsoft.com>

Re: [PATCH v2 13/15] uapi: hyperv: Add mshv driver headers hvhdk.h, hvhdk_mini.h, hvgdk.h, hvgdk_mini.h

[Nuno Das Neves]

On 8/25/2023 11:24 AM, Nuno Das Neves wrote:
> On 8/19/2023 3:26 AM, Greg KH wrote:
>>
>> My "strong" opinion is the one kernel development rule that we have,
>> "you can not break userspace".  So, if you change these
>> values/structures/whatever in the future, and userspace tools break,
>> that's not ok and the changes have to be reverted.
>>
>> If you can control both sides of the API here (with open tools that you
>> can guarantee everyone will always update to), then yes, you can change
>> the api in the future.
>>
> 
> This is true for us - we contribute and maintain support for this driver
> in Cloud Hypervisor[1], an open source VMM.
> 

Hi Greg,

Bringing up this discussion again so we can clear up any confusion on the
uapi headers in this patch set.

The headers consist of the ioctls in mshv.h, and the hypervisor ABIs in
the *hdk.h files. The ioctls depend on the hypervisor ABIs.

We will add (to the next version), an ioctl like KVM_GET_API_VERSION [1].
This will return a version number for the ioctl interface that increments
any time there is a breaking change. Userspace would be required to check
this before calling any other ioctl, and it can exit gracefully if there
is a mismatch.

That's how KVM evolved its userspace ABI. We want to use the same approach.

I also wanted to reiterate that we are the only maintainers and users of
the userspace code for this driver via Cloud Hypervisor [2]. We generate
rust bindings from these headers using bindgen [3].

Taking this into account, is the above a viable path for this patch set?

Thanks,
Nuno

[1] https://docs.kernel.org/virt/kvm/api.html#kvm-get-api-version
[2] https://github.com/cloud-hypervisor/cloud-hypervisor
[3] https://github.com/rust-lang/rust-bindgen

Re: [PATCH v2 13/15] uapi: hyperv: Add mshv driver headers hvhdk.h, hvhdk_mini.h, hvgdk.h, hvgdk_mini.h

[Greg KH]

On Tue, Oct 10, 2023 at 03:49:48PM -0700, Nuno Das Neves wrote:
> On 8/25/2023 11:24 AM, Nuno Das Neves wrote:
> > On 8/19/2023 3:26 AM, Greg KH wrote:
> > > 
> > > My "strong" opinion is the one kernel development rule that we have,
> > > "you can not break userspace".  So, if you change these
> > > values/structures/whatever in the future, and userspace tools break,
> > > that's not ok and the changes have to be reverted.
> > > 
> > > If you can control both sides of the API here (with open tools that you
> > > can guarantee everyone will always update to), then yes, you can change
> > > the api in the future.
> > > 
> > 
> > This is true for us - we contribute and maintain support for this driver
> > in Cloud Hypervisor[1], an open source VMM.
> > 
> 
> Hi Greg,
> 
> Bringing up this discussion again so we can clear up any confusion on the
> uapi headers in this patch set.
> 
> The headers consist of the ioctls in mshv.h, and the hypervisor ABIs in
> the *hdk.h files. The ioctls depend on the hypervisor ABIs.
> 
> We will add (to the next version), an ioctl like KVM_GET_API_VERSION [1].
> This will return a version number for the ioctl interface that increments
> any time there is a breaking change. Userspace would be required to check
> this before calling any other ioctl, and it can exit gracefully if there
> is a mismatch.
> 
> That's how KVM evolved its userspace ABI. We want to use the same approach.

That's one way to do interfaces, but there are better ways as you know.
What do you expect to change that is going to require such heavy-handed
treatment of structures and ioctls?

And how are you going to handle backwards compatiblity?

Versioning things is almost always a pain, and should only be done as a
last resort as a sign of an api that is not well understood at creation
time.  Surely you have studied how other hypervisor interfaces work and
know what you need to do for yours by now, right?  This isn't the first
hypervisor api in Linux like KVM was when it was introduced a few
decades ago.  Why not learn from past mistakes and design patterns
instead of just blindly imitating old apis that perhaps should not be
imitated at all?

> I also wanted to reiterate that we are the only maintainers and users of
> the userspace code for this driver via Cloud Hypervisor [2].

For today, maybe, but you can never guarantee that in the future as you
well know.

> We generate rust bindings from these headers using bindgen [3].

What does rust have to do with anything here?  You can use m4 to parse
the headers for all we care :)

> Taking this into account, is the above a viable path for this patch set?

I have no idea, sorry, I don't see any patches here to review as the
original set is long-gone from my queue.

Just submit your fixed up patch series based on the previous review
comments and it will be reviewed again, just like all kernel patches
are.  Why is this set somehow more special than anything else?

Perhaps you all should take the time to do some kernel patch reviews of
other stuff sent to the mailing lists to get an idea of how this whole
process works, and to get better integrated into the kernel development
community, before dumping a huge patchset on us with lots of process
questions like this?  Why are you asking the community to do a lot of
work and hand-holding when you aren't helping others out as well?

good luck!

greg k-h

Re: [PATCH v2 13/15] uapi: hyperv: Add mshv driver headers hvhdk.h, hvhdk_mini.h, hvgdk.h, hvgdk_mini.h

[Nuno Das Neves]

On 10/10/2023 11:42 PM, Greg KH wrote:
> On Tue, Oct 10, 2023 at 03:49:48PM -0700, Nuno Das Neves wrote:
>> On 8/25/2023 11:24 AM, Nuno Das Neves wrote:
>>> On 8/19/2023 3:26 AM, Greg KH wrote:
>>>>
>>>> My "strong" opinion is the one kernel development rule that we have,
>>>> "you can not break userspace".  So, if you change these
>>>> values/structures/whatever in the future, and userspace tools break,
>>>> that's not ok and the changes have to be reverted.
>>>>
>>>> If you can control both sides of the API here (with open tools that you
>>>> can guarantee everyone will always update to), then yes, you can change
>>>> the api in the future.
>>>>

We control both sides of the API. The code is open. No one else can use it
today, therefore we can guarantee all the users will stay updated.

> Just submit your fixed up patch series based on the previous review
> comments and it will be reviewed again, just like all kernel patches
> are.

I will do that.

> Perhaps you all should take the time to do some kernel patch reviews of
> other stuff sent to the mailing lists to get an idea of how this whole
> process works, and to get better integrated into the kernel development
> community,

That is a good suggestion, I will do that.

> before dumping a huge patchset on us with lots of process
> questions like this?  Why are you asking the community to do a lot of
> work and hand-holding when you aren't helping others out as well?

I take your point, sorry my questions came off that way. I will work to
improve on that :)

Thanks,
Nuno