On 6/10/2021 2:22 AM, Vitaly Kuznetsov wrote:

Nuno Das Neves [off-list ref] writes:

quoted

This patch series provides a userspace interface for creating and running guest
virtual machines while running on the Microsoft Hypervisor [0].

Since managing guest machines can only be done when Linux is the root partition,
this series depends on Wei Liu's patch series merged in 5.12:
https://lore.kernel.org/linux-hyperv/20210203150435.27941-1-wei.liu@kernel.org/ (local)

The first two patches provide some helpers for converting hypervisor status
codes to linux error codes, and printing hypervisor status codes to dmesg for
debugging.

Hyper-V related headers asm-generic/hyperv-tlfs.h and x86/asm/hyperv-tlfs.h are
split into uapi and non-uapi. The uapi versions contain structures used in both
the ioctl interface and the kernel.

The mshv API is introduced in drivers/hv/mshv_main.c. As each interface is
introduced, documentation is added in Documentation/virt/mshv/api.rst.
The API is file-desciptor based, like KVM. The entry point is /dev/mshv.

/dev/mshv ioctls:
MSHV_CHECK_EXTENSION
MSHV_CREATE_PARTITION

Partition (vm) ioctls:
MSHV_MAP_GUEST_MEMORY, MSHV_UNMAP_GUEST_MEMORY
MSHV_INSTALL_INTERCEPT
MSHV_ASSERT_INTERRUPT
MSHV_GET_PARTITION_PROPERTY, MSHV_SET_PARTITION_PROPERTY
MSHV_CREATE_VP

Vp (vcpu) ioctls:
MSHV_GET_VP_REGISTERS, MSHV_SET_VP_REGISTERS
MSHV_RUN_VP
MSHV_GET_VP_STATE, MSHV_SET_VP_STATE
MSHV_TRANSLATE_GVA
mmap() (register page)

[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.

Changes since RFC:
1. Moved code from virt/mshv to drivers/hv
2. Split hypercall helper functions and synic code to hv_call.c and hv_synic.c
3. MSHV_REQUEST_VERSION ioctl replaced with MSHV_CHECK_EXTENSION
3. Numerous suggestions, fixes, style changes, etc from Michael Kelley, Vitaly
   Kuznetsov, Wei Liu, and Vineeth Pillai
4. Added patch to enable hypervisor enlightenments on partition creation
5. Added Wei Liu's patch for GVA to GPA translation

Thank you for addressing these!

One nitpick though: could you please run your next submission through
'scripts/checkpatch.pl'? It reports a number of issues here, mostly
minor but still worth addressing, i.e.:

Whoops! Yes, I will fix these. Thank you

$ scripts/checkpatch.pl *.patch
...
---------------------------------------------------------------
0002-asm-generic-hyperv-convert-hyperv-statuses-to-string.patch
---------------------------------------------------------------
ERROR: Macros with complex values should be enclosed in parentheses
#95: FILE: include/asm-generic/hyperv-tlfs.h:192:
+#define __HV_STATUS_DEF(OP) \
+	OP(HV_STATUS_SUCCESS,				0x0) \
...

ERROR: Macros with complex values should be enclosed in parentheses
#119: FILE: include/asm-generic/hyperv-tlfs.h:216:
+#define __HV_MAKE_HV_STATUS_ENUM(NAME, VAL) NAME = (VAL),

ERROR: Macros with multiple statements should be enclosed in a do - while loop
#120: FILE: include/asm-generic/hyperv-tlfs.h:217:
+#define __HV_MAKE_HV_STATUS_CASE(NAME, VAL) case (NAME): return (#NAME);

WARNING: Macros with flow control statements should be avoided
#120: FILE: include/asm-generic/hyperv-tlfs.h:217:
+#define __HV_MAKE_HV_STATUS_CASE(NAME, VAL) case (NAME): return (#NAME);

WARNING: macros should not use a trailing semicolon
#120: FILE: include/asm-generic/hyperv-tlfs.h:217:
+#define __HV_MAKE_HV_STATUS_CASE(NAME, VAL) case (NAME): return (#NAME);

total: 3 errors, 2 warnings, 108 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
      mechanically convert to the typical style using --fix or --fix-inplace.

0002-asm-generic-hyperv-convert-hyperv-statuses-to-string.patch has
style problems, please review.
...
-------------------------------------------
0004-drivers-hv-check-extension-ioctl.patch
-------------------------------------------
WARNING: added, moved or deleted file(s), does MAINTAINERS need updating?
#36: 
new file mode 100644

WARNING: ENOTSUPP is not a SUSV4 error code, prefer EOPNOTSUPP
#131: FILE: drivers/hv/mshv_main.c:52:
+	return -ENOTSUPP;

total: 0 errors, 2 warnings, 137 lines checked

...

WARNING: Improper SPDX comment style for 'drivers/hv/hv_call.c', please use '//' instead
#94: FILE: drivers/hv/hv_call.c:1:
+/* SPDX-License-Identifier: GPL-2.0-only */

WARNING: Missing or malformed SPDX-License-Identifier tag in line 1
#94: FILE: drivers/hv/hv_call.c:1:
+/* SPDX-License-Identifier: GPL-2.0-only */

ERROR: "(foo*)" should be "(foo *)"
#178: FILE: drivers/hv/hv_call.c:85:
+				*(u64*)&input);

ERROR: "(foo*)" should be "(foo *)"
#201: FILE: drivers/hv/hv_call.c:108:
+			*(u64*)&input);

ERROR: "(foo*)" should be "(foo *)"
#215: FILE: drivers/hv/hv_call.c:122:
+	status = hv_do_fast_hypercall8(HVCALL_DELETE_PARTITION, *(u64*)&input);

total: 3 errors, 3 warnings, 330 lines checked

...
------------------------------------------------
0008-drivers-hv-map-and-unmap-guest-memory.patch
------------------------------------------------
ERROR: code indent should use tabs where possible
#101: FILE: drivers/hv/hv_call.c:222:
+                                                    HV_MAP_GPA_DEPOSIT_PAGES);$

WARNING: please, no spaces at the start of a line
#101: FILE: drivers/hv/hv_call.c:222:
+                                                    HV_MAP_GPA_DEPOSIT_PAGES);$

ERROR: code indent should use tabs where possible
#469: FILE: include/asm-generic/hyperv-tlfs.h:895:
+        u32 padding;$

WARNING: please, no spaces at the start of a line
#469: FILE: include/asm-generic/hyperv-tlfs.h:895:
+        u32 padding;$

ERROR: code indent should use tabs where possible
#477: FILE: include/asm-generic/hyperv-tlfs.h:903:
+        u32 padding;$

WARNING: please, no spaces at the start of a line
#477: FILE: include/asm-generic/hyperv-tlfs.h:903:
+        u32 padding;$

total: 3 errors, 3 warnings, 487 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
      mechanically convert to the typical style using --fix or --fix-inplace.

NOTE: Whitespace errors detected.
      You may wish to use scripts/cleanpatch or scripts/cleanfile

0008-drivers-hv-map-and-unmap-guest-memory.patch has style problems, please review.
---------------------------------------
0009-drivers-hv-create-vcpu-ioctl.patch
---------------------------------------
WARNING: Missing a blank line after declarations
#76: FILE: drivers/hv/mshv_main.c:75:
+	struct mshv_vp *vp = filp->private_data;
+	mshv_partition_put(vp->partition);

ERROR: trailing whitespace
#180: FILE: drivers/hv/mshv_main.c:376:
+^I$

total: 1 errors, 1 warnings, 210 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
      mechanically convert to the typical style using --fix or --fix-inplace.

NOTE: Whitespace errors detected.
      You may wish to use scripts/cleanpatch or scripts/cleanfile

0009-drivers-hv-create-vcpu-ioctl.patch has style problems, please review.
-------------------------------------------------------
0010-drivers-hv-get-and-set-vcpu-registers-ioctls.patch
-------------------------------------------------------
WARNING: braces {} are not necessary for single statement blocks
#690: FILE: drivers/hv/hv_call.c:326:
+		for (i = 0; i < rep_count; ++i) {
+			input_page->names[i] = registers[i].name;
+		}

WARNING: braces {} are not necessary for single statement blocks
#704: FILE: drivers/hv/hv_call.c:340:
+		for (i = 0; i < completed; ++i) {
+			registers[i].value = output_page[i];
+		}

WARNING: braces {} are not necessary for single statement blocks
#859: FILE: drivers/hv/mshv_main.c:121:
+	if (!registers) {
+		return -ENOMEM;
+	}

total: 0 errors, 3 warnings, 965 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
      mechanically convert to the typical style using --fix or --fix-inplace.

0010-drivers-hv-get-and-set-vcpu-registers-ioctls.patch has style problems, please review.
---------------------------------------------------------------
0011-drivers-hv-set-up-synic-pages-for-intercept-messages.patch
---------------------------------------------------------------
WARNING: added, moved or deleted file(s), does MAINTAINERS need updating?
#274: 
new file mode 100644

ERROR: code indent should use tabs where possible
#310: FILE: drivers/hv/hv_synic.c:32:
+                             MEMREMAP_WB);$

WARNING: please, no spaces at the start of a line
#310: FILE: drivers/hv/hv_synic.c:32:
+                             MEMREMAP_WB);$

total: 1 errors, 2 warnings, 574 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
      mechanically convert to the typical style using --fix or --fix-inplace.

NOTE: Whitespace errors detected.
      You may wish to use scripts/cleanpatch or scripts/cleanfile

0011-drivers-hv-set-up-synic-pages-for-intercept-messages.patch has style problems, please review.
------------------------------------------
0012-drivers-hv-run-vp-ioctl-and-isr.patch
------------------------------------------
WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable
#86: FILE: arch/x86/kernel/cpu/mshyperv.c:77:
+EXPORT_SYMBOL_GPL(hv_remove_mshv_irq);

WARNING: consider using a completion
#410: FILE: drivers/hv/mshv_main.c:344:
+	sema_init(&vp->run.sem, 0);

total: 0 errors, 2 warnings, 435 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
      mechanically convert to the typical style using --fix or --fix-inplace.

0012-drivers-hv-run-vp-ioctl-and-isr.patch has style problems, please review.
---------------------------------------------
...
-------------------------------------------
0016-drivers-hv-mmap-vp-register-page.patch
-------------------------------------------
WARNING: Missing a blank line after declarations
#222: FILE: drivers/hv/mshv_main.c:441:
+	struct mshv_vp *vp = vmf->vma->vm_file->private_data;
+	vmf->page = vp->register_page;

total: 0 errors, 1 warnings, 257 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
      mechanically convert to the typical style using --fix or --fix-inplace.

0016-drivers-hv-mmap-vp-register-page.patch has style problems, please review.
-----------------------------------------------------------
0017-drivers-hv-get-and-set-partition-property-ioctls.patch
-----------------------------------------------------------
ERROR: code indent should use tabs where possible
#205: FILE: include/asm-generic/hyperv-tlfs.h:890:
+        u32 padding;$

WARNING: please, no spaces at the start of a line
#205: FILE: include/asm-generic/hyperv-tlfs.h:890:
+        u32 padding;$

ERROR: code indent should use tabs where possible
#215: FILE: include/asm-generic/hyperv-tlfs.h:900:
+        u32 padding;$

WARNING: please, no spaces at the start of a line
#215: FILE: include/asm-generic/hyperv-tlfs.h:900:
+        u32 padding;$

total: 2 errors, 2 warnings, 258 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
      mechanically convert to the typical style using --fix or --fix-inplace.

NOTE: Whitespace errors detected.
      You may wish to use scripts/cleanpatch or scripts/cleanfile