[PATCH v7 0/7] VMware hypercalls enhancements

From: Alexey Makhalov
Date: Thu Mar 07 2024 - 16:30:11 EST


VMware hypercalls invocations were all spread out across the kernel
implementing same ABI as in-place asm-inline. With encrypted memory
and confidential computing it became harder to maintain every changes
in these hypercall implementations.

Intention of this patchset is to introduce arch independent VMware
hypercall API layer other subsystems such as device drivers can call
to, while hiding architecture specific implementation behind.

Second patch introduces the vmware_hypercall low and high bandwidth
families of functions, with little enhancements there.
Sixth patch adds tdx hypercall support

arm64 implementation of vmware_hypercalls is in drivers/gpu/drm/
vmwgfx/vmwgfx_msg_arm64.h and going to be moved to arch/arm64 with
a separate patchset with the introduction of VMware Linux guest
support for arm64.

No functional changes in drivers/input/mouse/vmmouse.c and
drivers/ptp/ptp_vmw.c

v6->v7 changes (only in patch 7):
- Addressed comments from H. Peter Anvin:
1. Removed vmware_tdx_hypercall_args(), moved args handling inside
vmware_tdx_hypercall().
2. Added pr_warn_once() for !hypervisor_is_type(X86_HYPER_VMWARE) case.
- Added ack by Dave Hansen.

v5->v6 change:
- Added ack by Kirill A. Shutemov in patch 7.

v4->v5 changes:
[patch 2]:
- Fixed the problem reported by Simon Horman where build fails after
patch 2 application. Do not undefine VMWARE_HYPERCALL for now, and
update vmwgfx, vmmouse and ptp_vmw code for new VMWARE_HYPERCALL macro.
- Introduce new patch 6 to undefine VMWARE_HYPERCALL, which is safe to do
after patches 3 to 5.
- [patch 7 (former patch 6)]: Add missing r15 (CPL) initialization.

v3->v4 changes: (no functional changes in patches 1-5)
[patch 2]:
- Added the comment with VMware hypercall ABI description.
[patch 6]:
- vmware_tdx_hypercall_args remove in6/out6 arguments as excessive.
- vmware_tdx_hypercall return ULONG_MAX on error to mimic bad hypercall
command error from the hypervisor.
- Replaced pr_warn by pr_warn_once as pointed by Kirill Shutemov.
- Fixed the warning reported by Intel's kernel test robot.
- Added the comment describing VMware TDX hypercall ABI.

v2->v3 changes: (no functional changes in patches 1-5)
- Improved commit message in patches 1, 2 and 5 as was suggested by
Borislav Petkov.
- To address Dave Hansen's concern, patch 6 was reorganized to avoid
exporting bare __tdx_hypercall and to make exported vmware_tdx_hypercall
VMWare guest specific.

v1->v2 changes (no functional changes):
- Improved commit message in patches 2 and 5.
- Added Reviewed-by for all patches.
- Added Ack from Dmitry Torokhov in patch 4. No fixes regarding reported
by Simon Horman gcc error in this patch.

Alexey Makhalov (7):
x86/vmware: Move common macros to vmware.h
x86/vmware: Introduce VMware hypercall API
ptp/vmware: Use VMware hypercall API
input/vmmouse: Use VMware hypercall API
drm/vmwgfx: Use VMware hypercall API
x86/vmware: Undefine VMWARE_HYPERCALL
x86/vmware: Add TDX hypercall support

arch/x86/include/asm/vmware.h | 331 +++++++++++++++++++---
arch/x86/kernel/cpu/vmware.c | 144 +++++-----
drivers/gpu/drm/vmwgfx/vmwgfx_msg.c | 173 ++++-------
drivers/gpu/drm/vmwgfx/vmwgfx_msg_arm64.h | 197 +++++++++----
drivers/gpu/drm/vmwgfx/vmwgfx_msg_x86.h | 185 ------------
drivers/input/mouse/vmmouse.c | 76 ++---
drivers/ptp/ptp_vmw.c | 12 +-
7 files changed, 593 insertions(+), 525 deletions(-)

--
2.39.0