[PATCH v3 0/5] hv: Remove dependencies on guest page size

From: Maya Nakamura
Date: Tue Jun 18 2019 - 03:14:32 EST

The Linux guest page size and hypervisor page size concepts are
different, even though they happen to be the same value on x86. Hyper-V
code mixes up the two, so this patchset begins to address that by
creating and using a set of Hyper-V specific page definitions.

A major benefit of those new definitions is that they support non-x86
architectures, such as ARM64, that use different page sizes. On ARM64,
the guest page size may not be 4096, and Hyper-V always runs with a
page size of 4096.

In this patchset, the first two patches lay the foundation for the
others, creating definitions and preparing for allocation of memory with
the size and alignment that Hyper-V expects as a page. Patch 3 applies
the page size definition where the guest VM and Hyper-V communicate, and
where the code intends to use the Hyper-V page size. The last two
patches set the ring buffer size to a fixed value, removing the
dependency on the guest page size.

This is the initial set of changes to the Hyper-V code, and future
patches will make additional changes using the same foundation, for
example, replace __vmalloc() and related functions when Hyper-V pages
are intended.

Changes in v3:
- [PATCH v2 2/5] Simplify expression for BUILD_BUG_ON().
- Add Link and Reviewed-by tags.

Change in v2:
- [PATCH 2/5] Replace with a new patch.

Maya Nakamura (5):
x86: hv: hyperv-tlfs.h: Create and use Hyper-V page definitions
x86: hv: hv_init.c: Add functions to allocate/deallocate page for
hv: vmbus: Replace page definition with Hyper-V specific one
HID: hv: Remove dependencies on PAGE_SIZE for ring buffer
Input: hv: Remove dependencies on PAGE_SIZE for ring buffer

arch/x86/hyperv/hv_init.c | 14 ++++++++++++++
arch/x86/include/asm/hyperv-tlfs.h | 12 +++++++++++-
drivers/hid/hid-hyperv.c | 4 ++--
drivers/hv/hyperv_vmbus.h | 8 ++++----
drivers/input/serio/hyperv-keyboard.c | 4 ++--
5 files changed, 33 insertions(+), 9 deletions(-)