linux-kernel - [PATCH v2 0/3] Introduce CONFIG_MSHV

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <1740076396-15086-1-git-send-email-nunodasneves@linux.microsoft.com>
Date: Thu, 20 Feb 2025 10:33:13 -0800
From: Nuno Das Neves <nunodasneves@...ux.microsoft.com>
To: linux-hyperv@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org,
	linux-arch@...r.kernel.org,
	iommu@...ts.linux.dev,
	mhklinux@...look.com,
	eahariha@...ux.microsoft.com
Cc: kys@...rosoft.com,
	haiyangz@...rosoft.com,
	wei.liu@...nel.org,
	decui@...rosoft.com,
	catalin.marinas@....com,
	will@...nel.org,
	tglx@...utronix.de,
	mingo@...hat.com,
	bp@...en8.de,
	dave.hansen@...ux.intel.com,
	x86@...nel.org,
	hpa@...or.com,
	daniel.lezcano@...aro.org,
	joro@...tes.org,
	robin.murphy@....com,
	arnd@...db.de,
	jinankjain@...ux.microsoft.com,
	muminulrussell@...il.com,
	skinsburskii@...ux.microsoft.com,
	mukeshrathor@...rosoft.com
Subject: [PATCH v2 0/3] Introduce CONFIG_MSHV_ROOT for root partition code

Running in the root partition is a unique and specialized case that
requires additional code. CONFIG_MSHV_ROOT allows Hyper-V guest kernels
to exclude this code, which is important since significant additional code
specific to the root partition is expected to be added over time.

To do this, change hv_root_partition to be a function which is stubbed out
to return false if CONFIG_MSHV_ROOT=n, and don't compile hv_proc.c at all,
stubbing out those functions with inline versions.

Store the partition type (guest or root) in an enum hv_current_partition_type,
which can be extended beyond just guest and root partition.

While at it, introduce hv_result_to_errno() to convert Hyper-V status codes
to regular linux errors. This is useful because the caller of a hypercall
helper function (such as those in hv_proc.c) usually can't and doesn't
interpret the Hyper-V status, so it is better to convert it to an error code
and reduce the possibility of misinterpreting it. This also alows the stubbed
versions of the hv_proc.c functions to just return a linux error code.

Signed-off-by: Nuno Das Neves <nunodasneves@...ux.microsoft.com>
---
Changes in v2:
* Add patch to convert hypercall statuses to linux error codes [Easwar
  Hariharan]
* While at it, split the original patch into two logical pieces, one to change
  hv_root_partition into a function, and one to introduce MSHV_CONFIG_ROOT
* Improve the clarity of and add an error message to
  hv_identify_partition_type() [Easwar Hariharan] [Michael Kelley]
* Better explain *why* the patches are useful, in the commit messages [Michael
  Kelley]
* Add a Kconfig comment explaining why PAGE_SIZE_4KB is needed [Michael Kelley]
* Minor style and typo fixes

Nuno Das Neves (3):
  hyperv: Convert hypercall statuses to linux error codes
  hyperv: Change hv_root_partition into a function
  hyperv: Add CONFIG_MSHV_ROOT to gate root partition support

 arch/arm64/hyperv/mshyperv.c       |  2 +
 arch/x86/hyperv/hv_init.c          | 10 ++---
 arch/x86/kernel/cpu/mshyperv.c     | 24 +----------
 drivers/clocksource/hyperv_timer.c |  4 +-
 drivers/hv/Kconfig                 | 16 +++++++
 drivers/hv/Makefile                |  3 +-
 drivers/hv/hv.c                    | 10 ++---
 drivers/hv/hv_common.c             | 69 +++++++++++++++++++++++++++---
 drivers/hv/hv_proc.c               |  6 +--
 drivers/hv/vmbus_drv.c             |  2 +-
 drivers/iommu/hyperv-iommu.c       |  4 +-
 include/asm-generic/mshyperv.h     | 40 ++++++++++++++---
 12 files changed, 137 insertions(+), 53 deletions(-)

-- 
2.34.1