kernel/drivers/hv/mshv_synic.c, branch master

mshv: add arm64 support for doorbell & intercept SINTs

2026-02-25T19:09:49Z

On x86, the HYPERVISOR_CALLBACK_VECTOR is used to receive synthetic interrupts (SINTs) from the hypervisor for doorbells and intercepts. There is no such vector reserved for arm64. On arm64, the hypervisor exposes a synthetic register that can be read to find the INTID that should be used for SINTs. This INTID is in the PPI range. To better unify the code paths, introduce mshv_sint_vector_init() that either reads the synthetic register and obtains the INTID (arm64) or just uses HYPERVISOR_CALLBACK_VECTOR as the interrupt vector (x86). Reviewed-by: Michael Kelley Reviewed-by: Stanislav Kinsburskii Signed-off-by: Anirudh Rayabharam (Microsoft) Signed-off-by: Wei Liu

mshv: refactor synic init and cleanup

2026-02-25T19:09:24Z

Rename mshv_synic_init() to mshv_synic_cpu_init() and mshv_synic_cleanup() to mshv_synic_cpu_exit() to better reflect that these functions handle per-cpu synic setup and teardown. Use mshv_synic_init/cleanup() to perform init/cleanup that is not per-cpu. Move all the synic related setup from mshv_parent_partition_init. Move the reboot notifier to mshv_synic.c because it currently only operates on the synic cpuhp state. Move out synic_pages from the global mshv_root since its use is now completely local to mshv_synic.c. This is in preparation for adding more stuff to mshv_synic_init(). No functional change. Reviewed-by: Michael Kelley Signed-off-by: Anirudh Rayabharam (Microsoft) Signed-off-by: Wei Liu

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51Z

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28Z

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

Drivers: hv: Rename fields for SynIC message and event pages

2025-11-15T06:18:14Z

Confidential VMBus requires interacting with two SynICs -- one provided by the host hypervisor, and one provided by the paravisor. Each SynIC requires its own message and event pages. Rename the existing host-accessible SynIC message and event pages with the "hyp_" prefix to clearly distinguish them from the paravisor ones. The field name is also changed in mshv_root.* for consistency. No functional changes. Signed-off-by: Roman Kisel Reviewed-by: Tianyu Lan Reviewed-by: Michael Kelley Signed-off-by: Wei Liu

Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs

2025-03-21T18:24:22Z

Provide a set of IOCTLs for creating and managing child partitions when running as root partition on Hyper-V. The new driver is enabled via CONFIG_MSHV_ROOT. A brief overview of the interface: MSHV_CREATE_PARTITION is the entry point, returning a file descriptor representing a child partition. IOCTLs on this fd can be used to map memory, create VPs, etc. Creating a VP returns another file descriptor representing that VP which in turn has another set of corresponding IOCTLs for running the VP, getting/setting state, etc. MSHV_ROOT_HVCALL is a generic "passthrough" hypercall IOCTL which can be used for a number of partition or VP hypercalls. This is for hypercalls that do not affect any state in the kernel driver, such as getting and setting VP registers and partition properties, translating addresses, etc. It is "passthrough" because the binary input and output for the hypercall is only interpreted by the VMM - the kernel driver does nothing but insert the VP and partition id where necessary (which are always in the same place), and execute the hypercall. Co-developed-by: Anirudh Rayabharam Signed-off-by: Anirudh Rayabharam Co-developed-by: Jinank Jain Signed-off-by: Jinank Jain Co-developed-by: Mukesh Rathor Signed-off-by: Mukesh Rathor Co-developed-by: Muminul Islam Signed-off-by: Muminul Islam Co-developed-by: Praveen K Paladugu Signed-off-by: Praveen K Paladugu Co-developed-by: Stanislav Kinsburskii Signed-off-by: Stanislav Kinsburskii Co-developed-by: Wei Liu Signed-off-by: Nuno Das Neves Reviewed-by: Roman Kisel Link: https://lore.kernel.org/r/1741980536-3865-11-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu Message-ID: <1741980536-3865-11-git-send-email-nunodasneves@linux.microsoft.com>