Pull hyperv updates from Wei Liu:
- Enhancements to Linux as the root partition for Microsoft Hypervisor:
- Support a new mode called L1VH, which allows Linux to drive the
hypervisor running the Azure Host directly
- Support for MSHV crash dump collection
- Allow Linux's memory management subsystem to better manage guest
memory regions
- Fix issues that prevented a clean shutdown of the whole system on
bare metal and nested configurations
- ARM64 support for the MSHV driver
- Various other bug fixes and cleanups
- Add support for Confidential VMBus for Linux guest on Hyper-V
- Secure AVIC support for Linux guests on Hyper-V
- Add the mshv_vtl driver to allow Linux to run as the secure kernel in
a higher virtual trust level for Hyper-V
* tag 'hyperv-next-signed-20251207' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (58 commits)
mshv: Cleanly shutdown root partition with MSHV
mshv: Use reboot notifier to configure sleep state
mshv: Add definitions for MSHV sleep state configuration
mshv: Add support for movable memory regions
mshv: Add refcount and locking to mem regions
mshv: Fix huge page handling in memory region traversal
mshv: Move region management to mshv_regions.c
mshv: Centralize guest memory region destruction
mshv: Refactor and rename memory region handling functions
mshv: adjust interrupt control structure for ARM64
Drivers: hv: use kmalloc_array() instead of kmalloc()
mshv: Add ioctl for self targeted passthrough hvcalls
Drivers: hv: Introduce mshv_vtl driver
Drivers: hv: Export some symbols for mshv_vtl
static_call: allow using STATIC_CALL_TRAMP_STR() from assembly
mshv: Extend create partition ioctl to support cpu features
mshv: Allow mappings that overlap in uaddr
mshv: Fix create memory region overlap check
mshv: add WQ_PERCPU to alloc_workqueue users
Drivers: hv: Use kmalloc_array() instead of kmalloc()
...
Pull SoC driver updates from Arnd Bergmann:
"This is the first half of the driver changes:
- A treewide interface change to the "syscore" operations for power
management, as a preparation for future Tegra specific changes
- Reset controller updates with added drivers for LAN969x, eic770 and
RZ/G3S SoCs
- Protection of system controller registers on Renesas and Google
SoCs, to prevent trivially triggering a system crash from e.g.
debugfs access
- soc_device identification updates on Nvidia, Exynos and Mediatek
- debugfs support in the ST STM32 firewall driver
- Minor updates for SoC drivers on AMD/Xilinx, Renesas, Allwinner, TI
- Cleanups for memory controller support on Nvidia and Renesas"
* tag 'soc-drivers-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (114 commits)
memory: tegra186-emc: Fix missing put_bpmp
Documentation: reset: Remove reset_controller_add_lookup()
reset: fix BIT macro reference
reset: rzg2l-usbphy-ctrl: Fix a NULL vs IS_ERR() bug in probe
reset: th1520: Support reset controllers in more subsystems
reset: th1520: Prepare for supporting multiple controllers
dt-bindings: reset: thead,th1520-reset: Add controllers for more subsys
dt-bindings: reset: thead,th1520-reset: Remove non-VO-subsystem resets
reset: remove legacy reset lookup code
clk: davinci: psc: drop unused reset lookup
reset: rzg2l-usbphy-ctrl: Add support for RZ/G3S SoC
reset: rzg2l-usbphy-ctrl: Add support for USB PWRRDY
dt-bindings: reset: renesas,rzg2l-usbphy-ctrl: Document RZ/G3S support
reset: eswin: Add eic7700 reset driver
dt-bindings: reset: eswin: Documentation for eic7700 SoC
reset: sparx5: add LAN969x support
dt-bindings: reset: microchip: Add LAN969x support
soc: rockchip: grf: Add select correct PWM implementation on RK3368
soc/tegra: pmc: Add USB wake events for Tegra234
amba: tegra-ahb: Fix device leak on SMMU enable
...
Root partitions running on MSHV currently attempt ACPI power-off, which
MSHV intercepts and triggers a Machine Check Exception (MCE), leading
to a kernel panic.
Root partitions panic with a trace similar to:
[ 81.306348] reboot: Power down
[ 81.314709] mce: [Hardware Error]: CPU 0: Machine Check Exception: 4 Bank 0: b2000000c0060001
[ 81.314711] mce: [Hardware Error]: TSC 3b8cb60a66 PPIN 11d98332458e4ea9
[ 81.314713] mce: [Hardware Error]: PROCESSOR 0:606a6 TIME 1759339405 SOCKET 0 APIC 0 microcode ffffffff
[ 81.314715] mce: [Hardware Error]: Run the above through 'mcelog --ascii'
[ 81.314716] mce: [Hardware Error]: Machine check: Processor context corrupt
[ 81.314717] Kernel panic - not syncing: Fatal machine check
To avoid this, configure the sleep state in the hypervisor and invoke
the HVCALL_ENTER_SLEEP_STATE hypercall as the final step in the shutdown
sequence. This ensures a clean and safe shutdown of the root partition.
Signed-off-by: Praveen K Paladugu <prapal@linux.microsoft.com>
Co-developed-by: Anatol Belski <anbelski@linux.microsoft.com>
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Reviewed-by: Easwar Hariharan <easwar.hariharan@linux.microsoft.com>
Acked-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Introduce support for movable memory regions in the Hyper-V root partition
driver to improve memory management flexibility and enable advanced use
cases such as dynamic memory remapping.
Mirror the address space between the Linux root partition and guest VMs
using HMM. The root partition owns the memory, while guest VMs act as
devices with page tables managed via hypercalls. MSHV handles VP intercepts
by invoking hmm_range_fault() and updating SLAT entries. When memory is
reclaimed, HMM invalidates the relevant regions, prompting MSHV to clear
SLAT entries; guest VMs will fault again on access.
Integrate mmu_interval_notifier for movable regions, implement handlers for
HMM faults and memory invalidation, and update memory region mapping logic
to support movable regions.
While MMU notifiers are commonly used in virtualization drivers, this
implementation leverages HMM (Heterogeneous Memory Management) for its
specialized functionality. HMM provides a framework for mirroring,
invalidation, and fault handling, reducing boilerplate and improving
maintainability compared to generic MMU notifiers.
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Introduce kref-based reference counting and spinlock protection for
memory regions in Hyper-V partition management. This change improves
memory region lifecycle management and ensures thread-safe access to the
region list.
Previously, the regions list was protected by the partition mutex.
However, this approach is too heavy for frequent fault and invalidation
operations. Finer grained locking is now used to improve efficiency and
concurrency.
This is a precursor to supporting movable memory regions. Fault and
invalidation handling for movable regions will require safe traversal of
the region list and holding a region reference while performing
invalidation or fault operations.
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
The previous code assumed that if a region's first page was huge, the
entire region consisted of huge pages and stored this in a large_pages
flag. This premise is incorrect not only for movable regions (where
pages can be split and merged on invalidate callbacks or page faults),
but even for pinned regions: THPs can be split and merged during
allocation, so a large, pinned region may contain a mix of huge and
regular pages.
This change removes the large_pages flag and replaces region-wide
assumptions with per-chunk inspection of the actual page size when
mapping, unmapping, sharing, and unsharing. This makes huge page
handling correct for mixed-page regions and avoids relying on stale
metadata that can easily become invalid as memory is remapped.
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Refactor memory region management functions from mshv_root_main.c into
mshv_regions.c for better modularity and code organization.
Adjust function calls and headers to use the new implementation. Improve
maintainability and separation of concerns in the mshv_root module.
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Centralize guest memory region destruction to prevent resource leaks and
inconsistent cleanup across unmap and partition destruction paths.
Unify region removal, encrypted partition access recovery, and region
invalidation to improve maintainability and reliability. Reduce code
duplication and make future updates less error-prone by encapsulating
cleanup logic in a single helper.
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Simplify and unify memory region management to improve code clarity and
reliability. Consolidate pinning and invalidation logic, adopt consistent
naming, and remove redundant checks to reduce complexity.
Enhance documentation and update call sites for maintainability.
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Interrupt control structure (union hv_interupt_control) has different
fields when it comes to x86 vs ARM64. Bring in the correct structure
from HyperV header files and adjust the existing interrupt routing
code accordingly.
Signed-off-by: Jinank Jain <jinankjain@microsoft.com>
Signed-off-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Replace kmalloc() with kmalloc_array() to prevent potential
overflow, as recommended in Documentation/process/deprecated.rst.
Signed-off-by: Gongwei Li <ligongwei@kylinos.cn>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Allow MSHV_ROOT_HVCALL IOCTL on the /dev/mshv fd. This IOCTL would
execute a passthrough hypercall targeting the root/parent partition
i.e. HV_PARTITION_ID_SELF.
This will be useful for the VMM to query things like supported
synthetic processor features, supported VMM capabiliites etc.
Since hypercalls targeting the host partition could potentially perform
privileged operations, allow only a limited set of hypercalls. To begin
with, allow only:
HVCALL_GET_PARTITION_PROPERTY
HVCALL_GET_PARTITION_PROPERTY_EX
Signed-off-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Provide an interface for Virtual Machine Monitor like OpenVMM and its
use as OpenHCL paravisor to control VTL0 (Virtual trust Level).
Expose devices and support IOCTLs for features like VTL creation,
VTL0 memory management, context switch, making hypercalls,
mapping VTL0 address space to VTL2 userspace, getting new VMBus
messages and channel events in VTL2 etc.
Co-developed-by: Roman Kisel <romank@linux.microsoft.com>
Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Co-developed-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Naman Jain <namjain@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Pull rseq updates from Thomas Gleixner:
"A large overhaul of the restartable sequences and CID management:
The recent enablement of RSEQ in glibc resulted in regressions which
are caused by the related overhead. It turned out that the decision to
invoke the exit to user work was not really a decision. More or less
each context switch caused that. There is a long list of small issues
which sums up nicely and results in a 3-4% regression in I/O
benchmarks.
The other detail which caused issues due to extra work in context
switch and task migration is the CID (memory context ID) management.
It also requires to use a task work to consolidate the CID space,
which is executed in the context of an arbitrary task and results in
sporadic uncontrolled exit latencies.
The rewrite addresses this by:
- Removing deprecated and long unsupported functionality
- Moving the related data into dedicated data structures which are
optimized for fast path processing.
- Caching values so actual decisions can be made
- Replacing the current implementation with a optimized inlined
variant.
- Separating fast and slow path for architectures which use the
generic entry code, so that only fault and error handling goes into
the TIF_NOTIFY_RESUME handler.
- Rewriting the CID management so that it becomes mostly invisible in
the context switch path. That moves the work of switching modes
into the fork/exit path, which is a reasonable tradeoff. That work
is only required when a process creates more threads than the
cpuset it is allowed to run on or when enough threads exit after
that. An artificial thread pool benchmarks which triggers this did
not degrade, it actually improved significantly.
The main effect in migration heavy scenarios is that runqueue lock
held time and therefore contention goes down significantly"
* tag 'core-rseq-2025-11-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (54 commits)
sched/mmcid: Switch over to the new mechanism
sched/mmcid: Implement deferred mode change
irqwork: Move data struct to a types header
sched/mmcid: Provide CID ownership mode fixup functions
sched/mmcid: Provide new scheduler CID mechanism
sched/mmcid: Introduce per task/CPU ownership infrastructure
sched/mmcid: Serialize sched_mm_cid_fork()/exit() with a mutex
sched/mmcid: Provide precomputed maximal value
sched/mmcid: Move initialization out of line
signal: Move MMCID exit out of sighand lock
sched/mmcid: Convert mm CID mask to a bitmap
cpumask: Cache num_possible_cpus()
sched/mmcid: Use cpumask_weighted_or()
cpumask: Introduce cpumask_weighted_or()
sched/mmcid: Prevent pointless work in mm_update_cpus_allowed()
sched/mmcid: Move scheduler code out of global header
sched: Fixup whitespace damage
sched/mmcid: Cacheline align MM CID storage
sched/mmcid: Use proper data structures
sched/mmcid: Revert the complex CID management
...
The existing mshv create partition ioctl does not provide a way to
specify which cpu features are enabled in the guest. Instead, it
attempts to enable all features and those that are not supported are
silently disabled by the hypervisor.
This was done to reduce unnecessary complexity and is sufficient for
many cases. However, new scenarios require fine-grained control over
these features.
Define a new mshv_create_partition_v2 structure which supports
passing the disabled processor and xsave feature bits through to the
create partition hypercall directly.
Introduce a new flag MSHV_PT_BIT_CPU_AND_XSAVE_FEATURES which enables
the new structure. If unset, the original mshv_create_partition struct
is used, with the old behavior of enabling all features.
Co-developed-by: Jinank Jain <jinankjain@microsoft.com>
Signed-off-by: Jinank Jain <jinankjain@microsoft.com>
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Currently the MSHV driver rejects mappings that would overlap in
userspace.
Some VMMs require the same memory to be mapped to different parts of
the guest's address space, and so working around this restriction is
difficult.
The hypervisor itself doesn't prohibit mappings that overlap in uaddr,
(really in SPA; system physical addresses), so supporting this in the
driver doesn't require any extra work: only the checks need to be
removed.
Since no userspace code until now has been able to overlap regions in
userspace, relaxing this constraint can't break any existing code.
Signed-off-by: Magnus Kulke <magnuskulke@linux.microsoft.com>
Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Currently if a user enqueues a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistency cannot be addressed without refactoring the API.
alloc_workqueue() treats all queues as per-CPU by default, while unbound
workqueues must opt-in via WQ_UNBOUND.
This default is suboptimal: most workloads benefit from unbound queues,
allowing the scheduler to place worker threads where they’re needed and
reducing noise when CPUs are isolated.
This continues the effort to refactor workqueue APIs, which began with
the introduction of new workqueues and a new alloc_workqueue flag in:
commit 128ea9f6cc ("workqueue: Add system_percpu_wq and system_dfl_wq")
commit 930c2ea566 ("workqueue: Add new WQ_PERCPU flag")
This change adds a new WQ_PERCPU flag to explicitly request
alloc_workqueue() to be per-cpu when WQ_UNBOUND has not been specified.
With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND),
any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND
must now use WQ_PERCPU.
Once migration is complete, WQ_UNBOUND can be removed and unbound will
become the implicit default.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Documentation/process/deprecated.rst recommends against the use of
kmalloc with dynamic size calculations due to the risk of overflow and
smaller allocation being made than the caller was expecting.
Replace kmalloc() with kmalloc_array() in hv_common.c to make the
intended allocation size clearer and avoid potential overflow issues.
The number of pages (pgcount) is bounded, so overflow is not a
practical concern here. However, using kmalloc_array() better reflects
the intent to allocate an array and improves consistency with other
allocations.
No functional change intended.
Signed-off-by: Rahul Kumar <rk0006818@gmail.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Update the log message in hv_common_init to explicitly state that the
reported version is for the Microsoft Hypervisor, not the host OS.
Previously, this message was accurate for guests running on Windows
hosts, where the host and hypervisor versions matched. With support for
Linux hosts running the Hyper-V hypervisor, the host OS and hypervisor
versions may differ.
This change avoids confusion by making it clear that the version refers to
the Microsoft Hypervisor regardless of the host operating system.
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Introduce HVCALL_MAP_STATS_PAGE2 which provides a map location (GPFN)
to map the stats to. This hypercall is required for L1VH partitions,
depending on the hypervisor version. This uses the same check as the
state page map location; mshv_use_overlay_gpfn().
Add mshv_map_vp_state_page() helpers to use this new hypercall or the
old one depending on availability.
For unmapping, the original HVCALL_UNMAP_STATS_PAGE works for both
cases.
Signed-off-by: Jinank Jain <jinankjain@linux.microsoft.com>
Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Easwar Hariharan <easwar.hariharan@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Some hypervisor APIs are gated by feature bits in the
"vmm capabilities" partition property. Store the capabilities on
mshv_root module init, using HVCALL_GET_PARTITION_PROPERTY_EX.
This is not supported on all hypervisors. In that case, just set the
capabilities to 0 and proceed as normal.
Signed-off-by: Purna Pavan Chandra Aekkaladevi <paekkaladevi@linux.microsoft.com>
Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Praveen K Paladugu <prapal@linux.microsoft.com>
Reviewed-by: Easwar Hariharan <easwar.hariharan@linux.microsoft.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
To establish the confidential VMBus connection the CoCo VM, the guest
first checks on the confidential VMBus availability, and then proceeds
to initializing the communication stack.
Implement that in the VMBus driver initialization.
Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
The confidential VMBus is supported by the protocol version
6.0 onwards.
Attempt to establish the VMBus 6.0 connection thus enabling
the confidential VMBus features when available.
Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
To make use of Confidential VMBus channels, initialize the
co_ring_buffers and co_external_memory fields of the channel
structure.
Advertise support upon negotiating the version and compute
values for those fields and initialize them.
Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
The confidential VMBus runs with the paravisor SynIC and requires
configuring it with the paravisor.
Add the functions for configuring the paravisor SynIC. Update
overall SynIC initialization logic to initialize the SynIC if it
is present. Finally, break out SynIC interrupt enable/disable
code into separate functions so that SynIC interrupts can be
enabled or disabled via the paravisor instead of the hypervisor
if the paravisor SynIC is present.
Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
The confidential VMBus requires support for the both hypervisor
facing SynIC and the paravisor one.
Rename the functions that enable and disable SynIC with the
hypervisor. No functional changes.
Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
When the confidential VMBus is available, the guest should post
messages to the paravisor.
Update hv_post_message() to post messages to the paravisor rather than
through GHCB or TD calls.
Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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.
Refactor and extend the existing code to add allocating and freeing
the message and event pages for the paravisor SynIC when it is
present.
Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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 <romank@linux.microsoft.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
hv_set_non_nested_msr() has special handling for SINT MSRs
when a paravisor is present. In addition to updating the MSR on the
host, the mirror MSR in the paravisor is updated, including with the
proxy bit. But with Confidential VMBus, the proxy bit must not be
used, so add a special case to skip it.
Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
The existing Hyper-V wrappers for getting and setting MSRs are
hv_get/set_msr(). Via hv_get/set_non_nested_msr(), they detect
when running in a CoCo VM with a paravisor, and use the TDX or
SNP guest-host communication protocol to bypass the paravisor
and go directly to the host hypervisor for SynIC MSRs. The "set"
function also implements the required special handling for the
SINT MSRs.
Provide functions that allow manipulating the SynIC registers
through the paravisor. Move vmbus_signal_eom() to a more
appropriate location (which also avoids breaking KVM).
Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
When Secure AVIC is enabled, VMBus driver should
call x2apic Secure AVIC interface to allow Hyper-V
to inject VMBus message interrupt.
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com>
Signed-off-by: Tianyu Lan <tiala@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
When the MSHV_ROOT_HVCALL ioctl is executing a hypercall, and gets
HV_STATUS_INSUFFICIENT_MEMORY, it deposits memory and then returns
-EAGAIN to userspace. The expectation is that the VMM will retry.
However, some VMM code in the wild doesn't do this and simply fails.
Rather than force the VMM to retry, change the ioctl to deposit
memory on demand and immediately retry the hypercall as is done with
all the other hypercall helper functions.
In addition to making the ioctl easier to use, removing the need for
multiple syscalls improves performance.
There is a complication: unlike the other hypercall helper functions,
in MSHV_ROOT_HVCALL the input is opaque to the kernel. This is
problematic for rep hypercalls, because the next part of the input
list can't be copied on each loop after depositing pages (this was
the original reason for returning -EAGAIN in this case).
Introduce hv_do_rep_hypercall_ex(), which adds a 'rep_start'
parameter. This solves the issue, allowing the deposit loop in
MSHV_ROOT_HVCALL to restart a rep hypercall after depositing pages
partway through.
Fixes: 621191d709 ("Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs")
Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
This value in the VP stats page is used to track if the VP can be
dispatched for execution when there are no fast interrupts injected.
The original value of 201 was used in a version of the hypervisor
which did not ship. It was subsequently changed to 202 so that is the
correct value.
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Several drivers can benefit from registering per-instance data along
with the syscore operations. To achieve this, move the modifiable fields
out of the syscore_ops structure and into a separate struct syscore that
can be registered with the framework. Add a void * driver data field for
drivers to store contextual data that will be passed to the syscore ops.
Acked-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Hypervisors invoke resume_user_mode_work() before entering the guest, which
clears TIF_NOTIFY_RESUME. The @regs argument is NULL as there is no user
space context available to them, so the rseq notify handler skips
inspecting the critical section, but updates the CPU/MM CID values
unconditionally so that the eventual pending rseq event is not lost on the
way to user space.
This is a pointless exercise as the task might be rescheduled before
actually returning to user space and it creates unnecessary work in the
vcpu_run() loops.
It's way more efficient to ignore that invocation based on @regs == NULL
and let the hypervisors re-raise TIF_NOTIFY_RESUME after returning from the
vcpu_run() loop before returning from the ioctl().
This ensures that a pending RSEQ update is not lost and the IDs are updated
before returning to user space.
Once the RSEQ handling is decoupled from TIF_NOTIFY_RESUME, this turns into
a NOOP.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Sean Christopherson <seanjc@google.com>
Link: https://patch.msgid.link/20251027084306.399495855@linutronix.de
With CONFIG_HYPERV and CONFIG_HYPERV_VMBUS separated, change CONFIG_HYPERV
to bool from tristate. CONFIG_HYPERV now becomes the core Hyper-V
hypervisor support, such as hypercalls, clocks/timers, Confidential
Computing setup, PCI passthru, etc. that doesn't involve VMBus or VMBus
devices.
Signed-off-by: Mukesh Rathor <mrathor@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
