linux-stable.git/arch/x86/kernel/cpu/hypervisor.c, branch linux-rolling-stable

x86/cpu: Detect FreeBSD Bhyve hypervisor

2025-09-15T12:06:44+00:00

Detect the Bhyve hypervisor and enable 15-bit MSI support if available.

Detecting Bhyve used to be a purely cosmetic issue of the kernel printing
'Hypervisor detected: Bhyve' at boot time.

But FreeBSD 15.0 will support¹ the 15-bit MSI enlightenment to support
more than 255 vCPUs (http://david.woodhou.se/ExtDestId.pdf) which means
there's now actually some functional reason to do so.

  ¹ https://github.com/freebsd/freebsd-src/commit/313a68ea20b4

  [ bp: Massage, move tail comment ontop. ]

Signed-off-by: David Woodhouse 
Signed-off-by: Borislav Petkov (AMD) 
Acked-by: Ahmed S. Darwish 
Link: https://lore.kernel.org/03802f6f7f5b5cf8c5e8adfe123c397ca8e21093.camel@infradead.org

x86/paravirt: Remove const mark from x86_hyper_xen_hvm variable

2019-07-17T06:09:59+00:00

.. as "nopv" support needs it to be changeable at boot up stage.

Checkpatch reports warning, so move variable declarations from
hypervisor.c to hypervisor.h

Signed-off-by: Zhenzhong Duan 
Reviewed-by: Juergen Gross 
Cc: Boris Ostrovsky 
Cc: Juergen Gross 
Cc: Stefano Stabellini 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Signed-off-by: Juergen Gross

x86: Add "nopv" parameter to disable PV extensions

2019-07-17T06:09:58+00:00

In virtualization environment, PV extensions (drivers, interrupts,
timers, etc) are enabled in the majority of use cases which is the
best option.

However, in some cases (kexec not fully working, benchmarking)
we want to disable PV extensions. We have "xen_nopv" for that purpose
but only for XEN. For a consistent admin experience a common command
line parameter "nopv" set across all PV guest implementations is a
better choice.

There are guest types which just won't work without PV extensions,
like Xen PV, Xen PVH and jailhouse. add a "ignore_nopv" member to
struct hypervisor_x86 set to true for those guest types and call
the detect functions only if nopv is false or ignore_nopv is true.

Suggested-by: Juergen Gross 
Signed-off-by: Zhenzhong Duan 
Reviewed-by: Juergen Gross 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: Jan Kiszka 
Cc: Boris Ostrovsky 
Cc: Stefano Stabellini 
Signed-off-by: Juergen Gross

x86: Add support for Linux guests on an ACRN hypervisor

2019-06-11T19:29:22+00:00

ACRN is an open-source hypervisor maintained by The Linux Foundation. It
is built for embedded IOT with small footprint and real-time features.
Add ACRN guest support so that it allows Linux to be booted under the
ACRN hypervisor. This adds only the barebones implementation.

 [ bp: Massage commit message and help text. ]

Co-developed-by: Jason Chen CJ 
Signed-off-by: Jason Chen CJ 
Signed-off-by: Zhao Yakui 
Signed-off-by: Borislav Petkov 
Reviewed-by: Thomas Gleixner 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: x86-ml 
Link: https://lkml.kernel.org/r/1559108037-18813-3-git-send-email-yakui.zhao@intel.com

x86/jailhouse: Add infrastructure for running in non-root cell

2018-01-14T20:11:54+00:00

The Jailhouse hypervisor is able to statically partition a multicore
system into multiple so-called cells. Linux is used as boot loader and
continues to run in the root cell after Jailhouse is enabled. Linux can
also run in non-root cells.

Jailhouse does not emulate usual x86 devices. It also provides no
complex ACPI but basic platform information that the boot loader
forwards via setup data. This adds the infrastructure to detect when
running in a non-root cell so that the platform can be configured as
required in succeeding steps.

Support is limited to x86-64 so far, primarily because no boot loader
stub exists for i386 and, thus, we wouldn't be able to test the 32-bit
path.

Signed-off-by: Jan Kiszka 
Signed-off-by: Thomas Gleixner 
Cc: jailhouse-dev@googlegroups.com
Link: https://lkml.kernel.org/r/7f823d077b38b1a70c526b40b403f85688c137d3.1511770314.git.jan.kiszka@siemens.com

x86/virt: Add enum for hypervisors to replace x86_hyper

2017-11-10T09:03:12+00:00

The x86_hyper pointer is only used for checking whether a virtual
device is supporting the hypervisor the system is running on.

Use an enum for that purpose instead and drop the x86_hyper pointer.

Signed-off-by: Juergen Gross 
Acked-by: Thomas Gleixner 
Acked-by: Xavier Deguillard 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: akataria@vmware.com
Cc: arnd@arndb.de
Cc: boris.ostrovsky@oracle.com
Cc: devel@linuxdriverproject.org
Cc: dmitry.torokhov@gmail.com
Cc: gregkh@linuxfoundation.org
Cc: haiyangz@microsoft.com
Cc: kvm@vger.kernel.org
Cc: kys@microsoft.com
Cc: linux-graphics-maintainer@vmware.com
Cc: linux-input@vger.kernel.org
Cc: moltmann@vmware.com
Cc: pbonzini@redhat.com
Cc: pv-drivers@vmware.com
Cc: rkrcmar@redhat.com
Cc: sthemmin@microsoft.com
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20171109132739.23465-3-jgross@suse.com
Signed-off-by: Ingo Molnar

x86/virt, x86/platform: Merge 'struct x86_hyper' into 'struct x86_platform' and 'struct x86_init'

2017-11-10T09:03:12+00:00

Instead of x86_hyper being either NULL on bare metal or a pointer to a
struct hypervisor_x86 in case of the kernel running as a guest merge
the struct into x86_platform and x86_init.

This will remove the need for wrappers making it hard to find out what
is being called. With dummy functions added for all callbacks testing
for a NULL function pointer can be removed, too.

Suggested-by: Ingo Molnar 
Signed-off-by: Juergen Gross 
Acked-by: Thomas Gleixner 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: akataria@vmware.com
Cc: boris.ostrovsky@oracle.com
Cc: devel@linuxdriverproject.org
Cc: haiyangz@microsoft.com
Cc: kvm@vger.kernel.org
Cc: kys@microsoft.com
Cc: pbonzini@redhat.com
Cc: rkrcmar@redhat.com
Cc: rusty@rustcorp.com.au
Cc: sthemmin@microsoft.com
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20171109132739.23465-2-jgross@suse.com
Signed-off-by: Ingo Molnar

x86/cpu: remove hypervisor specific set_cpu_features

2017-05-02T09:14:30+00:00

There is no user of x86_hyper->set_cpu_features() any more. Remove it.

Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Cc: x86@kernel.org
Signed-off-by: Juergen Gross 
Reviewed-by: Boris Ostrovsky 
Signed-off-by: Juergen Gross

x86/xen: add CONFIG_XEN_PV to Kconfig

2017-05-02T08:50:19+00:00

All code to support Xen PV will get under this new option. For the
beginning, check for it in the common code.

Signed-off-by: Vitaly Kuznetsov 
Reviewed-by: Juergen Gross 
Signed-off-by: Juergen Gross

x86/xen: separate PV and HVM hypervisors

2017-05-02T08:49:44+00:00

As a preparation to splitting the code we need to untangle it:

x86_hyper_xen -> x86_hyper_xen_hvm and x86_hyper_xen_pv
xen_platform() -> xen_platform_hvm() and xen_platform_pv()
xen_cpu_up_prepare() -> xen_cpu_up_prepare_pv() and xen_cpu_up_prepare_hvm()
xen_cpu_dead() -> xen_cpu_dead_pv() and xen_cpu_dead_pv_hvm()

Add two parameters to xen_cpuhp_setup() to pass proper cpu_up_prepare and
cpu_dead hooks. xen_set_cpu_features() is now PV-only so the redundant
xen_pv_domain() check can be dropped.

Signed-off-by: Vitaly Kuznetsov 
Reviewed-by: Juergen Gross 
Signed-off-by: Juergen Gross