linux-stable/drivers/xen/Kconfig

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# SPDX-License-Identifier: GPL-2.0-only
menu "Xen driver support"
depends on XEN
config XEN_BALLOON
bool "Xen memory balloon driver"
default y
help
The balloon driver allows the Xen domain to request more memory from
the system to expand the domain's memory allocation, or alternatively
return unneeded memory to the system.
config XEN_BALLOON_MEMORY_HOTPLUG
bool "Memory hotplug support for Xen balloon driver"
depends on XEN_BALLOON && MEMORY_HOTPLUG
default y
help
Memory hotplug support for Xen balloon driver allows expanding memory
available for the system above limit declared at system startup.
It is very useful on critical systems which require long
run without rebooting.
It's also very useful for non PV domains to obtain unpopulated physical
memory ranges to use in order to map foreign memory or grants.
Memory could be hotplugged in following steps:
1) target domain: ensure that memory auto online policy is in
effect by checking /sys/devices/system/memory/auto_online_blocks
file (should be 'online').
2) control domain: xl mem-max <target-domain> <maxmem>
where <maxmem> is >= requested memory size,
3) control domain: xl mem-set <target-domain> <memory>
where <memory> is requested memory size; alternatively memory
could be added by writing proper value to
/sys/devices/system/xen_memory/xen_memory0/target or
/sys/devices/system/xen_memory/xen_memory0/target_kb on the
target domain.
Alternatively, if memory auto onlining was not requested at step 1
the newly added memory can be manually onlined in the target domain
by doing the following:
for i in /sys/devices/system/memory/memory*/state; do \
[ "`cat "$i"`" = offline ] && echo online > "$i"; done
or by adding the following line to udev rules:
SUBSYSTEM=="memory", ACTION=="add", RUN+="/bin/sh -c '[ -f /sys$devpath/state ] && echo online > /sys$devpath/state'"
config XEN_MEMORY_HOTPLUG_LIMIT
int "Hotplugged memory limit (in GiB) for a PV guest"
default 512
depends on XEN_HAVE_PVMMU
depends on MEMORY_HOTPLUG
help
Maximum amount of memory (in GiB) that a PV guest can be
expanded to when using memory hotplug.
A PV guest can have more memory than this limit if is
started with a larger maximum.
This value is used to allocate enough space in internal
tables needed for physical memory administration.
config XEN_SCRUB_PAGES_DEFAULT
bool "Scrub pages before returning them to system by default"
depends on XEN_BALLOON
default y
help
Scrub pages before returning them to the system for reuse by
other domains. This makes sure that any confidential data
is not accidentally visible to other domains. It is more
secure, but slightly less efficient. This can be controlled with
xen_scrub_pages=0 parameter and
/sys/devices/system/xen_memory/xen_memory0/scrub_pages.
This option only sets the default value.
If in doubt, say yes.
config XEN_DEV_EVTCHN
tristate "Xen /dev/xen/evtchn device"
default y
help
The evtchn driver allows a userspace process to trigger event
channels and to receive notification of an event channel
firing.
If in doubt, say yes.
config XEN_BACKEND
bool "Backend driver support"
default XEN_DOM0
help
Support for backend device drivers that provide I/O services
to other virtual machines.
config XENFS
tristate "Xen filesystem"
select XEN_PRIVCMD
default y
help
The xen filesystem provides a way for domains to share
information with each other and with the hypervisor.
For example, by reading and writing the "xenbus" file, guests
may pass arbitrary information to the initial domain.
If in doubt, say yes.
config XEN_COMPAT_XENFS
bool "Create compatibility mount point /proc/xen"
depends on XENFS
default y
help
The old xenstore userspace tools expect to find "xenbus"
under /proc/xen, but "xenbus" is now found at the root of the
xenfs filesystem. Selecting this causes the kernel to create
the compatibility mount point /proc/xen if it is running on
a xen platform.
If in doubt, say yes.
config XEN_SYS_HYPERVISOR
bool "Create xen entries under /sys/hypervisor"
depends on SYSFS
select SYS_HYPERVISOR
default y
help
Create entries under /sys/hypervisor describing the Xen
hypervisor environment. When running native or in another
virtual environment, /sys/hypervisor will still be present,
but will have no xen contents.
config XEN_XENBUS_FRONTEND
tristate
config XEN_GNTDEV
tristate "userspace grant access device driver"
depends on XEN
default m
select MMU_NOTIFIER
help
Allows userspace processes to use grants.
config XEN_GNTDEV_DMABUF
bool "Add support for dma-buf grant access device driver extension"
depends on XEN_GNTDEV && XEN_GRANT_DMA_ALLOC
select DMA_SHARED_BUFFER
help
Allows userspace processes and kernel modules to use Xen backed
dma-buf implementation. With this extension grant references to
the pages of an imported dma-buf can be exported for other domain
use and grant references coming from a foreign domain can be
converted into a local dma-buf for local export.
config XEN_GRANT_DEV_ALLOC
tristate "User-space grant reference allocator driver"
depends on XEN
default m
help
Allows userspace processes to create pages with access granted
to other domains. This can be used to implement frontend drivers
or as part of an inter-domain shared memory channel.
config XEN_GRANT_DMA_ALLOC
bool "Allow allocating DMA capable buffers with grant reference module"
depends on XEN && HAS_DMA
help
Extends grant table module API to allow allocating DMA capable
buffers and mapping foreign grant references on top of it.
The resulting buffer is similar to one allocated by the balloon
driver in that proper memory reservation is made by
({increase|decrease}_reservation and VA mappings are updated if
needed).
This is useful for sharing foreign buffers with HW drivers which
cannot work with scattered buffers provided by the balloon driver,
but require DMAable memory instead.
config SWIOTLB_XEN
def_bool y
depends on XEN_PV || ARM || ARM64
select DMA_OPS
select SWIOTLB
xen-pciback: allow compiling on other archs than x86 Xen-pciback driver was designed to be built for x86 only. But it can also be used by other architectures, e.g. Arm. Currently PCI backend implements multiple functionalities at a time, such as: 1. It is used as a database for assignable PCI devices, e.g. xl pci-assignable-{add|remove|list} manipulates that list. So, whenever the toolstack needs to know which PCI devices can be passed through it reads that from the relevant sysfs entries of the pciback. 2. It is used to hold the unbound PCI devices list, e.g. when passing through a PCI device it needs to be unbound from the relevant device driver and bound to pciback (strictly speaking it is not required that the device is bound to pciback, but pciback is again used as a database of the passed through PCI devices, so we can re-bind the devices back to their original drivers when guest domain shuts down) 3. Device reset for the devices being passed through 4. Para-virtualised use-cases support The para-virtualised part of the driver is not always needed as some architectures, e.g. Arm or x86 PVH Dom0, are not using backend-frontend model for PCI device passthrough. For such use-cases make the very first step in splitting the xen-pciback driver into two parts: Xen PCI stub and PCI PV backend drivers. For that add new configuration options CONFIG_XEN_PCI_STUB and CONFIG_XEN_PCIDEV_STUB, so the driver can be limited in its functionality, e.g. no support for para-virtualised scenario. x86 platform will continue using CONFIG_XEN_PCIDEV_BACKEND for the fully featured backend driver. Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Signed-off-by: Anastasiia Lukianenko <anastasiia_lukianenko@epam.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20211028143620.144936-1-andr2000@gmail.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2021-10-28 14:36:20 +00:00
config XEN_PCI_STUB
bool
config XEN_PCIDEV_STUB
tristate "Xen PCI-device stub driver"
depends on PCI && !X86 && XEN
depends on XEN_BACKEND
select XEN_PCI_STUB
default m
help
The PCI device stub driver provides limited version of the PCI
device backend driver without para-virtualized support for guests.
If you select this to be a module, you will need to make sure no
other driver has bound to the device(s) you want to make visible to
other guests.
The "hide" parameter (only applicable if backend driver is compiled
into the kernel) allows you to bind the PCI devices to this module
from the default device drivers. The argument is the list of PCI BDFs:
xen-pciback.hide=(03:00.0)(04:00.0)
If in doubt, say m.
xen/pciback: xen pci backend driver. This is the host side counterpart to the frontend driver in drivers/pci/xen-pcifront.c. The PV protocol is also implemented by frontend drivers in other OSes too, such as the BSDs. The PV protocol is rather simple. There is page shared with the guest, which has the 'struct xen_pci_sharedinfo' embossed in it. The backend has a thread that is kicked every-time the structure is changed and based on the operation field it performs specific tasks: XEN_PCI_OP_conf_[read|write]: Read/Write 0xCF8/0xCFC filtered data. (conf_space*.c) Based on which field is probed, we either enable/disable the PCI device, change power state, read VPD, etc. The major goal of this call is to provide a Physical IRQ (PIRQ) to the guest. The PIRQ is Xen hypervisor global IRQ value irrespective of the IRQ is tied in to the IO-APIC, or is a vector. For GSI type interrupts, the PIRQ==GSI holds. For MSI/MSI-X the PIRQ value != Linux IRQ number (thought PIRQ==vector). Please note, that with Xen, all interrupts (except those level shared ones) are injected directly to the guest - there is no host interaction. XEN_PCI_OP_[enable|disable]_msi[|x] (pciback_ops.c) Enables/disables the MSI/MSI-X capability of the device. These operations setup the MSI/MSI-X vectors for the guest and pass them to the frontend. When the device is activated, the interrupts are directly injected in the guest without involving the host. XEN_PCI_OP_aer_[detected|resume|mmio|slotreset]: In case of failure, perform the appropriate AER commands on the guest. Right now that is a cop-out - we just kill the guest. Besides implementing those commands, it can also - hide a PCI device from the host. When booting up, the user can specify xen-pciback.hide=(1:0:0)(BDF..) so that host does not try to use the device. The driver was lifted from linux-2.6.18.hg tree and fixed up so that it could compile under v3.0. Per suggestion from Jesse Barnes moved the driver to drivers/xen/xen-pciback. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2009-10-13 21:22:20 +00:00
config XEN_PCIDEV_BACKEND
tristate "Xen PCI-device backend driver"
depends on PCI && X86 && XEN
depends on XEN_BACKEND
xen-pciback: allow compiling on other archs than x86 Xen-pciback driver was designed to be built for x86 only. But it can also be used by other architectures, e.g. Arm. Currently PCI backend implements multiple functionalities at a time, such as: 1. It is used as a database for assignable PCI devices, e.g. xl pci-assignable-{add|remove|list} manipulates that list. So, whenever the toolstack needs to know which PCI devices can be passed through it reads that from the relevant sysfs entries of the pciback. 2. It is used to hold the unbound PCI devices list, e.g. when passing through a PCI device it needs to be unbound from the relevant device driver and bound to pciback (strictly speaking it is not required that the device is bound to pciback, but pciback is again used as a database of the passed through PCI devices, so we can re-bind the devices back to their original drivers when guest domain shuts down) 3. Device reset for the devices being passed through 4. Para-virtualised use-cases support The para-virtualised part of the driver is not always needed as some architectures, e.g. Arm or x86 PVH Dom0, are not using backend-frontend model for PCI device passthrough. For such use-cases make the very first step in splitting the xen-pciback driver into two parts: Xen PCI stub and PCI PV backend drivers. For that add new configuration options CONFIG_XEN_PCI_STUB and CONFIG_XEN_PCIDEV_STUB, so the driver can be limited in its functionality, e.g. no support for para-virtualised scenario. x86 platform will continue using CONFIG_XEN_PCIDEV_BACKEND for the fully featured backend driver. Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Signed-off-by: Anastasiia Lukianenko <anastasiia_lukianenko@epam.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20211028143620.144936-1-andr2000@gmail.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2021-10-28 14:36:20 +00:00
select XEN_PCI_STUB
default m
xen/pciback: xen pci backend driver. This is the host side counterpart to the frontend driver in drivers/pci/xen-pcifront.c. The PV protocol is also implemented by frontend drivers in other OSes too, such as the BSDs. The PV protocol is rather simple. There is page shared with the guest, which has the 'struct xen_pci_sharedinfo' embossed in it. The backend has a thread that is kicked every-time the structure is changed and based on the operation field it performs specific tasks: XEN_PCI_OP_conf_[read|write]: Read/Write 0xCF8/0xCFC filtered data. (conf_space*.c) Based on which field is probed, we either enable/disable the PCI device, change power state, read VPD, etc. The major goal of this call is to provide a Physical IRQ (PIRQ) to the guest. The PIRQ is Xen hypervisor global IRQ value irrespective of the IRQ is tied in to the IO-APIC, or is a vector. For GSI type interrupts, the PIRQ==GSI holds. For MSI/MSI-X the PIRQ value != Linux IRQ number (thought PIRQ==vector). Please note, that with Xen, all interrupts (except those level shared ones) are injected directly to the guest - there is no host interaction. XEN_PCI_OP_[enable|disable]_msi[|x] (pciback_ops.c) Enables/disables the MSI/MSI-X capability of the device. These operations setup the MSI/MSI-X vectors for the guest and pass them to the frontend. When the device is activated, the interrupts are directly injected in the guest without involving the host. XEN_PCI_OP_aer_[detected|resume|mmio|slotreset]: In case of failure, perform the appropriate AER commands on the guest. Right now that is a cop-out - we just kill the guest. Besides implementing those commands, it can also - hide a PCI device from the host. When booting up, the user can specify xen-pciback.hide=(1:0:0)(BDF..) so that host does not try to use the device. The driver was lifted from linux-2.6.18.hg tree and fixed up so that it could compile under v3.0. Per suggestion from Jesse Barnes moved the driver to drivers/xen/xen-pciback. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2009-10-13 21:22:20 +00:00
help
The PCI device backend driver allows the kernel to export arbitrary
PCI devices to other guests. If you select this to be a module, you
will need to make sure no other driver has bound to the device(s)
you want to make visible to other guests.
The parameter "passthrough" allows you specify how you want the PCI
devices to appear in the guest. You can choose the default (0) where
PCI topology starts at 00.00.0, or (1) for passthrough if you want
the PCI devices topology appear the same as in the host.
xen/pciback: xen pci backend driver. This is the host side counterpart to the frontend driver in drivers/pci/xen-pcifront.c. The PV protocol is also implemented by frontend drivers in other OSes too, such as the BSDs. The PV protocol is rather simple. There is page shared with the guest, which has the 'struct xen_pci_sharedinfo' embossed in it. The backend has a thread that is kicked every-time the structure is changed and based on the operation field it performs specific tasks: XEN_PCI_OP_conf_[read|write]: Read/Write 0xCF8/0xCFC filtered data. (conf_space*.c) Based on which field is probed, we either enable/disable the PCI device, change power state, read VPD, etc. The major goal of this call is to provide a Physical IRQ (PIRQ) to the guest. The PIRQ is Xen hypervisor global IRQ value irrespective of the IRQ is tied in to the IO-APIC, or is a vector. For GSI type interrupts, the PIRQ==GSI holds. For MSI/MSI-X the PIRQ value != Linux IRQ number (thought PIRQ==vector). Please note, that with Xen, all interrupts (except those level shared ones) are injected directly to the guest - there is no host interaction. XEN_PCI_OP_[enable|disable]_msi[|x] (pciback_ops.c) Enables/disables the MSI/MSI-X capability of the device. These operations setup the MSI/MSI-X vectors for the guest and pass them to the frontend. When the device is activated, the interrupts are directly injected in the guest without involving the host. XEN_PCI_OP_aer_[detected|resume|mmio|slotreset]: In case of failure, perform the appropriate AER commands on the guest. Right now that is a cop-out - we just kill the guest. Besides implementing those commands, it can also - hide a PCI device from the host. When booting up, the user can specify xen-pciback.hide=(1:0:0)(BDF..) so that host does not try to use the device. The driver was lifted from linux-2.6.18.hg tree and fixed up so that it could compile under v3.0. Per suggestion from Jesse Barnes moved the driver to drivers/xen/xen-pciback. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2009-10-13 21:22:20 +00:00
The "hide" parameter (only applicable if backend driver is compiled
into the kernel) allows you to bind the PCI devices to this module
from the default device drivers. The argument is the list of PCI BDFs:
xen-pciback.hide=(03:00.0)(04:00.0)
xen/pciback: xen pci backend driver. This is the host side counterpart to the frontend driver in drivers/pci/xen-pcifront.c. The PV protocol is also implemented by frontend drivers in other OSes too, such as the BSDs. The PV protocol is rather simple. There is page shared with the guest, which has the 'struct xen_pci_sharedinfo' embossed in it. The backend has a thread that is kicked every-time the structure is changed and based on the operation field it performs specific tasks: XEN_PCI_OP_conf_[read|write]: Read/Write 0xCF8/0xCFC filtered data. (conf_space*.c) Based on which field is probed, we either enable/disable the PCI device, change power state, read VPD, etc. The major goal of this call is to provide a Physical IRQ (PIRQ) to the guest. The PIRQ is Xen hypervisor global IRQ value irrespective of the IRQ is tied in to the IO-APIC, or is a vector. For GSI type interrupts, the PIRQ==GSI holds. For MSI/MSI-X the PIRQ value != Linux IRQ number (thought PIRQ==vector). Please note, that with Xen, all interrupts (except those level shared ones) are injected directly to the guest - there is no host interaction. XEN_PCI_OP_[enable|disable]_msi[|x] (pciback_ops.c) Enables/disables the MSI/MSI-X capability of the device. These operations setup the MSI/MSI-X vectors for the guest and pass them to the frontend. When the device is activated, the interrupts are directly injected in the guest without involving the host. XEN_PCI_OP_aer_[detected|resume|mmio|slotreset]: In case of failure, perform the appropriate AER commands on the guest. Right now that is a cop-out - we just kill the guest. Besides implementing those commands, it can also - hide a PCI device from the host. When booting up, the user can specify xen-pciback.hide=(1:0:0)(BDF..) so that host does not try to use the device. The driver was lifted from linux-2.6.18.hg tree and fixed up so that it could compile under v3.0. Per suggestion from Jesse Barnes moved the driver to drivers/xen/xen-pciback. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2009-10-13 21:22:20 +00:00
If in doubt, say m.
config XEN_PVCALLS_FRONTEND
tristate "XEN PV Calls frontend driver"
depends on INET && XEN
select XEN_XENBUS_FRONTEND
help
Experimental frontend for the Xen PV Calls protocol
(https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It
sends a small set of POSIX calls to the backend, which
implements them.
config XEN_PVCALLS_BACKEND
tristate "XEN PV Calls backend driver"
depends on INET && XEN && XEN_BACKEND
help
Experimental backend for the Xen PV Calls protocol
(https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It
allows PV Calls frontends to send POSIX calls to the backend,
which implements them.
If in doubt, say n.
config XEN_SCSI_BACKEND
tristate "XEN SCSI backend driver"
depends on XEN && XEN_BACKEND && TARGET_CORE
help
The SCSI backend driver allows the kernel to export its SCSI Devices
to other guests via a high-performance shared-memory interface.
Only needed for systems running as XEN driver domains (e.g. Dom0) and
if guests need generic access to SCSI devices.
config XEN_PRIVCMD
tristate "Xen hypercall passthrough driver"
depends on XEN
default m
help
The hypercall passthrough driver allows privileged user programs to
perform Xen hypercalls. This driver is normally required for systems
running as Dom0 to perform privileged operations, but in some
disaggregated Xen setups this driver might be needed for other
domains, too.
xen/acpi-processor: C and P-state driver that uploads said data to hypervisor. This driver solves three problems: 1). Parse and upload ACPI0007 (or PROCESSOR_TYPE) information to the hypervisor - aka P-states (cpufreq data). 2). Upload the the Cx state information (cpuidle data). 3). Inhibit CPU frequency scaling drivers from loading. The reason for wanting to solve 1) and 2) is such that the Xen hypervisor is the only one that knows the CPU usage of different guests and can make the proper decision of when to put CPUs and packages in proper states. Unfortunately the hypervisor has no support to parse ACPI DSDT tables, hence it needs help from the initial domain to provide this information. The reason for 3) is that we do not want the initial domain to change P-states while the hypervisor is doing it as well - it causes rather some funny cases of P-states transitions. For this to work, the driver parses the Power Management data and uploads said information to the Xen hypervisor. It also calls acpi_processor_notify_smm() to inhibit the other CPU frequency scaling drivers from being loaded. Everything revolves around the 'struct acpi_processor' structure which gets updated during the bootup cycle in different stages. At the startup, when the ACPI parser starts, the C-state information is processed (processor_idle) and saved in said structure as 'power' element. Later on, the CPU frequency scaling driver (powernow-k8 or acpi_cpufreq), would call the the acpi_processor_* (processor_perflib functions) to parse P-states information and populate in the said structure the 'performance' element. Since we do not want the CPU frequency scaling drivers from loading we have to call the acpi_processor_* functions to parse the P-states and call "acpi_processor_notify_smm" to stop them from loading. There is also one oddity in this driver which is that under Xen, the physical online CPU count can be different from the virtual online CPU count. Meaning that the macros 'for_[online|possible]_cpu' would process only up to virtual online CPU count. We on the other hand want to process the full amount of physical CPUs. For that, the driver checks if the ACPI IDs count is different from the APIC ID count - which can happen if the user choose to use dom0_max_vcpu argument. In such a case a backup of the PM structure is used and uploaded to the hypervisor. [v1-v2: Initial RFC implementations that were posted] [v3: Changed the name to passthru suggested by Pasi Kärkkäinen <pasik@iki.fi>] [v4: Added vCPU != pCPU support - aka dom0_max_vcpus support] [v5: Cleaned up the driver, fix bug under Athlon XP] [v6: Changed the driver to a CPU frequency governor] [v7: Jan Beulich <jbeulich@suse.com> suggestion to make it a cpufreq scaling driver made me rework it as driver that inhibits cpufreq scaling driver] [v8: Per Jan's review comments, fixed up the driver] [v9: Allow to continue even if acpi_processor_preregister_perf.. fails] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-02-03 21:03:20 +00:00
config XEN_ACPI_PROCESSOR
tristate "Xen ACPI processor"
depends on XEN && XEN_PV_DOM0 && X86 && ACPI_PROCESSOR && CPU_FREQ
default m
xen/acpi-processor: C and P-state driver that uploads said data to hypervisor. This driver solves three problems: 1). Parse and upload ACPI0007 (or PROCESSOR_TYPE) information to the hypervisor - aka P-states (cpufreq data). 2). Upload the the Cx state information (cpuidle data). 3). Inhibit CPU frequency scaling drivers from loading. The reason for wanting to solve 1) and 2) is such that the Xen hypervisor is the only one that knows the CPU usage of different guests and can make the proper decision of when to put CPUs and packages in proper states. Unfortunately the hypervisor has no support to parse ACPI DSDT tables, hence it needs help from the initial domain to provide this information. The reason for 3) is that we do not want the initial domain to change P-states while the hypervisor is doing it as well - it causes rather some funny cases of P-states transitions. For this to work, the driver parses the Power Management data and uploads said information to the Xen hypervisor. It also calls acpi_processor_notify_smm() to inhibit the other CPU frequency scaling drivers from being loaded. Everything revolves around the 'struct acpi_processor' structure which gets updated during the bootup cycle in different stages. At the startup, when the ACPI parser starts, the C-state information is processed (processor_idle) and saved in said structure as 'power' element. Later on, the CPU frequency scaling driver (powernow-k8 or acpi_cpufreq), would call the the acpi_processor_* (processor_perflib functions) to parse P-states information and populate in the said structure the 'performance' element. Since we do not want the CPU frequency scaling drivers from loading we have to call the acpi_processor_* functions to parse the P-states and call "acpi_processor_notify_smm" to stop them from loading. There is also one oddity in this driver which is that under Xen, the physical online CPU count can be different from the virtual online CPU count. Meaning that the macros 'for_[online|possible]_cpu' would process only up to virtual online CPU count. We on the other hand want to process the full amount of physical CPUs. For that, the driver checks if the ACPI IDs count is different from the APIC ID count - which can happen if the user choose to use dom0_max_vcpu argument. In such a case a backup of the PM structure is used and uploaded to the hypervisor. [v1-v2: Initial RFC implementations that were posted] [v3: Changed the name to passthru suggested by Pasi Kärkkäinen <pasik@iki.fi>] [v4: Added vCPU != pCPU support - aka dom0_max_vcpus support] [v5: Cleaned up the driver, fix bug under Athlon XP] [v6: Changed the driver to a CPU frequency governor] [v7: Jan Beulich <jbeulich@suse.com> suggestion to make it a cpufreq scaling driver made me rework it as driver that inhibits cpufreq scaling driver] [v8: Per Jan's review comments, fixed up the driver] [v9: Allow to continue even if acpi_processor_preregister_perf.. fails] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-02-03 21:03:20 +00:00
help
This ACPI processor uploads Power Management information to the Xen
hypervisor.
To do that the driver parses the Power Management data and uploads
said information to the Xen hypervisor. Then the Xen hypervisor can
select the proper Cx and Pxx states. It also registers itself as the
SMM so that other drivers (such as ACPI cpufreq scaling driver) will
not load.
To compile this driver as a module, choose M here: the module will be
called xen_acpi_processor If you do not know what to choose, select
M here. If the CPUFREQ drivers are built in, select Y here.
xen/acpi-processor: C and P-state driver that uploads said data to hypervisor. This driver solves three problems: 1). Parse and upload ACPI0007 (or PROCESSOR_TYPE) information to the hypervisor - aka P-states (cpufreq data). 2). Upload the the Cx state information (cpuidle data). 3). Inhibit CPU frequency scaling drivers from loading. The reason for wanting to solve 1) and 2) is such that the Xen hypervisor is the only one that knows the CPU usage of different guests and can make the proper decision of when to put CPUs and packages in proper states. Unfortunately the hypervisor has no support to parse ACPI DSDT tables, hence it needs help from the initial domain to provide this information. The reason for 3) is that we do not want the initial domain to change P-states while the hypervisor is doing it as well - it causes rather some funny cases of P-states transitions. For this to work, the driver parses the Power Management data and uploads said information to the Xen hypervisor. It also calls acpi_processor_notify_smm() to inhibit the other CPU frequency scaling drivers from being loaded. Everything revolves around the 'struct acpi_processor' structure which gets updated during the bootup cycle in different stages. At the startup, when the ACPI parser starts, the C-state information is processed (processor_idle) and saved in said structure as 'power' element. Later on, the CPU frequency scaling driver (powernow-k8 or acpi_cpufreq), would call the the acpi_processor_* (processor_perflib functions) to parse P-states information and populate in the said structure the 'performance' element. Since we do not want the CPU frequency scaling drivers from loading we have to call the acpi_processor_* functions to parse the P-states and call "acpi_processor_notify_smm" to stop them from loading. There is also one oddity in this driver which is that under Xen, the physical online CPU count can be different from the virtual online CPU count. Meaning that the macros 'for_[online|possible]_cpu' would process only up to virtual online CPU count. We on the other hand want to process the full amount of physical CPUs. For that, the driver checks if the ACPI IDs count is different from the APIC ID count - which can happen if the user choose to use dom0_max_vcpu argument. In such a case a backup of the PM structure is used and uploaded to the hypervisor. [v1-v2: Initial RFC implementations that were posted] [v3: Changed the name to passthru suggested by Pasi Kärkkäinen <pasik@iki.fi>] [v4: Added vCPU != pCPU support - aka dom0_max_vcpus support] [v5: Cleaned up the driver, fix bug under Athlon XP] [v6: Changed the driver to a CPU frequency governor] [v7: Jan Beulich <jbeulich@suse.com> suggestion to make it a cpufreq scaling driver made me rework it as driver that inhibits cpufreq scaling driver] [v8: Per Jan's review comments, fixed up the driver] [v9: Allow to continue even if acpi_processor_preregister_perf.. fails] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-02-03 21:03:20 +00:00
config XEN_MCE_LOG
bool "Xen platform mcelog"
depends on XEN_PV_DOM0 && X86_MCE
help
Allow kernel fetching MCE error from Xen platform and
converting it into Linux mcelog format for mcelog tools
config XEN_HAVE_PVMMU
bool
config XEN_EFI
def_bool y
depends on (ARM || ARM64 || X86_64) && EFI
config XEN_AUTO_XLATE
def_bool y
depends on ARM || ARM64 || XEN_PVHVM
help
Support for auto-translated physmap guests.
config XEN_ACPI
def_bool y
depends on X86 && ACPI
config XEN_SYMS
bool "Xen symbols"
depends on X86 && XEN_DOM0 && XENFS
default y if KALLSYMS
help
Exports hypervisor symbols (along with their types and addresses) via
/proc/xen/xensyms file, similar to /proc/kallsyms
config XEN_HAVE_VPMU
bool
config XEN_FRONT_PGDIR_SHBUF
tristate
2020-09-01 08:33:26 +00:00
config XEN_UNPOPULATED_ALLOC
bool "Use unpopulated memory ranges for guest mappings"
depends on ZONE_DEVICE
2020-09-01 08:33:26 +00:00
default XEN_BACKEND || XEN_GNTDEV || XEN_DOM0
help
Use unpopulated memory ranges in order to create mappings for guest
memory regions, including grant maps and foreign pages. This avoids
having to balloon out RAM regions in order to obtain physical memory
space to create such mappings.
config XEN_GRANT_DMA_IOMMU
bool
select IOMMU_API
config XEN_GRANT_DMA_OPS
bool
select DMA_OPS
config XEN_VIRTIO
bool "Xen virtio support"
depends on VIRTIO
select XEN_GRANT_DMA_OPS
select XEN_GRANT_DMA_IOMMU if OF
help
Enable virtio support for running as Xen guest. Depending on the
guest type this will require special support on the backend side
(qemu or kernel, depending on the virtio device types used).
If in doubt, say n.
config XEN_VIRTIO_FORCE_GRANT
bool "Require Xen virtio support to use grants"
depends on XEN_VIRTIO
help
Require virtio for Xen guests to use grant mappings.
This will avoid the need to give the backend the right to map all
of the guest memory. This will need support on the backend side
(e.g. qemu or kernel, depending on the virtio device types used).
endmenu