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183d03cc4f
Add the xen pci platform device driver that is responsible for initializing the grant table and xenbus in PV on HVM mode. Few changes to xenbus and grant table are necessary to allow the delayed initialization in HVM mode. Grant table needs few additional modifications to work in HVM mode. The Xen PCI platform device raises an irq every time an event has been delivered to us. However these interrupts are only delivered to vcpu 0. The Xen PCI platform interrupt handler calls xen_hvm_evtchn_do_upcall that is a little wrapper around __xen_evtchn_do_upcall, the traditional Xen upcall handler, the very same used with traditional PV guests. When running on HVM the event channel upcall is never called while in progress because it is a normal Linux irq handler (and we cannot switch the irq chip wholesale to the Xen PV ones as we are running QEMU and might have passed in PCI devices), therefore we cannot be sure that evtchn_upcall_pending is 0 when returning. For this reason if evtchn_upcall_pending is set by Xen we need to loop again on the event channels set pending otherwise we might loose some event channel deliveries. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
75 lines
2.4 KiB
Plaintext
75 lines
2.4 KiB
Plaintext
menu "Xen driver support"
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depends on XEN
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config XEN_BALLOON
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bool "Xen memory balloon driver"
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default y
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help
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The balloon driver allows the Xen domain to request more memory from
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the system to expand the domain's memory allocation, or alternatively
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return unneeded memory to the system.
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config XEN_SCRUB_PAGES
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bool "Scrub pages before returning them to system"
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depends on XEN_BALLOON
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default y
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help
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Scrub pages before returning them to the system for reuse by
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other domains. This makes sure that any confidential data
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is not accidentally visible to other domains. Is it more
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secure, but slightly less efficient.
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If in doubt, say yes.
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config XEN_DEV_EVTCHN
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tristate "Xen /dev/xen/evtchn device"
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default y
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help
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The evtchn driver allows a userspace process to triger event
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channels and to receive notification of an event channel
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firing.
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If in doubt, say yes.
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config XENFS
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tristate "Xen filesystem"
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default y
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help
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The xen filesystem provides a way for domains to share
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information with each other and with the hypervisor.
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For example, by reading and writing the "xenbus" file, guests
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may pass arbitrary information to the initial domain.
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If in doubt, say yes.
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config XEN_COMPAT_XENFS
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bool "Create compatibility mount point /proc/xen"
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depends on XENFS
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default y
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help
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The old xenstore userspace tools expect to find "xenbus"
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under /proc/xen, but "xenbus" is now found at the root of the
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xenfs filesystem. Selecting this causes the kernel to create
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the compatibility mount point /proc/xen if it is running on
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a xen platform.
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If in doubt, say yes.
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config XEN_SYS_HYPERVISOR
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bool "Create xen entries under /sys/hypervisor"
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depends on SYSFS
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select SYS_HYPERVISOR
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default y
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help
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Create entries under /sys/hypervisor describing the Xen
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hypervisor environment. When running native or in another
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virtual environment, /sys/hypervisor will still be present,
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but will have no xen contents.
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config XEN_PLATFORM_PCI
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tristate "xen platform pci device driver"
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depends on XEN
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default m
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help
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Driver for the Xen PCI Platform device: it is responsible for
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initializing xenbus and grant_table when running in a Xen HVM
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domain. As a consequence this driver is required to run any Xen PV
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frontend on Xen HVM.
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endmenu
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