Xen

Xen is a completely free and open source virtual machine monitor for x86 computer platforms that has been designed from the ground up to support execution of multiple guest operating systems in isolated environments on a single machine. It is one of the most powerful virtual machine solutions for Linux, UNIX and POSIX OSes.

Features at a glance

Key features include support for EFI (Extensible Firmware Interface), supports up to 4095 host CPUs on the 64-bit hardware platform, supports dom0 kernels compressed with the xz compression method, supports per-device interrupt remapping, as well as multiple PCI segments.

Among other supported architectures, Xen works well on X86-64, ARMv7 + Virtualization Extensions, as well as on the brand-new ARMv8 architecture. Xen also supports several Linux kernel-based operating systems, including Red Hat Enterprise Linux, SuSE, Debian, OpenMandriva and many othes, as well as various BSD flavors.

Getting started with Xen

Xen can be found on the main software repositories of modern GNU/Linux distributions, which means that it can easily installed from your Software Center app. It is mainly distributed as a source package that can be optimized for a specific operating system/hardware architecture.

If you’re a hardcore Linux user and want to install Xen from sources, download the latest release from either Softoware or the project’s official website (see the homepage link at the end of the article), save it on your Home directory, and use an archive manager tool to extract its contents.

The, open a terminal emulator app, navigate to the location where you have extracted the archive files (e.g. cd /home/softoware/xen-4.5.0 - replace ‘softoware’ with your username), run the ‘./configure && make’ command to configure and compile the program, followed by the ‘sudo make install’ command to install it system wide after a successful compilation process.

What is new in this release:

• c30ab3d97c: SUPPORT.md: Add missing support lifetime information
• 5f6000a985: adapt SUPPORT.md to match 4.11
• f9e1bddbc8: SUPPORT.md: Fix a typo
• 3614c7d949: SUPPORT.md: Document the new text ordering rule
• 6f8e8bae87: SUPPORT.md: Move descriptions up before Status info
• 2e02212848: docs/Makefile: Format SUPPORT.md into the toplevel
• 73c8c2c211: docs/Makefile: Introduce GENERATE_PANDOC_RULE_RAW
• c07d2195b0: docs/gen-html-index: Support documents at the toplevel
• 0609dd1c5e: docs/gen-html-index: Extract titles from HTML documents
• a3459c741e: SUPPORT.md: Syntax: Provide a title rather than a spurious empty section
• de3ccf0790: SUPPORT.md: Syntax: Fix a typo "States"
• f7a7eeac29: SUPPORT.md: Syntax: Fix some bullet lists
• cba8690ea8: x86: fix slow int80 path after XPTI additions
• d27de97cd1: libxl: Specify format of inserted cdrom
• 656c14780c: x86/msr: Correct the emulation behaviour of MSR_PRED_CMD
• 8d37ee1d10: x86/VT-x: Fix determination of EFER.LMA in vmcs_dump_vcpu()
• 696b24dfe1: x86/HVM: suppress I/O completion for port output
• 41015e7945: x86/pv: Fix up erroneous segments for 32bit syscall entry
• 4f12a18bc2: x86/XPTI: reduce .text.entry
• 649e617335: x86: log XPTI enabled status
• bd26592fdf: x86: disable XPTI when RDCL_NO
• afece29fe9: x86/pv: Fix the handing of writes to %dr7
• 2e34343fb2: xen/arm: Relax ARM_SMCCC_ARCH_WORKAROUND_1 discovery
• d9756ca980: xen/arm: vpsci: Rework the logic to start AArch32 vCPU in Thumb mode
• e2ee191d3d: xen/arm: vpsci: Introduce and use PSCI_INVALID_ADDRESS
• 2efc116c68: xen/arm: psci: Consolidate PSCI version print
• 51742fbc08: xen/arm: vpsci: Remove parameter 'ver' from do_common_cpu
• 4fcd9d14b1: xen/arm64: Kill PSCI_GET_VERSION as a variant-2 workaround
• 1ef0574d3b: xen/arm64: Add ARM_SMCCC_ARCH_WORKAROUND_1 BP hardening support
• ee109adca7: xen/arm: smccc: Implement SMCCC v1.1 inline primitive
• b2682eddc2: xen/arm: psci: Detect SMCCC version
• 9746779afb: xen/arm: smccc: Add macros SMCCC_VERSION, SMCCC_VERSION_{MINOR, MAJOR}
• 1d99ad5b35: xen/arm64: Print a per-CPU message with the BP hardening method used
• 9beb8a4461: xen/arm64: Implement a fast path for handling SMCCC_ARCH_WORKAROUND_1
• ef4b4d7ab0: xen/arm: Adapt smccc.h to be able to use it in assembly code
• df71252060: xen/arm: vsmc: Implement SMCCC_ARCH_WORKAROUND_1 BP hardening support
• 7f9ebebcec: xen/arm: vsmc: Implement SMCCC 1.1
• 4eb96e3eda: xen/arm: vpsci: Add support for PSCI 1.1
• 3087ba8278: xen/arm: psci: Rework the PSCI definitions
• 76a6dddcf8: xen/arm: vpsci: Move PSCI function dispatching from vsmc.c to vpsci.c
• 0f92968bcf: x86/vlapic: clear TMR bit upon acceptance of edge-triggered interrupt to IRR
• 9e9185f661: SUPPORT.md: Specify support for various image formats
• e87e798673: SUPPORT.md: Clarify that the PV keyboard protocol includes mouse support
• 6131a2c0ed: cpufreq/ondemand: fix race while offlining CPU
• 47621a4ed1: x86: remove CR reads from exit-to-guest path
• 489cfbc1b9: x86: slightly reduce Meltdown band-aid overhead
• 860f470ba1: x86/xpti: don't map stack guard pages
• 8462c575d9: x86/xpti: Hide almost all of .text and all .data/.rodata/.bss mappings
• cee48d83cb: x86: ignore guest microcode loading attempts
• 20db434e90: ocaml: fix arm build
• 0d2f9c89f7: Merge branch 'merge-comet-staging-4.10-v1' into staging-4.10
• a1189f93ef: libxl/pvh: force PVH guests to use the xenstore shutdown
• c37114cbf8: x86/HVM: don't give the wrong impression of WRMSR succeeding
• 5ede9f9600: x86/PV: fix off-by-one in I/O bitmap limit check
• 7e0796d3fe: grant: Release domain lock on 'map' path in cache_flush
• b9aa790d31: x86/pv: Avoid leaking other guests' MSR_TSC_AUX values into PV context
• 4867afbc95: x86/nmi: start NMI watchdog on CPU0 after SMP bootstrap
• 3deb58f832: x86/srat: fix end calculation in nodes_cover_memory()
• 3376822f15: x86/hvm/dmop: only copy what is needed to/from the guest
• 37dd90787e: x86/entry: Use 32bit xors rater than 64bit xors for clearing GPRs
• 296705818c: x86/emul: Fix the decoding of segment overrides in 64bit mode
• 0857b09aae: x86/spec_ctrl: Fix several bugs in SPEC_CTRL_ENTRY_FROM_INTR_IST
• 4195d40e31: x86/srat: fix the end pfn check in valid_numa_range()
• ab62fc3171: x86: reduce Meltdown band-aid IPI overhead
• 0e10f28586: x86/NMI: invert condition in nmi_show_execution_state()
• a05fc8e5be: x86/emul: Fix the emulation of invlpga
• 083bd83354: ignores: update .hgignore
• b0e975c822: ignores: update list of git ignored files
• def29407de: firmware/shim: better filtering of intermediate files during Xen tree setup
• 8c3bbc7c2b: firmware/shim: better filtering of dependency files during Xen tree setup
• cee8bb62ff: build: remove shim related targets
• 08a941bdac: shim: allow building of just the shim with build-ID-incapable linker
• 7dc817b750: firmware/shim: avoid mkdir error during Xen tree setup
• 21080841ae: firmware/shim: correctly handle errors during Xen tree setup
• dc4a23b115: firmware/shim: update Makefile
• da7543dd32: x86/shim: don't use 32-bit compare on boolean variable
• 9fd27db52a: xen/pvshim: fix GNTTABOP_query_size hypercall forwarding with SMAP
• 6d9b6bf418: Revert "x86/boot: Map more than the first 16MB"
• 79f04299ca: x86: relocate pvh_info
• 9ce99ad413: xen/shim: stash RSDP address for ACPI driver
• 186c2f57bd: libxl: lower shim related message to level DEBUG
• 357bf02e49: x86/shim: use credit scheduler
• 81306edf86: x86/guest: clean up guest/xen.h
• 14e1a434f4: libxl: remove whitespaces introduced in 62982da926
• b869742c99: xen/pvshim: switch shim.c to use typesafe mfn_to_page and virt_to_mfn
• d691e41793: xen/pvshim: fix coding style issues
• ee478f4737: xen/pvshim: re-order replace_va_mapping code
• f05a7c5148: xen/pvshim: identity pin shim vCPUs to pCPUs
• 7027acfc1f: tools: fix arm build after bdf693ee61b48
• bc513e82ed: Don't build xen-shim for 32 bit build host
• af63193017: Revert "x86/guest: use the vcpu_info area from shared_info"
• a44e83b712: x86/shim: commit shim.config changes for 4.10 branch
• da3a46d017: Merge tag '4.10.0-shim-comet-3' into staging-4.10
• b6a6458b13: xen/arm: Flush TLBs before turning on the MMU to avoid stale entries
• e3dfd5d1dd: xen/arm: vgic: Make sure the number of SPIs is a multiple of 32
• a6780c122b: x86/hvm: Disallow the creation of HVM domains without Local APIC emulation
• 16edf98e95: gnttab: don't blindly free status pages upon version change
• e2ceb2ed66: gnttab/ARM: don't corrupt shared GFN array
• 1b1c059099: memory: don't implicitly unpin for decrease-reservation
• 5e91fc4d3b: xen/arm: cpuerrata: Actually check errata on non-boot CPUs
• 3921128fcb: xen/arm: vsmc: Don't implement function IDs that don't exist
• cd2e1436b1: xen/arm: vpsci: Removing dummy MIGRATE and MIGRATE_INFO_UP_CPU
• 3181472a5c: x86/idle: Clear SPEC_CTRL while idle
• 5644514050: x86/cpuid: Offer Indirect Branch Controls to guests
• db12743f2d: x86/ctxt: Issue a speculation barrier between vcpu contexts
• bc0e599a83: x86/boot: Calculate the most appropriate BTI mitigation to use
• fc81946cea: x86/entry: Avoid using alternatives in NMI/#MC paths
• ce7d7c0168: x86/entry: Organise the clobbering of the RSB/RAS on entry to Xen
• a695f8dce7: x86/entry: Organise the use of MSR_SPEC_CTRL at each entry/exit point
• 92efbe8658: x86/hvm: Permit guests direct access to MSR_{SPEC_CTRL,PRED_CMD}
• 8baba874d6: x86/migrate: Move MSR_SPEC_CTRL on migrate
• 79891ef944: x86/msr: Emulation of MSR_{SPEC_CTRL,PRED_CMD} for guests
• 641c11ef29: x86/cpuid: Handling of IBRS/IBPB, STIBP and IBRS for guests
• 05eba93a0a: x86: fix GET_STACK_END
• a69cfdf0c1: x86/acpi: process softirqs while printing CPU ACPI data
• 0f4be6e2c4: xen/x86: report domain id on cpuid
• 0a7e6b50e0: x86/svm: Offer CPUID Faulting to AMD HVM guests as well
• 65ee6e043a: x86/cmdline: Introduce a command line option to disable IBRS/IBPB, STIBP and IBPB
• 129880dd8f: x86/feature: Definitions for Indirect Branch Controls
• c513244d8e: x86: Introduce alternative indirect thunks
• 0e12c2c881: x86/amd: Try to set lfence as being Dispatch Serialising
• 6aaf353f2e: x86/boot: Report details of speculative mitigations
• 32babfc19a: x86: Support indirect thunks from assembly code
• 47bbcb2dd1: x86: Support compiling with indirect branch thunks
• 8743fc2ef7: common/wait: Clarifications to wait infrastructure
• 1830b20b6b: x86/entry: Erase guest GPR state on entry to Xen
• ab95cb0d94: x86/hvm: Use SAVE_ALL to construct the cpu_user_regs frame after VMExit
• d02ef3d274: x86/entry: Rearrange RESTORE_ALL to restore register in stack order
• e32f814160: x86: Introduce a common cpuid_policy_updated()
• c534ab4e94: x86/hvm: Rename update_guest_vendor() callback to cpuid_policy_changed()
• be3138b6f6: x86/alt: Introduce ALTERNATIVE{,_2} macros
• 79012ead93: x86/alt: Break out alternative-asm into a separate header file
• bbd093c503: xen/arm32: entry: Document the purpose of r11 in the traps handler
• a69a8b5fdc: xen/arm32: Invalidate icache on guest exist for Cortex-A15
• f167ebf6b3: xen/arm32: Invalidate BTB on guest exit for Cortex A17 and 12
• c4c0187839: xen/arm32: Add skeleton to harden branch predictor aliasing attacks
• 19ad8a7287: xen/arm32: entry: Add missing trap_reset entry
• 3caf32c470: xen/arm32: Add missing MIDR values for Cortex-A17 and A12
• df7be94f26: xen/arm32: entry: Consolidate DEFINE_TRAP_ENTRY_* macros
• f379b70609: SUPPORT.md: Fix version and Initial-Release
• 728fadb586: xen/arm: cpuerrata: Remove percpu.h include
• 928112900e: xen/arm64: Implement branch predictor hardening for affected Cortex-A CPUs
• cae6e1572f: xen/arm64: Add skeleton to harden the branch predictor aliasing attacks
• d1f4283a1d: xen/arm: cpuerrata: Add MIDR_ALL_VERSIONS
• 0f7a4faafb: xen/arm64: Add missing MIDR values for Cortex-A72, A73 and A75
• b829d42829: xen/arm: Introduce enable callback to enable a capabilities on each online CPU
• fa23f2aaa2: xen/pvh: place the trampoline at page 0x1
• 79f797c3f4: firmware/shim: fix build process to use POSIX find options
• 69f4d872e5: x86/guest: use the vcpu_info area from shared_info
• 7cccd6f748: x86: allow Meltdown band-aid to be disabled
• 234f481337: x86: Meltdown band-aid against malicious 64-bit PV guests
• 57dc197cf0: x86/mm: Always set _PAGE_ACCESSED on L4e updates
• 7209b8bf08: x86: Don't use potentially incorrect CPUID values for topology information
• 910dd005da: x86/entry: Remove support for partial cpu_user_regs frames
• 50d24b9530: x86/upcall: inject a spurious event after setting upcall vector
• c89c622b89: x86/E820: don't overrun array
• 3b8d88d4fa: x86/IRQ: conditionally preserve access permission on map error paths
• 6f1979c8e4: -xen-attach is needed for pvh boot with qemu-xen
• 0a515eeb96: xen/pvshim: map vcpu_info earlier for APs
• 0e2d64ae8f: xl: pvshim: Provide and document xl config
• ab9e3854dd: libxl: pvshim: Introduce pvshim_extra
• abdde49edc: libxl: pvshim: Provide first-class config settings to enable shim mode
• 321ef983a0: xen/shim: allow DomU to have as many vcpus as available
• c9083de0ae: xen/shim: crash instead of reboot in shim mode
• b5be9c817d: xen/pvshim: use default position for the m2p mappings
• 9d60bc96be: xen/shim: modify shim_mem parameter behaviour
• 29dd3142bf: xen/pvshim: memory hotplug
• 5b6c3ffa1d: xen/pvshim: support vCPU hotplug
• 004646a1dd: xen/pvshim: set max_pages to the value of tot_pages
• 7dcc20e0c8: xen/pvshim: add shim_mem cmdline parameter
• 83c838c9f8: xen/pvshim: add migration support
• cc7d96b98c: x86/pv-shim: shadow PV console's page for L2 DomU
• 7f5eb7d04e: xen/pvshim: add grant table operations
• bbad376ab1: xen/pvshim: forward evtchn ops between L0 Xen and L2 DomU
• da4518c559: xen/pvshim: set correct domid value
• 1cd703979f: xen/pvshim: modify Dom0 builder in order to build a DomU
• 60dd95357c: xen: mark xenstore/console pages as RAM
• 0ba5d8c275: xen/pvshim: skip Dom0-only domain builder parts
• 4ba6447e7d: xen/pvh: do not mark the low 1MB as IO mem
• 2b8a95a296: xen/x86: make VGA support selectable
• cdb1fb4921: xen/arm: bootfdt: Use proper default for #address-cells and #size-cells
• a40186478c: xen/arm: gic-v3: Bail out if gicv3_cpu_init fail
• 3784256866: tools/firmware: Build and install xen-shim
• b5ead1fad3: x86/shim: Kconfig and command line options
• aa96a59dc2: x86/guest: use PV console for Xen/Dom0 I/O
• 7477359b9a: x86/guest: add PV console code
• cb5dc94ba7: x86/guest: setup event channel upcall vector
• 3b058a3eab: x86: don't swallow the first command line item in guest mode
• 5a543c6f39: x86: read wallclock from Xen when running in pvh mode
• 949eb11d58: x86: APIC timer calibration when running as a guest
• f5ca36927e: x86: xen pv clock time source
• 68e7a08436: x86/guest: map per-cpu vcpu_info area.
• d2df09c92b: xen/guest: fetch vCPU ID from Xen
• efa15c993b: x86/guest: map shared_info page
• 83186a8e69: xen/pvshim: keep track of used PFN ranges
• 1fa5444834: xen: introduce rangeset_claim_range
• 10128f33aa: xen/console: Introduce console=xen
• 2f5a012143: x86/pvh: Retrieve memory map from Xen
• 9752c7422b: x86/shutdown: Support for using SCHEDOP_{shutdown,reboot}
• b38cc15b2f: x86/guest: Hypercall support
• 3d1afab1f6: x86/entry: Probe for Xen early during boot
• 31b664a93f: x86/boot: Map more than the first 16MB
• db65173fe7: x86/entry: Early PVH boot code
• 51f937a39b: x86: produce a binary that can be booted as PVH
• 887c705600: x86: introduce ELFNOTE macro
• f575701f3c: x86/link: Relocate program headers
• af2f50b2b6: x86/Kconfig: Options for Xen and PVH support
• b538a13a68: x86: Common cpuid faulting support
• 57dc22b80d: x86/fixmap: Modify fix_to_virt() to return a void pointer
• 48811d481c: tools/ocaml: Extend domain_create() to take arch_domainconfig
• 78898c9d1b: tools/ocaml: Expose arch_config in domaininfo
• e7c8187b91: xen/domctl: Return arch_config via getdomaininfo
• 9e46ae12ed: ACPICA: Make ACPI Power Management Timer (PM Timer) optional.
• ff1fb8fe53: x86/link: Introduce and use SECTION_ALIGN
• 92a6295c30: x86/time: Print a more helpful error when a platform timer can't be found
• 78e9cc3488: xen/common: Widen the guest logging buffer slightly
• 667275050d: tools/libxc: Multi modules support
• 4621c10f48: tools/libelf: fix elf notes check for PVH guest
• 40938b5d56: tools/libxc: remove extraneous newline in xc_dom_load_acpi
• 5840f40e88: xen/x86: report domain id on cpuid
• caff7f9b59: x86/svm: Offer CPUID Faulting to AMD HVM guests as well
• 69e302e59c: x86/upcall: inject a spurious event after setting upcall vector
• a87ec4833a: x86/msr: Free msr_vcpu_policy during vcpu destruction
• 9dc5eda576: x86/vmx: Don't use hvm_inject_hw_exception() in long_mode_do_msr_write()
• 135b67e9bd: xen/efi: Fix build with clang-5.0
• 682a9d8d37: gnttab: improve GNTTABOP_cache_flush locking
• 19dcd8e47d: gnttab: correct GNTTABOP_cache_flush empty batch handling
• e5364c32c6: x86/microcode: Add support for fam17h microcode loading
• e2dc7b584f: x86/mm: drop bogus paging mode assertion
• c8f4f45e04: x86/mb2: avoid Xen image when looking for module/crashkernel position
• 4150501b71: x86/vvmx: don't enable vmcs shadowing for nested guests
• ab7be6ce4a: xen/pv: Construct d0v0's GDT properly

What is new in version 4.10.1:

• c30ab3d97c: SUPPORT.md: Add missing support lifetime information
• 5f6000a985: adapt SUPPORT.md to match 4.11
• f9e1bddbc8: SUPPORT.md: Fix a typo
• 3614c7d949: SUPPORT.md: Document the new text ordering rule
• 6f8e8bae87: SUPPORT.md: Move descriptions up before Status info
• 2e02212848: docs/Makefile: Format SUPPORT.md into the toplevel
• 73c8c2c211: docs/Makefile: Introduce GENERATE_PANDOC_RULE_RAW
• c07d2195b0: docs/gen-html-index: Support documents at the toplevel
• 0609dd1c5e: docs/gen-html-index: Extract titles from HTML documents
• a3459c741e: SUPPORT.md: Syntax: Provide a title rather than a spurious empty section
• de3ccf0790: SUPPORT.md: Syntax: Fix a typo "States"
• f7a7eeac29: SUPPORT.md: Syntax: Fix some bullet lists
• cba8690ea8: x86: fix slow int80 path after XPTI additions
• d27de97cd1: libxl: Specify format of inserted cdrom
• 656c14780c: x86/msr: Correct the emulation behaviour of MSR_PRED_CMD
• 8d37ee1d10: x86/VT-x: Fix determination of EFER.LMA in vmcs_dump_vcpu()
• 696b24dfe1: x86/HVM: suppress I/O completion for port output
• 41015e7945: x86/pv: Fix up erroneous segments for 32bit syscall entry
• 4f12a18bc2: x86/XPTI: reduce .text.entry
• 649e617335: x86: log XPTI enabled status
• bd26592fdf: x86: disable XPTI when RDCL_NO
• afece29fe9: x86/pv: Fix the handing of writes to %dr7
• 2e34343fb2: xen/arm: Relax ARM_SMCCC_ARCH_WORKAROUND_1 discovery
• d9756ca980: xen/arm: vpsci: Rework the logic to start AArch32 vCPU in Thumb mode
• e2ee191d3d: xen/arm: vpsci: Introduce and use PSCI_INVALID_ADDRESS
• 2efc116c68: xen/arm: psci: Consolidate PSCI version print
• 51742fbc08: xen/arm: vpsci: Remove parameter 'ver' from do_common_cpu
• 4fcd9d14b1: xen/arm64: Kill PSCI_GET_VERSION as a variant-2 workaround
• 1ef0574d3b: xen/arm64: Add ARM_SMCCC_ARCH_WORKAROUND_1 BP hardening support
• ee109adca7: xen/arm: smccc: Implement SMCCC v1.1 inline primitive
• b2682eddc2: xen/arm: psci: Detect SMCCC version
• 9746779afb: xen/arm: smccc: Add macros SMCCC_VERSION, SMCCC_VERSION_{MINOR, MAJOR}
• 1d99ad5b35: xen/arm64: Print a per-CPU message with the BP hardening method used
• 9beb8a4461: xen/arm64: Implement a fast path for handling SMCCC_ARCH_WORKAROUND_1
• ef4b4d7ab0: xen/arm: Adapt smccc.h to be able to use it in assembly code
• df71252060: xen/arm: vsmc: Implement SMCCC_ARCH_WORKAROUND_1 BP hardening support
• 7f9ebebcec: xen/arm: vsmc: Implement SMCCC 1.1
• 4eb96e3eda: xen/arm: vpsci: Add support for PSCI 1.1
• 3087ba8278: xen/arm: psci: Rework the PSCI definitions
• 76a6dddcf8: xen/arm: vpsci: Move PSCI function dispatching from vsmc.c to vpsci.c
• 0f92968bcf: x86/vlapic: clear TMR bit upon acceptance of edge-triggered interrupt to IRR
• 9e9185f661: SUPPORT.md: Specify support for various image formats
• e87e798673: SUPPORT.md: Clarify that the PV keyboard protocol includes mouse support
• 6131a2c0ed: cpufreq/ondemand: fix race while offlining CPU
• 47621a4ed1: x86: remove CR reads from exit-to-guest path
• 489cfbc1b9: x86: slightly reduce Meltdown band-aid overhead
• 860f470ba1: x86/xpti: don't map stack guard pages
• 8462c575d9: x86/xpti: Hide almost all of .text and all .data/.rodata/.bss mappings
• cee48d83cb: x86: ignore guest microcode loading attempts
• 20db434e90: ocaml: fix arm build
• 0d2f9c89f7: Merge branch 'merge-comet-staging-4.10-v1' into staging-4.10
• a1189f93ef: libxl/pvh: force PVH guests to use the xenstore shutdown
• c37114cbf8: x86/HVM: don't give the wrong impression of WRMSR succeeding
• 5ede9f9600: x86/PV: fix off-by-one in I/O bitmap limit check
• 7e0796d3fe: grant: Release domain lock on 'map' path in cache_flush
• b9aa790d31: x86/pv: Avoid leaking other guests' MSR_TSC_AUX values into PV context
• 4867afbc95: x86/nmi: start NMI watchdog on CPU0 after SMP bootstrap
• 3deb58f832: x86/srat: fix end calculation in nodes_cover_memory()
• 3376822f15: x86/hvm/dmop: only copy what is needed to/from the guest
• 37dd90787e: x86/entry: Use 32bit xors rater than 64bit xors for clearing GPRs
• 296705818c: x86/emul: Fix the decoding of segment overrides in 64bit mode
• 0857b09aae: x86/spec_ctrl: Fix several bugs in SPEC_CTRL_ENTRY_FROM_INTR_IST
• 4195d40e31: x86/srat: fix the end pfn check in valid_numa_range()
• ab62fc3171: x86: reduce Meltdown band-aid IPI overhead
• 0e10f28586: x86/NMI: invert condition in nmi_show_execution_state()
• a05fc8e5be: x86/emul: Fix the emulation of invlpga
• 083bd83354: ignores: update .hgignore
• b0e975c822: ignores: update list of git ignored files
• def29407de: firmware/shim: better filtering of intermediate files during Xen tree setup
• 8c3bbc7c2b: firmware/shim: better filtering of dependency files during Xen tree setup
• cee8bb62ff: build: remove shim related targets
• 08a941bdac: shim: allow building of just the shim with build-ID-incapable linker
• 7dc817b750: firmware/shim: avoid mkdir error during Xen tree setup
• 21080841ae: firmware/shim: correctly handle errors during Xen tree setup
• dc4a23b115: firmware/shim: update Makefile
• da7543dd32: x86/shim: don't use 32-bit compare on boolean variable
• 9fd27db52a: xen/pvshim: fix GNTTABOP_query_size hypercall forwarding with SMAP
• 6d9b6bf418: Revert "x86/boot: Map more than the first 16MB"
• 79f04299ca: x86: relocate pvh_info
• 9ce99ad413: xen/shim: stash RSDP address for ACPI driver
• 186c2f57bd: libxl: lower shim related message to level DEBUG
• 357bf02e49: x86/shim: use credit scheduler
• 81306edf86: x86/guest: clean up guest/xen.h
• 14e1a434f4: libxl: remove whitespaces introduced in 62982da926
• b869742c99: xen/pvshim: switch shim.c to use typesafe mfn_to_page and virt_to_mfn
• d691e41793: xen/pvshim: fix coding style issues
• ee478f4737: xen/pvshim: re-order replace_va_mapping code
• f05a7c5148: xen/pvshim: identity pin shim vCPUs to pCPUs
• 7027acfc1f: tools: fix arm build after bdf693ee61b48
• bc513e82ed: Don't build xen-shim for 32 bit build host
• af63193017: Revert "x86/guest: use the vcpu_info area from shared_info"
• a44e83b712: x86/shim: commit shim.config changes for 4.10 branch
• da3a46d017: Merge tag '4.10.0-shim-comet-3' into staging-4.10
• b6a6458b13: xen/arm: Flush TLBs before turning on the MMU to avoid stale entries
• e3dfd5d1dd: xen/arm: vgic: Make sure the number of SPIs is a multiple of 32
• a6780c122b: x86/hvm: Disallow the creation of HVM domains without Local APIC emulation
• 16edf98e95: gnttab: don't blindly free status pages upon version change
• e2ceb2ed66: gnttab/ARM: don't corrupt shared GFN array
• 1b1c059099: memory: don't implicitly unpin for decrease-reservation
• 5e91fc4d3b: xen/arm: cpuerrata: Actually check errata on non-boot CPUs
• 3921128fcb: xen/arm: vsmc: Don't implement function IDs that don't exist
• cd2e1436b1: xen/arm: vpsci: Removing dummy MIGRATE and MIGRATE_INFO_UP_CPU
• 3181472a5c: x86/idle: Clear SPEC_CTRL while idle
• 5644514050: x86/cpuid: Offer Indirect Branch Controls to guests
• db12743f2d: x86/ctxt: Issue a speculation barrier between vcpu contexts
• bc0e599a83: x86/boot: Calculate the most appropriate BTI mitigation to use
• fc81946cea: x86/entry: Avoid using alternatives in NMI/#MC paths
• ce7d7c0168: x86/entry: Organise the clobbering of the RSB/RAS on entry to Xen
• a695f8dce7: x86/entry: Organise the use of MSR_SPEC_CTRL at each entry/exit point
• 92efbe8658: x86/hvm: Permit guests direct access to MSR_{SPEC_CTRL,PRED_CMD}
• 8baba874d6: x86/migrate: Move MSR_SPEC_CTRL on migrate
• 79891ef944: x86/msr: Emulation of MSR_{SPEC_CTRL,PRED_CMD} for guests
• 641c11ef29: x86/cpuid: Handling of IBRS/IBPB, STIBP and IBRS for guests
• 05eba93a0a: x86: fix GET_STACK_END
• a69cfdf0c1: x86/acpi: process softirqs while printing CPU ACPI data
• 0f4be6e2c4: xen/x86: report domain id on cpuid
• 0a7e6b50e0: x86/svm: Offer CPUID Faulting to AMD HVM guests as well
• 65ee6e043a: x86/cmdline: Introduce a command line option to disable IBRS/IBPB, STIBP and IBPB
• 129880dd8f: x86/feature: Definitions for Indirect Branch Controls
• c513244d8e: x86: Introduce alternative indirect thunks
• 0e12c2c881: x86/amd: Try to set lfence as being Dispatch Serialising
• 6aaf353f2e: x86/boot: Report details of speculative mitigations
• 32babfc19a: x86: Support indirect thunks from assembly code
• 47bbcb2dd1: x86: Support compiling with indirect branch thunks
• 8743fc2ef7: common/wait: Clarifications to wait infrastructure
• 1830b20b6b: x86/entry: Erase guest GPR state on entry to Xen
• ab95cb0d94: x86/hvm: Use SAVE_ALL to construct the cpu_user_regs frame after VMExit
• d02ef3d274: x86/entry: Rearrange RESTORE_ALL to restore register in stack order
• e32f814160: x86: Introduce a common cpuid_policy_updated()
• c534ab4e94: x86/hvm: Rename update_guest_vendor() callback to cpuid_policy_changed()
• be3138b6f6: x86/alt: Introduce ALTERNATIVE{,_2} macros
• 79012ead93: x86/alt: Break out alternative-asm into a separate header file
• bbd093c503: xen/arm32: entry: Document the purpose of r11 in the traps handler
• a69a8b5fdc: xen/arm32: Invalidate icache on guest exist for Cortex-A15
• f167ebf6b3: xen/arm32: Invalidate BTB on guest exit for Cortex A17 and 12
• c4c0187839: xen/arm32: Add skeleton to harden branch predictor aliasing attacks
• 19ad8a7287: xen/arm32: entry: Add missing trap_reset entry
• 3caf32c470: xen/arm32: Add missing MIDR values for Cortex-A17 and A12
• df7be94f26: xen/arm32: entry: Consolidate DEFINE_TRAP_ENTRY_* macros
• f379b70609: SUPPORT.md: Fix version and Initial-Release
• 728fadb586: xen/arm: cpuerrata: Remove percpu.h include
• 928112900e: xen/arm64: Implement branch predictor hardening for affected Cortex-A CPUs
• cae6e1572f: xen/arm64: Add skeleton to harden the branch predictor aliasing attacks
• d1f4283a1d: xen/arm: cpuerrata: Add MIDR_ALL_VERSIONS
• 0f7a4faafb: xen/arm64: Add missing MIDR values for Cortex-A72, A73 and A75
• b829d42829: xen/arm: Introduce enable callback to enable a capabilities on each online CPU
• fa23f2aaa2: xen/pvh: place the trampoline at page 0x1
• 79f797c3f4: firmware/shim: fix build process to use POSIX find options
• 69f4d872e5: x86/guest: use the vcpu_info area from shared_info
• 7cccd6f748: x86: allow Meltdown band-aid to be disabled
• 234f481337: x86: Meltdown band-aid against malicious 64-bit PV guests
• 57dc197cf0: x86/mm: Always set _PAGE_ACCESSED on L4e updates
• 7209b8bf08: x86: Don't use potentially incorrect CPUID values for topology information
• 910dd005da: x86/entry: Remove support for partial cpu_user_regs frames
• 50d24b9530: x86/upcall: inject a spurious event after setting upcall vector
• c89c622b89: x86/E820: don't overrun array
• 3b8d88d4fa: x86/IRQ: conditionally preserve access permission on map error paths
• 6f1979c8e4: -xen-attach is needed for pvh boot with qemu-xen
• 0a515eeb96: xen/pvshim: map vcpu_info earlier for APs
• 0e2d64ae8f: xl: pvshim: Provide and document xl config
• ab9e3854dd: libxl: pvshim: Introduce pvshim_extra
• abdde49edc: libxl: pvshim: Provide first-class config settings to enable shim mode
• 321ef983a0: xen/shim: allow DomU to have as many vcpus as available
• c9083de0ae: xen/shim: crash instead of reboot in shim mode
• b5be9c817d: xen/pvshim: use default position for the m2p mappings
• 9d60bc96be: xen/shim: modify shim_mem parameter behaviour
• 29dd3142bf: xen/pvshim: memory hotplug
• 5b6c3ffa1d: xen/pvshim: support vCPU hotplug
• 004646a1dd: xen/pvshim: set max_pages to the value of tot_pages
• 7dcc20e0c8: xen/pvshim: add shim_mem cmdline parameter
• 83c838c9f8: xen/pvshim: add migration support
• cc7d96b98c: x86/pv-shim: shadow PV console's page for L2 DomU
• 7f5eb7d04e: xen/pvshim: add grant table operations
• bbad376ab1: xen/pvshim: forward evtchn ops between L0 Xen and L2 DomU
• da4518c559: xen/pvshim: set correct domid value
• 1cd703979f: xen/pvshim: modify Dom0 builder in order to build a DomU
• 60dd95357c: xen: mark xenstore/console pages as RAM
• 0ba5d8c275: xen/pvshim: skip Dom0-only domain builder parts
• 4ba6447e7d: xen/pvh: do not mark the low 1MB as IO mem
• 2b8a95a296: xen/x86: make VGA support selectable
• cdb1fb4921: xen/arm: bootfdt: Use proper default for #address-cells and #size-cells
• a40186478c: xen/arm: gic-v3: Bail out if gicv3_cpu_init fail
• 3784256866: tools/firmware: Build and install xen-shim
• b5ead1fad3: x86/shim: Kconfig and command line options
• aa96a59dc2: x86/guest: use PV console for Xen/Dom0 I/O
• 7477359b9a: x86/guest: add PV console code
• cb5dc94ba7: x86/guest: setup event channel upcall vector
• 3b058a3eab: x86: don't swallow the first command line item in guest mode
• 5a543c6f39: x86: read wallclock from Xen when running in pvh mode
• 949eb11d58: x86: APIC timer calibration when running as a guest
• f5ca36927e: x86: xen pv clock time source
• 68e7a08436: x86/guest: map per-cpu vcpu_info area.
• d2df09c92b: xen/guest: fetch vCPU ID from Xen
• efa15c993b: x86/guest: map shared_info page
• 83186a8e69: xen/pvshim: keep track of used PFN ranges
• 1fa5444834: xen: introduce rangeset_claim_range
• 10128f33aa: xen/console: Introduce console=xen
• 2f5a012143: x86/pvh: Retrieve memory map from Xen
• 9752c7422b: x86/shutdown: Support for using SCHEDOP_{shutdown,reboot}
• b38cc15b2f: x86/guest: Hypercall support
• 3d1afab1f6: x86/entry: Probe for Xen early during boot
• 31b664a93f: x86/boot: Map more than the first 16MB
• db65173fe7: x86/entry: Early PVH boot code
• 51f937a39b: x86: produce a binary that can be booted as PVH
• 887c705600: x86: introduce ELFNOTE macro
• f575701f3c: x86/link: Relocate program headers
• af2f50b2b6: x86/Kconfig: Options for Xen and PVH support
• b538a13a68: x86: Common cpuid faulting support
• 57dc22b80d: x86/fixmap: Modify fix_to_virt() to return a void pointer
• 48811d481c: tools/ocaml: Extend domain_create() to take arch_domainconfig
• 78898c9d1b: tools/ocaml: Expose arch_config in domaininfo
• e7c8187b91: xen/domctl: Return arch_config via getdomaininfo
• 9e46ae12ed: ACPICA: Make ACPI Power Management Timer (PM Timer) optional.
• ff1fb8fe53: x86/link: Introduce and use SECTION_ALIGN
• 92a6295c30: x86/time: Print a more helpful error when a platform timer can't be found
• 78e9cc3488: xen/common: Widen the guest logging buffer slightly
• 667275050d: tools/libxc: Multi modules support
• 4621c10f48: tools/libelf: fix elf notes check for PVH guest
• 40938b5d56: tools/libxc: remove extraneous newline in xc_dom_load_acpi
• 5840f40e88: xen/x86: report domain id on cpuid
• caff7f9b59: x86/svm: Offer CPUID Faulting to AMD HVM guests as well
• 69e302e59c: x86/upcall: inject a spurious event after setting upcall vector
• a87ec4833a: x86/msr: Free msr_vcpu_policy during vcpu destruction
• 9dc5eda576: x86/vmx: Don't use hvm_inject_hw_exception() in long_mode_do_msr_write()
• 135b67e9bd: xen/efi: Fix build with clang-5.0
• 682a9d8d37: gnttab: improve GNTTABOP_cache_flush locking
• 19dcd8e47d: gnttab: correct GNTTABOP_cache_flush empty batch handling
• e5364c32c6: x86/microcode: Add support for fam17h microcode loading
• e2dc7b584f: x86/mm: drop bogus paging mode assertion
• c8f4f45e04: x86/mb2: avoid Xen image when looking for module/crashkernel position
• 4150501b71: x86/vvmx: don't enable vmcs shadowing for nested guests
• ab7be6ce4a: xen/pv: Construct d0v0's GDT properly

What is new in version :

• These releases contain many bug fixes and improvements.

What is new in version 4.9.0:

• New Features:
• Boot Xen on EFI platforms using GRUB2 (x86): From Xen Project 4.9 and GRUB2 2.02 onwards, the Xen Project Hypervisor can be booted using the multiboot2 protocol on legacy BIOS and EFI x86 platforms. Partial support for the multiboot2 protocol was also introduced into network boot firmware (iPXE). This makes the Xen Project boot process much more flexible. Boot configurations can be changed directly from within a bootloader (without having to use text editors) and boot configurations are more portable across different platforms.
• Near native latency for embedded and automotive environments: The "null" scheduler enables use-cases where every virtual CPU can be assigned to a physical CPU (commonly needed for embedded and automotive environments) removing almost all of the scheduler overheads in such environments. Usage of the "null" scheduler also guarantees significantly lower latency and more predictable performance. The new vwfi parameter for ARM (virtual Wait For Interrupt) allows fine-grained control of how the Xen Project Hypervisor handles WFI instructions. Setting vwfi to "native" reduces interrupt latency by approximately 60%. Benchmarks on Xilinx Zynq Ultrascale+ MPSoC's have shown a maximum interrupt latency of less than 2 microseconds, which is extremely close to hardware limits, and should be small enough for the vast majority of embedded use cases.
• Xen 4.9 includes new standard ABIs for sharing devices between virtual machines (including reference implementations) for a number of embedded, automotive and cloud native computing use-cases.
• For embedded/automotive, a virtual sound ABI was added implementing audio playback and capture as well as volume control and the possibility to mute/unmute audio sources. In addition a new virtual display ABI for complex display devices exposing multiple framebuffers and displays has been added. Multi-touch support has been added to the virtual keyboard/mouse protocol enabling touch screens.
• Xen 4.9 also introduces a Xen transport for 9pfs, which is a remote filesystem protocol originally written for Plan 9. During the Xen 4.9 release cycle, a Xen 9pfs frontend was upstreamed in the Linux kernel and a backend in QEMU. It is now possible to share a filesystem (not necessarily a block device) from a virtual machine to another, which is a requirement for adding Xen support to many container engines, such as CoreOS rkt.
• The PV Calls ABI has been introduced to allow forwarding POSIX requests across guests: a POSIX function call originating from an app in a DomU can be forwarded and implemented in Dom0. For example, guest networking socket calls can be executed to Dom0, enabling a new networking model which is a natural fit for cloud-native apps.
• Improvements to Existing Functionality:
• Xenstored optimisations: Xenstore daemons allow Dom0 and guests access to system configuration information. C-xenstored scalability limits have been increased to allow large hosts (about >1000 domains) to run efficiently. Transaction handling has been improved for better performance, smaller memory footprint and fewer transaction conflicts. Dynamic debugging capabilities have been added.
• DMOP (Device Model Operation Hypercall): In Xen 4.9 the interface between Xen and QEMU was completely re-worked and consolidated. There is now only a single hypercall in Xen (the DMOP hypercall), which is carefully designed to allow the privcmd driver to audit any QEMU memory ranges and parameters that are passed to Xen via DMOP. The Linux privcmd driver enables DMOP auditing, which significantly limits the capability of a compromised QEMU to attack the hypervisor.
• Alternative runtime patching and GICv3 support for ARM32: Alternative runtime patching which enables the hypervisor to apply workarounds for erratas affecting the processor and to apply optimizations specific to a CPU and GICv3 support was extended for 32-bit ARM platforms, bringing this functionality to embedded use-cases.
• Intel and x86 Feature Support: The latest version of the Xen Project hypervisor adds the support of Neural Network Instructions AVX512_4VNNIW and Multiply Accumulation Single precision AVX512_4FMAPS as subfamilies of AVX512 instruction sets. With these instructions enabled in Xen for both HVM and PV guests, programs in guest OSes can take full advantage of these important instructions to speed up machine learning computing. This Xen release also further enhances VT-d Posted Interrupt (PI) optimization, Machine Check Exception(MCE) handling, and more.
• System Error Detection (ARM): Xen on ARM made a step forward in reliability and serviceability with the introduction of System Error detection and reporting, a key feature for customers with highly available systems.
• GCOV support: We removed the old GCOV implementation and replaced it with an updated version that supports more formats and exposes a more generic interface.
• Re-work and hardening of x86 emulation code for security: Hardware-assisted virtualisation provides hypervisors with the ability to execute most privileged instructions natively and securely. However, for some boundary cases, it is still necessary to emulate x86 instructions in software. In Xen 4.9, the project completely re-worked the x86 emulation code, added support for new instructions, audited the code against security vulnerabilities and created AFL based test fuzzing tests that are regularly run against the emulator.
• Updated support for Microsoft's Hyper-V Hypervisor Top-Level Functional Specification (also known as Viridian Enlightenments): Xen implements a subset of version 5.0 of the Hyper-V Hypervisor TLFS, which enables Xen to run Windows guests at similar performance as it would run on Hyper-V. In addition, this work lays the groundwork to enable us to run Hyper-V within Xen in the future using nested virtualization.
• Multi-Release Long-Term Development:
• Transition from PVHv1 to PVHv2: Xen Project 4.8 laid the groundwork for re-architecting and simplifying PVH, focussing on the DomU guest ABI, which enabled Guest operating system developers to start porting their OSes to this mode. Support for FreeBSD is in progress, while support for Linux is committed. Xen 4.9 added Dom0 builder support and support for multiple virtual Intel I/O Advanced Programmable Interrupt Controllers (vIO APIC). PVHv2 for interrupt routing and PCI emulation is currently being peer reviewed and can be expected early in the Xen 4.10 release cycle. This lays the groundwork for a PVHv2 Dom0. For PVHv2 DomU support, PCI Passthrough and a major re-work of the xl/libxl and libvirt user interfaces for PVH have been started. Support for PVHv1 has been removed from the Xen Codebase.
• Reworking the Xen-QEMU integration to protect against QEMU security vulnerabilities: In Xen Project 4.8, we embarked on an effort to re-work Xen-QEMU integration which amounts to sandboxing QEMU within Dom0. Significant progress was made in Xen 4.9 towards this goal, with the implementation of DMOP. Other changes such de-privileging QEMU in Dom0 and changes to the Linux privcmd driver have been mostly completed in Xen 4.9. Changes that are currently designed, but net yet implemented, are necessary changes to libxl and QEMU's usage of XenStore.

What is new in version 4.8.1 / 4.9.0 RC5:

• update Xen version to 4.8.1
• oxenstored: trim history in the frequent_ops function
• oxenstored transaction conflicts: improve logging
• oxenstored: don't wake to issue no conflict-credit
• oxenstored: do not commit read-only transactions
• oxenstored: allow self-conflicts
• oxenstored: blame the connection that caused a transaction conflict
• oxenstored: track commit history
• oxenstored: discard old commit-history on txn end
• oxenstored: only record operations with side-effects in history
• oxenstored: support commit history tracking
• oxenstored: add transaction info relevant to history-tracking
• oxenstored: ignore domains with no conflict-credit
• oxenstored: handling of domain conflict-credit
• oxenstored: comments explaining some variables
• xenstored: Log when the write transaction rate limit bites
• xenstored: apply a write transaction rate limit
• tools/libxenctrl: fix error check after opening libxenforeignmemory
• libxl: correct xenstore entry for empty cdrom
• x86: use 64 bit mask when masking away mfn bits
• memory: properly check guest memory ranges in XENMEM_exchange handling
• xen: sched: don't call hooks of the wrong scheduler via VCPU2OP
• x86/EFI: avoid Xen image when looking for module/kexec position
• x86/EFI: avoid IOMMU faults on [_end,__2M_rwdata_end)
• x86/EFI: avoid overrunning mb_modules[]
• build/clang: fix XSM dummy policy when using clang 4.0
• x86: drop unneeded __packed attributes
• arm: xen_size should be paddr_t for consistency
• xen/arm: alternative: Register re-mapped Xen area as a temporary virtual region
• QEMU_TAG update
• arm: read/write rank->vcpu atomically
• xen/arm: p2m: Perform local TLB invalidation on vCPU migration
• xen/arm: Introduce INVALID_VCPU_ID
• xen/arm: Set nr_cpu_ids to available number of cpus
• xen/arm: acpi: Relax hw domain mapping attributes to p2m_mmio_direct_c
• Revert "xen/arm: Map mmio-sram nodes as un-cached memory"
• xen/arm: dt: Relax hw domain mapping attributes to p2m_mmio_direct_c
• xen/arm: flush icache as well when XEN_DOMCTL_cacheflush is issued
• xen/arm: fix GIC_INVALID_LR
• fix out of bound access to mode_strings
• missing vgic_unlock_rank in gic_remove_irq_from_guest
• xen/arm: Fix macro for ARM Jazelle CPU feature identification
• xen/arm: traps: Emulate ICC_SRE_EL1 as RAZ/WI
• xen/arm: Fix misplaced parentheses for PSCI version check
• arm/irq: Reorder check when the IRQ is already used by someone
• Don't clear HCR_VM bit when updating VTTBR.
• x86/emul: Correct the decoding of mov to/from cr/dr
• x86emul: correct decoding of vzero{all,upper}
• xen: credit2: don't miss accounting while doing a credit reset.
• xen: credit2: always mark a tickled pCPU as... tickled!
• x86/layout: Correct Xen's idea of its own memory layout
• x86/vmx: Don't leak host syscall MSR state into HVM guests
• xen/arm: fix affected memory range by dcache clean functions
• xen/arm: introduce vwfi parameter
• arm/p2m: remove the page from p2m->pages list before freeing it
• QEMU_TAG update
• VMX: fix VMCS race on context-switch paths
• xen/p2m: Fix p2m_flush_table for non-nested cases
• x86/ept: allow write-combining on !mfn_valid() MMIO mappings again
• IOMMU: always call teardown callback
• x86/emulate: don't assume that addr_size == 32 implies protected mode
• xen: credit2: fix shutdown/suspend when playing with cpupools.
• xen: credit2: never consider CPUs outside of our cpupool.
• xen: credit2: use the correct scratch cpumask.
• x86/hvm: do not set msr_tsc_adjust on hvm_set_guest_tsc_fixed
• x86emul: correct FPU stub asm() constraints
• x86: segment attribute handling adjustments
• x86emul: LOCK check adjustments
• x86emul: VEX.B is ignored in compatibility mode
• x86/xstate: Fix array overrun on hardware with LWP
• arm/p2m: Fix regression during domain shutdown with active mem_access
• libxl: fix libxl_set_memory_target
• xen/arm: gic-v3: Make sure read from ICC_IAR1_EL1 is visible on the redistributor
• x86/cpu: Don't update this_cpu for get_cpu_vendor(, gcv_guest)
• x86/emul: Correct the return value handling of VMFUNC
• x86/boot: fix build with certain older gcc versions
• x86emul: CMPXCHG16B requires an aligned operand
• VT-d: correct dma_msi_set_affinity()
• x86emul: ignore most segment bases for 64-bit mode in is_aligned()
• x86emul: MOVNTI does not allow REP prefixes
• x86/VPMU: clear the overflow status of which counter happened to overflow
• x86/hvm: don't unconditionally create a default ioreq server
• libelf: section index 0 is special
• x86emul: CMPXCHG{8,16}B ignore prefixes
• xen: Fix determining when domain creation is complete
• x86emul: correct PUSHF/POPF
• init/FreeBSD: fix incorrect usage of $rc_pids in xendriverdomain
• init/FreeBSD: add rc control variables
• init/FreeBSD: fix xencommons so it can only be launched by Dom0
• init/FreeBSD: remove xendriverdomain_precmd
• init/FreeBSD: set correct PATH for xl devd
• xsm: allow relevant permission during migrate and gpu-passthrough.
• libxl: init_acpi_config should return rc in exit path, and set to 0 on success
• x86/emul: add likely()/unlikely() to test harness
• x86/HVM: add missing NULL check before using VMFUNC hook
• x86: force EFLAGS.IF on when exiting to PV guests
• x86/emul: Correct the handling of eflags with SYSCALL
• QEMU_TAG update
• update Xen version to 4.8.1-pre
• In addition, this release also contains the following fixes to qemu-traditional:
• cirrus/vnc: zap drop bitblit support from console code.
• cirrus: add blit_is_unsafe call to cirrus_bitblt_cputovideo
• cirrus: fix oob access issue (CVE-2017-2615)
• qemu: ioport_read, ioport_write: be defensive about 32-bit addresses