KVM/arm64 fixes for 7.2, take #3
- Fix a tiny buglet when propagating the deactivation of an interrupt
from a nested guest, which happened to trigger a gold plated CPU bug
on a particular implementation
- Fix a race between LPI unmapping and mapping, resulting in leaked
LPIs
- Make LPI mapping more robust on memory allocation failure
- Fix the handling of the EL2 tracing clock being disabled
- A couple of Sashiko-driven fixes for corner cases in the EL2 tracing
code
- Add missing sysreg tracepoint for the EL2 code
- Tidy-up the mutual exclusion of guest-memfd and MTE
- Update Fuad's email address to point to @linux.dev
FOLL_LONGTERM pinning fails for some memory types, such as file-backed
guest memory. As a result, kvm_s390_adapter_map() returns -EINVAL and
irqfd adapter registration fails even though interrupt delivery could
still work via the existing non-atomic path.
When FOLL_LONGTERM pinning fails, verify that the page is accessible
using a short-term pin instead. If the short-term pin succeeds, unpin
the page and add a map entry with pinned=false to preserve MAP/UNMAP
symmetry. The non-atomic irqfd path already performs short-term pinning
for interrupt delivery, so this restores the previous behavior for
memory that cannot be pinned long-term.
get_map_info() is updated to return NULL for unpinned entries so that
the atomic irqfd fast path falls back to the non-atomic path.
kvm_s390_adapter_unmap() and kvm_s390_unmap_all_adapters() skip dirty
marking and unpin for unpinned entries.
Update Documentation/virt/kvm/devices/s390_flic.rst to reflect the
new MAP/UNMAP behavior.
Fixes: c9a5688380 ("KVM: s390: Add map/unmap ioctl and clean mappings post-guest")
Signed-off-by: Jaehoon Kim <jhkim@linux.ibm.com>
Reviewed-by: Douglas Freimuth <freimuth@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
The user cannot use MTE on VMAs created by mapping a guest_memfd file,
as arch_calc_vm_flag_bits() does not set VM_MTE_ALLOWED.
When creating a guest_memfd backed memslot,
kvm_arch_prepare_memory_region() rejects the memslot if MTE is enabled for
the VM and if guest_memfd has been mapped in a VMA that intersects the
memslot.
However, the documentation for KVM_SET_USER_MEMORY_REGION2 explicitly
states that the only condition for userspace_addr is for it to be a legal
userspace address, but the mapping is not required to be valid nor
populated at memslot creation.
If userspace sets userspace_addr to an address that hasn't been mapped, or
if userspace_addr belongs to a VMA that isn't backed by the guest_memfd
file, or if the VMA doesn't intersect the memslot, memslot creation is
successful and KVM ends up with a VM with MTE and guest_memfd-backed
memslots.
The same happens if the order is reversed: when userspace enables MTE, KVM
does not check if memslots backed by guest_memfd are already present.
Fix both issues by rejecting guest_memfd-backed memslots when MTE is
enabled, and by rejecting MTE when guest_memfd-backed memslots are already
present.
Fixes: 32e200bd6e ("KVM: arm64: Enable support for guest_memfd backed memory")
Tested-by: Fuad Tabba <fuad.tabba@linux.dev>
Reviewed-by: Fuad Tabba <fuad.tabba@linux.dev>
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Link: https://patch.msgid.link/20260722090354.94245-1-alexandru.elisei@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
Pull kvm fixes from Paolo Bonzini:
"s390:
- Fix S390_USER_OPEREXEC so it can now be enabled regardless of other
unrelated capabilities
- Fix handling of the _PAGE_UNUSED pte bit that could lead to guest
memory corruption in some scenarios
- A bunch of misc gmap fixes (locking, behaviour under memory
pressure)
- Fix CMMA dirty tracking
x86:
- Tidy up some WARN_ON() and BUG_ON(), replacing them with
WARN_ON_ONCE() or KVM_BUG_ON(). All of these have obviously never
triggered, or somebody would have been annoyed earlier, but still...
- Fix missing interrupt due to stale CR8 intercept
- Add a statistic that can come in handy to debug leaks as well as
the vulnerability to a class of recently-discovered issues
- Do not ask arch/x86/kernel to export
default_cpu_present_to_apicid() just for KVM"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (22 commits)
x86/apic: KVM: Use cpu_physical_id() to get APIC ID of running vCPU for AVIC
KVM: x86/mmu: Expose number of shadow MMU shadow pages as a stat
KVM: x86: Unconditionally recompute CR8 intercept on PPR update
KVM: VMX: Grab vmcs12 on CR8 interception update iff vCPU is in guest mode
KVM: x86: WARN (once) if RTC pending EOI tracking goes off the rails
KVM: x86: WARN and fail kvm_set_irq() if a PIC or I/O APIC vector is invalid
KVM: x86: Bug the VM, not the kernel, if the ISR count {under,over}flows
KVM: x86/mmu: Bug the VM, not the host kernel, if KVM write-protects upper SPTEs
KVM: x86: Replace BUG_ON() with WARN_ON_ONCE() on "bad" nested GPA translation
KVM: Replace guest-triggerable BUG_ON() in ioeventfd datamatch with get_unaligned()
KVM: s390: Return failure in case of failure in kvm_s390_set_cmma_bits()
KVM: s390: selftests: Fix cmma selftest
KVM: s390: Fix cmma dirty tracking
KVM: s390: Fix locking in kvm_s390_set_mem_control()
KVM: s390: Fix handle_{sske,pfmf} under memory pressure
KVM: s390: Fix code typo in gmap_protect_asce_top_level()
KVM: s390: Do not set special large pages dirty
KVM: s390: Fix dat_peek_cmma() overflow
s390/mm: Fix handling of _PAGE_UNUSED pte bit
KVM: s390: Fix typo in UCONTROL documentation
...
* Fix S390_USER_OPEREXEC so it can now be enabled regardless of other
unrelated capabilities
* Fix handling of the _PAGE_UNUSED pte bit that could lead to guest
memory corruption in some scenarios
* A bunch of misc gmap fixes (locking, behaviour under memory pressure)
* Fix CMMA dirty tracking
Pull kvm updates from Paolo Bonzini:
"arm64:
This is a bit of an odd merge window on the KVM/arm64 front. There
is absolutely no new feature in the pull request. It is purely
fixes, because it is simply becoming too hard to review new stuff
when so many AI-fuelled fixes hit the list.
- Significant cleanup of the vgic-v5 PPI support which was merged in
7.1. This makes the code more maintainable, and squashes a couple
of bugs in the meantime
- Set of fixes for the handling of the MMU in an NV context,
particularly VNCR-triggered faults. S1POE support is fixed as well
- Large set of pKVM fixes, mostly addressing recurring issues around
hypervisor tracking of donated pages in obscure cases where the
donation could fail and leave things in a bizarre state
- Fixes for the so-called "lazy vgic init", which resulted in
sleeping operations in non-preemptible sections. This turned out to
be far more invasive than initially expected..
- Reduce the overhead of L1/L2 context switch by not touching the FP
registers
- Fix the way non-implemented page sizes are dealt with when a guest
insist on using them for S2 translation
- The usual set of low-impact fixes and cleanups all over the map
Loongarch:
- On a request for lazy FPU load, load all FPU state that the VM
supports instead of enabling only the part (FPU, LSX or LASX) that
caused the FPU load request
- Some enhancements about interrupt injection
- Some bug fixes and other small changes
RISC-V:
- Batch G-stage TLB flushes for GPA range based page table updates
- Convert HGEI line management to fully per-HART
- Fix missing CSR dirty marking when FWFT state updated via ONE_REG
- Fix stale FWFT feature exposure to Guest/VM
- Speed up dirty logging write faults using MMU rwlock and atomic PTE
updates using cmpxchg() for permission-only changes
- Use flexible array for APLIC IRQ state
- Use kvm_slot_dirty_track_enabled() for logging enable check on a
memslot
- Avoid skipping valid pages in kvm_riscv_gstage_wp_range()
- Avoid skipping valid pages in kvm_riscv_gstage_unmap_range()
- Use endian-specific __lelong for NACL shared memory
S390:
- KVM_PRE_FAULT_MEMORY support
- Support for 2G hugepages
- Support for the ASTFLEIE 2 facility
- Support for fast inject using kvm_arch_set_irq_inatomic
- Fix potential leak of uninitialized bytes
- A few more misc gmap fixes
x86:
- Generic support for the more granular permissions allowed by EPT,
namely "read" (which was previously usurping the U bit) and
separate execution bits for kernel and userspace
- Do not assume that all page tables start with U=1/W=1/NX=0 at the
root, as AMD GMET needs to have U=0 at the root
- Introduce common assembly macros for use within Intel and AMD
vendor-specific vmentry code. This touches the SPEC_CTRL handling,
which is now entirely done in assembly for Intel (by reusing the
AMD code that already existed), and register save/restore which
uses some macro magic to compute the offsets in the struct. Both of
these are preparatory changes for upcoming APX support
- Clean up KVM's register tracking and storage, primarily to prepare
for APX support, which expands the maximum number of GPRs from 16
to 32
- Keep a single copy of the PDPTRs rather than two, since
architecturally there is just one
- Handle EXIT_FASTPATH_EXIT_USERSPACE in vendor code to ensure vendor
code gets a chance to handle things like reaping the PML buffer
- Update KVM's view of PV async enabling if and only if the MSR write
fully succeeds
- Fix a variety of issues where the emulator doesn't honor
guest-debug state, and clean up related code along the way
- Synthesize EPT Violation and #NPF "error code" bits when injecting
faults into L1 that didn't originate in hardware (in which case the
VMCS/VMCB doesn't hold relevant information)
- Add support for virtualizing (well, emulating) AMD's flavor of
CPL>0 CPUID faulting
- Clean up the GPR APIs so that KVM's use of "raw" is consistent, and
fix a variety of minor bugs along the way
- Fix an OOB memory access due to not checking the VP ID when
handling a Hyper-V PV TLB flush for L2
- Fix a bug in the mediated PMU's handling of fixed counters that
allowed the guest to bypass the PMU event filter
- Allow userspace to return EAGAIN when handling SNP and TDX
hypercalls, so the KVM can forward a "retry" status code to the
guest, and reserve all unused error codes for future usage
- Overhaul the TDP MMU => S-EPT code to move as much S-EPT specific
logic as possible into the TDX code, and to funnel (almost) all
S-EPT updates into a single chokepoint. The motivation is largely
to prepare for upcoming Dynamic PAMT support, but the cleanups are
nice to have on their own
- Plug a hole in shadow page table handling, where KVM fails to
recursively zap nested EPT/NPT shadow page tables when the nested
hypervisor tears down its own EPT/NPT page tables from the bottom
up
x86 (Intel):
- Support for nested MBEC (Mode-Based Execute Control), see above in
the generic section; also run with MBEC enabled even for non-nested
mode
- Use the kernel's "enum pg_level" in the TDX APIs instead of the
TDX-Module's level definitions (which are 0-based)
- Rework the TDX memory APIs to not require/assume that guest memory
is backed by "struct page" (in prepartion for guest_memfd hugepage
support)
- Fix a largely benign bug where KVM TDX would incorrectly state it
could emulate several x2APIC MSRs
- Use the "safe" WRMSR API when proxying LBR MSR writes as the
to-be-written value is guest controlled and completely unvalidated
x86 (AMD):
- Support for nested GMET (Guest Mode Execution Trap), see above in
the generic section; also run with GMET enabled even for non-nested
mode
- Fixes and minor cleanups to GHCB handling, on top of the earlier
work already merged into 7.1-rc
- Ensure KVM's copy of CR0 and CR3 are up-to-date prior to invoking
fastpath handlers
- Add support for virtualizing gPAT (KVM previously just used L1's
PAT when running L2)
- Fix goofs where KVM mishandles side effects (e.g. single-step and
PMC updates) when emulating VMRUN
- Fix a variety of bugs in AVIC's handling of x2APIC MSR
interception, most notably where KVM didn't disable interception of
IRR, ISR, and TMR regs
- Add support for virtualizing Host-Only/Guest-Only bits in the
mediated PMU
- Don't advertise support for unusable VM types, and account for VM
types that are disabled by firmware, e.g. to mitigate security
vulnerabilities
- Rewrite the SEV {en,de}crypt debug ioctls as they were riddle with
bugs and unnecessarily complicated, and add comprehensive tests
- Clean up and deduplicate the SEV page pinning code
- Fix minor goofs related to writing back CPUID information after
firmware rejects a CPUID page for an SNP vCPU
Generic:
- Rename invalidate_begin() to invalidate_start() throughout KVM to
follow the kernel's nomenclature, e.g. for mmu_notifiers
- Use guard() to cleanup up various KVM+VFIO flows
- Minor cleanups
guest_memfd:
- Return -EEXIST instead of -EINVAL if userspace attempts to bind a
gmem range to multiple memslots, and fix the test that was supposed
to ensure KVM returns -EEXIST
- Treat memslot binding offsets and sizes as unsigned values to fix a
bug where KVM interprets a large "offset + size" as a negative
value and allows a nonsensical offset
- Use the inode number instead of the page offset for the NUMA
interleaving index to fix a bug where the effective index would
jump by two for consecutive pages (the caller also adds in the page
offset)
Selftests:
- Randomize the dirty log test's delay when reaping the bitmap on the
first pass, as always waiting only 1ms hid a KVM RISC-V bug as the
test reaped the bitmap before KVM could build up enough state to
hit the bug
- A pile of one-off fixes and cleanups"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (326 commits)
KVM: x86/mmu: Ensure hugepage is in by slot before checking max mapping level
KVM: x86: Fix shadow paging use-after-free due to unexpected role
KVM: s390: Introducing kvm_arch_set_irq_inatomic fast inject
KVM: s390: Enable adapter_indicators_set to use mapped pages
KVM: s390: Add map/unmap ioctl and clean mappings post-guest
riscv: kvm: Use endian-specific __lelong for NACL shared memory
KVM: selftests: access_tracking_perf_test: bump number of NUMA nodes to 32
KVM: s390: vsie: Implement ASTFLEIE facility 2
KVM: s390: vsie: Refactor handle_stfle
s390/sclp: Detect ASTFLEIE 2 facility
KVM: s390: Minor refactor of base/ext facility lists
KVM: x86/mmu: move pdptrs out of the MMU
KVM: x86: check that kvm_handle_invpcid is only invoked with shadow paging
KVM: nSVM: invalidate cached PDPTRs across nested NPT transitions
KVM: nVMX: remove unnecessary code in prepare_vmcs02_rare
KVM: x86: remove nested_mmu from mmu_is_nested()
KVM: arm64: vgic-its: Make ABI commit helpers return void
KVM: s390: Initialize KVM_S390_GET_CMMA_BITS memory
LoongArch: KVM: Add missing slots_lock for device register/unregister
LoongArch: KVM: Validate irqchip index in irqfd routing
...
Pull documentation updates from Jonathan Corbet:
"Things have calmed down a bit on the docs front, with no earthshaking
changes this time around:
- Ongoing work on the Japanese and Portuguese translations
- Better integration of the MAINTAINERS file into the rendered
documents, including a search interface
- A seemingly infinite supply of fixes for typos, minor grammatical
issues, and related problems that LLMs find with abandon"
* tag 'docs-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/docs/linux: (93 commits)
docs: pt_BR: Translate 3.Early-stage.rst into Portuguese
docs: pt_BR: update "Purpose of Defconfigs" section in maintainer-soc.rst
Documentation: bug-hunting.rst: fix grammar
docs/ja_JP: translate submitting-patches.rst (interleaved-replies)
docs: Fix minor grammatical error
docs/{it_it,sp_SP,zh_CN,zh_TW}: update references to removed CONFIG_DEBUG_SLAB
Documentation: process: fix brackets
Documentation: arch: fix brackets
docs/dyndbg: explain flags parse 1st
docs/dyndbg: update examples \012 to \n
docs: kernel-parameters: Fix stale sticore file paths
docs: real-time: Fix duplicated sched(7) text
docs: kgdb: Fix stale source file paths
docs: sonypi: Fix stale header file path
docs: kernel-parameters: Remove sa1100ir IrDA parameter
iommu: Documentation: rearrange, update kernel-parameters
docs: md: fix grammar in speed_limit description
docs: changes.rst: restore pahole 1.26 minimum (regressed by sort)
Documentation: Fix syntax of kmalloc_objs example in coding style doc
docs: pt_BR: update maintainer-handbooks
...
KVM: s390: New features for 7.2
New features for 7.2 for KVM/s390:
* KVM_PRE_FAULT_MEMORY support
* Support for 2G hugepages
* Support for the ASTFLEIE 2 facility
* kvm_arch_set_irq_inatomic Fast Inject
* Fix potential leak of uninitialized bytes
KVM/arm64 updates for 7.2
* New features:
- None. Zilch. Nada. Que dalle.
* Fixes and other improvements:
- Significant cleanup of the vgic-v5 PPI support which was merged in
7.1. This makes the code more maintainable, and squashes a couple
of bugs in the meantime.
- Set of fixes for the handling of the MMU in an NV context,
particularly VNCR-triggered faults. S1POE support is fixed
as well.
- Large set of pKVM fixes, mostly addressing recurring issues
around hypervisor tracking of donated pages in obscure cases
where the donation could fail and leave things in a bizarre
state.
- Fixes for the so-called "lazy vgic init", which resulted in
sleeping operations in non-preemptible sections. This turned
out to be far more invasive than initially expected...
- Reduce the overhead of L1/L2 context switch by not touching
the FP registers.
- Fix the way non-implemented page sizes are dealt with when
a guest insist on using them for S2 translation.
- The usual set of low-impact fixes and cleanups all over the map.
KVM SVM changes for 7.2
- Add support for virtualizing gPAT (KVM previously just used L1's PAT when
running L2).
- Fix goofs where KVM mishandles side effects (e.g. single-step and PMC
updates) when emulating VMRUN.
- Fix a variety of bugs in AVIC's handling of x2APIC MSR interception, most
notably where KVM didn't disable interception of IRR, ISR, and TMR regs.
- Add support for virtualizing Host-Only/Guest-Only bits in the mediated PMU.
KVM misc x86 changes for 7.2
- Handle EXIT_FASTPATH_EXIT_USERSPACE in vendor code to ensure vendor code
gets a chance to handle things like reaping the PML buffer.
- Ensure KVM's copy of CR0 and CR3 are up-to-date on SVM prior to invoking
fastpath handlers.
- Update KVM's view of PV async enabling if and only if the MSR write fully
succeeds.
- Fix a variety of issues where the emulator doesn't honor guest-debug state,
and clean up related code along the way.
- Synthesize EPT Violation and #NPF "error code" bits when injecting faults
into L1 that didn't originate in hardware (in which case the VMCS/VMCB
doesn't hold relevant information).
- Add support for virtualizing (well, emulating) AMD's flavor of CPL>0 CPUID
faulting.
- Clean up the GPR APIs so that KVM's use of "raw" is consistent, and fix a
variety of minor bugs along the way.
- Fix an OOB memory access due to not checking the VP ID when handling a
Hyper-V PV TLB flush for L2.
- Fix a bug in the mediated PMU's handling of fixed counters that allowed the
guest to bypass the PMU event filter.
- Allow userspace to return EAGAIN when handling SNP and TDX hypercalls, so
the KVM can forward a "retry" status code to the guest, and reserve all
unused error codes for future usage.
- Misc fixes and cleanups.
* kvm-arm64/vgic-v5-PPI-fixes:
: .
: Substantial cleanup of the vgic-v5 PPI support. From the original
: cover letter:
:
: "With the GICv5 PPi support merged in, it has become obvious that a few
: things could be improved, both from the correctness and maintainability
: angles."
: .
KVM: arm64: Fix arch timer interrupts for GICv3-on-GICv5 guests
irqchip/gic-v5: Immediately exec priority drop following activate
Documentation: KVM: Clarify that PMU_V3_IRQ IntID requirements for GICv5
Documentation: KVM: Fix typos in VGICv5 documentation
KVM: arm64: selftests: Improve error handling for GICv5 PPI selftest
KVM: arm64: selftests: Cleanup unused vars in GICv5 PPI selftest
KVM: arm64: selftests: Add missing GIC CDEN to no-vgic-v5 selftest
KVM: arm64: vgic-v5: Atomically assign bits to PPI DVI bitmap
KVM: arm64: vgic-v5: Add missing trap handing for NV triage
KVM: arm64: vgic-v5: Limit support to 64 PPIs
KVM: arm64: vgic: Rationalise per-CPU irq accessor
KVM: arm64: vgic-v5: Drop defensive checks from vgic_v5_ppi_queue_irq_unlock()
KVM: arm64: vgic: Consolidate vgic_allocate_private_irqs_locked()
KVM: arm64: vgic: Constify struct irq_ops usage
KVM: arm64: vgic-v5: Drop pointless ARM64_HAS_GICV5_CPUIF check
KVM: arm64: vgic-v5: Remove use of __assign_bit() with a constant
KVM: arm64: vgic-v5: Move PPI caps into kvm_vgic_global_state
KVM: arm64: vgic-v5: Add for_each_visible_v5_ppi() iterator
Signed-off-by: Marc Zyngier <maz@kernel.org>
MAPGPA request from TDX VMs gets split into chunks by KVM using a loop
of userspace exits until the complete range is handled.
In some cases userspace VMM might decide to break the MAPGPA operation
and continue it later. For example: in the case of intrahost migration
userspace might decide to continue the MAPGPA operation after the
migration is completed.
Allow userspace to signal to TDX guests that the MAPGPA operation should
be retried the next time the guest is scheduled.
This is potentially a breaking change since if userspace sets
hypercall.ret to a value other than EBUSY or EINVAL an EINVAL error code
will be returned to userspace. As of now QEMU never sets hypercall.ret
to a non-zero value after handling KVM_EXIT_HYPERCALL so this change
should be safe.
Reviewed-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Vishal Annapurve <vannapurve@google.com>
Co-developed-by: Sagi Shahar <sagis@google.com>
Signed-off-by: Sagi Shahar <sagis@google.com>
Link: https://patch.msgid.link/20260305222627.4193305-2-sagis@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Add a 'gpat' field to kvm_svm_nested_state_hdr to carry L2's guest PAT
value across save and restore.
When KVM_X86_QUIRK_NESTED_SVM_SHARED_PAT is disabled and the vCPU is in
guest mode with nested NPT enabled, save vmcb02's g_pat into the header on
KVM_GET_NESTED_STATE, and restore it on KVM_SET_NESTED_STATE.
Host-initiated accesses to IA32_PAT (via KVM_GET/SET_MSRS) always target
L1's hPAT, so they cannot be used to save or restore gPAT. The separate
header field ensures that KVM_GET/SET_MSRS and KVM_GET/SET_NESTED_STATE are
independent and can be ordered arbitrarily during save and restore.
Note that struct kvm_svm_nested_state_hdr is included in a union padded to
120 bytes, so there is room to add the gpat field without changing any
offsets.
Fixes: cc440cdad5 ("KVM: nSVM: implement KVM_GET_NESTED_STATE and KVM_SET_NESTED_STATE")
Signed-off-by: Jim Mattson <jmattson@google.com>
Link: https://patch.msgid.link/20260407190343.325299-9-jmattson@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Define a quirk to control whether nested SVM shares L1's PAT with L2
(legacy behavior) or gives L2 its own independent gPAT (correct behavior
per the APM).
When the quirk is enabled (default), L2 shares L1's PAT, preserving the
legacy KVM behavior. When userspace disables the quirk, KVM correctly
virtualizes the PAT for nested SVM guests, giving L2 a separate gPAT as
specified in the AMD architecture.
Signed-off-by: Jim Mattson <jmattson@google.com>
Link: https://patch.msgid.link/20260407190343.325299-2-jmattson@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Paolo Bonzini
Jaehoon KimandChristian Borntraeger
Alexandru EliseiandMarc Zyngier
Linus Torvalds
Eric FarmanandClaudio Imbrenda
Carlos LópezandSean Christopherson
Vishal AnnapurveandSean Christopherson
Sakurai ShunandJonathan Corbet
Sascha BischoffandMarc Zyngier
Jim MattsonandSean Christopherson
Ninad NaikandPaolo Bonzini