linux.git/include/uapi/linux/kvm.h, branch v5.9-rc4

Merge tag 'kvm-s390-next-5.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvm-next-5.6

2020-08-03T18:19:13+00:00

KVM: s390: Enhancement for 5.9
- implement diagnose 318

KVM: x86: Add a capability for GUEST_MAXPHYADDR < HOST_MAXPHYADDR support

2020-07-10T21:01:53+00:00

This patch adds a new capability KVM_CAP_SMALLER_MAXPHYADDR which
allows userspace to query if the underlying architecture would
support GUEST_MAXPHYADDR < HOST_MAXPHYADDR and hence act accordingly
(e.g. qemu can decide if it should warn for -cpu ..,phys-bits=X)

The complications in this patch are due to unexpected (but documented)
behaviour we see with NPF vmexit handling in AMD processor.  If
SVM is modified to add guest physical address checks in the NPF
and guest #PF paths, we see the followning error multiple times in
the 'access' test in kvm-unit-tests:

            test pte.p pte.36 pde.p: FAIL: pte 2000021 expected 2000001
            Dump mapping: address: 0x123400000000
            ------L4: 24c3027
            ------L3: 24c4027
            ------L2: 24c5021
            ------L1: 1002000021

This is because the PTE's accessed bit is set by the CPU hardware before
the NPF vmexit. This is handled completely by hardware and cannot be fixed
in software.

Therefore, availability of the new capability depends on a boolean variable
allow_smaller_maxphyaddr which is set individually by VMX and SVM init
routines. On VMX it's always set to true, on SVM it's only set to true
when NPT is not enabled.

CC: Tom Lendacky 
CC: Babu Moger 
Signed-off-by: Mohammed Gamal 
Message-Id: <20200710154811.418214-10-mgamal@redhat.com>
Signed-off-by: Paolo Bonzini

kvm: x86: Add "last CPU" to some KVM_EXIT information

2020-07-08T20:21:45+00:00

More often than not, a failed VM-entry in an x86 production
environment is induced by a defective CPU. To help identify the bad
hardware, include the id of the last logical CPU to run a vCPU in the
information provided to userspace on a KVM exit for failed VM-entry or
for KVM internal errors not associated with emulation. The presence of
this additional information is indicated by a new capability,
KVM_CAP_LAST_CPU.

Signed-off-by: Jim Mattson 
Reviewed-by: Oliver Upton 
Reviewed-by: Peter Shier 
Message-Id: <20200603235623.245638-5-jmattson@google.com>
Signed-off-by: Paolo Bonzini

s390/kvm: diagnose 0x318 sync and reset

2020-06-23T08:55:33+00:00

DIAGNOSE 0x318 (diag318) sets information regarding the environment
the VM is running in (Linux, z/VM, etc) and is observed via
firmware/service events.

This is a privileged s390x instruction that must be intercepted by
SIE. Userspace handles the instruction as well as migration. Data
is communicated via VCPU register synchronization.

The Control Program Name Code (CPNC) is stored in the SIE block. The
CPNC along with the Control Program Version Code (CPVC) are stored
in the kvm_vcpu_arch struct.

This data is reset on load normal and clear resets.

Signed-off-by: Collin Walling 
Reviewed-by: Janosch Frank 
Acked-by: Cornelia Huck 
Reviewed-by: David Hildenbrand 
Link: https://lore.kernel.org/r/20200622154636.5499-3-walling@linux.ibm.com
[borntraeger@de.ibm.com: fix sync_reg position]
Signed-off-by: Christian Borntraeger

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2020-06-03T22:13:47+00:00

Pull kvm updates from Paolo Bonzini:
 "ARM:
   - Move the arch-specific code into arch/arm64/kvm

   - Start the post-32bit cleanup

   - Cherry-pick a few non-invasive pre-NV patches

  x86:
   - Rework of TLB flushing

   - Rework of event injection, especially with respect to nested
     virtualization

   - Nested AMD event injection facelift, building on the rework of
     generic code and fixing a lot of corner cases

   - Nested AMD live migration support

   - Optimization for TSC deadline MSR writes and IPIs

   - Various cleanups

   - Asynchronous page fault cleanups (from tglx, common topic branch
     with tip tree)

   - Interrupt-based delivery of asynchronous "page ready" events (host
     side)

   - Hyper-V MSRs and hypercalls for guest debugging

   - VMX preemption timer fixes

  s390:
   - Cleanups

  Generic:
   - switch vCPU thread wakeup from swait to rcuwait

  The other architectures, and the guest side of the asynchronous page
  fault work, will come next week"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (256 commits)
  KVM: selftests: fix rdtsc() for vmx_tsc_adjust_test
  KVM: check userspace_addr for all memslots
  KVM: selftests: update hyperv_cpuid with SynDBG tests
  x86/kvm/hyper-v: Add support for synthetic debugger via hypercalls
  x86/kvm/hyper-v: enable hypercalls regardless of hypercall page
  x86/kvm/hyper-v: Add support for synthetic debugger interface
  x86/hyper-v: Add synthetic debugger definitions
  KVM: selftests: VMX preemption timer migration test
  KVM: nVMX: Fix VMX preemption timer migration
  x86/kvm/hyper-v: Explicitly align hcall param for kvm_hyperv_exit
  KVM: x86/pmu: Support full width counting
  KVM: x86/pmu: Tweak kvm_pmu_get_msr to pass 'struct msr_data' in
  KVM: x86: announce KVM_FEATURE_ASYNC_PF_INT
  KVM: x86: acknowledgment mechanism for async pf page ready notifications
  KVM: x86: interrupt based APF 'page ready' event delivery
  KVM: introduce kvm_read_guest_offset_cached()
  KVM: rename kvm_arch_can_inject_async_page_present() to kvm_arch_can_dequeue_async_page_present()
  KVM: x86: extend struct kvm_vcpu_pv_apf_data with token info
  Revert "KVM: async_pf: Fix #DF due to inject "Page not Present" and "Page Ready" exceptions simultaneously"
  KVM: VMX: Replace zero-length array with flexible-array
  ...

x86/kvm/hyper-v: Add support for synthetic debugger interface

2020-06-01T08:26:11+00:00

Add support for Hyper-V synthetic debugger (syndbg) interface.
The syndbg interface is using MSRs to emulate a way to send/recv packets
data.

The debug transport dll (kdvm/kdnet) will identify if Hyper-V is enabled
and if it supports the synthetic debugger interface it will attempt to
use it, instead of trying to initialize a network adapter.

Reviewed-by: Vitaly Kuznetsov 
Signed-off-by: Jon Doron 
Message-Id: <20200529134543.1127440-4-arilou@gmail.com>
Signed-off-by: Paolo Bonzini

x86/kvm/hyper-v: Explicitly align hcall param for kvm_hyperv_exit

2020-06-01T08:26:09+00:00

The problem the patch is trying to address is the fact that 'struct
kvm_hyperv_exit' has different layout on when compiling in 32 and 64 bit
modes.

In 64-bit mode the default alignment boundary is 64 bits thus
forcing extra gaps after 'type' and 'msr' but in 32-bit mode the
boundary is at 32 bits thus no extra gaps.

This is an issue as even when the kernel is 64 bit, the userspace using
the interface can be both 32 and 64 bit but the same 32 bit userspace has
to work with 32 bit kernel.

The issue is fixed by forcing the 64 bit layout, this leads to ABI
change for 32 bit builds and while we are obviously breaking '32 bit
userspace with 32 bit kernel' case, we're fixing the '32 bit userspace
with 64 bit kernel' one.

As the interface has no (known) users and 32 bit KVM is rather baroque
nowadays, this seems like a reasonable decision.

Reviewed-by: Vitaly Kuznetsov 
Signed-off-by: Jon Doron 
Message-Id: <20200424113746.3473563-2-arilou@gmail.com>
Reviewed-by: Roman Kagan 
Signed-off-by: Paolo Bonzini

KVM: x86: announce KVM_FEATURE_ASYNC_PF_INT

2020-06-01T08:26:08+00:00

Introduce new capability to indicate that KVM supports interrupt based
delivery of 'page ready' APF events. This includes support for both
MSR_KVM_ASYNC_PF_INT and MSR_KVM_ASYNC_PF_ACK.

Signed-off-by: Vitaly Kuznetsov 
Message-Id: <20200525144125.143875-8-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini

kvm: add capability for halt polling

2020-04-24T16:53:17+00:00

KVM_CAP_HALT_POLL is a per-VM capability that lets userspace
control the halt-polling time, allowing halt-polling to be tuned or
disabled on particular VMs.

With dynamic halt-polling, a VM's VCPUs can poll from anywhere from
[0, halt_poll_ns] on each halt. KVM_CAP_HALT_POLL sets the
upper limit on the poll time.

Signed-off-by: David Matlack 
Signed-off-by: Jon Cargille 
Reviewed-by: Jim Mattson 
Message-Id: <20200417221446.108733-1-jcargill@google.com>
Signed-off-by: Paolo Bonzini

docs: fix broken references for ReST files that moved around

2020-04-20T21:45:03+00:00

Some broken references happened due to shifting files around
and ReST renames. Those can't be auto-fixed by the script,
so let's fix them manually.

Signed-off-by: Mauro Carvalho Chehab 
Acked-by: Corentin Labbe 
Link: https://lore.kernel.org/r/64773a12b4410aaf3e3be89e3ec7e34de2484eea.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet