linux-stable.git/include/uapi/linux/kvm.h, branch v5.17.7

KVM: PPC: reserve capability 210 for KVM_CAP_PPC_AIL_MODE_3

2022-02-22T14:06:54+00:00

Add KVM_CAP_PPC_AIL_MODE_3 to advertise the capability to set the AIL
resource mode to 3 with the H_SET_MODE hypercall. This capability
differs between processor types and KVM types (PR, HV, Nested HV), and
affects guest-visible behaviour.

QEMU will implement a cap-ail-mode-3 to control this behaviour[1], and
use the KVM CAP if available to determine KVM support[2].

Reviewed-by: Fabiano Rosas 
Signed-off-by: Nicholas Piggin 
Signed-off-by: Paolo Bonzini

kvm: Move KVM_GET_XSAVE2 IOCTL definition at the end of kvm.h

2022-01-31T14:21:56+00:00

This way we can more easily find the next free IOCTL number when
adding new IOCTLs.

Fixes: be50b2065dfa ("kvm: x86: Add support for getting/setting expanded xstate buffer")
Signed-off-by: Janosch Frank 
Message-Id: <20220128154025.102666-1-frankja@linux.ibm.com>
Signed-off-by: Paolo Bonzini

KVM: x86: add system attribute to retrieve full set of supported xsave states

2022-01-28T12:33:32+00:00

Because KVM_GET_SUPPORTED_CPUID is meant to be passed (by simple-minded
VMMs) to KVM_SET_CPUID2, it cannot include any dynamic xsave states that
have not been enabled.  Probing those, for example so that they can be
passed to ARCH_REQ_XCOMP_GUEST_PERM, requires a new ioctl or arch_prctl.
The latter is in fact worse, even though that is what the rest of the
API uses, because it would require supported_xcr0 to be moved from the
KVM module to the kernel just for this use.  In addition, the value
would be nonsensical (or an error would have to be returned) until
the KVM module is loaded in.

Therefore, to limit the growth of system ioctls, add a /dev/kvm
variant of KVM_{GET,HAS}_DEVICE_ATTR, and implement it in x86
with just one group (0) and attribute (KVM_X86_XCOMP_GUEST_SUPP).

Signed-off-by: Paolo Bonzini

kvm: x86: Add support for getting/setting expanded xstate buffer

2022-01-14T18:44:41+00:00

With KVM_CAP_XSAVE, userspace uses a hardcoded 4KB buffer to get/set
xstate data from/to KVM. This doesn't work when dynamic xfeatures
(e.g. AMX) are exposed to the guest as they require a larger buffer
size.

Introduce a new capability (KVM_CAP_XSAVE2). Userspace VMM gets the
required xstate buffer size via KVM_CHECK_EXTENSION(KVM_CAP_XSAVE2).
KVM_SET_XSAVE is extended to work with both legacy and new capabilities
by doing properly-sized memdup_user() based on the guest fpu container.
KVM_GET_XSAVE is kept for backward-compatible reason. Instead,
KVM_GET_XSAVE2 is introduced under KVM_CAP_XSAVE2 as the preferred
interface for getting xstate buffer (4KB or larger size) from KVM
(Link: https://lkml.org/lkml/2021/12/15/510)

Also, update the api doc with the new KVM_GET_XSAVE2 ioctl.

Signed-off-by: Guang Zeng 
Signed-off-by: Wei Wang 
Signed-off-by: Jing Liu 
Signed-off-by: Kevin Tian 
Signed-off-by: Yang Zhong 
Message-Id: <20220105123532.12586-19-yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini

KVM: x86/xen: Add KVM_IRQ_ROUTING_XEN_EVTCHN and event channel delivery

2022-01-07T15:44:45+00:00

This adds basic support for delivering 2 level event channels to a guest.

Initially, it only supports delivery via the IRQ routing table, triggered
by an eventfd. In order to do so, it has a kvm_xen_set_evtchn_fast()
function which will use the pre-mapped shared_info page if it already
exists and is still valid, while the slow path through the irqfd_inject
workqueue will remap the shared_info page if necessary.

It sets the bits in the shared_info page but not the vcpu_info; that is
deferred to __kvm_xen_has_interrupt() which raises the vector to the
appropriate vCPU.

Add a 'verbose' mode to xen_shinfo_test while adding test cases for this.

Signed-off-by: David Woodhouse 
Message-Id: <20211210163625.2886-5-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini

RISC-V: KVM: Add VM capability to allow userspace get GPA bits

2022-01-06T09:46:58+00:00

The number of GPA bits supported for a RISC-V Guest/VM is based on the
MMU mode used by the G-stage translation. The KVM RISC-V will detect and
use the best possible MMU mode for the G-stage in kvm_arch_init().

We add a generic VM capability KVM_CAP_VM_GPA_BITS which can be used by
the KVM userspace to get the number of GPA (guest physical address) bits
supported for a Guest/VM.

Signed-off-by: Anup Patel 
Reviewed-and-tested-by: Atish Patra

KVM: SEV: Add support for SEV intra host migration

2021-11-11T15:35:27+00:00

For SEV to work with intra host migration, contents of the SEV info struct
such as the ASID (used to index the encryption key in the AMD SP) and
the list of memory regions need to be transferred to the target VM.
This change adds a commands for a target VMM to get a source SEV VM's sev
info.

Signed-off-by: Peter Gonda 
Suggested-by: Sean Christopherson 
Reviewed-by: Marc Orr 
Cc: Marc Orr 
Cc: Paolo Bonzini 
Cc: Sean Christopherson 
Cc: David Rientjes 
Cc: Dr. David Alan Gilbert 
Cc: Brijesh Singh 
Cc: Tom Lendacky 
Cc: Vitaly Kuznetsov 
Cc: Wanpeng Li 
Cc: Jim Mattson 
Cc: Joerg Roedel 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: "H. Peter Anvin" 
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Message-Id: <20211021174303.385706-3-pgonda@google.com>
Signed-off-by: Paolo Bonzini

KVM: x86: On emulation failure, convey the exit reason, etc. to userspace

2021-10-25T10:48:24+00:00

Should instruction emulation fail, include the VM exit reason, etc. in
the emulation_failure data passed to userspace, in order that the VMM
can report it as a debugging aid when describing the failure.

Suggested-by: Joao Martins 
Signed-off-by: David Edmondson 
Reviewed-by: Sean Christopherson 
Message-Id: <20210920103737.2696756-4-david.edmondson@oracle.com>
Signed-off-by: Paolo Bonzini

KVM: x86: Clarify the kvm_run.emulation_failure structure layout

2021-10-25T10:48:24+00:00

Until more flags for kvm_run.emulation_failure flags are defined, it
is undetermined whether new payload elements corresponding to those
flags will be additive or alternative. As a hint to userspace that an
alternative is possible, wrap the current payload elements in a union.

Suggested-by: Sean Christopherson 
Signed-off-by: David Edmondson 
Reviewed-by: Sean Christopherson 
Message-Id: <20210920103737.2696756-2-david.edmondson@oracle.com>
Signed-off-by: Paolo Bonzini

KVM: x86: Report host tsc and realtime values in KVM_GET_CLOCK

2021-10-18T18:43:44+00:00

Handling the migration of TSCs correctly is difficult, in part because
Linux does not provide userspace with the ability to retrieve a (TSC,
realtime) clock pair for a single instant in time. In lieu of a more
convenient facility, KVM can report similar information in the kvm_clock
structure.

Provide userspace with a host TSC & realtime pair iff the realtime clock
is based on the TSC. If userspace provides KVM_SET_CLOCK with a valid
realtime value, advance the KVM clock by the amount of elapsed time. Do
not step the KVM clock backwards, though, as it is a monotonic
oscillator.

Suggested-by: Paolo Bonzini 
Signed-off-by: Oliver Upton 
Signed-off-by: Paolo Bonzini 
Message-Id: <20210916181538.968978-5-oupton@google.com>
Signed-off-by: Paolo Bonzini