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  1. 28 2月, 2020 1 次提交
  3. 13 2月, 2020 1 次提交
  5. 31 1月, 2020 1 次提交
  7. 23 1月, 2020 1 次提交
  9. 30 11月, 2019 1 次提交
  11. 28 11月, 2019 1 次提交
  13. 22 10月, 2019 2 次提交
    • C
      KVM: arm/arm64: Allow user injection of external data aborts · da345174
      由 Christoffer Dall 提交于 
      In some scenarios, such as buggy guest or incorrect configuration of the
VMM and firmware description data, userspace will detect a memory access
to a portion of the IPA, which is not mapped to any MMIO region.

For this purpose, the appropriate action is to inject an external abort
to the guest.  The kernel already has functionality to inject an
external abort, but we need to wire up a signal from user space that
lets user space tell the kernel to do this.

It turns out, we already have the set event functionality which we can
perfectly reuse for this.
Signed-off-by: NChristoffer Dall <christoffer.dall@arm.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
      da345174
    • C
      KVM: arm/arm64: Allow reporting non-ISV data aborts to userspace · c726200d
      由 Christoffer Dall 提交于 
      For a long time, if a guest accessed memory outside of a memslot using
any of the load/store instructions in the architecture which doesn't
supply decoding information in the ESR_EL2 (the ISV bit is not set), the
kernel would print the following message and terminate the VM as a
result of returning -ENOSYS to userspace:

  load/store instruction decoding not implemented

The reason behind this message is that KVM assumes that all accesses
outside a memslot is an MMIO access which should be handled by
userspace, and we originally expected to eventually implement some sort
of decoding of load/store instructions where the ISV bit was not set.

However, it turns out that many of the instructions which don't provide
decoding information on abort are not safe to use for MMIO accesses, and
the remaining few that would potentially make sense to use on MMIO
accesses, such as those with register writeback, are not used in
practice.  It also turns out that fetching an instruction from guest
memory can be a pretty horrible affair, involving stopping all CPUs on
SMP systems, handling multiple corner cases of address translation in
software, and more.  It doesn't appear likely that we'll ever implement
this in the kernel.

What is much more common is that a user has misconfigured his/her guest
and is actually not accessing an MMIO region, but just hitting some
random hole in the IPA space.  In this scenario, the error message above
is almost misleading and has led to a great deal of confusion over the
years.

It is, nevertheless, ABI to userspace, and we therefore need to
introduce a new capability that userspace explicitly enables to change
behavior.

This patch introduces KVM_CAP_ARM_NISV_TO_USER (NISV meaning Non-ISV)
which does exactly that, and introduces a new exit reason to report the
event to userspace.  User space can then emulate an exception to the
guest, restart the guest, suspend the guest, or take any other
appropriate action as per the policy of the running system.
Reported-by: NHeinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: NChristoffer Dall <christoffer.dall@arm.com>
Reviewed-by: NAlexander Graf <graf@amazon.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
      c726200d
  15. 21 10月, 2019 1 次提交
    • F
      KVM: PPC: Report single stepping capability · 1a9167a2
      由 Fabiano Rosas 提交于 
      When calling the KVM_SET_GUEST_DEBUG ioctl, userspace might request
the next instruction to be single stepped via the
KVM_GUESTDBG_SINGLESTEP control bit of the kvm_guest_debug structure.

This patch adds the KVM_CAP_PPC_GUEST_DEBUG_SSTEP capability in order
to inform userspace about the state of single stepping support.

We currently don't have support for guest single stepping implemented
in Book3S HV so the capability is only present for Book3S PR and
BookE.
Signed-off-by: NFabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>
      1a9167a2
  17. 24 9月, 2019 1 次提交
  19. 11 9月, 2019 1 次提交
  21. 09 9月, 2019 1 次提交
    • M
      KVM: arm/arm64: vgic: Allow more than 256 vcpus for KVM_IRQ_LINE · 92f35b75
      由 Marc Zyngier 提交于 
      While parts of the VGIC support a large number of vcpus (we
bravely allow up to 512), other parts are more limited.

One of these limits is visible in the KVM_IRQ_LINE ioctl, which
only allows 256 vcpus to be signalled when using the CPU or PPI
types. Unfortunately, we've cornered ourselves badly by allocating
all the bits in the irq field.

Since the irq_type subfield (8 bit wide) is currently only taking
the values 0, 1 and 2 (and we have been careful not to allow anything
else), let's reduce this field to only 4 bits, and allocate the
remaining 4 bits to a vcpu2_index, which acts as a multiplier:

  vcpu_id = 256 * vcpu2_index + vcpu_index

With that, and a new capability (KVM_CAP_ARM_IRQ_LINE_LAYOUT_2)
allowing this to be discovered, it becomes possible to inject
PPIs to up to 4096 vcpus. But please just don't.

Whilst we're there, add a clarification about the use of KVM_IRQ_LINE
on arm, which is not completely conditionned by KVM_CAP_IRQCHIP.
Reported-by: NZenghui Yu <yuzenghui@huawei.com>
Reviewed-by: NEric Auger <eric.auger@redhat.com>
Reviewed-by: NZenghui Yu <yuzenghui@huawei.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
      92f35b75
  23. 29 8月, 2019 1 次提交
  25. 24 7月, 2019 1 次提交
  27. 20 7月, 2019 1 次提交
  29. 11 7月, 2019 1 次提交
    • E
      KVM: x86: PMU Event Filter · 66bb8a06
      由 Eric Hankland 提交于 
      Some events can provide a guest with information about other guests or the
host (e.g. L3 cache stats); providing the capability to restrict access
to a "safe" set of events would limit the potential for the PMU to be used
in any side channel attacks. This change introduces a new VM ioctl that
sets an event filter. If the guest attempts to program a counter for
any blacklisted or non-whitelisted event, the kernel counter won't be
created, so any RDPMC/RDMSR will show 0 instances of that event.
Signed-off-by: NEric Hankland <ehankland@google.com>
[Lots of changes. All remaining bugs are probably mine. - Paolo]
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      66bb8a06
  31. 19 6月, 2019 1 次提交
    • L
      KVM: x86: Modify struct kvm_nested_state to have explicit fields for data · 6ca00dfa
      由 Liran Alon 提交于 
      Improve the KVM_{GET,SET}_NESTED_STATE structs by detailing the format
of VMX nested state data in a struct.

In order to avoid changing the ioctl values of
KVM_{GET,SET}_NESTED_STATE, there is a need to preserve
sizeof(struct kvm_nested_state). This is done by defining the data
struct as "data.vmx[0]". It was the most elegant way I found to
preserve struct size while still keeping struct readable and easy to
maintain. It does have a misfortunate side-effect that now it has to be
accessed as "data.vmx[0]" rather than just "data.vmx".

Because we are already modifying these structs, I also modified the
following:
* Define the "format" field values as macros.
* Rename vmcs_pa to vmcs12_pa for better readability.
Signed-off-by: NLiran Alon <liran.alon@oracle.com>
[Remove SVM stubs, add KVM_STATE_NESTED_VMX_VMCS12_SIZE. - Paolo]
Reviewed-by: NLiran Alon <liran.alon@oracle.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      6ca00dfa
  33. 18 6月, 2019 1 次提交
  35. 15 6月, 2019 1 次提交
  37. 05 6月, 2019 2 次提交
  39. 08 5月, 2019 1 次提交
  41. 01 5月, 2019 3 次提交
  43. 30 4月, 2019 2 次提交
  45. 29 4月, 2019 1 次提交
  47. 24 4月, 2019 2 次提交
    • A
      KVM: arm64: Add capability to advertise ptrauth for guest · a243c16d
      由 Amit Daniel Kachhap 提交于 
      This patch advertises the capability of two cpu feature called address
pointer authentication and generic pointer authentication. These
capabilities depend upon system support for pointer authentication and
VHE mode.

The current arm64 KVM partially implements pointer authentication and
support of address/generic authentication are tied together. However,
separate ABI requirements for both of them is added so that any future
isolated implementation will not require any ABI changes.
Signed-off-by: NAmit Daniel Kachhap <amit.kachhap@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Christoffer Dall <christoffer.dall@arm.com>
Cc: kvmarm@lists.cs.columbia.edu
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
      a243c16d
    • A
      KVM: arm64: Add userspace flag to enable pointer authentication · a22fa321
      由 Amit Daniel Kachhap 提交于 
      Now that the building blocks of pointer authentication are present, lets
add userspace flags KVM_ARM_VCPU_PTRAUTH_ADDRESS and
KVM_ARM_VCPU_PTRAUTH_GENERIC. These flags will enable pointer
authentication for the KVM guest on a per-vcpu basis through the ioctl
KVM_ARM_VCPU_INIT.

This features will allow the KVM guest to allow the handling of
pointer authentication instructions or to treat them as undefined
if not set.

Necessary documentations are added to reflect the changes done.
Reviewed-by: NDave Martin <Dave.Martin@arm.com>
Signed-off-by: NAmit Daniel Kachhap <amit.kachhap@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Christoffer Dall <christoffer.dall@arm.com>
Cc: kvmarm@lists.cs.columbia.edu
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
      a22fa321
  49. 19 4月, 2019 4 次提交
  51. 16 4月, 2019 1 次提交
  53. 29 3月, 2019 5 次提交
    • D
      KVM: arm64/sve: Document KVM API extensions for SVE · 50036ad0
      由 Dave Martin 提交于 
      This patch adds sections to the KVM API documentation describing
the extensions for supporting the Scalable Vector Extension (SVE)
in guests.
Signed-off-by: NDave Martin <Dave.Martin@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
      50036ad0
    • D
      KVM: Document errors for KVM_GET_ONE_REG and KVM_SET_ONE_REG · 395f562f
      由 Dave Martin 提交于 
      KVM_GET_ONE_REG and KVM_SET_ONE_REG return some error codes that
are not documented (but hopefully not surprising either).  To give
an indication of what these may mean, this patch adds brief
documentation.
Signed-off-by: NDave Martin <Dave.Martin@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
      395f562f
    • D
      KVM: Documentation: Document arm64 core registers in detail · fd3bc912
      由 Dave Martin 提交于 
      Since the the sizes of individual members of the core arm64
registers vary, the list of register encodings that make sense is
not a simple linear sequence.

To clarify which encodings to use, this patch adds a brief list
to the documentation.
Signed-off-by: NDave Martin <Dave.Martin@arm.com>
Reviewed-by: NJulien Grall <julien.grall@arm.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
      fd3bc912
    • P
      Documentation: kvm: clarify KVM_SET_USER_MEMORY_REGION · e2788c4a
      由 Paolo Bonzini 提交于 
      The documentation does not mention how to delete a slot, add the
information.
Reported-by: NNathaniel McCallum <npmccallum@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      e2788c4a
    • S
      KVM: doc: Document the life cycle of a VM and its resources · 919f6cd8
      由 Sean Christopherson 提交于 
      The series to add memcg accounting to KVM allocations[1] states:

  There are many KVM kernel memory allocations which are tied to the
  life of the VM process and should be charged to the VM process's
  cgroup.

While it is correct to account KVM kernel allocations to the cgroup of
the process that created the VM, it's technically incorrect to state
that the KVM kernel memory allocations are tied to the life of the VM
process.  This is because the VM itself, i.e. struct kvm, is not tied to
the life of the process which created it, rather it is tied to the life
of its associated file descriptor.  In other words, kvm_destroy_vm() is
not invoked until fput() decrements its associated file's refcount to
zero.  A simple example is to fork() in Qemu and have the child sleep
indefinitely; kvm_destroy_vm() isn't called until Qemu closes its file
descriptor *and* the rogue child is killed.

The allocations are guaranteed to be *accounted* to the process which
created the VM, but only because KVM's per-{VM,vCPU} ioctls reject the
ioctl() with -EIO if kvm->mm != current->mm.  I.e. the child can keep
the VM "alive" but can't do anything useful with its reference.

Note that because 'struct kvm' also holds a reference to the mm_struct
of its owner, the above behavior also applies to userspace allocations.

Given that mucking with a VM's file descriptor can lead to subtle and
undesirable behavior, e.g. memcg charges persisting after a VM is shut
down, explicitly document a VM's lifecycle and its impact on the VM's
resources.

Alternatively, KVM could aggressively free resources when the creating
process exits, e.g. via mmu_notifier->release().  However, mmu_notifier
isn't guaranteed to be available, and freeing resources when the creator
exits is likely to be error prone and fragile as KVM would need to
ensure that it only freed resources that are truly out of reach. In
practice, the existing behavior shouldn't be problematic as a properly
configured system will prevent a child process from being moved out of
the appropriate cgroup hierarchy, i.e. prevent hiding the process from
the OOM killer, and will prevent an unprivileged user from being able to
to hold a reference to struct kvm via another method, e.g. debugfs.

[1]https://patchwork.kernel.org/patch/10806707/Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      919f6cd8