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  1. 04 12月, 2020 5 次提交
  3. 31 10月, 2020 1 次提交
  5. 29 10月, 2020 1 次提交
  7. 30 9月, 2020 4 次提交
  9. 29 9月, 2020 4 次提交
  11. 16 9月, 2020 7 次提交
  13. 11 9月, 2020 1 次提交
  15. 21 8月, 2020 2 次提交
  17. 10 7月, 2020 2 次提交
  19. 07 7月, 2020 2 次提交
  21. 06 7月, 2020 4 次提交
  23. 09 6月, 2020 3 次提交
    • M
      KVM: arm64: Remove host_cpu_context member from vcpu structure · 07da1ffa
      由 Marc Zyngier 提交于 
      For very long, we have kept this pointer back to the per-cpu
host state, despite having working per-cpu accessors at EL2
for some time now.

Recent investigations have shown that this pointer is easy
to abuse in preemptible context, which is a sure sign that
it would better be gone. Not to mention that a per-cpu
pointer is faster to access at all times.
Reported-by: NAndrew Scull <ascull@google.com>
Acked-by: Mark Rutland <mark.rutland@arm.com
Reviewed-by: NAndrew Scull <ascull@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
      07da1ffa
    • M
      KVM: arm64: Handle PtrAuth traps early · 29eb5a3c
      由 Marc Zyngier 提交于 
      The current way we deal with PtrAuth is a bit heavy handed:

- We forcefully save the host's keys on each vcpu_load()
- Handling the PtrAuth trap forces us to go all the way back
  to the exit handling code to just set the HCR bits

Overall, this is pretty cumbersome. A better approach would be
to handle it the same way we deal with the FPSIMD registers:

- On vcpu_load() disable PtrAuth for the guest
- On first use, save the host's keys, enable PtrAuth in the
  guest

Crucially, this can happen as a fixup, which is done very early
on exit. We can then reenter the guest immediately without
leaving the hypervisor role.

Another thing is that it simplify the rest of the host handling:
exiting all the way to the host means that the only possible
outcome for this trap is to inject an UNDEF.
Reviewed-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
      29eb5a3c
    • M
      KVM: arm64: Save the host's PtrAuth keys in non-preemptible context · ef3e40a7
      由 Marc Zyngier 提交于 
      When using the PtrAuth feature in a guest, we need to save the host's
keys before allowing the guest to program them. For that, we dump
them in a per-CPU data structure (the so called host context).

But both call sites that do this are in preemptible context,
which may end up in disaster should the vcpu thread get preempted
before reentering the guest.

Instead, save the keys eagerly on each vcpu_load(). This has an
increased overhead, but is at least safe.

Cc: stable@vger.kernel.org
Reviewed-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
      ef3e40a7
  25. 04 6月, 2020 1 次提交
    • P
      KVM: let kvm_destroy_vm_debugfs clean up vCPU debugfs directories · d56f5136
      由 Paolo Bonzini 提交于 
      After commit 63d04348 ("KVM: x86: move kvm_create_vcpu_debugfs after
last failure point") we are creating the pre-vCPU debugfs files
after the creation of the vCPU file descriptor.  This makes it
possible for userspace to reach kvm_vcpu_release before
kvm_create_vcpu_debugfs has finished.  The vcpu->debugfs_dentry
then does not have any associated inode anymore, and this causes
a NULL-pointer dereference in debugfs_create_file.

The solution is simply to avoid removing the files; they are
cleaned up when the VM file descriptor is closed (and that must be
after KVM_CREATE_VCPU returns).  We can stop storing the dentry
in struct kvm_vcpu too, because it is not needed anywhere after
kvm_create_vcpu_debugfs returns.

Reported-by: syzbot+705f4401d5a93a59b87d@syzkaller.appspotmail.com
Fixes: 63d04348 ("KVM: x86: move kvm_create_vcpu_debugfs after last failure point")
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      d56f5136
  27. 31 5月, 2020 1 次提交
  29. 25 5月, 2020 1 次提交
  31. 16 5月, 2020 1 次提交