Re: [GIT PULL] KVM: Common changes for 6.12

[Paolo Bonzini]

On Sat, Sep 14, 2024 at 3:14 AM Sean Christopherson <seanjc@xxxxxxxxxx> wrote:
>
> Fix a long-standing goof in the coalesced IO code, and a lurking bug in
> kvm_clear_guest().
>
> The following changes since commit 47ac09b91befbb6a235ab620c32af719f8208399:
>
>   Linux 6.11-rc4 (2024-08-18 13:17:27 -0700)
>
> are available in the Git repository at:
>
>   https://github.com/kvm-x86/linux.git tags/kvm-x86-generic-6.12
>
> for you to fetch changes up to 025dde582bbf31e7618f9283594ef5e2408e384b:
>
>   KVM: Harden guest memory APIs against out-of-bounds accesses (2024-09-09 20:15:34 -0700)

Pulled, thanks.

Paolo

> ----------------------------------------------------------------
> KVK generic changes for 6.12:
>
>  - Fix a bug that results in KVM prematurely exiting to userspace for coalesced
>    MMIO/PIO in many cases, clean up the related code, and add a testcase.
>
>  - Fix a bug in kvm_clear_guest() where it would trigger a buffer overflow _if_
>    the gpa+len crosses a page boundary, which thankfully is guaranteed to not
>    happen in the current code base.  Add WARNs in more helpers that read/write
>    guest memory to detect similar bugs.
>
> ----------------------------------------------------------------
> Ilias Stamatis (1):
>       KVM: Fix coalesced_mmio_has_room() to avoid premature userspace exit
>
> Sean Christopherson (4):
>       KVM: selftests: Add a test for coalesced MMIO (and PIO on x86)
>       KVM: Clean up coalesced MMIO ring full check
>       KVM: Write the per-page "segment" when clearing (part of) a guest page
>       KVM: Harden guest memory APIs against out-of-bounds accesses
>
>  tools/testing/selftests/kvm/Makefile            |   3 +
>  tools/testing/selftests/kvm/coalesced_io_test.c | 236 ++++++++++++++++++++++++
>  tools/testing/selftests/kvm/include/kvm_util.h  |  26 +++
>  virt/kvm/coalesced_mmio.c                       |  31 +---
>  virt/kvm/kvm_main.c                             |  11 +-
>  5 files changed, 283 insertions(+), 24 deletions(-)
>  create mode 100644 tools/testing/selftests/kvm/coalesced_io_test.c
>