Re: [GIT PULL] KVM: x86: Misc changes for 6.9

[Paolo Bonzini]

On 3/8/24 23:36, Sean Christopherson wrote:
> A variety of one-off cleanups and fixes, along with two medium sized series to
> (1) improve the "force immediate exit" code and (2) clean up the "vCPU preempted
> in-kernel" checks used for directed yield.
>
> The following changes since commit 41bccc98fb7931d63d03f326a746ac4d429c1dd3:
>
>    Linux 6.8-rc2 (2024-01-28 17:01:12 -0800)
>
> are available in the Git repository at:
>
>    https://github.com/kvm-x86/linux.git tags/kvm-x86-misc-6.9
>
> for you to fetch changes up to 78ccfce774435a08d9c69ce434099166cc7952c8:
>
>    KVM: SVM: Rename vmplX_ssp -> plX_ssp (2024-02-27 12:22:43 -0800)

Queued, thanks.

Paolo

> ----------------------------------------------------------------
> KVM x86 misc changes for 6.9:
>
>   - Explicitly initialize a variety of on-stack variables in the emulator that
>     triggered KMSAN false positives (though in fairness in KMSAN, it's comically
>     difficult to see that the uninitialized memory is never truly consumed).
>
>   - Fix the deubgregs ABI for 32-bit KVM, and clean up code related to reading
>     DR6 and DR7.
>
>   - Rework the "force immediate exit" code so that vendor code ultimately
>     decides how and when to force the exit.  This allows VMX to further optimize
>     handling preemption timer exits, and allows SVM to avoid sending a duplicate
>     IPI (SVM also has a need to force an exit).
>
>   - Fix a long-standing bug where kvm_has_noapic_vcpu could be left elevated if
>     vCPU creation ultimately failed, and add WARN to guard against similar bugs.
>
>   - Provide a dedicated arch hook for checking if a different vCPU was in-kernel
>     (for directed yield), and simplify the logic for checking if the currently
>     loaded vCPU is in-kernel.
>
>   - Misc cleanups and fixes.
>
> ----------------------------------------------------------------
> John Allen (1):
>        KVM: SVM: Rename vmplX_ssp -> plX_ssp
>
> Julian Stecklina (2):
>        KVM: x86: Clean up partially uninitialized integer in emulate_pop()
>        KVM: x86: rename push to emulate_push for consistency
>
> Mathias Krause (1):
>        KVM: x86: Fix broken debugregs ABI for 32 bit kernels
>
> Nikolay Borisov (1):
>        KVM: x86: Use mutex guards to eliminate __kvm_x86_vendor_init()
>
> Sean Christopherson (14):
>        KVM: x86: Make kvm_get_dr() return a value, not use an out parameter
>        KVM: x86: Open code all direct reads to guest DR6 and DR7
>        KVM: x86: Plumb "force_immediate_exit" into kvm_entry() tracepoint
>        KVM: VMX: Re-enter guest in fastpath for "spurious" preemption timer exits
>        KVM: VMX: Handle forced exit due to preemption timer in fastpath
>        KVM: x86: Move handling of is_guest_mode() into fastpath exit handlers
>        KVM: VMX: Handle KVM-induced preemption timer exits in fastpath for L2
>        KVM: x86: Fully defer to vendor code to decide how to force immediate exit
>        KVM: x86: Move "KVM no-APIC vCPU" key management into local APIC code
>        KVM: x86: Sanity check that kvm_has_noapic_vcpu is zero at module_exit()
>        KVM: Add dedicated arch hook for querying if vCPU was preempted in-kernel
>        KVM: x86: Rely solely on preempted_in_kernel flag for directed yield
>        KVM: x86: Clean up directed yield API for "has pending interrupt"
>        KVM: Add a comment explaining the directed yield pending interrupt logic
>
> Thomas Prescher (1):
>        KVM: x86/emulator: emulate movbe with operand-size prefix
>
>   arch/x86/include/asm/kvm-x86-ops.h |   1 -
>   arch/x86/include/asm/kvm_host.h    |   8 +--
>   arch/x86/include/asm/svm.h         |   8 +--
>   arch/x86/kvm/emulate.c             |  45 +++++++--------
>   arch/x86/kvm/kvm_emulate.h         |   2 +-
>   arch/x86/kvm/lapic.c               |  27 ++++++++-
>   arch/x86/kvm/smm.c                 |  15 ++---
>   arch/x86/kvm/svm/svm.c             |  25 ++++-----
>   arch/x86/kvm/trace.h               |   9 ++-
>   arch/x86/kvm/vmx/nested.c          |   2 +-
>   arch/x86/kvm/vmx/vmx.c             |  85 +++++++++++++++++-----------
>   arch/x86/kvm/vmx/vmx.h             |   2 -
>   arch/x86/kvm/x86.c                 | 110 ++++++++++++-------------------------
>   include/linux/kvm_host.h           |   1 +
>   virt/kvm/kvm_main.c                |  21 ++++++-
>   15 files changed, 184 insertions(+), 177 deletions(-)