Minor fixes related GUEST_MEMFD. I _just_ posted these, and they've only
been in -next for one night, but I am sending this now to ensure you see it
asap, as patch 1 in particular affects KVM's ABI, i.e. really should land
in 6.8 before GUEST_MEMFD support is officially released.
The following changes since commit c48617fbbe831d4c80fe84056033f17b70a31136:
Merge tag 'kvmarm-fixes-6.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD (2024-02-21 05:18:56 -0500)
are available in the Git repository at:
https://github.com/kvm-x86/linux.git tags/kvm-x86-guest_memfd_fixes-6.8
for you to fetch changes up to 2dfd2383034421101300a3b7325cf339a182d218:
KVM: selftests: Add a testcase to verify GUEST_MEMFD and READONLY are exclusive (2024-02-22 17:07:06 -0800)
----------------------------------------------------------------
KVM GUEST_MEMFD fixes for 6.8:
- Make KVM_MEM_GUEST_MEMFD mutually exclusive with KVM_MEM_READONLY to
avoid creating ABI that KVM can't sanely support.
- Update documentation for KVM_SW_PROTECTED_VM to make it abundantly
clear that such VMs are purely a development and testing vehicle, and
come with zero guarantees.
- Limit KVM_SW_PROTECTED_VM guests to the TDP MMU, as the long term plan
is to support confidential VMs with deterministic private memory (SNP
and TDX) only in the TDP MMU.
- Fix a bug in a GUEST_MEMFD negative test that resulted in false passes
when verifying that KVM_MEM_GUEST_MEMFD memslots can't be dirty logged.
----------------------------------------------------------------
Sean Christopherson (5):
KVM: Make KVM_MEM_GUEST_MEMFD mutually exclusive with KVM_MEM_READONLY
KVM: x86: Update KVM_SW_PROTECTED_VM docs to make it clear they're a WIP
KVM: x86/mmu: Restrict KVM_SW_PROTECTED_VM to the TDP MMU
KVM: selftests: Create GUEST_MEMFD for relevant invalid flags testcases
KVM: selftests: Add a testcase to verify GUEST_MEMFD and READONLY are exclusive
Documentation/virt/kvm/api.rst | 5 +++++
arch/x86/kvm/Kconfig | 7 ++++---
arch/x86/kvm/x86.c | 2 +-
tools/testing/selftests/kvm/set_memory_region_test.c | 12 +++++++++++-
virt/kvm/kvm_main.c | 8 +++++++-
5 files changed, 28 insertions(+), 6 deletions(-)
On Fri, Feb 23, 2024, Sean Christopherson wrote:
> Minor fixes related GUEST_MEMFD. I _just_ posted these, and they've only
> been in -next for one night, but I am sending this now to ensure you see it
> asap, as patch 1 in particular affects KVM's ABI, i.e. really should land
> in 6.8 before GUEST_MEMFD support is officially released.
>
> The following changes since commit c48617fbbe831d4c80fe84056033f17b70a31136:
>
> Merge tag 'kvmarm-fixes-6.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD (2024-02-21 05:18:56 -0500)
>
> are available in the Git repository at:
>
> https://github.com/kvm-x86/linux.git tags/kvm-x86-guest_memfd_fixes-6.8
>
> for you to fetch changes up to 2dfd2383034421101300a3b7325cf339a182d218:
>
> KVM: selftests: Add a testcase to verify GUEST_MEMFD and READONLY are exclusive (2024-02-22 17:07:06 -0800)
>
> ----------------------------------------------------------------
> KVM GUEST_MEMFD fixes for 6.8:
>
> - Make KVM_MEM_GUEST_MEMFD mutually exclusive with KVM_MEM_READONLY to
> avoid creating ABI that KVM can't sanely support.
>
> - Update documentation for KVM_SW_PROTECTED_VM to make it abundantly
> clear that such VMs are purely a development and testing vehicle, and
> come with zero guarantees.
>
> - Limit KVM_SW_PROTECTED_VM guests to the TDP MMU, as the long term plan
> is to support confidential VMs with deterministic private memory (SNP
> and TDX) only in the TDP MMU.
>
> - Fix a bug in a GUEST_MEMFD negative test that resulted in false passes
> when verifying that KVM_MEM_GUEST_MEMFD memslots can't be dirty logged.
>
> ----------------------------------------------------------------
> Sean Christopherson (5):
> KVM: Make KVM_MEM_GUEST_MEMFD mutually exclusive with KVM_MEM_READONLY
Almost forgot, just as an FYI, this has a minor conflict with your kvm/kvm-uapi
branch. I've been fixing it up in kvm-x86/next, and IIUC you don't feed kvm/master
into -next, so I don't think Stephen will see a conflict?
> KVM: x86: Update KVM_SW_PROTECTED_VM docs to make it clear they're a WIP
> KVM: x86/mmu: Restrict KVM_SW_PROTECTED_VM to the TDP MMU
> KVM: selftests: Create GUEST_MEMFD for relevant invalid flags testcases
> KVM: selftests: Add a testcase to verify GUEST_MEMFD and READONLY are exclusive
>
> Documentation/virt/kvm/api.rst | 5 +++++
> arch/x86/kvm/Kconfig | 7 ++++---
> arch/x86/kvm/x86.c | 2 +-
> tools/testing/selftests/kvm/set_memory_region_test.c | 12 +++++++++++-
> virt/kvm/kvm_main.c | 8 +++++++-
> 5 files changed, 28 insertions(+), 6 deletions(-)
On Fri, Feb 23, 2024 at 10:32 PM Sean Christopherson <seanjc@googlecom> wrote:
>
> On Fri, Feb 23, 2024, Sean Christopherson wrote:
> > Minor fixes related GUEST_MEMFD. I _just_ posted these, and they've only
> > been in -next for one night, but I am sending this now to ensure you see it
> > asap, as patch 1 in particular affects KVM's ABI, i.e. really should land
> > in 6.8 before GUEST_MEMFD support is officially released.
> >
> > The following changes since commit c48617fbbe831d4c80fe84056033f17b70a31136:
> >
> > Merge tag 'kvmarm-fixes-6.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD (2024-02-21 05:18:56 -0500)
> >
> > are available in the Git repository at:
> >
> > https://github.com/kvm-x86/linux.git tags/kvm-x86-guest_memfd_fixes-68
> >
> > for you to fetch changes up to 2dfd2383034421101300a3b7325cf339a182d218:
> >
> > KVM: selftests: Add a testcase to verify GUEST_MEMFD and READONLY are exclusive (2024-02-22 17:07:06 -0800)
> >
> > ----------------------------------------------------------------
> > KVM GUEST_MEMFD fixes for 6.8:
> >
> > - Make KVM_MEM_GUEST_MEMFD mutually exclusive with KVM_MEM_READONLY to
> > avoid creating ABI that KVM can't sanely support.
> >
> > - Update documentation for KVM_SW_PROTECTED_VM to make it abundantly
> > clear that such VMs are purely a development and testing vehicle, and
> > come with zero guarantees.
> >
> > - Limit KVM_SW_PROTECTED_VM guests to the TDP MMU, as the long term plan
> > is to support confidential VMs with deterministic private memory (SNP
> > and TDX) only in the TDP MMU.
> >
> > - Fix a bug in a GUEST_MEMFD negative test that resulted in false passes
> > when verifying that KVM_MEM_GUEST_MEMFD memslots can't be dirty logged.
> >
> > ----------------------------------------------------------------
> > Sean Christopherson (5):
> > KVM: Make KVM_MEM_GUEST_MEMFD mutually exclusive with KVM_MEM_READONLY
>
> Almost forgot, just as an FYI, this has a minor conflict with your kvm/kvm-uapi
> branch. I've been fixing it up in kvm-x86/next, and IIUC you don't feed kvm/master
> into -next, so I don't think Stephen will see a conflict?
I do feed it in linux-next, so he would, but it's not a big deal. I'll
pull it into kvm-next as well.
Paolo