Windows Server 2016 with Hyper-V enabled fails to boot on OVMF with SMM
(OVMF_CODE-need-smm.fd). Turns out that the SMM emulation code in KVM
does not handle nested virtualization very well, leading to a whole bunch
of issues.
For example, Hyper-V uses descriptor table exiting (SECONDARY_EXEC_DESC)
so when the SMM handler tries to switch from real mode a VM exit occurs
and is forwarded to a clueless L1.
This series fixes it by switching the vcpu to !guest_mode, i.e. to the L1
state, before entering SMM and then switching back to L2 after the RSM
instruction is emulated.
Patches 1 and 2 are common for both Intel and AMD, patch 3 fixes Intel,
and patches 5-6 AMD. Patch 4 adds more state to the SMRAM save area as
prescribed by the Intel SDM. It is however not required to make Windows
work.
v1->v2:
* Moved left_smm detection to emulator_set_hflags (couldn't quite get rid
of the field despite my original claim) (Paolo)
* Moved the kvm_x86_ops->post_leave_smm() call a few statements down so
it really runs after all state has been synced.
* Added the smi_allowed callback (new patch 2) to avoid running into
WARN_ON_ONCE(vmx->nested.nested_run_pending) on Intel.
Ladi Prosek (6):
KVM: x86: introduce ISA specific SMM entry/exit callbacks
KVM: x86: introduce ISA specific smi_allowed callback
KVM: nVMX: fix SMI injection in guest mode
KVM: nVMX: save nested EPT information in SMRAM state save map
KVM: nSVM: refactor nested_svm_vmrun
KVM: nSVM: fix SMI injection in guest mode
arch/x86/include/asm/kvm_emulate.h | 1 +
arch/x86/include/asm/kvm_host.h | 9 ++
arch/x86/kvm/svm.c | 186 ++++++++++++++++++++++++-------------
arch/x86/kvm/vmx.c | 91 ++++++++++++++++--
arch/x86/kvm/x86.c | 17 +++-
5 files changed, 227 insertions(+), 77 deletions(-)
