KVM: nVMX: Synthesize nested VM-Exit for supported emulation intercepts

Browse source

When emulating an instruction on behalf of L2 that L1 wants to intercept,
generate a nested VM-Exit instead of injecting a #UD into L2.  Now that
(most of) the necessary information is available, synthesizing a VM-Exit
isn't terribly difficult.

Punt on decoding the ModR/M for descriptor table exits for now.  There is
no evidence that any hypervisor intercepts descriptor table accesses *and*
uses the EXIT_QUALIFICATION to expedite emulation, i.e. it's not worth
delaying basic support for.

To avoid doing more harm than good, e.g. by putting L2 into an infinite
or effectively corrupting its code stream, inject #UD if the instruction
length is nonsensical.

Link: https://lore.kernel.org/r/20250201015518.689704-11-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

...

This commit is contained in:

Sean Christopherson 2025-01-31 17:55:17 -08:00

parent fbd1e0f195

commit 79a14afc60

1 changed files with 56 additions and 14 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

70

arch/x86/kvm/vmx/vmx.c

View file