KVM: x86/mmu: add support for MBEC to EPT page table walks

Browse source

Extend the page walker to support moving bit 10 of the PTEs
into ACC_USER_EXEC_MASK and bit 6 of the exit qualification of
EPT violation VM exits.

Note that while mmu_has_mbec()/cr4_smep affect the interpretation of
ACC_USER_EXEC_MASK and add bit 10 as a "present bit" in guest EPT page
table entries, they do not affect how KVM operates on SPTEs.  That's
because the MMU uses explicit ACC_USER_EXEC_MASK/shadow_xu_mask even for
the non-nested EPT; the only difference is that ACC_USER_EXEC_MASK and
ACC_EXEC_MASK will always be set in tandem outside the nested scenario.

Tested-by: David Riley <d.riley@proxmox.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

...

This commit is contained in:

Paolo Bonzini 2026-04-08 11:42:08 -04:00

parent 9c167cb3c1

commit d220bcf026

4 changed files with 43 additions and 8 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

13

arch/x86/kvm/mmu/mmu.c

View file

27

arch/x86/kvm/mmu/paging_tmpl.h

View file

2

arch/x86/kvm/mmu/spte.h

View file

9

arch/x86/kvm/vmx/nested.c

View file