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| author | Sean Christopherson <seanjc@google.com> | 2022-05-13 19:50:00 +0000 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-06-08 04:47:10 -0400 |
| commit | b8b9156ec6ef69baa487185205f2be833267776b (patch) | |
| tree | deeda5b7f1d98faa0dbce6c2203335077d908c46 /arch/x86/kernel/cpu/feat_ctl.c | |
| parent | 9fb3565743d58352f00964bf47213b88aff4bb82 (diff) | |
| download | linux-b8b9156ec6ef69baa487185205f2be833267776b.tar.gz linux-b8b9156ec6ef69baa487185205f2be833267776b.tar.bz2 linux-b8b9156ec6ef69baa487185205f2be833267776b.zip | |
KVM: x86/mmu: Comment FNAME(sync_page) to document TLB flushing logic
Add a comment to FNAME(sync_page) to explain why the TLB flushing logic
conspiculously doesn't handle the scenario of guest protections being
reduced. Specifically, if synchronizing a SPTE drops execute protections,
KVM will not emit a TLB flush, whereas dropping writable or clearing A/D
bits does trigger a flush via mmu_spte_update(). Architecturally, until
the GPTE is implicitly or explicitly flushed from the guest's perspective,
KVM is not required to flush any old, stale translations.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Message-Id: <20220513195000.99371-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kernel/cpu/feat_ctl.c')
0 files changed, 0 insertions, 0 deletions