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| author | Sean Christopherson <seanjc@google.com> | 2021-06-22 20:56:58 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-06-25 01:00:38 +0300 |
| commit | 0337f585f57fc80a50e0645ca709512687185c72 (patch) | |
| tree | 03be858743652d364f1376ede740c753512eeea5 /arch/x86/kvm/mmu/spte.c | |
| parent | 479a1efc8119d8699cca73d00625b28003d0a1f8 (diff) | |
| download | linux-0337f585f57fc80a50e0645ca709512687185c72.tar.xz | |
KVM: x86/mmu: Rename unsync helper and update related comments
Rename mmu_need_write_protect() to mmu_try_to_unsync_pages() and update
a variety of related, stale comments. Add several new comments to call
out subtle details, e.g. that upper-level shadow pages are write-tracked,
and that can_unsync is false iff KVM is in the process of synchronizing
pages.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622175739.3610207-14-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/mmu/spte.c')
| -rw-r--r-- | arch/x86/kvm/mmu/spte.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c index 8e8e8da740a0..246e61e0771e 100644 --- a/arch/x86/kvm/mmu/spte.c +++ b/arch/x86/kvm/mmu/spte.c @@ -147,13 +147,19 @@ int make_spte(struct kvm_vcpu *vcpu, unsigned int pte_access, int level, /* * Optimization: for pte sync, if spte was writable the hash * lookup is unnecessary (and expensive). Write protection - * is responsibility of mmu_get_page / kvm_sync_page. + * is responsibility of kvm_mmu_get_page / kvm_mmu_sync_roots. * Same reasoning can be applied to dirty page accounting. */ if (!can_unsync && is_writable_pte(old_spte)) goto out; - if (mmu_need_write_protect(vcpu, gfn, can_unsync)) { + /* + * Unsync shadow pages that are reachable by the new, writable + * SPTE. Write-protect the SPTE if the page can't be unsync'd, + * e.g. it's write-tracked (upper-level SPs) or has one or more + * shadow pages and unsync'ing pages is not allowed. + */ + if (mmu_try_to_unsync_pages(vcpu, gfn, can_unsync)) { pgprintk("%s: found shadow page for %llx, marking ro\n", __func__, gfn); ret |= SET_SPTE_WRITE_PROTECTED_PT; |