| Message ID | b16bac1fd1357aaf39e425aab2177d3f89ee8318.1625186503.git.isaku.yamahata@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: X86: TDX support | expand |
On 03/07/21 00:04, isaku.yamahata@intel.com wrote: > From: Sean Christopherson <sean.j.christopherson@intel.com> > > Return the old SPTE when clearing a SPTE and push the "old SPTE present" > check to the caller. Private shadow page support will use the old SPTE > in rmap_remove() to determine whether or not there is a linked private > shadow page. > > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> > --- > arch/x86/kvm/mmu/mmu.c | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > index 0259781cee6a..6b0c8c84aabe 100644 > --- a/arch/x86/kvm/mmu/mmu.c > +++ b/arch/x86/kvm/mmu/mmu.c > @@ -542,9 +542,9 @@ static bool mmu_spte_update(u64 *sptep, u64 new_spte) > * Rules for using mmu_spte_clear_track_bits: > * It sets the sptep from present to nonpresent, and track the > * state bits, it is used to clear the last level sptep. > - * Returns non-zero if the PTE was previously valid. > + * Returns the old PTE. > */ > -static int mmu_spte_clear_track_bits(u64 *sptep) > +static u64 mmu_spte_clear_track_bits(u64 *sptep) > { > kvm_pfn_t pfn; > u64 old_spte = *sptep; > @@ -555,7 +555,7 @@ static int mmu_spte_clear_track_bits(u64 *sptep) > old_spte = __update_clear_spte_slow(sptep, shadow_init_value); > > if (!is_shadow_present_pte(old_spte)) > - return 0; > + return old_spte; > > pfn = spte_to_pfn(old_spte); > > @@ -572,7 +572,7 @@ static int mmu_spte_clear_track_bits(u64 *sptep) > if (is_dirty_spte(old_spte)) > kvm_set_pfn_dirty(pfn); > > - return 1; > + return old_spte; > } > > /* > @@ -1104,7 +1104,9 @@ static u64 *rmap_get_next(struct rmap_iterator *iter) > > static void drop_spte(struct kvm *kvm, u64 *sptep) > { > - if (mmu_spte_clear_track_bits(sptep)) > + u64 old_spte = mmu_spte_clear_track_bits(sptep); > + > + if (is_shadow_present_pte(old_spte)) > rmap_remove(kvm, sptep); > } > > Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 0259781cee6a..6b0c8c84aabe 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -542,9 +542,9 @@ static bool mmu_spte_update(u64 *sptep, u64 new_spte) * Rules for using mmu_spte_clear_track_bits: * It sets the sptep from present to nonpresent, and track the * state bits, it is used to clear the last level sptep. - * Returns non-zero if the PTE was previously valid. + * Returns the old PTE. */ -static int mmu_spte_clear_track_bits(u64 *sptep) +static u64 mmu_spte_clear_track_bits(u64 *sptep) { kvm_pfn_t pfn; u64 old_spte = *sptep; @@ -555,7 +555,7 @@ static int mmu_spte_clear_track_bits(u64 *sptep) old_spte = __update_clear_spte_slow(sptep, shadow_init_value); if (!is_shadow_present_pte(old_spte)) - return 0; + return old_spte; pfn = spte_to_pfn(old_spte); @@ -572,7 +572,7 @@ static int mmu_spte_clear_track_bits(u64 *sptep) if (is_dirty_spte(old_spte)) kvm_set_pfn_dirty(pfn); - return 1; + return old_spte; } /* @@ -1104,7 +1104,9 @@ static u64 *rmap_get_next(struct rmap_iterator *iter) static void drop_spte(struct kvm *kvm, u64 *sptep) { - if (mmu_spte_clear_track_bits(sptep)) + u64 old_spte = mmu_spte_clear_track_bits(sptep); + + if (is_shadow_present_pte(old_spte)) rmap_remove(kvm, sptep); }