diff options
Diffstat (limited to 'arch/x86/kvm')
| -rw-r--r-- | arch/x86/kvm/mmu.c | 40 |
1 files changed, 27 insertions, 13 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index cfef95969335..b8b5259c8ebb 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -528,27 +528,19 @@ static void mmu_spte_set(u64 *sptep, u64 new_spte) __set_spte(sptep, new_spte); } -/* Rules for using mmu_spte_update: - * Update the state bits, it means the mapped pfn is not changed. - * - * Whenever we overwrite a writable spte with a read-only one we - * should flush remote TLBs. Otherwise rmap_write_protect - * will find a read-only spte, even though the writable spte - * might be cached on a CPU's TLB, the return value indicates this - * case. - * - * Returns true if the TLB needs to be flushed +/* + * Update the SPTE (excluding the PFN), but do not track changes in its + * accessed/dirty status. */ -static bool mmu_spte_update(u64 *sptep, u64 new_spte) +static u64 mmu_spte_update_no_track(u64 *sptep, u64 new_spte) { u64 old_spte = *sptep; - bool flush = false; WARN_ON(!is_shadow_present_pte(new_spte)); if (!is_shadow_present_pte(old_spte)) { mmu_spte_set(sptep, new_spte); - return flush; + return old_spte; } if (!spte_has_volatile_bits(old_spte)) @@ -558,6 +550,28 @@ static bool mmu_spte_update(u64 *sptep, u64 new_spte) WARN_ON(spte_to_pfn(old_spte) != spte_to_pfn(new_spte)); + return old_spte; +} + +/* Rules for using mmu_spte_update: + * Update the state bits, it means the mapped pfn is not changed. + * + * Whenever we overwrite a writable spte with a read-only one we + * should flush remote TLBs. Otherwise rmap_write_protect + * will find a read-only spte, even though the writable spte + * might be cached on a CPU's TLB, the return value indicates this + * case. + * + * Returns true if the TLB needs to be flushed + */ +static bool mmu_spte_update(u64 *sptep, u64 new_spte) +{ + bool flush = false; + u64 old_spte = mmu_spte_update_no_track(sptep, new_spte); + + if (!is_shadow_present_pte(old_spte)) + return false; + /* * For the spte updated out of mmu-lock is safe, since * we always atomically update it, see the comments in |