On 07/24/2018 07:35 AM, Paolo Bonzini wrote: > On 24/07/2018 10:17, Tianyu Lan wrote: >> mmu_set_spte() flushes remote tlbs for drop_parent_pte/drop_spte() >> and set_spte() separately. This may introduce redundant flush. This >> patch is to combine these flushes and check flush request after >> calling set_spte(). >> >> Signed-off-by: Lan Tianyu <[email protected]> > > Looks good, but I'd like a second opinion. Guangrong, Junaid, can you > review this? > > Thanks, > > Paolo > >> --- >> arch/x86/kvm/mmu.c | 7 ++++--- >> 1 file changed, 4 insertions(+), 3 deletions(-) >> >> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c >> index 22a7984..8f21632 100644 >> --- a/arch/x86/kvm/mmu.c >> +++ b/arch/x86/kvm/mmu.c >> @@ -2901,6 +2901,7 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, u64 >> *sptep, unsigned pte_access, >> int rmap_count; >> int set_spte_ret; >> int ret = RET_PF_RETRY; >> + bool flush = false; >> >> pgprintk("%s: spte %llx write_fault %d gfn %llx\n", __func__, >> *sptep, write_fault, gfn); >> @@ -2917,12 +2918,12 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, u64 >> *sptep, unsigned pte_access, >> >> child = page_header(pte & PT64_BASE_ADDR_MASK); >> drop_parent_pte(child, sptep); >> - kvm_flush_remote_tlbs(vcpu->kvm); >> + flush = true; >> } else if (pfn != spte_to_pfn(*sptep)) { >> pgprintk("hfn old %llx new %llx\n", >> spte_to_pfn(*sptep), pfn); >> drop_spte(vcpu->kvm, sptep); >> - kvm_flush_remote_tlbs(vcpu->kvm); >> + flush = true; >> } else >> was_rmapped = 1; >> } >> @@ -2934,7 +2935,7 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, u64 >> *sptep, unsigned pte_access, >> ret = RET_PF_EMULATE; >> kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu); >> } >> - if (set_spte_ret & SET_SPTE_NEED_REMOTE_TLB_FLUSH) >> + if (set_spte_ret & SET_SPTE_NEED_REMOTE_TLB_FLUSH || flush) >> kvm_flush_remote_tlbs(vcpu->kvm); >> >> if (unlikely(is_mmio_spte(*sptep))) >> >
Reviewed-by: Junaid Shahid <[email protected]>
