| Message ID | 20200605213853.14959-8-sean.j.christopherson@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: Cleanup and unify kvm_mmu_memory_cache usage | expand |
On Fri, Jun 5, 2020 at 2:39 PM Sean Christopherson <sean.j.christopherson@intel.com> wrote: > > Topup memory caches after walking the GVA->GPA translation during a > shadow page fault, there is no need to ensure the caches are full when > walking the GVA. As of commit f5a1e9f89504f ("KVM: MMU: remove call > to kvm_mmu_pte_write from walk_addr"), the FNAME(walk_addr) flow no > longer add rmaps via kvm_mmu_pte_write(). > > This avoids allocating memory in the case that the GVA is unmapped in > the guest, and also provides a paper trail of why/when the memory caches > need to be filled. > > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Ben Gardon <bgardon@google.com> > --- > arch/x86/kvm/mmu/paging_tmpl.h | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h > index 38c576495048..3de32122f601 100644 > --- a/arch/x86/kvm/mmu/paging_tmpl.h > +++ b/arch/x86/kvm/mmu/paging_tmpl.h > @@ -791,10 +791,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code, > > pgprintk("%s: addr %lx err %x\n", __func__, addr, error_code); > > - r = mmu_topup_memory_caches(vcpu); > - if (r) > - return r; > - > /* > * If PFEC.RSVD is set, this is a shadow page fault. > * The bit needs to be cleared before walking guest page tables. > @@ -822,6 +818,10 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code, > return RET_PF_EMULATE; > } > > + r = mmu_topup_memory_caches(vcpu); > + if (r) > + return r; > + > vcpu->arch.write_fault_to_shadow_pgtable = false; > > is_self_change_mapping = FNAME(is_self_change_mapping)(vcpu, > -- > 2.26.0 >
diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h index 38c576495048..3de32122f601 100644 --- a/arch/x86/kvm/mmu/paging_tmpl.h +++ b/arch/x86/kvm/mmu/paging_tmpl.h @@ -791,10 +791,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code, pgprintk("%s: addr %lx err %x\n", __func__, addr, error_code); - r = mmu_topup_memory_caches(vcpu); - if (r) - return r; - /* * If PFEC.RSVD is set, this is a shadow page fault. * The bit needs to be cleared before walking guest page tables. @@ -822,6 +818,10 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code, return RET_PF_EMULATE; } + r = mmu_topup_memory_caches(vcpu); + if (r) + return r; + vcpu->arch.write_fault_to_shadow_pgtable = false; is_self_change_mapping = FNAME(is_self_change_mapping)(vcpu,
Topup memory caches after walking the GVA->GPA translation during a shadow page fault, there is no need to ensure the caches are full when walking the GVA. As of commit f5a1e9f89504f ("KVM: MMU: remove call to kvm_mmu_pte_write from walk_addr"), the FNAME(walk_addr) flow no longer add rmaps via kvm_mmu_pte_write(). This avoids allocating memory in the case that the GVA is unmapped in the guest, and also provides a paper trail of why/when the memory caches need to be filled. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> --- arch/x86/kvm/mmu/paging_tmpl.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)