Most of the time, calls to get_guest_pgd result in calling kvm_read_cr3 (the exception is only nested TDP). Check if that is the case if retpolines are enabled, thus avoiding an expensive indirect call. Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> --- arch/x86/kvm/mmu.h | 10 ++++++++++ arch/x86/kvm/mmu/mmu.c | 15 ++++++++------- arch/x86/kvm/mmu/paging_tmpl.h | 2 +- arch/x86/kvm/x86.c | 2 +- 4 files changed, 20 insertions(+), 9 deletions(-) diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h index 1d0c1904d69a..6ee4436e46f1 100644 --- a/arch/x86/kvm/mmu.h +++ b/arch/x86/kvm/mmu.h @@ -116,6 +116,16 @@ static inline void kvm_mmu_load_pgd(struct kvm_vcpu *vcpu) vcpu->arch.mmu->shadow_root_level); } +extern unsigned long kvm_get_guest_cr3(struct kvm_vcpu *vcpu); +static inline unsigned long kvm_mmu_get_guest_pgd(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) +{ +#ifdef CONFIG_RETPOLINE + if (mmu->get_guest_pgd == kvm_get_guest_cr3) + return kvm_read_cr3(vcpu); +#endif + return mmu->get_guest_pgd(vcpu); +} + struct kvm_page_fault { /* arguments to kvm_mmu_do_page_fault. */ const gpa_t addr; diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index b2c1c4eb6007..7051040e15b3 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3435,7 +3435,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) unsigned i; int r; - root_pgd = mmu->get_guest_pgd(vcpu); + root_pgd = kvm_mmu_get_guest_pgd(vcpu, mmu); root_gfn = root_pgd >> PAGE_SHIFT; if (mmu_check_root(vcpu, root_gfn)) @@ -3854,12 +3854,13 @@ static void shadow_page_table_clear_flood(struct kvm_vcpu *vcpu, gva_t addr) static bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, gfn_t gfn) { + struct kvm_mmu *mmu = vcpu->arch.mmu; struct kvm_arch_async_pf arch; arch.token = (vcpu->arch.apf.id++ << 12) | vcpu->vcpu_id; arch.gfn = gfn; - arch.direct_map = vcpu->arch.mmu->direct_map; - arch.cr3 = vcpu->arch.mmu->get_guest_pgd(vcpu); + arch.direct_map = mmu->direct_map; + arch.cr3 = kvm_mmu_get_guest_pgd(vcpu, mmu); return kvm_setup_async_pf(vcpu, cr2_or_gpa, kvm_vcpu_gfn_to_hva(vcpu, gfn), &arch); @@ -4208,7 +4209,7 @@ void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd) } EXPORT_SYMBOL_GPL(kvm_mmu_new_pgd); -static unsigned long get_cr3(struct kvm_vcpu *vcpu) +unsigned long kvm_get_guest_cr3(struct kvm_vcpu *vcpu) { return kvm_read_cr3(vcpu); } @@ -4767,7 +4768,7 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu) context->invlpg = NULL; context->shadow_root_level = kvm_mmu_get_tdp_level(vcpu); context->direct_map = true; - context->get_guest_pgd = get_cr3; + context->get_guest_pgd = kvm_get_guest_cr3; context->get_pdptr = kvm_pdptr_read; context->inject_page_fault = kvm_inject_page_fault; context->root_level = role_regs_to_root_level(®s); @@ -4942,7 +4943,7 @@ static void init_kvm_softmmu(struct kvm_vcpu *vcpu) kvm_init_shadow_mmu(vcpu, ®s); - context->get_guest_pgd = get_cr3; + context->get_guest_pgd = kvm_get_guest_cr3; context->get_pdptr = kvm_pdptr_read; context->inject_page_fault = kvm_inject_page_fault; } @@ -4974,7 +4975,7 @@ static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu) return; g_context->mmu_role.as_u64 = new_role.as_u64; - g_context->get_guest_pgd = get_cr3; + g_context->get_guest_pgd = kvm_get_guest_cr3; g_context->get_pdptr = kvm_pdptr_read; g_context->inject_page_fault = kvm_inject_page_fault; g_context->root_level = new_role.base.level; diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h index 252c77805eb9..80b4b291002a 100644 --- a/arch/x86/kvm/mmu/paging_tmpl.h +++ b/arch/x86/kvm/mmu/paging_tmpl.h @@ -362,7 +362,7 @@ static int FNAME(walk_addr_generic)(struct guest_walker *walker, trace_kvm_mmu_pagetable_walk(addr, access); retry_walk: walker->level = mmu->root_level; - pte = mmu->get_guest_pgd(vcpu); + pte = kvm_mmu_get_guest_pgd(vcpu, mmu); have_ad = PT_HAVE_ACCESSED_DIRTY(mmu); #if PTTYPE == 64 diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 6552360d8888..da33d3a88a8d 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -12190,7 +12190,7 @@ void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work) return; if (!vcpu->arch.mmu->direct_map && - work->arch.cr3 != vcpu->arch.mmu->get_guest_pgd(vcpu)) + work->arch.cr3 != kvm_mmu_get_guest_pgd(vcpu, vcpu->arch.mmu)) return; kvm_mmu_do_page_fault(vcpu, work->cr2_or_gpa, 0, true); -- 2.31.1