On Mon, Oct 04, 2010 at 05:56:25PM +0200, Gleb Natapov wrote: > When page is swapped in it is mapped into guest memory only after guest > tries to access it again and generate another fault. To save this fault > we can map it immediately since we know that guest is going to access > the page. Do it only when tdp is enabled for now. Shadow paging case is > more complicated. CR[034] and EFER registers should be switched before > doing mapping and then switched back. > > Acked-by: Rik van Riel <[email protected]> > Signed-off-by: Gleb Natapov <[email protected]> > --- > arch/x86/include/asm/kvm_host.h | 4 +++- > arch/x86/kvm/mmu.c | 16 ++++++++-------- > arch/x86/kvm/paging_tmpl.h | 6 +++--- > arch/x86/kvm/x86.c | 7 +++++++ > virt/kvm/async_pf.c | 2 ++ > 5 files changed, 23 insertions(+), 12 deletions(-) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index 5f154d3..b9f263e 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -240,7 +240,7 @@ struct kvm_mmu { > void (*new_cr3)(struct kvm_vcpu *vcpu); > void (*set_cr3)(struct kvm_vcpu *vcpu, unsigned long root); > unsigned long (*get_cr3)(struct kvm_vcpu *vcpu); > - int (*page_fault)(struct kvm_vcpu *vcpu, gva_t gva, u32 err); > + int (*page_fault)(struct kvm_vcpu *vcpu, gva_t gva, u32 err, bool > no_apf); > void (*inject_page_fault)(struct kvm_vcpu *vcpu); > void (*free)(struct kvm_vcpu *vcpu); > gpa_t (*gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t gva, u32 access, > @@ -838,6 +838,8 @@ void kvm_arch_async_page_not_present(struct kvm_vcpu > *vcpu, > struct kvm_async_pf *work); > void kvm_arch_async_page_present(struct kvm_vcpu *vcpu, > struct kvm_async_pf *work); > +void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, > + struct kvm_async_pf *work); > extern bool kvm_find_async_pf_gfn(struct kvm_vcpu *vcpu, gfn_t gfn); > > #endif /* _ASM_X86_KVM_HOST_H */ > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index 4d49b5e..d85fda8 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -2558,7 +2558,7 @@ static gpa_t nonpaging_gva_to_gpa_nested(struct > kvm_vcpu *vcpu, gva_t vaddr, > } > > static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva, > - u32 error_code) > + u32 error_code, bool no_apf) > { > gfn_t gfn; > int r; > @@ -2594,8 +2594,8 @@ static bool can_do_async_pf(struct kvm_vcpu *vcpu) > return kvm_x86_ops->interrupt_allowed(vcpu); > } > > -static bool try_async_pf(struct kvm_vcpu *vcpu, gfn_t gfn, gva_t gva, > - pfn_t *pfn) > +static bool try_async_pf(struct kvm_vcpu *vcpu, bool no_apf, gfn_t gfn, > + gva_t gva, pfn_t *pfn) > { > bool async; > > @@ -2606,7 +2606,7 @@ static bool try_async_pf(struct kvm_vcpu *vcpu, gfn_t > gfn, gva_t gva, > > put_page(pfn_to_page(*pfn)); > > - if (can_do_async_pf(vcpu)) { > + if (!no_apf && can_do_async_pf(vcpu)) { > trace_kvm_try_async_get_page(async, *pfn); > if (kvm_find_async_pf_gfn(vcpu, gfn)) { > vcpu->async_pf.work = kvm_double_apf; > @@ -2620,8 +2620,8 @@ static bool try_async_pf(struct kvm_vcpu *vcpu, gfn_t > gfn, gva_t gva, > return false; > } > > -static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, > - u32 error_code) > +static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, u32 error_code, > + bool no_apf) > { > pfn_t pfn; > int r; > @@ -2643,7 +2643,7 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t > gpa, > mmu_seq = vcpu->kvm->mmu_notifier_seq; > smp_rmb(); > > - if (try_async_pf(vcpu, gfn, gpa, &pfn)) > + if (try_async_pf(vcpu, no_apf, gfn, gpa, &pfn)) > return 0; > > /* mmio */ > @@ -3306,7 +3306,7 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t > cr2, u32 error_code) > int r; > enum emulation_result er; > > - r = vcpu->arch.mmu.page_fault(vcpu, cr2, error_code); > + r = vcpu->arch.mmu.page_fault(vcpu, cr2, error_code, false); > if (r < 0) > goto out; > > diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h > index 8154353..9ad90f8 100644 > --- a/arch/x86/kvm/paging_tmpl.h > +++ b/arch/x86/kvm/paging_tmpl.h > @@ -530,8 +530,8 @@ out_gpte_changed: > * Returns: 1 if we need to emulate the instruction, 0 otherwise, or > * a negative value on error. > */ > -static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, > - u32 error_code) > +static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 > error_code, > + bool no_apf) > { > int write_fault = error_code & PFERR_WRITE_MASK; > int user_fault = error_code & PFERR_USER_MASK; > @@ -574,7 +574,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t > addr, > mmu_seq = vcpu->kvm->mmu_notifier_seq; > smp_rmb(); > > - if (try_async_pf(vcpu, walker.gfn, addr, &pfn)) > + if (try_async_pf(vcpu, no_apf, walker.gfn, addr, &pfn)) > return 0; > > /* mmio */ > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 8dd9ac2..48fd59d 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -6123,6 +6123,13 @@ void kvm_set_rflags(struct kvm_vcpu *vcpu, unsigned > long rflags) > } > EXPORT_SYMBOL_GPL(kvm_set_rflags); > > +void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf > *work) > +{ > + if (!tdp_enabled || is_error_page(work->page)) > + return; > + vcpu->arch.mmu.page_fault(vcpu, work->gva, 0, true); > +} > +
Can't you set a bit in vcpu->requests instead, and handle it in "out:" at the end of vcpu_enter_guest? To have a single entry point for pagefaults, after vmexit handling. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
