| Message ID | 1547026933-31226-8-git-send-email-karahmed@amazon.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM/X86: Introduce a new guest mapping interface | expand |
On Wed, Jan 09, 2019 at 10:42:07AM +0100, KarimAllah Ahmed wrote: > Use kvm_vcpu_map when mapping the virtual APIC page since using > kvm_vcpu_gpa_to_page() and kmap() will only work for guest memory that has > a "struct page". > > One additional semantic change is that the virtual host mapping lifecycle > has changed a bit. It now has the same lifetime of the pinning of the > virtual APIC page on the host side. Could you expand a bit on the 'same lifetime .. on the host side' to be obvious for folks what exactly the semantic is? And how does this ring with this comment: > > Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> > --- > v4 -> v5: > - unmap with dirty flag > > v1 -> v2: > - Do not change the lifecycle of the mapping (pbonzini) .. Where Paolo does not want the semantics of the mapping to be changed? Code wise feel free to smack my Reviewed-by on it, but obviously the question on the above comment needs to be resolved. Thank you. > - Use pfn_to_hpa instead of gfn_to_gpa > --- > arch/x86/kvm/vmx/nested.c | 32 +++++++++++--------------------- > arch/x86/kvm/vmx/vmx.c | 5 ++--- > arch/x86/kvm/vmx/vmx.h | 2 +- > 3 files changed, 14 insertions(+), 25 deletions(-) > > diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c > index 4127ad9..dcff99d 100644 > --- a/arch/x86/kvm/vmx/nested.c > +++ b/arch/x86/kvm/vmx/nested.c > @@ -229,10 +229,7 @@ static void free_nested(struct kvm_vcpu *vcpu) > kvm_release_page_dirty(vmx->nested.apic_access_page); > vmx->nested.apic_access_page = NULL; > } > - if (vmx->nested.virtual_apic_page) { > - kvm_release_page_dirty(vmx->nested.virtual_apic_page); > - vmx->nested.virtual_apic_page = NULL; > - } > + kvm_vcpu_unmap(&vmx->nested.virtual_apic_map, true); > if (vmx->nested.pi_desc_page) { > kunmap(vmx->nested.pi_desc_page); > kvm_release_page_dirty(vmx->nested.pi_desc_page); > @@ -2817,6 +2814,7 @@ static void nested_get_vmcs12_pages(struct kvm_vcpu *vcpu) > { > struct vmcs12 *vmcs12 = get_vmcs12(vcpu); > struct vcpu_vmx *vmx = to_vmx(vcpu); > + struct kvm_host_map *map; > struct page *page; > u64 hpa; > > @@ -2849,11 +2847,7 @@ static void nested_get_vmcs12_pages(struct kvm_vcpu *vcpu) > } > > if (nested_cpu_has(vmcs12, CPU_BASED_TPR_SHADOW)) { > - if (vmx->nested.virtual_apic_page) { /* shouldn't happen */ > - kvm_release_page_dirty(vmx->nested.virtual_apic_page); > - vmx->nested.virtual_apic_page = NULL; > - } > - page = kvm_vcpu_gpa_to_page(vcpu, vmcs12->virtual_apic_page_addr); > + map = &vmx->nested.virtual_apic_map; > > /* > * If translation failed, VM entry will fail because > @@ -2868,11 +2862,9 @@ static void nested_get_vmcs12_pages(struct kvm_vcpu *vcpu) > * control. But such a configuration is useless, so > * let's keep the code simple. > */ > - if (!is_error_page(page)) { > - vmx->nested.virtual_apic_page = page; > - hpa = page_to_phys(vmx->nested.virtual_apic_page); > - vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, hpa); > - } > + if (!kvm_vcpu_map(vcpu, gpa_to_gfn(vmcs12->virtual_apic_page_addr), map)) > + vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, pfn_to_hpa(map->pfn)); > + > } > > if (nested_cpu_has_posted_intr(vmcs12)) { > @@ -3279,11 +3271,12 @@ static void vmx_complete_nested_posted_interrupt(struct kvm_vcpu *vcpu) > > max_irr = find_last_bit((unsigned long *)vmx->nested.pi_desc->pir, 256); > if (max_irr != 256) { > - vapic_page = kmap(vmx->nested.virtual_apic_page); > + vapic_page = vmx->nested.virtual_apic_map.hva; > + if (!vapic_page) > + return; > + > __kvm_apic_update_irr(vmx->nested.pi_desc->pir, > vapic_page, &max_irr); > - kunmap(vmx->nested.virtual_apic_page); > - > status = vmcs_read16(GUEST_INTR_STATUS); > if ((u8)max_irr > ((u8)status & 0xff)) { > status &= ~0xff; > @@ -3917,10 +3910,7 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason, > kvm_release_page_dirty(vmx->nested.apic_access_page); > vmx->nested.apic_access_page = NULL; > } > - if (vmx->nested.virtual_apic_page) { > - kvm_release_page_dirty(vmx->nested.virtual_apic_page); > - vmx->nested.virtual_apic_page = NULL; > - } > + kvm_vcpu_unmap(&vmx->nested.virtual_apic_map, true); > if (vmx->nested.pi_desc_page) { > kunmap(vmx->nested.pi_desc_page); > kvm_release_page_dirty(vmx->nested.pi_desc_page); > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c > index 71d88df..e13308e 100644 > --- a/arch/x86/kvm/vmx/vmx.c > +++ b/arch/x86/kvm/vmx/vmx.c > @@ -3627,14 +3627,13 @@ static bool vmx_guest_apic_has_interrupt(struct kvm_vcpu *vcpu) > > if (WARN_ON_ONCE(!is_guest_mode(vcpu)) || > !nested_cpu_has_vid(get_vmcs12(vcpu)) || > - WARN_ON_ONCE(!vmx->nested.virtual_apic_page)) > + WARN_ON_ONCE(!vmx->nested.virtual_apic_map.gfn)) > return false; > > rvi = vmx_get_rvi(); > > - vapic_page = kmap(vmx->nested.virtual_apic_page); > + vapic_page = vmx->nested.virtual_apic_map.hva; > vppr = *((u32 *)(vapic_page + APIC_PROCPRI)); > - kunmap(vmx->nested.virtual_apic_page); > > return ((rvi & 0xf0) > (vppr & 0xf0)); > } > diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h > index 6fb69d8..f618f52 100644 > --- a/arch/x86/kvm/vmx/vmx.h > +++ b/arch/x86/kvm/vmx/vmx.h > @@ -142,7 +142,7 @@ struct nested_vmx { > * pointers, so we must keep them pinned while L2 runs. > */ > struct page *apic_access_page; > - struct page *virtual_apic_page; > + struct kvm_host_map virtual_apic_map; > struct page *pi_desc_page; > > struct kvm_host_map msr_bitmap_map; > -- > 2.7.4 >
On Wed, 2019-01-23 at 12:57 -0500, Konrad Rzeszutek Wilk wrote: > On Wed, Jan 09, 2019 at 10:42:07AM +0100, KarimAllah Ahmed wrote: > > > > Use kvm_vcpu_map when mapping the virtual APIC page since using > > kvm_vcpu_gpa_to_page() and kmap() will only work for guest memory that has > > a "struct page". > > > > One additional semantic change is that the virtual host mapping lifecycle > > has changed a bit. It now has the same lifetime of the pinning of the > > virtual APIC page on the host side. > > Could you expand a bit on the 'same lifetime .. on the host side' to be > obvious for folks what exactly the semantic is? > > And how does this ring with this comment: > > > > > > Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> > > --- > > v4 -> v5: > > - unmap with dirty flag > > > > v1 -> v2: > > - Do not change the lifecycle of the mapping (pbonzini) > > .. Where Paolo does not want the semantics of the mapping to be changed? > > Code wise feel free to smack my Reviewed-by on it, but obviously the > question on the above comment needs to be resolved. Ah, right. So there was two life-cycle changes: 1- Lazily unmap the mapping and only do it on: a) release b) if the gfn is different. This was done as an optimization (i.e. cache of a single entry). This is the first life-cycle change that Paolo asked me to do seperately and suggested to create a PFN cache instead. This has indeed been dropped between v1 -> v2 switch. 2- The life-cycle change now is the fact that the kvm_vcpu_map interface does: a) map to a virtual address b) translate a gfn to a pfn. The original code was doing the kmap in one location and the gfn_to_page in another. Using kvm_vcpu_map means that both kmap+gfn_to_page will be tied together and will not be done seperately. So far no one complained about this one so I kept it :D > > Thank you. > > > > > - Use pfn_to_hpa instead of gfn_to_gpa > > --- > > arch/x86/kvm/vmx/nested.c | 32 +++++++++++--------------------- > > arch/x86/kvm/vmx/vmx.c | 5 ++--- > > arch/x86/kvm/vmx/vmx.h | 2 +- > > 3 files changed, 14 insertions(+), 25 deletions(-) > > > > diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c > > index 4127ad9..dcff99d 100644 > > --- a/arch/x86/kvm/vmx/nested.c > > +++ b/arch/x86/kvm/vmx/nested.c > > @@ -229,10 +229,7 @@ static void free_nested(struct kvm_vcpu *vcpu) > > kvm_release_page_dirty(vmx->nested.apic_access_page); > > vmx->nested.apic_access_page = NULL; > > } > > - if (vmx->nested.virtual_apic_page) { > > - kvm_release_page_dirty(vmx->nested.virtual_apic_page); > > - vmx->nested.virtual_apic_page = NULL; > > - } > > + kvm_vcpu_unmap(&vmx->nested.virtual_apic_map, true); > > if (vmx->nested.pi_desc_page) { > > kunmap(vmx->nested.pi_desc_page); > > kvm_release_page_dirty(vmx->nested.pi_desc_page); > > @@ -2817,6 +2814,7 @@ static void nested_get_vmcs12_pages(struct kvm_vcpu *vcpu) > > { > > struct vmcs12 *vmcs12 = get_vmcs12(vcpu); > > struct vcpu_vmx *vmx = to_vmx(vcpu); > > + struct kvm_host_map *map; > > struct page *page; > > u64 hpa; > > > > @@ -2849,11 +2847,7 @@ static void nested_get_vmcs12_pages(struct kvm_vcpu *vcpu) > > } > > > > if (nested_cpu_has(vmcs12, CPU_BASED_TPR_SHADOW)) { > > - if (vmx->nested.virtual_apic_page) { /* shouldn't happen */ > > - kvm_release_page_dirty(vmx->nested.virtual_apic_page); > > - vmx->nested.virtual_apic_page = NULL; > > - } > > - page = kvm_vcpu_gpa_to_page(vcpu, vmcs12->virtual_apic_page_addr); > > + map = &vmx->nested.virtual_apic_map; > > > > /* > > * If translation failed, VM entry will fail because > > @@ -2868,11 +2862,9 @@ static void nested_get_vmcs12_pages(struct kvm_vcpu *vcpu) > > * control. But such a configuration is useless, so > > * let's keep the code simple. > > */ > > - if (!is_error_page(page)) { > > - vmx->nested.virtual_apic_page = page; > > - hpa = page_to_phys(vmx->nested.virtual_apic_page); > > - vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, hpa); > > - } > > + if (!kvm_vcpu_map(vcpu, gpa_to_gfn(vmcs12->virtual_apic_page_addr), map)) > > + vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, pfn_to_hpa(map->pfn)); > > + > > } > > > > if (nested_cpu_has_posted_intr(vmcs12)) { > > @@ -3279,11 +3271,12 @@ static void vmx_complete_nested_posted_interrupt(struct kvm_vcpu *vcpu) > > > > max_irr = find_last_bit((unsigned long *)vmx->nested.pi_desc->pir, 256); > > if (max_irr != 256) { > > - vapic_page = kmap(vmx->nested.virtual_apic_page); > > + vapic_page = vmx->nested.virtual_apic_map.hva; > > + if (!vapic_page) > > + return; > > + > > __kvm_apic_update_irr(vmx->nested.pi_desc->pir, > > vapic_page, &max_irr); > > - kunmap(vmx->nested.virtual_apic_page); > > - > > status = vmcs_read16(GUEST_INTR_STATUS); > > if ((u8)max_irr > ((u8)status & 0xff)) { > > status &= ~0xff; > > @@ -3917,10 +3910,7 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason, > > kvm_release_page_dirty(vmx->nested.apic_access_page); > > vmx->nested.apic_access_page = NULL; > > } > > - if (vmx->nested.virtual_apic_page) { > > - kvm_release_page_dirty(vmx->nested.virtual_apic_page); > > - vmx->nested.virtual_apic_page = NULL; > > - } > > + kvm_vcpu_unmap(&vmx->nested.virtual_apic_map, true); > > if (vmx->nested.pi_desc_page) { > > kunmap(vmx->nested.pi_desc_page); > > kvm_release_page_dirty(vmx->nested.pi_desc_page); > > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c > > index 71d88df..e13308e 100644 > > --- a/arch/x86/kvm/vmx/vmx.c > > +++ b/arch/x86/kvm/vmx/vmx.c > > @@ -3627,14 +3627,13 @@ static bool vmx_guest_apic_has_interrupt(struct kvm_vcpu *vcpu) > > > > if (WARN_ON_ONCE(!is_guest_mode(vcpu)) || > > !nested_cpu_has_vid(get_vmcs12(vcpu)) || > > - WARN_ON_ONCE(!vmx->nested.virtual_apic_page)) > > + WARN_ON_ONCE(!vmx->nested.virtual_apic_map.gfn)) > > return false; > > > > rvi = vmx_get_rvi(); > > > > - vapic_page = kmap(vmx->nested.virtual_apic_page); > > + vapic_page = vmx->nested.virtual_apic_map.hva; > > vppr = *((u32 *)(vapic_page + APIC_PROCPRI)); > > - kunmap(vmx->nested.virtual_apic_page); > > > > return ((rvi & 0xf0) > (vppr & 0xf0)); > > } > > diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h > > index 6fb69d8..f618f52 100644 > > --- a/arch/x86/kvm/vmx/vmx.h > > +++ b/arch/x86/kvm/vmx/vmx.h > > @@ -142,7 +142,7 @@ struct nested_vmx { > > * pointers, so we must keep them pinned while L2 runs. > > */ > > struct page *apic_access_page; > > - struct page *virtual_apic_page; > > + struct kvm_host_map virtual_apic_map; > > struct page *pi_desc_page; > > > > struct kvm_host_map msr_bitmap_map; > > -- > > 2.7.4 > > Amazon Development Center Germany GmbH Krausenstr. 38 10117 Berlin Geschaeftsfuehrer: Christian Schlaeger, Ralf Herbrich Ust-ID: DE 289 237 879 Eingetragen am Amtsgericht Charlottenburg HRB 149173 B
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 4127ad9..dcff99d 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -229,10 +229,7 @@ static void free_nested(struct kvm_vcpu *vcpu) kvm_release_page_dirty(vmx->nested.apic_access_page); vmx->nested.apic_access_page = NULL; } - if (vmx->nested.virtual_apic_page) { - kvm_release_page_dirty(vmx->nested.virtual_apic_page); - vmx->nested.virtual_apic_page = NULL; - } + kvm_vcpu_unmap(&vmx->nested.virtual_apic_map, true); if (vmx->nested.pi_desc_page) { kunmap(vmx->nested.pi_desc_page); kvm_release_page_dirty(vmx->nested.pi_desc_page); @@ -2817,6 +2814,7 @@ static void nested_get_vmcs12_pages(struct kvm_vcpu *vcpu) { struct vmcs12 *vmcs12 = get_vmcs12(vcpu); struct vcpu_vmx *vmx = to_vmx(vcpu); + struct kvm_host_map *map; struct page *page; u64 hpa; @@ -2849,11 +2847,7 @@ static void nested_get_vmcs12_pages(struct kvm_vcpu *vcpu) } if (nested_cpu_has(vmcs12, CPU_BASED_TPR_SHADOW)) { - if (vmx->nested.virtual_apic_page) { /* shouldn't happen */ - kvm_release_page_dirty(vmx->nested.virtual_apic_page); - vmx->nested.virtual_apic_page = NULL; - } - page = kvm_vcpu_gpa_to_page(vcpu, vmcs12->virtual_apic_page_addr); + map = &vmx->nested.virtual_apic_map; /* * If translation failed, VM entry will fail because @@ -2868,11 +2862,9 @@ static void nested_get_vmcs12_pages(struct kvm_vcpu *vcpu) * control. But such a configuration is useless, so * let's keep the code simple. */ - if (!is_error_page(page)) { - vmx->nested.virtual_apic_page = page; - hpa = page_to_phys(vmx->nested.virtual_apic_page); - vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, hpa); - } + if (!kvm_vcpu_map(vcpu, gpa_to_gfn(vmcs12->virtual_apic_page_addr), map)) + vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, pfn_to_hpa(map->pfn)); + } if (nested_cpu_has_posted_intr(vmcs12)) { @@ -3279,11 +3271,12 @@ static void vmx_complete_nested_posted_interrupt(struct kvm_vcpu *vcpu) max_irr = find_last_bit((unsigned long *)vmx->nested.pi_desc->pir, 256); if (max_irr != 256) { - vapic_page = kmap(vmx->nested.virtual_apic_page); + vapic_page = vmx->nested.virtual_apic_map.hva; + if (!vapic_page) + return; + __kvm_apic_update_irr(vmx->nested.pi_desc->pir, vapic_page, &max_irr); - kunmap(vmx->nested.virtual_apic_page); - status = vmcs_read16(GUEST_INTR_STATUS); if ((u8)max_irr > ((u8)status & 0xff)) { status &= ~0xff; @@ -3917,10 +3910,7 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason, kvm_release_page_dirty(vmx->nested.apic_access_page); vmx->nested.apic_access_page = NULL; } - if (vmx->nested.virtual_apic_page) { - kvm_release_page_dirty(vmx->nested.virtual_apic_page); - vmx->nested.virtual_apic_page = NULL; - } + kvm_vcpu_unmap(&vmx->nested.virtual_apic_map, true); if (vmx->nested.pi_desc_page) { kunmap(vmx->nested.pi_desc_page); kvm_release_page_dirty(vmx->nested.pi_desc_page); diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 71d88df..e13308e 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -3627,14 +3627,13 @@ static bool vmx_guest_apic_has_interrupt(struct kvm_vcpu *vcpu) if (WARN_ON_ONCE(!is_guest_mode(vcpu)) || !nested_cpu_has_vid(get_vmcs12(vcpu)) || - WARN_ON_ONCE(!vmx->nested.virtual_apic_page)) + WARN_ON_ONCE(!vmx->nested.virtual_apic_map.gfn)) return false; rvi = vmx_get_rvi(); - vapic_page = kmap(vmx->nested.virtual_apic_page); + vapic_page = vmx->nested.virtual_apic_map.hva; vppr = *((u32 *)(vapic_page + APIC_PROCPRI)); - kunmap(vmx->nested.virtual_apic_page); return ((rvi & 0xf0) > (vppr & 0xf0)); } diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index 6fb69d8..f618f52 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -142,7 +142,7 @@ struct nested_vmx { * pointers, so we must keep them pinned while L2 runs. */ struct page *apic_access_page; - struct page *virtual_apic_page; + struct kvm_host_map virtual_apic_map; struct page *pi_desc_page; struct kvm_host_map msr_bitmap_map;
Use kvm_vcpu_map when mapping the virtual APIC page since using kvm_vcpu_gpa_to_page() and kmap() will only work for guest memory that has a "struct page". One additional semantic change is that the virtual host mapping lifecycle has changed a bit. It now has the same lifetime of the pinning of the virtual APIC page on the host side. Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> --- v4 -> v5: - unmap with dirty flag v1 -> v2: - Do not change the lifecycle of the mapping (pbonzini) - Use pfn_to_hpa instead of gfn_to_gpa --- arch/x86/kvm/vmx/nested.c | 32 +++++++++++--------------------- arch/x86/kvm/vmx/vmx.c | 5 ++--- arch/x86/kvm/vmx/vmx.h | 2 +- 3 files changed, 14 insertions(+), 25 deletions(-)