| Message ID | 1458150252-25683-2-git-send-email-paul.durrant@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
> -----Original Message----- > From: Paul Durrant [mailto:paul.durrant@citrix.com] > Sent: 16 March 2016 17:44 > To: xen-devel@lists.xenproject.org > Cc: Paul Durrant; Keir (Xen.org); Jan Beulich; Andrew Cooper > Subject: [PATCH v3 1/2] x86/hvm/viridian: keep APIC assist page mapped... > > ... for the lifetime of the domain. > > If Xen is to make use of the APIC assist enlightenment then a persistent > mapping needs to be kept, rather than the temporary one which is currently > used only to initialize the page content. > > This patch also adds a comment block at the top of the source with > information on the latest version of the spec. from Microsoft and the > current URL where it may be found. > > Signed-off-by: Paul Durrant <paul.durrant@citrix.com> > Cc: Keir Fraser <keir@xen.org> > Cc: Jan Beulich <jbeulich@suse.com> > Cc: Andrew Cooper <andrew.cooper3@citrix.com> > --- > > v2: > - Re-instated warning if the initialization of an APIC assist page fails. > - Added up-to-date information about the viridian specification to the > comment block at the top of the source. > --- > xen/arch/x86/hvm/hvm.c | 2 + > xen/arch/x86/hvm/viridian.c | 76 ++++++++++++++++++++++++++++--- > ------- > xen/include/asm-x86/hvm/viridian.h | 8 +++- > 3 files changed, 65 insertions(+), 21 deletions(-) > > diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c > index 4ea51d7..f446ee4 100644 > --- a/xen/arch/x86/hvm/hvm.c > +++ b/xen/arch/x86/hvm/hvm.c > @@ -2606,6 +2606,8 @@ int hvm_vcpu_initialise(struct vcpu *v) > > void hvm_vcpu_destroy(struct vcpu *v) > { > + viridian_vcpu_deinit(v); > + > hvm_all_ioreq_servers_remove_vcpu(v->domain, v); > > if ( hvm_altp2m_supported() ) > diff --git a/xen/arch/x86/hvm/viridian.c b/xen/arch/x86/hvm/viridian.c > index 1ee22aa..e990163 100644 > --- a/xen/arch/x86/hvm/viridian.c > +++ b/xen/arch/x86/hvm/viridian.c > @@ -1,7 +1,12 @@ > > /********************************************************** > ******************** > * viridian.c > * > - * An implementation of the Viridian hypercall interface. > + * An implementation of some Viridian enlightenments. See Microsoft's > + * Hypervisor Top Level Functional Specification (v4.0b) at: > + * > + * https://msdn.microsoft.com/en- > us/virtualization/hyperv_on_windows/develop/tlfs > + * > + * for more information. > */ > > #include <xen/sched.h> > @@ -163,7 +168,7 @@ static void dump_apic_assist(const struct vcpu *v) > { > const union viridian_apic_assist *aa; > > - aa = &v->arch.hvm_vcpu.viridian.apic_assist; > + aa = &v->arch.hvm_vcpu.viridian.apic_assist.msr; > > printk(XENLOG_G_INFO "%pv: VIRIDIAN APIC_ASSIST: enabled: %x pfn: > %lx\n", > v, aa->fields.enabled, (unsigned long)aa->fields.pfn); > @@ -217,9 +222,9 @@ static void enable_hypercall_page(struct domain *d) > static void initialize_apic_assist(struct vcpu *v) > { > struct domain *d = v->domain; > - unsigned long gmfn = v->arch.hvm_vcpu.viridian.apic_assist.fields.pfn; > + unsigned long gmfn = v- > >arch.hvm_vcpu.viridian.apic_assist.msr.fields.pfn; > struct page_info *page = get_page_from_gfn(d, gmfn, NULL, > P2M_ALLOC); > - uint8_t *p; > + void *va; > > /* > * We don't yet make use of the APIC assist page but by setting > @@ -227,25 +232,49 @@ static void initialize_apic_assist(struct vcpu *v) > * bound to support the MSR. We therefore do just enough to keep > windows > * happy. > * > - * See http://msdn.microsoft.com/en- > us/library/ff538657%28VS.85%29.aspx for > - * details of how Windows uses the page. > + * See section 13.3.4.1 of the specification for details of this > + * enlightenment. > */ > > - if ( !page || !get_page_type(page, PGT_writable_page) ) > + if ( !page ) > + goto fail; > + > + if ( !get_page_type(page, PGT_writable_page) ) > { > - if ( page ) > - put_page(page); > - gdprintk(XENLOG_WARNING, "Bad GMFN %lx (MFN %lx)\n", gmfn, > - page ? page_to_mfn(page) : INVALID_MFN); > - return; > + put_page(page); > + goto fail; > } > > - p = __map_domain_page(page); > + va = __map_domain_page_global(page); > + if ( !va ) > + { > + put_page_and_type(page); > + goto fail; > + } > > - *(u32 *)p = 0; > + *(uint32_t *)va = 0; > > - unmap_domain_page(p); > + v->arch.hvm_vcpu.viridian.apic_assist.page = page; > + v->arch.hvm_vcpu.viridian.apic_assist.va = va; > + return; > + > + fail: > + gdprintk(XENLOG_WARNING, "Bad GMFN %lx (MFN %lx)\n", gmfn, > + page ? page_to_mfn(page) : INVALID_MFN); > +} > + > +static void teardown_apic_assist(struct vcpu *v) > +{ > + struct page_info *page = v->arch.hvm_vcpu.viridian.apic_assist.page; > + void *va = v->arch.hvm_vcpu.viridian.apic_assist.va; > > + if ( !va ) > + return; > + > + v->arch.hvm_vcpu.viridian.apic_assist.va = NULL; > + v->arch.hvm_vcpu.viridian.apic_assist.page = NULL; > + > + unmap_domain_page_global(va); > put_page_and_type(page); > } > > @@ -374,9 +403,9 @@ int wrmsr_viridian_regs(uint32_t idx, uint64_t val) > > case VIRIDIAN_MSR_APIC_ASSIST: > perfc_incr(mshv_wrmsr_apic_msr); > - v->arch.hvm_vcpu.viridian.apic_assist.raw = val; > + v->arch.hvm_vcpu.viridian.apic_assist.msr.raw = val; > dump_apic_assist(v); > - if (v->arch.hvm_vcpu.viridian.apic_assist.fields.enabled) > + if ( v->arch.hvm_vcpu.viridian.apic_assist.msr.fields.enabled ) Actually there's an omission here. If the MSR had previously been set then we potentially leak a mapping so there needs to be a teardown before the (re-)initialize. Paul > initialize_apic_assist(v); > break; > > @@ -485,7 +514,7 @@ int rdmsr_viridian_regs(uint32_t idx, uint64_t *val) > > case VIRIDIAN_MSR_APIC_ASSIST: > perfc_incr(mshv_rdmsr_apic_msr); > - *val = v->arch.hvm_vcpu.viridian.apic_assist.raw; > + *val = v->arch.hvm_vcpu.viridian.apic_assist.msr.raw; > break; > > case VIRIDIAN_MSR_REFERENCE_TSC: > @@ -521,6 +550,11 @@ int rdmsr_viridian_regs(uint32_t idx, uint64_t *val) > return 1; > } > > +void viridian_vcpu_deinit(struct vcpu *v) > +{ > + teardown_apic_assist(v); > +} > + > static DEFINE_PER_CPU(cpumask_t, ipi_cpumask); > > int viridian_hypercall(struct cpu_user_regs *regs) > @@ -721,7 +755,7 @@ static int viridian_save_vcpu_ctxt(struct domain *d, > hvm_domain_context_t *h) > for_each_vcpu( d, v ) { > struct hvm_viridian_vcpu_context ctxt; > > - ctxt.apic_assist = v->arch.hvm_vcpu.viridian.apic_assist.raw; > + ctxt.apic_assist = v->arch.hvm_vcpu.viridian.apic_assist.msr.raw; > > if ( hvm_save_entry(VIRIDIAN_VCPU, v->vcpu_id, h, &ctxt) != 0 ) > return 1; > @@ -747,7 +781,9 @@ static int viridian_load_vcpu_ctxt(struct domain *d, > hvm_domain_context_t *h) > if ( hvm_load_entry(VIRIDIAN_VCPU, h, &ctxt) != 0 ) > return -EINVAL; > > - v->arch.hvm_vcpu.viridian.apic_assist.raw = ctxt.apic_assist; > + v->arch.hvm_vcpu.viridian.apic_assist.msr.raw = ctxt.apic_assist; > + if ( v->arch.hvm_vcpu.viridian.apic_assist.msr.fields.enabled ) > + initialize_apic_assist(v); > > return 0; > } > diff --git a/xen/include/asm-x86/hvm/viridian.h b/xen/include/asm- > x86/hvm/viridian.h > index c4319d7..ee3a120 100644 > --- a/xen/include/asm-x86/hvm/viridian.h > +++ b/xen/include/asm-x86/hvm/viridian.h > @@ -21,7 +21,11 @@ union viridian_apic_assist > > struct viridian_vcpu > { > - union viridian_apic_assist apic_assist; > + struct { > + union viridian_apic_assist msr; > + struct page_info *page; > + void *va; > + } apic_assist; > }; > > union viridian_guest_os_id > @@ -117,6 +121,8 @@ viridian_hypercall(struct cpu_user_regs *regs); > void viridian_time_ref_count_freeze(struct domain *d); > void viridian_time_ref_count_thaw(struct domain *d); > > +void viridian_vcpu_deinit(struct vcpu *v); > + > #endif /* __ASM_X86_HVM_VIRIDIAN_H__ */ > > /* > -- > 2.1.4
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c index 4ea51d7..f446ee4 100644 --- a/xen/arch/x86/hvm/hvm.c +++ b/xen/arch/x86/hvm/hvm.c @@ -2606,6 +2606,8 @@ int hvm_vcpu_initialise(struct vcpu *v) void hvm_vcpu_destroy(struct vcpu *v) { + viridian_vcpu_deinit(v); + hvm_all_ioreq_servers_remove_vcpu(v->domain, v); if ( hvm_altp2m_supported() ) diff --git a/xen/arch/x86/hvm/viridian.c b/xen/arch/x86/hvm/viridian.c index 1ee22aa..e990163 100644 --- a/xen/arch/x86/hvm/viridian.c +++ b/xen/arch/x86/hvm/viridian.c @@ -1,7 +1,12 @@ /****************************************************************************** * viridian.c * - * An implementation of the Viridian hypercall interface. + * An implementation of some Viridian enlightenments. See Microsoft's + * Hypervisor Top Level Functional Specification (v4.0b) at: + * + * https://msdn.microsoft.com/en-us/virtualization/hyperv_on_windows/develop/tlfs + * + * for more information. */ #include <xen/sched.h> @@ -163,7 +168,7 @@ static void dump_apic_assist(const struct vcpu *v) { const union viridian_apic_assist *aa; - aa = &v->arch.hvm_vcpu.viridian.apic_assist; + aa = &v->arch.hvm_vcpu.viridian.apic_assist.msr; printk(XENLOG_G_INFO "%pv: VIRIDIAN APIC_ASSIST: enabled: %x pfn: %lx\n", v, aa->fields.enabled, (unsigned long)aa->fields.pfn); @@ -217,9 +222,9 @@ static void enable_hypercall_page(struct domain *d) static void initialize_apic_assist(struct vcpu *v) { struct domain *d = v->domain; - unsigned long gmfn = v->arch.hvm_vcpu.viridian.apic_assist.fields.pfn; + unsigned long gmfn = v->arch.hvm_vcpu.viridian.apic_assist.msr.fields.pfn; struct page_info *page = get_page_from_gfn(d, gmfn, NULL, P2M_ALLOC); - uint8_t *p; + void *va; /* * We don't yet make use of the APIC assist page but by setting @@ -227,25 +232,49 @@ static void initialize_apic_assist(struct vcpu *v) * bound to support the MSR. We therefore do just enough to keep windows * happy. * - * See http://msdn.microsoft.com/en-us/library/ff538657%28VS.85%29.aspx for - * details of how Windows uses the page. + * See section 13.3.4.1 of the specification for details of this + * enlightenment. */ - if ( !page || !get_page_type(page, PGT_writable_page) ) + if ( !page ) + goto fail; + + if ( !get_page_type(page, PGT_writable_page) ) { - if ( page ) - put_page(page); - gdprintk(XENLOG_WARNING, "Bad GMFN %lx (MFN %lx)\n", gmfn, - page ? page_to_mfn(page) : INVALID_MFN); - return; + put_page(page); + goto fail; } - p = __map_domain_page(page); + va = __map_domain_page_global(page); + if ( !va ) + { + put_page_and_type(page); + goto fail; + } - *(u32 *)p = 0; + *(uint32_t *)va = 0; - unmap_domain_page(p); + v->arch.hvm_vcpu.viridian.apic_assist.page = page; + v->arch.hvm_vcpu.viridian.apic_assist.va = va; + return; + + fail: + gdprintk(XENLOG_WARNING, "Bad GMFN %lx (MFN %lx)\n", gmfn, + page ? page_to_mfn(page) : INVALID_MFN); +} + +static void teardown_apic_assist(struct vcpu *v) +{ + struct page_info *page = v->arch.hvm_vcpu.viridian.apic_assist.page; + void *va = v->arch.hvm_vcpu.viridian.apic_assist.va; + if ( !va ) + return; + + v->arch.hvm_vcpu.viridian.apic_assist.va = NULL; + v->arch.hvm_vcpu.viridian.apic_assist.page = NULL; + + unmap_domain_page_global(va); put_page_and_type(page); } @@ -374,9 +403,9 @@ int wrmsr_viridian_regs(uint32_t idx, uint64_t val) case VIRIDIAN_MSR_APIC_ASSIST: perfc_incr(mshv_wrmsr_apic_msr); - v->arch.hvm_vcpu.viridian.apic_assist.raw = val; + v->arch.hvm_vcpu.viridian.apic_assist.msr.raw = val; dump_apic_assist(v); - if (v->arch.hvm_vcpu.viridian.apic_assist.fields.enabled) + if ( v->arch.hvm_vcpu.viridian.apic_assist.msr.fields.enabled ) initialize_apic_assist(v); break; @@ -485,7 +514,7 @@ int rdmsr_viridian_regs(uint32_t idx, uint64_t *val) case VIRIDIAN_MSR_APIC_ASSIST: perfc_incr(mshv_rdmsr_apic_msr); - *val = v->arch.hvm_vcpu.viridian.apic_assist.raw; + *val = v->arch.hvm_vcpu.viridian.apic_assist.msr.raw; break; case VIRIDIAN_MSR_REFERENCE_TSC: @@ -521,6 +550,11 @@ int rdmsr_viridian_regs(uint32_t idx, uint64_t *val) return 1; } +void viridian_vcpu_deinit(struct vcpu *v) +{ + teardown_apic_assist(v); +} + static DEFINE_PER_CPU(cpumask_t, ipi_cpumask); int viridian_hypercall(struct cpu_user_regs *regs) @@ -721,7 +755,7 @@ static int viridian_save_vcpu_ctxt(struct domain *d, hvm_domain_context_t *h) for_each_vcpu( d, v ) { struct hvm_viridian_vcpu_context ctxt; - ctxt.apic_assist = v->arch.hvm_vcpu.viridian.apic_assist.raw; + ctxt.apic_assist = v->arch.hvm_vcpu.viridian.apic_assist.msr.raw; if ( hvm_save_entry(VIRIDIAN_VCPU, v->vcpu_id, h, &ctxt) != 0 ) return 1; @@ -747,7 +781,9 @@ static int viridian_load_vcpu_ctxt(struct domain *d, hvm_domain_context_t *h) if ( hvm_load_entry(VIRIDIAN_VCPU, h, &ctxt) != 0 ) return -EINVAL; - v->arch.hvm_vcpu.viridian.apic_assist.raw = ctxt.apic_assist; + v->arch.hvm_vcpu.viridian.apic_assist.msr.raw = ctxt.apic_assist; + if ( v->arch.hvm_vcpu.viridian.apic_assist.msr.fields.enabled ) + initialize_apic_assist(v); return 0; } diff --git a/xen/include/asm-x86/hvm/viridian.h b/xen/include/asm-x86/hvm/viridian.h index c4319d7..ee3a120 100644 --- a/xen/include/asm-x86/hvm/viridian.h +++ b/xen/include/asm-x86/hvm/viridian.h @@ -21,7 +21,11 @@ union viridian_apic_assist struct viridian_vcpu { - union viridian_apic_assist apic_assist; + struct { + union viridian_apic_assist msr; + struct page_info *page; + void *va; + } apic_assist; }; union viridian_guest_os_id @@ -117,6 +121,8 @@ viridian_hypercall(struct cpu_user_regs *regs); void viridian_time_ref_count_freeze(struct domain *d); void viridian_time_ref_count_thaw(struct domain *d); +void viridian_vcpu_deinit(struct vcpu *v); + #endif /* __ASM_X86_HVM_VIRIDIAN_H__ */ /*
... for the lifetime of the domain. If Xen is to make use of the APIC assist enlightenment then a persistent mapping needs to be kept, rather than the temporary one which is currently used only to initialize the page content. This patch also adds a comment block at the top of the source with information on the latest version of the spec. from Microsoft and the current URL where it may be found. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Keir Fraser <keir@xen.org> Cc: Jan Beulich <jbeulich@suse.com> Cc: Andrew Cooper <andrew.cooper3@citrix.com> --- v2: - Re-instated warning if the initialization of an APIC assist page fails. - Added up-to-date information about the viridian specification to the comment block at the top of the source. --- xen/arch/x86/hvm/hvm.c | 2 + xen/arch/x86/hvm/viridian.c | 76 ++++++++++++++++++++++++++++---------- xen/include/asm-x86/hvm/viridian.h | 8 +++- 3 files changed, 65 insertions(+), 21 deletions(-)