> -----Original Message-----
> From: Konrad Rzeszutek Wilk [mailto:[email protected]]
> Sent: 15 March 2016 23:20
> To: Paul Durrant
> Cc: [email protected]; Andrew Cooper; Keir (Xen.org); Jan
> Beulich
> Subject: Re: [Xen-devel] [PATCH 1/2] x86/hvm/viridian: keep APIC assist
> page mapped...
>
> On Tue, Mar 15, 2016 at 04:14:15PM +0000, Paul Durrant wrote:
> > ... 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.
> >
> > Signed-off-by: Paul Durrant <[email protected]>
> > Cc: Keir Fraser <[email protected]>
> > Cc: Jan Beulich <[email protected]>
> > Cc: Andrew Cooper <[email protected]>
> > ---
> > xen/arch/x86/hvm/viridian.c | 54 +++++++++++++++++++++++++++--
> ---------
> > xen/include/asm-x86/hvm/viridian.h | 6 ++++-
> > 2 files changed, 43 insertions(+), 17 deletions(-)
> >
> > diff --git a/xen/arch/x86/hvm/viridian.c b/xen/arch/x86/hvm/viridian.c
> > index 6bd844b..c779290 100644
> > --- a/xen/arch/x86/hvm/viridian.c
> > +++ b/xen/arch/x86/hvm/viridian.c
> > @@ -163,7 +163,7 @@ 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 +217,9 @@ 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
> > @@ -231,21 +231,40 @@ static void initialize_apic_assist(struct vcpu *v)
> > * details of how Windows uses the page.
> > */
> >
> > - if ( !page || !get_page_type(page, PGT_writable_page) )
> > + if ( !page )
> > + return;
> > +
> > + 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);
> > + put_page(page);
>
> You don't want to report errors in case this goes south?
>
Well, the guest should keep on running but without the enlightenment. You're
right that I should probably keep the warning though.
Paul
> > return;
> > }
> >
> > - p = __map_domain_page(page);
> > + va = __map_domain_page_global(page);
> > + if ( !va )
> > + {
> > + put_page_and_type(page);
> > + return;
> > + }
> >
> > - *(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;
> > +}
> > +
> > +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 +393,9 @@ 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 +504,7 @@ 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:
> > @@ -530,6 +549,7 @@ int viridian_vcpu_init(struct vcpu *v)
> > void viridian_vcpu_deinit(struct vcpu *v)
> > {
> > free_cpumask_var(v->arch.hvm_vcpu.viridian.flush_cpumask);
> > + teardown_apic_assist(v);
> > }
> >
> > int viridian_hypercall(struct cpu_user_regs *regs)
> > @@ -728,7 +748,7 @@ 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;
> > @@ -754,7 +774,9 @@ 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 2eec85e..c60c113 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;
> > cpumask_var_t flush_cpumask;
> > };
> >
> > --
> > 2.1.4
> >
> >
> > _______________________________________________
> > Xen-devel mailing list
> > [email protected]
> > http://lists.xen.org/xen-devel
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