From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: Paul Durrant <paul.durrant@citrix.com>
Cc: xen-devel@lists.xenproject.org, Keir Fraser <keir@xen.org>,
Jan Beulich <jbeulich@suse.com>,
Andrew Cooper <andrew.cooper3@citrix.com>
Subject: Re: [PATCH 1/2] x86/hvm/viridian: keep APIC assist page mapped...
Date: Tue, 15 Mar 2016 19:20:01 -0400 [thread overview]
Message-ID: <20160315232001.GD29285@char.us.oracle.com> (raw)
In-Reply-To: <1458058456-7345-2-git-send-email-paul.durrant@citrix.com>
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 <paul.durrant@citrix.com>
> Cc: Keir Fraser <keir@xen.org>
> Cc: Jan Beulich <jbeulich@suse.com>
> Cc: Andrew Cooper <andrew.cooper3@citrix.com>
> ---
> 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?
> 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
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel
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next prev parent reply other threads:[~2016-03-15 23:20 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-15 16:14 [PATCH 0/2] x86/hvm/viridian: APIC assist Paul Durrant
2016-03-15 16:14 ` [PATCH 1/2] x86/hvm/viridian: keep APIC assist page mapped Paul Durrant
2016-03-15 23:20 ` Konrad Rzeszutek Wilk [this message]
2016-03-16 14:46 ` Paul Durrant
2016-03-15 16:14 ` [PATCH 2/2] x86/hvm/viridian: Enable APIC assist enlightenment Paul Durrant
2016-03-15 23:18 ` Konrad Rzeszutek Wilk
2016-03-16 15:02 ` Paul Durrant
2016-03-16 16:28 ` Jan Beulich
2016-03-16 17:23 ` Paul Durrant
2016-03-17 8:12 ` Jan Beulich
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