Re: [PATCH for-next v3 06/12] x86/domain: push some code down to hvm_domain_initialise

[Wei Liu <wei.liu2@citrix.com>]

On Wed, May 31, 2017 at 07:06:08PM +0100, Wei Liu wrote:
> On Wed, Apr 26, 2017 at 04:54:51PM +0100, Wei Liu wrote:
> > We want to have a single entry point to initialise hvm guest.  To do
> > this, the setting of hap_enabled and creation of the per domain mappings
> > is deferred, but that's not a problem.
> > 
> > No functional change.
> > 
> > Signed-off-by: Wei Liu <wei.liu2@citrix.com>
> > Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
> > ---
> > v3: update commit message
> > 
> > v2:
> > 1. reorder things to avoid rename labels
> > 2. add config to hvm_domain_initialise
> > 
> > Cc: Jan Beulich <jbeulich@suse.com>
> > Cc: Andrew Cooper <andrew.cooper3@citrix.com>
> > ---
> >  xen/arch/x86/domain.c         | 14 +++-----------
> >  xen/arch/x86/hvm/hvm.c        | 11 ++++++++++-
> >  xen/include/asm-x86/hvm/hvm.h |  3 ++-
> >  3 files changed, 15 insertions(+), 13 deletions(-)
> > 
> > diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
> > index cea80803a5..80775a0362 100644
> > --- a/xen/arch/x86/domain.c
> > +++ b/xen/arch/x86/domain.c
> > @@ -598,16 +598,8 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags,
> >          d->arch.emulation_flags = emflags;
> >      }
> >  
> > -    if ( is_hvm_domain(d) )
> > -    {
> > -        d->arch.hvm_domain.hap_enabled =
> > -            hvm_funcs.hap_supported && (domcr_flags & DOMCRF_hap);
> 
> paging_domain_init calls hap_enabled. hap_enabled uses
> d->arch.hvm_domain.hap_enabled to determine if it should call hap_init.
> 
> We can't call hvm_domain_initialise before paging_domain_init because
> it needs paging to be initialised.
> 
> So I can't push setting this field to hvm_domain_initialise.
> 
> If you think there is a better way to clean this up please let me know.

And the new patch.

---8<---
From 63a4595004550e485793c11fed363e6f7417a3bb Mon Sep 17 00:00:00 2001
From: Wei Liu <wei.liu2@citrix.com>
Date: Mon, 24 Apr 2017 19:00:35 +0100
Subject: [PATCH] x86/domain: push per-domain mapping creation down to
 hvm_domain_initialise

We want to have a single entry point to initialise hvm guest.  Push
the per-domain mapping creation down to hvm_domain_initialise.

We can't move setting hap_enabled yet because that field needs to be
set before paging initialisation. Document that.

While at it, supply hvm_domain_initialise with more arguments. Though
they aren't used yet, they might be required in the future.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
 xen/arch/x86/domain.c         | 19 ++++++++-----------
 xen/arch/x86/hvm/hvm.c        |  9 ++++++++-
 xen/include/asm-x86/hvm/hvm.h |  3 ++-
 3 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 06c46f9c49..1c572bafb0 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -598,16 +598,8 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags,
         d->arch.emulation_flags = emflags;
     }
 
-    if ( is_hvm_domain(d) )
-    {
-        d->arch.hvm_domain.hap_enabled =
-            hvm_funcs.hap_supported && (domcr_flags & DOMCRF_hap);
-
-        rc = create_perdomain_mapping(d, PERDOMAIN_VIRT_START, 0, NULL, NULL);
-    }
-    else if ( is_idle_domain(d) )
-        rc = 0;
-    else
+    rc = 0; /* HVM and idle domain */
+    if ( is_pv_domain(d) )
     {
         d->arch.pv_domain.gdt_ldt_l1tab =
             alloc_xenheap_pages(0, MEMF_node(domain_to_node(d)));
@@ -635,6 +627,11 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags,
     HYPERVISOR_COMPAT_VIRT_START(d) =
         is_pv_domain(d) ? __HYPERVISOR_COMPAT_VIRT_START : ~0u;
 
+    /* Need to determine if HAP is enabled before initialising paging */
+    if ( is_hvm_domain(d) )
+        d->arch.hvm_domain.hap_enabled =
+            hvm_funcs.hap_supported && (domcr_flags & DOMCRF_hap);
+
     if ( !is_idle_domain(d) )
     {
         if ( (rc = paging_domain_init(d, domcr_flags)) != 0 )
@@ -674,7 +671,7 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags,
 
     if ( is_hvm_domain(d) )
     {
-        if ( (rc = hvm_domain_initialise(d)) != 0 )
+        if ( (rc = hvm_domain_initialise(d, domcr_flags, config)) != 0 )
             goto fail;
     }
     else
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 273bcff9ba..f3c25aded6 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -536,7 +536,8 @@ static int hvm_print_line(
     return X86EMUL_OKAY;
 }
 
-int hvm_domain_initialise(struct domain *d)
+int hvm_domain_initialise(struct domain *d, unsigned long domcr_flags,
+                          struct xen_arch_domainconfig *config)
 {
     unsigned int nr_gsis;
     int rc;
@@ -554,6 +555,10 @@ int hvm_domain_initialise(struct domain *d)
     INIT_LIST_HEAD(&d->arch.hvm_domain.write_map.list);
     INIT_LIST_HEAD(&d->arch.hvm_domain.g2m_ioport_list);
 
+    rc = create_perdomain_mapping(d, PERDOMAIN_VIRT_START, 0, NULL, NULL);
+    if ( rc )
+        goto fail;
+
     hvm_init_cacheattr_region_list(d);
 
     rc = paging_enable(d, PG_refcounts|PG_translate|PG_external);
@@ -637,6 +642,8 @@ int hvm_domain_initialise(struct domain *d)
     xfree(d->arch.hvm_domain.irq);
  fail0:
     hvm_destroy_cacheattr_region_list(d);
+    destroy_perdomain_mapping(d, PERDOMAIN_VIRT_START, 0);
+ fail:
     return rc;
 }
 
diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h
index 7a85b2e3b5..b687e03dce 100644
--- a/xen/include/asm-x86/hvm/hvm.h
+++ b/xen/include/asm-x86/hvm/hvm.h
@@ -236,7 +236,8 @@ extern s8 hvm_port80_allowed;
 extern const struct hvm_function_table *start_svm(void);
 extern const struct hvm_function_table *start_vmx(void);
 
-int hvm_domain_initialise(struct domain *d);
+int hvm_domain_initialise(struct domain *d, unsigned long domcr_flags,
+                          struct xen_arch_domainconfig *config);
 void hvm_domain_relinquish_resources(struct domain *d);
 void hvm_domain_destroy(struct domain *d);
 void hvm_domain_soft_reset(struct domain *d);
-- 
2.11.0


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